U.S. patent application number 15/245221 was filed with the patent office on 2017-03-09 for compositions for the production of objects using additive manufacturing.
This patent application is currently assigned to Eastman Chemical Company. The applicant listed for this patent is Eastman Chemical Company. Invention is credited to Ludovic Gardet.
Application Number | 20170066873 15/245221 |
Document ID | / |
Family ID | 58190862 |
Filed Date | 2017-03-09 |
United States Patent
Application |
20170066873 |
Kind Code |
A1 |
Gardet; Ludovic |
March 9, 2017 |
COMPOSITIONS FOR THE PRODUCTION OF OBJECTS USING ADDITIVE
MANUFACTURING
Abstract
Objects can be produced using an additive manufacturing process
and the objects can be removed from the substrates on which the
objects are formed. An object can include a plurality of layers of
a polymeric material that includes units of a diacid component and
units of a glycol component. A process can be used to form the
object that includes depositing a plurality of layers of the
polymeric material onto a substrate to form the object. In some
cases, the plurality of layers are deposited onto the substrate
according to a predetermined design.
Inventors: |
Gardet; Ludovic; (Nice,
FR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Eastman Chemical Company |
Kingsport |
TN |
US |
|
|
Assignee: |
Eastman Chemical Company
Kingsport
TN
|
Family ID: |
58190862 |
Appl. No.: |
15/245221 |
Filed: |
August 24, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62215950 |
Sep 9, 2015 |
|
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|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B29C 64/106 20170801;
B33Y 70/00 20141201; C08G 63/181 20130101; C08L 67/02 20130101;
C08G 63/199 20130101; C08G 63/16 20130101; B32B 27/36 20130101;
B33Y 10/00 20141201; B29C 64/118 20170801 |
International
Class: |
C08G 63/199 20060101
C08G063/199; B33Y 70/00 20060101 B33Y070/00; B33Y 10/00 20060101
B33Y010/00; B33Y 80/00 20060101 B33Y080/00 |
Claims
1. An article comprising: a plurality of layers of a polymeric
material that includes units of a diacid component and units of a
glycol component, wherein the units of the diacid component are
derived from a first diacid and a second diacid.
2. The article of claim 1, wherein the plurality of layers are
arranged according to a design.
3. The article of claim 1, wherein the first diacid is terephthalic
acid and the second diacid is isophthalic acid, a
cyclohexanedicarboxylic acid, a naphthalenedicarboxylic acid, a
stilbenedicarboxylic acid, or a combination thereof.
4. The article of claim 1, wherein the diacid component includes
from about 40 mole % to about 60 mole % of units derived from the
first diacid and from about 40 mole % to about 60 mole % of units
derived from the second diacid.
5. The article of claim 1, wherein the diacid component includes
from about 45 mole % to about 55 mole % of units derived from
terephthalic acid and from about 45 mole % to about 55 mole % of
units derived from isophthalic acid.
6. The article of claim 1, wherein the units of the glycol
component are derived from cyclohexanedimethanol.
7. The article of claim 1, wherein the glycol component includes
from about 75 mole % to about 98 mole % of units derived from a
first glycol and from about 2 mole % to about 25 mole % of units
derived from one or more second glycols.
8. The article of claim 7, wherein the first glycol includes
cyclohexanedimethanol and the one or more second glycols include
ethylene glycol, a propanediol, neopentyl glycol, a butanediol, a
pentanediol, a hexanediol, p-xylene glycol, or a combination
thereof.
9. The article of any one of claims 1-8, wherein the polymeric
material has an inherent viscosity from about 0.55 dL/g to about
0.7 dL/g, a density no greater than about 1.25 g/cm.sup.3, a glass
transition temperature of at least about 80.degree. C., and a
crystallization half-time no greater than about 300 minutes.
10. An article comprising: a body comprised of a polymeric material
that includes units of a diacid component and units of a glycol
component, wherein: the body has a diameter from about 1 mm to
about 5 mm and a length of at least about 3 cm; and an inherent
viscosity loss of an object formed from the polymeric material
relative to the polymeric material before forming the object is no
greater than about 0.9%.
11. The article of claim 10, wherein the polymeric material has a
zero shear viscosity no greater than about 3000 Poise.
12. The article of claim 10, wherein the polymeric material has an
elongation at break of at least about 75%.
13. The article of claim 10, wherein the polymeric material has a
density no greater than about 1.25 g/cm.sup.3.
14. The article of claim 10, wherein the polymeric material has a
glass transition temperature of at least about 80.degree. C.
15. The article of claim 10, wherein the body has a length of at
least about 30 cm.
16. The article of claim 10, wherein the body has a diameter from
about 1.5 mm to about 3 mm and a length of at least about 2 m.
17. The article of any one of claims 10-16, wherein the units of
the glycol component are derived from cyclohexanedimethanol, from
about 40 mole % to about 60 mole % of the units of the diacid
component are derived from terephthalic acid, and from about 40
mole % to about 60 mole % of the units of the diacid component are
derived from isophthalic acid.
Description
BACKGROUND
[0001] Additive manufacturing is a process used to produce
three-dimensional (3D) objects. Additive manufacturing can be
performed by extruding a material through a nozzle and depositing
(typically layer-by-layer) the material onto a substrate to form an
object. In some instances, the material used to form the layers of
the 3D object may be referred to herein as "build material."
Extrusion-based additive manufacturing is sometimes called "fused
deposition modeling.RTM." (FDM.RTM.), which is a trademark of
Stratasys Ltd. Of Edina, Minn., "fused filament fabrication" (FFF),
or more generally, "3D printing."
[0002] Additive manufacturing processes often utilize electronic
data that represents an object, such as a computer-aided design
(CAD) model of the object, to form the object. The electronic data
can be processed by a computing device component of the additive
manufacturing apparatus (e.g., a 3D printer) to form the object.
For example, an electronic representation of the object can be
mathematically sliced into multiple horizontal layers. The
horizontal layers can have contours that will produce the shape of
the object being formed by the additive manufacturing apparatus.
The computing device component can generate a build path to form
the contours for each horizontal layer and send control signals to
the extrusion portion of the additive manufacturing apparatus to
move a nozzle along the build path to deposit an amount of the
build material to form each of the horizontal layers. The
horizontal layers are formed on top of each other by depositing
fluent strands (also referred to as "roads") of the build material
in a layer-by-layer manner onto a platform or a build substrate.
For example, the additive manufacturing system can move an
extrusion head, the build substrate, or both the extrusion head and
the build substrate vertically and horizontally relative to each
other to form the object. The build material from which the object
is formed hardens shortly after extrusion to form a solid 3D
object.
SUMMARY
[0003] The disclosure is directed to compositions for producing
objects using an additive manufacturing process. The compositions
can be formed into a filament that is used in an additive
manufacturing process to produce an object.
[0004] An article can comprise a plurality of layers of a polymeric
material that includes units of a diacid component and units of a
glycol component. The units of the diacid component can be derived
from a first acid and a second acid. A process can be used to form
the article that includes depositing a plurality of layers of a
polymeric material onto a substrate. In some cases, the plurality
of layers are deposited onto the substrate according to a
predetermined design.
[0005] An article can also comprise a body including a polymeric
material that includes units of a diacid component and units of a
glycol component, where the units of the diacid component are
derived from a first acid and a second acid. The body of the
article can have a diameter from about 1 mm to about 5 mm and a
length of at least about 3 cm. The article can be formed by a
process that includes combining a diacid component and a glycol
component to form a polymeric material and extruding the polymeric
material to form a filament.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The detailed description is described with reference to the
accompanying figures. In the figures, the left-most digit(s) of a
reference number identifies the figure in which the reference
number first appears. The same reference numbers in different
figures indicates similar or identical items.
[0007] FIG. 1 illustrates example components of a first example
additive manufacturing system.
[0008] FIG. 2 illustrates example components of a second example
additive manufacturing system.
[0009] FIG. 3 illustrates a side view of multiple layers of an
object being deposited onto a substrate during an additive
manufacturing process.
[0010] FIG. 4 is a flow diagram of an example process of forming an
object on a substrate by depositing a plurality of layers of a
polymeric material onto a substrate and removing the object from
the substrate.
[0011] FIG. 5 shows an example object produced from a first
polymeric material at an extrusion rate of about 1 mm.sup.3/s where
the filament is heated at different temperatures before extruding
the filament to form the object.
[0012] FIG. 6 shows another example object produced from a second
polymeric material at an extrusion rate of about 2 mm.sup.3/s,
where the filament is heated at different temperatures before
extruding the filament to form the object.
[0013] FIG. 7 shows an object produced from the first polymeric
material at a temperature of about 235.degree. C. using an
extrusion based additive manufacturing apparatus, where the
extrusion rate at which the layers of the object were formed
increased with increasing height of the object.
[0014] FIG. 8 shows an object produced from the second polymeric
material at a temperature of about 235.degree. C. using an
extrusion based additive manufacturing apparatus, where the
extrusion rate at which the layers of the object were formed
increased with increasing height of the object.
DETAILED DESCRIPTION
[0015] The present disclosure is directed to, among other things,
techniques, systems, and materials for producing objects using an
additive manufacturing system. An object can be produced by
depositing one or more layers of a build material on a surface of
the substrate according to a predetermined design, which may be
based on three-dimensional (3D) model data. The build material can
be formed in the shape of a filament. The filament can be formed by
combining a glycol component and a diacid component to produce a
polymeric material and extruding the polymeric material. In some
cases, the polymeric material can include a co-polyester having
units derived from cyclohexanedimethanol and units derived from
terephthalic acid, isophthalic acid, cyclohexanedicarboxylic acid,
naphthalenedicarboxylic acid, stilbenedicarboxylic acid,
2,2,4,4-Tetramethyl-1,3-cyclobutanediol, or a combination
thereof.
[0016] The object formed using the techniques, systems, and
materials disclosed herein can be intended for any suitable
application including, without limitation, modeling, rapid
prototyping, production, and the like. Additionally, the system
used to create the object can be implemented in any suitable
context including end-consumer systems, prosumer systems, or
professional-grade additive manufacturing systems. For example,
additive manufacturing systems, such as extrusion-based 3D
printers, and materials for implementing the techniques disclosed
herein can be manufactured and sold to consumers for at-home
building of objects (e.g., "do-it-yourself" 3D printing kits,
desktop 3D printers, packages including the substrate (e.g., a
polymeric sheet) for use in 3D printers, and the like). A
"package," as used herein, is meant to describe a collection of
items or components that are packaged for commercial sale to
consumers and usable as, or with, an additive manufacturing system.
To illustrate, a package can include a filament of a build
material. In addition, components of an additive manufacturing
system can be offered as a bundle package, such as a 3D printer,
build material filament, and/or a substrate that is to be used in
the 3D printer to form objects. Instructions may be included in, or
on, the package as well (e.g., printed text on the package or on a
slip of paper inside the package), instructing a consumer to use
the packaged contents in a specified manner.
[0017] Additionally, or alternatively, the materials and processes
described herein can be implemented to mass manufacture objects
with high throughput at additive manufacturing facilities.
Industries that can benefit from the techniques, systems, and
materials described herein include, without limitation, cosmetics
(e.g., cosmetic container manufacturing), beverage container
manufacturing, product enclosure manufacturing, and so on.
[0018] The techniques and systems disclosed herein can result in
polymeric materials that can be used to form objects using additive
manufacturing techniques. The polymeric materials can include
properties that are conducive to forming the polymeric materials
into a filament. For example, polymeric materials described herein
for forming objects using additive manufacturing processes can have
physical properties that enable the polymeric materials to be
subject to extrusion and also to be rolled into a filament.
[0019] The polymeric materials can also have physical attributes
that are conducive to additive manufacturing processes. To
illustrate, the polymeric materials can have a viscosity and melt
stability at temperatures utilized to form objects using additive
manufacturing systems. In particular, the polymeric materials
described herein have a viscosity that enables the polymeric
materials to flow through an extrusion head with minimal, if any,
clogging. Additionally, the melt stability of the polymeric
materials minimizes degradation of the polymeric materials at
temperatures that can be used to produce objects using additive
manufacturing techniques.
[0020] Further, the polymeric materials can have physical
properties that minimize shrinkage after extrusion and also provide
sufficient adhesion with a substrate on which an object is being
formed. Sufficient adhesion between the substrate and a build
material used to form an object via additive manufacturing can
minimize defects in the object. In many situations, selecting a
build material, substrate, and additive manufacturing system to
achieve sufficient adhesion characteristics at an interface between
the substrate and the object can be based on a number of factors.
For example, if a partially completed object does not have
sufficient adhesion with the substrate, the partially completed
object can move and change its position on the substrate.
Accordingly, subsequent layers of the build material can be
deposited in a manner that causes a shape of the object to deviate
from an intended shape. In another example, without sufficient
adhesion between a build material and the substrate on which an
object is being formed, the partially completed object can become
detached from the substrate preventing the completion of the
object.
[0021] Further, there can be some defects in objects that are
caused by the adhesion between a build material used to form an
object and the substrate on which the object is formed. In
particular, the substrate, the object, or both can be damaged in
some way when the object is removed from the substrate. For
example, a physical object or tool, such as a chisel or knife, or a
chemical process may be used to remove an object from the substrate
and cause damage to the object and/or substrate, such as causing
chips or flakes of material to be separated from the body of the
object or the substrate.
[0022] The techniques and systems described herein can be
implemented in a number of ways. Example implementations are
provided below with reference to the following figures.
[0023] FIG. 1 illustrates example components of a first example
additive manufacturing system 100. The system 100 can be configured
to manufacture objects by utilizing additive manufacturing
principles. For example, the system 100 can be considered a fused
deposition modeling.RTM. (FDM.RTM.) system, a fused filament
fabrication (FFF) system, or more generally, a 3D printing system
(or 3D printer). In particular, the system 100 can be used to
produce an object 102 by depositing layers of a build material on a
substrate 104 that is disposed on a platform 106. After the object
102 is completed, the object 102 can be separated from the
substrate 104. In some cases, the object 102 can be removed from
the substrate 104 by hand, with a tool, by bending the substrate,
or combinations thereof. In other cases, a layer can be formed on
the substrate 104 that can aid in the removal of the object 102
from the substrate 104. To illustrate, a water-dispersible layer
can be formed between layers of the object 102 and the substrate
104. The water-dispersible layer can include material that provides
sufficient adhesion between the substrate 104 and the layers of the
object 102 such that defects can be minimized in the formation of
the object 102. The object 102 can be removed from the substrate
104 by breaking down the water-dispersible layer through contact
with an amount of water.
[0024] The substrate 104 can be positioned on the platform 106,
where the platform 106 is configured to support the substrate 104.
In this manner, the substrate 104 can be provided on the platform
106 as a "working surface" for building the object 102 on the
substrate 104. The substrate 104 can include a glass material, in
some cases. In other cases, the substrate 104 can include one or
more polymeric materials.
[0025] The substrate 104 can be removably mounted, attached, or
fastened to the platform 106 using an attachment mechanism
including, without limitation, one or more bolts, clamps, hooks,
latches, locks, nails, nuts, pins, screws, slots, retainers,
adhesive, Velcro.RTM., tape, or any other suitable attachment
mechanism that allows for the substrate 104 to be secured to the
platform 106 during the formation of the object 102, yet to also be
removable after the object 102 is formed. In some cases, suction
can be applied to the substrate 104 to hold the substrate 104 in
place during formation of the object 102. For example, one or more
holes can be provided in the platform 106 and suction, or a vacuum,
can be applied via the one or more holes to force the substrate 104
toward the platform 106. In some examples, mounting the substrate
104 on the platform 106 can include setting (laying or placing) the
substrate 104 on the platform 106 without any additional securing
mechanism.
[0026] The system 100 can include a housing 108 for a number of the
components of the system 100. The housing 108 can be formed from a
number of materials, such as one or more metals, one or more
polymers, or a combination thereof. The system 100 can also include
an extrusion head 110. The extrusion head 110 can be configured to
extrude build material onto the substrate 104 during the process of
forming the object 102. The extrusion head 110 can be any suitable
type of extrusion head 110 configured to receive material and to
extrude the material through a nozzle (or tip) that includes an
orifice from which fluent strands or "roads" of the build material
can be deposited onto the substrate 104 in a layer-by-layer manner
to form the object 102. Nozzles of varying-sized orifices can be
utilized for depositing roads of build material having different
thicknesses from the extrusion head 110.
[0027] The extrusion head 110 can include a heating element that
heats the build material to a temperature that causes the build
material to become flowable before extruding the build material
onto the substrate 104. The temperature applied to heat the build
material in the extrusion head 110 can be at least about
180.degree. C., at least about 190.degree. C., at least about
200.degree. C., or at least about 210.degree. C. Additionally, the
temperature applied to heat the build material in the extrusion
head 112 can be no greater than about 260.degree. C., no greater
than about 250.degree. C., no greater than about 240.degree. C., no
greater than about 230.degree. C., or no greater than about
220.degree. C. In an illustrative example, the temperature applied
to heat the build material in the extrusion head 110 can be
included in a range of about 175.degree. C. to about 275.degree. C.
In another illustrative example, the temperature applied to heat
the build material in the extrusion head 112 can be included in a
range of about 195.degree. C. to about 245.degree. C. In an
additional illustrative example, the temperature applied to heat
the build material in the extrusion head 112 can be included in a
range of about 220.degree. C. to about 240.degree. C.
[0028] During operation of the system 100, the substrate 104 can be
initially positioned below the extrusion head 110 in a direction
along the Z-axis shown in FIG. 1 at a time prior to the first layer
of build material being deposited. The distance at which the
substrate 104 is spaced below the extrusion head 110 can be any
suitable distance allowing for the deposition of fluent strands or
"roads" of build material at a desired thickness. In some
instances, a distance between the substrate 104 and the extrusion
head 110 prior to deposition of the first layer of build material
can be from about 0.02 mm to about 4 mm. As layers of the build
material are deposited to form the object 102, the extrusion head
110 can be moved a distance in increments in the Z-direction that
allows for depositing a next layer of build material at a specified
thickness. In some examples, the incremented distance can be about
0.1 mm.
[0029] The extrusion head 110 can be coupled to a horizontal rail
112. The extrusion head 110 can move along the horizontal rail 112
in the X-direction. The extrusion head 110 can move along the
horizontal rail 112 by the use of one or more stepper motors, one
or more servo motors, one or more microcontrollers, one or more
belts, combinations thereof, and the like. The system 100 can also
include a first vertical rail 114 and a second vertical rail 116.
Optionally, the horizontal rail 112 can be coupled to the first
vertical rail 114 and the second vertical rail 116, such that the
horizontal rail 112 can move vertically in the Z-direction along
the first vertical rail 114 and the second vertical rail 116.
[0030] The extrusion head 110 can move along the horizontal rail
112 and/or the first vertical rail 114 and the second vertical rail
116 at a speed of at least about 5 mm/second, at least about 10
mm/second, at least about 25 mm/second, at least about 50
mm/second, at least about 75 mm/second or at least about 125
mm/second. In addition, the extrusion head 110 can move along the
horizontal rail 112 and/or the first vertical rail 114 and the
second vertical rail 116 at a speed no greater than about 400
mm/second, no greater than about 350 mm/second, no greater than
about 300 mm/second, no greater than about 250 mm/second, no
greater than about 200 mm/second, or no greater than about 150
mm/second. In an illustrative example, the extrusion head 110 can
move along the horizontal rail 112 and/or the first vertical rail
114 and the second vertical rail 116 at a speed included in a range
of about 2 mm/second to about 500 mm/second. In another
illustrative example, the extrusion head 110 can move along the
horizontal rail 112 and/or the first vertical rail 114 and the
second vertical rail 116 at a speed included in a range of about 20
mm/second to about 300 mm/second. In an additional illustrative
example, the extrusion head 110 can move along the horizontal rail
112 and/or the first vertical rail 114 and the second vertical rail
116 at a speed included in a range of about 30 mm/second to about
100 mm/second.
[0031] The system 100 can also include a material source 118 that
stores a build material for forming objects using the system 100.
The material source 118 can be coupled to the extrusion head 110 by
a supply line 120. The material source 118 can include a material
bay or housing containing a spool of build material filament that
can be unwound from the spool by a motor or drive unit. In some
examples, supplying of the build material through the supply line
120 can be turned on or off, and the build material can be advanced
in both forward and backward directions along the supply line 120.
Retraction of the build material along the supply line 120 toward
the material source 118 can minimize "drool" at the extrusion head
110 and/or allow for recycling of unused build material after
finishing the object 102. Moreover, the rate at which the build
material is supplied to the extrusion head 110 can be controlled by
a drive unit (e.g., worm drive) at varying speeds so that speeds
can be increased or decreased.
[0032] An extrusion rate at which the build material flows through
the extrusion head 110 can be at least about 3 mm.sup.3/s, at least
about 3.5 mm.sup.3/s, at least about 4 mm.sup.3/s, at least about
4.5 mm.sup.3/s, at least about 5 mm.sup.3/s, at least about 5.5
mm.sup.3/s, at least about 6 mm.sup.3/s, at least about 10
mm.sup.3/s, at least about 20 mm.sup.3/s, at least about 50
mm.sup.3/s, at least about 100 mm.sup.3/s, at least about 200
mm.sup.3/s, at least about 500 mm.sup.3/s, at least about 1000
mm.sup.3/s, or at least about 2000 mm.sup.3/s. Also, an extrusion
rate at which the build material flows through the extrusion head
110 can be no greater than about 10 mm.sup.3/s, no greater than
about 9.5 mm.sup.3/s, no greater than about 9 mm.sup.3/s, no
greater than about 8.5 mm.sup.3/s, no greater than about 8
mm.sup.3/s, no greater than about 7.5 mm.sup.3/s, no greater than
about 7 mm.sup.3/s, or no greater than about 6.5 mm.sup.3/s. In an
illustrative example, an extrusion rate at which the build material
flows through the extrusion head 110 can be from about 2 mm.sup.3/s
to about 8400 mm.sup.3/s. In an illustrative example, an extrusion
rate at which the build material flows through the extrusion head
110 can be from about 2 mm.sup.3/s to about 12 mm.sup.3/s. In
another illustrative example, an extrusion rate at which the build
material flows through the extrusion head 110 can be from about 4
mm.sup.3/s to about 10 mm.sup.3/s. In an additional illustrative
example, an extrusion rate at which the build material flows
through the extrusion head can be from about 7 mm.sup.3/s to about
9 mm.sup.3/s. In an illustrative example, an extrusion rate at
which the build material flows through the extrusion head can be
from about 7 mm.sup.3/s to about 8400 mm.sup.3/s. In an
illustrative example, an extrusion rate at which the build material
flows through the extrusion head can be from about 100 mm.sup.3/s
to about 8400 mm.sup.3/s.
[0033] The build material stored by the material source 118 can
include a polymeric material. For example, the build material can
include a thermoplastic polymer. To illustrate, the build material
can include a thermoplastic resin. Additionally, the build material
can include a polyester. Further, the build material can include a
copolymer. Optionally, the build material can include a
copolyester.
[0034] The build material can include units of an acid component
and units of a glycol component. The units of the acid component
can be derived from one or more particular acids, while the units
of the glycol component can be derived from one or more particular
glycols. Additionally, the build material can include 100 mole % of
the acid component and 100 mole % of the glycol component. In some
cases, a portion of the glycol component or a portion of the acid
component can include a branching agent. For example, the acid
component or the glycol component can include at least about 0.1
mole % of a branching agent or no greater than about 1.5 mole % of
a branching agent. The branching agent can include one or more of
trimellitic anhydride, trimellitic acid, pyromellitic dianhydride,
trimesic acid, hemimellitic acid, glycerol, trimethylolpropane,
pentaerythritol, 1,2,4-butanetriol, 1,2,6-hexanetriol, sorbitol,
1,1,4,4-tetrakis(hydroxymethy)cyclohexane, dipentaerythritol, or
combinations thereof.
[0035] The acid component can include units derived from one or
more acids. In some cases, the acid component can include a diacid
component. For example, the acid component can include units of a
first acid and units of one or more second acids. To illustrate,
the first acid can include terephthalic acid. In addition, the one
or more second acids can be selected from a group of diacids
including isophthalic acid, 1,3-cyclohexanedicarboxylic acid,
1,4cyclohexanedicarboxylic acid, a naphthalenedicarboxylic acid, a
stilbenedicarboxylic acid, sebacic acid, dimethylmalonic acid,
succinic acid, or combinations thereof. In some particular
examples, the naphthalenedicarboxylic acid can include
1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid,
2,6-naphthalenedicarboxylic acid, or 2,7-naphthalenedicarboxylic
acid.
[0036] The acid component can include at least about 30 mole % of
units derived from the first acid, at least about 35 mole % of
units derived from the first acid, at least about 38 mole % of
units derived from the first acid, at least about 42 mole % of
units derived from the first acid, at least about 45 mole % of
units derived from the first acid, at least about 48 mole % of
units derived from the first acid, at least about 50 mole % of
units derived from the first acid, or at least about 52 mole % of
units derived from the first acid. In addition, the acid component
can include no greater than about 75 mole % of units derived from
the first acid, no greater than about 70 mole % of units derived
from the first acid, no greater than about 68 mole % of units
derived from the first acid, no greater than about 65 mole % of
units derived from the first acid, no greater than about 62 mole %
of units derived from the first acid, no greater than about 60 mole
% of units derived from the first acid, no greater than about 58
mole % of units derived from the first acid, or no greater than
about 55 mole % of units derived from the first acid. In an
illustrative example, the acid component can include from about 30
mole % to about 75 mole % of units derived from the first acid. In
another illustrative example, the acid component can include from
about 35 mole % to about 65 mole % of units derived from the first
acid. In an additional illustrative example, the acid component can
include from about 40 mole % to about 60 mole % of units derived
from the first acid. In a further illustrative example, the acid
component can include from about 45 mole % to about 55 mole % of
units derived from the first acid.
[0037] Additionally, the acid component can include at least about
30 mole % of units derived from the one or more second acids, at
least about 35 mole % of units derived from the one or more second
acids, at least about 38 mole % of units derived from the one or
more second acids, at least about 42 mole % of units derived from
the one or more second acids, at least about 45 mole % of units
derived from the one or more second acids, at least about 48 mole %
of units derived from the one or more second acids, at least about
50 mole % of units derived from the one or more second acids, or at
least about 52 mole % of units derived from the one or more second
acids. In addition, the acid component can include no greater than
about 75 mole % of units derived from the one or more second acids,
no greater than about 70 mole % of units derived from the one or
more second acids, no greater than about 68 mole % of units derived
from the one or more second acids, no greater than about 65 mole %
of units derived from the one or more second acids, no greater than
about 62 mole % of units derived from the one or more second acids,
no greater than about 60 mole % of units derived from the one or
more second acids, no greater than about 58 mole % of units derived
from the one or more second acids, or no greater than about 55 mole
% of units derived from the one or more second acids. In an
illustrative example, the acid component can include from about 30
mole % to about 75 mole % of units derived from the one or more
second acids. In another illustrative example, the acid component
can include from about 35 mole % to about 65 mole % of units
derived from the one or more second acids. In an additional
illustrative example, the acid component can include from about 40
mole % to about 60 mole % of units derived from the one or more
second acids. In a further illustrative example, the acid component
can include from about 45 mole % to about 55 mole % of units
derived from the one or more second acids.
[0038] Further, the acid component can include, in some cases,
amounts of units derived from additional acids, such as additional
aliphatic dibasic acids having 4 to about 40 carbon atoms,
additional cycloaliphatic dibasic acids having about 4 to about 40
carbon atoms, additional aromatic dibasic acids having about 4 to
about 40 carbon atoms, or combinations thereof. In a particular
example, the acid component can include no greater than about 10
mole % of units derived from one or more of the additional acids,
no greater than about 8 mole % of units derived from one or more of
the additional acids, no greater than about 6 mole % of units
derived from one or more of the additional acids, or no greater
than about 4 mole % of units derived from one or more of the
additional acids. Additionally, the acid component can include at
least about 0.5 mole % of units derived from one or more of the
additional acids, at least about 1 mole % of units derived from one
or more of the additional acids, or at least about 2 mole % of
units derived from one or more of the additional acids. In an
illustrative example, the acid component can include from about 0.5
mole % to about 10 mole % of units derived from one or more of the
additional acids.
[0039] Optionally, esters of the acids can be used to form the
polymeric material of the build material. In an example, lower
alkyl esters of the acids can be used to form the polymeric
material. In a particular example, methyl esters of the acids can
be used to form the polymeric material. In an illustrative example,
esters of terephthalic acid, esters of isophthalic acid, esters of
1,3-cyclohexanedicarboxylic acid, esters of 1,4
cyclohexanedicarboxylic acid, esters of a naphthalenedicarboxylic
acid, esters of a stilbenedicarboxylic acid, or combinations
thereof, can be used to form the polymeric material.
[0040] The glycol component can include units derived from
cyclohexanedimethanol. Optionally, the polymeric material of the
build material can include multiple glycols. For example, the
glycol component can include units derived from a first glycol and
units derived from on-e or more second glycols. To illustrate, the
first glycol can include cyclohexanedimethanol and the one or more
second glycols can include one or more glycols including about 2 to
about 20 carbon atoms. In a particular example, the one or more
second glycols can include ethylene glycol, 1,2-propanediol,
1,3-propanediol, neopentyl glycol, 1,4-butanediol, 1,5-pentanediol,
1,6-hexanediol, p-xylene glycol, or combinations thereof. In some
cases, the build material can include polyethylene glycols,
polytetramethylene glycols,
2,2,4,4-Tetramethyl-1,3-cyclobutanediol, or a combination
thereof.
[0041] Optionally, when the glycol component includes units derived
from multiple glycols, the glycol component can include at least
about 75 mole % of units derived from the first glycol, at least
about 78 mole % of units derived from the first glycol, at least
about 80 mole % of units derived from the first glycol, at least
about 82 mole % of units derived from the first glycol, or at least
about 85% of units derived from the first glycol. In addition, when
the glycol component includes units derived from multiple glycols,
the glycol component can include no greater than about 98 mole % of
units derived from the first glycol, no greater than about 95 mole
% of units derived from the first glycol, no greater than about 92
mole % of units derived from the first glycol, no greater than
about 90 mole % of units derived from the first glycol, or no
greater than about 88 mole % of units derived from the first
glycol. In an illustrative example, when the glycol component
includes units derived from multiple glycols, the glycol component
can include from about 75 mole % to about 98 mole% of units derived
from the first glycol. In another illustrative example, when the
glycol component includes units derived from multiple glycols, the
glycol component can include from about 85 mole % to about 95 mole
% of units derived from the first glycol.
[0042] Furthermore, when the glycol component includes units
derived from multiple glycols, the glycol component can include no
greater than about 25 mole % of units derived from the one or more
second glycols, no greater than about 22 mole % of units derived
from the one or more second glycols, no greater than about 20 mole
% of units derived from the one or more second glycols, no greater
than about 18 mole % of units derived from the one or more second
glycols, no greater than about 15 mole % of units derived from the
one or more second glycols, or no greater than about 12 mole % of
units derived from the one or more second glycols. In some cases,
when the glycol component includes units derived from multiple
glycols, the glycol component can include at least about 1 mole %
of units derived from the one or more second glycols, at least
about 3 mole % of units derived from the one or more second
glycols, at least about 5 mole % of units derived from the one or
more second glycols, at least about 8 mole % of units derived from
the one or more second glycols, or at least about 10 mole % of
units derived from the one or more second glycols. In an
illustrative example, when the glycol component includes units
derived from multiple glycols, the glycol component can include
from about 2 mole % to about 25 mole % of units derived from the
one or more second glycols. In another illustrative example, when
the glycol component includes units derived from multiple glycols,
the glycol component can include from about 5 mole % to about 15
mole % of units derived from the one or more second glycols.
[0043] In one particular example, the polymeric material of the
build material can be comprised of an acid component including from
about 48 mole % to about 55 mole % units derived from terephthalic
acid and from about 44 mole % to about 52 mole % units derived from
isophthalic acid and a glycol component including units derived
from 1,4-cyclohexanedimethanol. In another particular example, the
polymeric material can be comprised of an acid component including
from about 47 mole % to about 53 mole % units derived from
terephthalic acid and from about 47 mole % to about 53 mole % units
derived from isophthalic acid and a glycol component including
units derived from 1,4-cyclohexanedimethanol.
[0044] Filament of the build material can have a diameter of at
least about 0.5 mm, at least about 1 mm, at least about 1.5 mm, or
at least about 2 mm. In addition, filament of the build material
can have a diameter no greater than about 5 mm, no greater than
about 4 mm, no greater than about 3 mm, or no greater than about
2.5 mm. In an illustrative example, the diameter of filament of the
build material can be about 0.3 mm to about 6 mm. In an additional
illustrative example, the diameter of the filament of the build
material can be from about 1 mm to about 5 mm. In another
illustrative example, the diameter of the filament of the build
material can be from about 1.5 mm to about 3 mm. Further, filament
of the build material can have a length from about 3 cm to about 10
cm, from about 15 cm to about 25 m, from about 30 cm to about 5 m,
or from about 50 cm to about 1 m. In some cases, filament of the
build material can have a length of at least about 3 cm, at least
about 5 cm, at least about 10 cm, at least about 20 cm, at least
about 30 cm, at least about 50 cm, at least about 1 m, at least
about 2 m, or at least about 5 m. In other cases, filament of the
build material can have a length no greater than about 25 m, no
greater than about 20 m, no greater than about 15 m, no greater
than about 12 m, no greater than about 10 m, no greater than about
8 m, or no greater than about 6 m. Additionally, filament of the
build material can have a length of no greater than about 500 m, no
greater than about 400 m, no greater than about 300 m, no greater
than about 200 m, no greater than about 100 m, or no greater than
about 50 m. In an illustrative example, filament of the build
material can have a length from about 10 m to 500 m. In another
illustrative example, filament of the build material can have a
length from about 25 m to about 300 m. In an additional
illustrative example, filament of the build material can have a
length from about 50 m to about 200 m.
[0045] Optionally, the platform 106 can be heated to aid in the
adhesion of the object 102 to the substrate 104 during the
formation of the object 102. In an illustrative example, the
platform 106 can be heated at a temperature included in a range of
about 30.degree. C. to about 125.degree. C. Heating of the platform
106 can be performed by any suitable heating elements, such as
electrical elements that can be turned on or off, gas heating
elements below the platform 106, or any other suitable heating
element. In some situations, though, the platform 106 may not be
heated. In another illustrative example, the platform 106 can be
heated at a temperature included in a range of about 40.degree. C.
to about 90.degree. C. In some instances, the temperature at which
the platform 106 is heated can depend on a glass transition
temperature of the build material being deposited onto the
substrate 104 to form the object 102. Further, heating the platform
106 can provide an anti-warping effect on the build material used
to form the object 102.
[0046] The system 100 can include a control system 122. The control
system 122 can include one or more hardware processor devices and
one or more physical memory devices. The one or more physical
memory devices can be examples of computer storage media for
storing instructions which are executed by the one or more
processors to perform various functions. The one or more physical
memory devices can include both volatile memory and non-volatile
memory (e.g., RAM, ROM, or the like). The one or more physical
memory devices can also include one or more cache memory devices,
one or more buffers, one or more flash memory devices, or a
combination thereof. The system 100 can also include one or more
additional components, such as one or more input/output devices.
For example, the system 100 can include a keyboard, a mouse, a
touch screen, a display, speakers, a microphone, a camera,
combinations thereof, and the like. The system 100 can also include
one or more communication interfaces for exchanging data with other
devices, such as via a network, direct connection, or the like. For
example, the communication interfaces can facilitate communications
within a wide variety of networks or connections, such as one or
more wired networks or wired connections and/or one or more
wireless networks or wireless connections.
[0047] The control system 122 can include, be coupled to, or obtain
data from a computer-aided design (CAD) system to provide a digital
representation of the object 102 to be formed by the system 100.
Any suitable CAD software program can be utilized to create the
digital representation of the object 102. For example, a user can
design, using a 3D modeling software program executing on a host
computer, an object having a particular shape with specified
dimensions, such as the object 102, that is to be manufactured
using the system 100. In order to translate the geometry of the
object 102 into computer-readable instructions or commands usable
by a processor or a suitable controller in forming the object 102,
the control system 122 can mathematically slice the digital
representation of the object 102 into multiple horizontal layers.
The control system 122 can then design build paths along which
build material is to be deposited in a layer-by-layer fashion to
form the object 102.
[0048] The control system 122 can manage and/or direct one or more
components of the system 100, such as the extrusion head 110, by
controlling movement of those components according to a numerically
controlled computer-aided manufacturing (CAM) program along
computer-controlled paths. Optionally, the control system 122 can
control one or more components of the system 100 to move according
to script written in a programming language, such as Python. The
script can be used to produce code in a numerical programming
language, such as G-code, that the control system 122 can execute.
The movement of the various components of the system 100, such as
the extrusion head 110, can be performed by the use of stepper
motors, servo motors, microcontrollers, combinations thereof, and
the like.
[0049] As build material is supplied to the extrusion head 110, the
control system 122 directs the movement of the extrusion head 110
along the horizontal rail 112 and/or the vertical rails 114, 116 so
that the extrusion head 110 can follow a predetermined build path
while depositing build material for each layer of the object 102.
In this sense, the rails 112, 114, 116 allow the extrusion head 110
to move two-dimensionally and/or three-dimensionally in vertical
and/or horizontal directions as shown by the arrows in FIG. 1.
Additionally, or alternatively, the platform 106 can be movable in
two-dimensions and/or three-dimensions, and such movement can be
controlled by the control system 122 to provide similar relative
movement between the substrate 104 and platform 106 and the
extrusion head 110 so that multiple roads of build material can be
deposited by moving the extrusion head 110 and/or the platform 106
in a two-dimensional (2D) horizontal plane (i.e., X-Y plane) to
form each layer of the object 102, and then multiple successive
layers can be deposited on top of one another by moving the
extrusion head 110 and/or the platform 106 in a vertical
Z-direction.
[0050] Optionally, the substrate 104, the build material of the
material source 118, or a combination thereof, can be included in a
package that can be purchased and used in conjunction with the
system 100. The package can also include instructions on how to
form objects using the filament of build material with the system
100. For example, the instructions can indicate settings for the
system 100, such as a temperature to heat the build material in the
extrusion head 110, that correspond with the composition of the
filament of build material.
[0051] The object 102 can be formed in a controlled environment,
such as by confining individual ones of the components of the
system 100 to a chamber or other enclosure formed by the housing
108 where temperature, and optionally other parameters (e.g.,
pressure) can be controlled and maintained at a desired level by
elements configured to control temperature, pressure, etc. (e.g.,
heating elements, pumps, etc.). In some instances, the temperature
applied to the build material can correspond to a temperature at or
above the creep-relaxation temperature of the build material. This
can allow more gradual cooling of the build material as it is
deposited onto the substrate 104 so as to prevent warping of the
layers of the object 102 upon deposition.
[0052] Although FIG. 1 illustrates one illustrative example of
certain components of an additive manufacturing system usable for
carrying out the techniques disclosed herein, it is to be
appreciated that the configuration and inclusion of certain
components shown in FIG. 1 is one, non-limiting, example of a
suitable additive manufacturing system. Namely, other types and
configurations of additive manufacturing systems can be utilized
with the techniques and materials disclosed herein without changing
the basic characteristics of the additive manufacturing system 100,
and the additive manufacturing system 100 can be implemented as any
suitable size for a particular industry or application, such as
industrial-sized for commercial object production and/or testing,
desktop-sized, handheld for consumer-use, and so on. For example, a
handheld additive manufacturing system can be utilized to form the
object 102 on the substrate 104 or a conveyor arrangement can be
utilized to form the object 102 on the substrate 104. One
illustrative example of a suitable handheld system is the
3Doodler.RTM., a 3D printing pen from WobbleWorks LLC.
[0053] FIG. 2 illustrates example components of a second example
additive manufacturing system 200. The system 200 is similar to
that of the additive manufacturing system 100 of FIG. 1, except
that the system 200 is arranged in a delta machine configuration.
Thus, some components of the system 200 are not shown in FIG. 2 and
the details with respect to some of the components of the system
200 shown in FIG. 2 are omitted because the features of these
components have been described previously in the description of
FIG. 1.
[0054] The system 200 can include an extrusion head 202 that is
coupled to a first arm 204, a second arm 206, and a third arm 208.
The first arm 204 can be movably coupled to a first rail 210, the
second arm 206 can be movably coupled to a second rail 212, and the
third arm 208 can be movably coupled to a third rail 214. In
addition, the extrusion head 214 can be coupled to the first arm
204, the second arm 206, and the third arm 208. Further, the system
200 can include a platform 216. Optionally, a substrate 218 can be
disposed on the platform 216. In some cases, the substrate 218 can
be removably attached to the platform 216.
[0055] The first arm 204, the second arm 206, and the third arm 208
can be controlled by a control system (not shown) to move in a
manner that positions the extrusion head 202 to form an object 220.
In particular, the first arm 204, the second arm 206, and the third
arm 208 can move the extrusion head 202 according to a
predetermined design to form layers of the object 220. The
polymeric material used to produce the object 220 can be provided
to the extrusion head 202 via a supply line 222. In some cases, the
supply line 222 can feed a filament into the extrusion head 202 to
produce the object 220.
[0056] FIG. 3 illustrates a side view of multiple layers of an
object 300 being deposited onto a substrate 302 during an additive
manufacturing process. As discussed previously with reference to
FIG. 1 and FIG. 2, during the additive manufacturing process of
forming an object on a substrate, build material is supplied to an
extrusion head 304 and, optionally, the build material is heated.
The build material is then deposited in roads onto a surface. In
the illustrative example of FIG. 3, the build material is deposited
directly onto the substrate 302. In other cases, the build material
can be deposited onto a layer (not shown) disposed on the substrate
302, such as a layer that can be removed in order to separate the
object 300 from the substrate 302. A first layer 306(1) of build
material is shown as being deposited onto the substrate 302
according to a predetermined build path, which can represent a
beginning of the additive manufacturing process. As the extrusion
head 304 moves at a predetermined speed according to a
predetermined design for the object 300, multiple additional layers
306(2), 306(3), 306(N-1), 306(N) of the build material can be
deposited in a layer-by-layer fashion onto previously deposited
layers to form the object 300 on the substrate 302. Depositing
build material to form the layers 306(1)-306(N) can cause at least
a partial interface to be formed between each of the layers
306(1)-306(N). The at least partial interface can be visible to a
human eye without or with aid, such as a type of microscope. For
example, an interface can be formed between the layer 306(1) and
the layer 306(2). In another example, an interface can be formed
between the layer 306(2) and the layer 306(3). The object 300 can
be formed with 100% infill (i.e., a solid object), or with less
than 100% infill (at least a partially hollow interior portion of
the object 300).
[0057] The substrate 302 can include a glass material. In addition,
the substrate 302 can include a polymeric material. In some cases,
the substrate 302 can include a coating of the polymeric material.
In other instances, the substrate 302 can be made substantially of
the polymeric material. In an example, the substrate 302 can
include a thermoplastic polymer. The substrate 302 can also include
a polyester. Additionally, the substrate 302 can include a
glycol-modified polyethylene terephthalate. Further, the substrate
302 can include a copolymer. To illustrate, the substrate 302 can
include a copolyester. Optionally, the substrate 302 can include a
polylactic acid, an acrylonitrile butadiene styrene copolymer, a
polycarbonate, a polyamide, a polyetherimide, a polystyrene, a
polyphenylsulfone, a polysulfone, a polyethersulfone, a
polyphenylene, a poly(methyl methacrylate), or a combination
thereof.
[0058] The build material for the object 300 can include one or
more polymeric materials. The one or more polymeric materials can
include any of the build materials described previously with
respect to forming the object 102 of FIG. 1. In a particular
example, the build material for the layers 306(1)-306(N) of the
object 300 can comprise a copolyester having units of an acid
component and units of a glycol component.
[0059] The build material used to form the layers 306(1)-306(N) can
have particular physical properties that are conducive to forming
objects in an additive manufacturing process. For example, the
build material used to form the layers 306(1)-306(N) can have an
inherent viscosity of at least about 0.4 dL/g, at least about 0.5
dL/g, at least about 0.55 dL/g, at least about 0.6 dL/g, or at
least about 0.65 dL/g. Additionally, the build material used to
form the layers 306(1)-306(N) can have an inherent viscosity of no
greater than about 0.9 dL/g, no greater than about 0.8 dL/g, no
greater than about 0.75 dL/g, or no greater than about 0.7 dL/g. In
an illustrative example, the build material of the layers
306(1)-306(N) can have an inherent viscosity from about 0.4 dL/g to
about 0.9 dL/g. In another illustrative example, the build material
of the layers 306(1)-306(N) can have an inherent viscosity from
about 0.5 dL/g to about 0.8 dL/g. In an additional illustrative
example, the build material of the layers 306(1)-306(N) can have an
inherent viscosity from 0.55 dL/g to about 0.7 dL/g. The inherent
viscosity can be measured at about 25.degree. C. in 100 ml of a
60/40 solution of phenol/tetrachlorethane including about 0.5 g of
the polymer.
[0060] Additionally, the build material used to form the layers
306(1)-306(N) can have a glass transition temperature of at least
about 70.degree. C., at least about 72.degree. C., at least about
75.degree. C., at least about 78.degree. C., or at least about
80.degree. C. Additionally, the build material used to form the
layers 306(1)-306(N) can have a glass transition temperature no
greater than about 110.degree. C., no greater than about
100.degree. C., no greater than about 95.degree. C., no greater
than about 92.degree. C., no greater than about 90.degree. C., no
greater than about 88.degree. C., or no greater than about
85.degree. C. In an illustrative example, the build material used
to form the layers 306(1)-306(N) can have a glass transition
temperature from about 70.degree. C. to about 110.degree. C. In
another illustrative example, the build material used to form the
layers 306(1)-306(N) can have a glass transition temperature from
about 75.degree. C. to about 100.degree. C. In an additional
illustrative example, the build material used to form the layers
306(1)-306(N) can have a glass transition temperature from about
80.degree. C. to about 90.degree. C. The glass transition
temperature can be measured using a differential scanning
calorimeter (DSC) at a scan rate of about 20.degree. C.
[0061] Further, the build material used to form the layers
306(1)-306(N) can have a density of at least about 0.8 g/cm.sup.3,
at least about 0.85 g/cm.sup.3, at least about 0.9 g/cm.sup.3, at
least about 0.95 g/cm.sup.3, at least about 1 g/cm.sup.3, or at
least about 1.05 g/cm.sup.3. Optionally, the build material used to
form the layers 306(1)-306(N) can have a density no greater than
about 1.35 g/cm.sup.3, no greater than about 1.30 g/cm.sup.3, no
greater than about 1.25 g/cm.sup.3, no greater than about 1.2
g/cm.sup.3, no greater than about 1.15 g/cm.sup.3, or no greater
than about 1.1 g/cm.sup.3. In an illustrative example, the build
material used to form the layers 306(1)-306(N) can have a density
from about 0.75 g/cm.sup.3 to about 1.4 g/cm.sup.3. In another
illustrative example, the build material used to form the layers
306(1)-306(N) can have a density from about 0.9 g/cm.sup.3 to about
1.3 g/cm.sup.3. In a further illustrative example, the build
material used to form the layers 306(1)-306(N) can have a density
from about 1.15 g/cm.sup.3 to about 1.25 g/cm.sup.3. The density
can be measured using the American Society for Testing and
Materials (ASTM) D 792 standard as of the date of filing of this
patent application.
[0062] Also, the build material used to form the layers
306(1)-306(N) can have a tensile strength at yield of at least
about 30 MPa, at least about 35 MPa, at least about 40 MPa, at
least about 45 MPa, or at least about 50 MPa. Further, the build
material used to form the layers 306(1)-306(N) can have a tensile
strength at yield no greater than about 80 MPa, no greater than
about 75 MPa, no greater than about 70 MPa, no greater than about
65 MPa, no greater than about 60 MPa, or no greater than about 55
MPa. In an illustrative example, the build material used to form
the layers 306(1)-306(N) can have a tensile strength at yield from
about 25 MPa to about 100 MPa. In another illustrative example, the
build material used to form the layers 306(1)-306(N) can have a
tensile strength at yield from about 35 MPa to about 60 MPa. In an
additional illustrative example, the build material used to form
the layers 306(1)-306(N) can have a tensile strength at yield from
about 45 MPa to about 55 MPa. The tensile strength at yield can be
measured according to the ASTM D638 standard at the time of filing
of this patent application.
[0063] The build material used to form the layers 306(1)-306(N) can
also have an elongation at break of at least about 80%, at least
about 95%, at least about 110%, at least about 125%, at least about
140%, or at least about 155%. In addition, the build material used
to form the layers 306(1)-306(N) can have an elongation at break of
no greater than about 230%, no greater than about 215%, no greater
than about 200%, no greater than about 185%, or no greater than
about 170%. In an illustrative example, the build material used to
form the layers 306(1)-306(N) can have an elongation at break from
about 75% to about 250%. In another illustrative example, the build
material used to form the layers 306(1)-306(N) can have an
elongation at break from about 95% to about 205%. In an additional
illustrative example, the build material used to form the layers
306(1)-306(N) can have an elongation at break from about 80% to
about 120%. In a further illustrative example, the build material
used to form the layers 306(1)-306(N) can have an elongation at
break from about 180% to about 220%. The elongation at break can be
measured according to the ASTM D638 standard at the time of filing
of this patent application.
[0064] Additionally, the build material used to form the layers
306(1)-306(N) can have a crystallization half time of at least
about 80 minutes, at least about 90 minutes, at least about 100
minutes, at least about 110 minutes, at least about 120 minutes, or
at least about 130 minutes. The build material used to form the
layers 306(1)-306(N) can also have a crystallization half time of
no greater than about 1000 minutes, no greater than about 1000
minutes, no greater than about 750 minutes, no greater than about
500 minutes, no greater than about 400 minutes, no greater than
about 300 minutes, or no greater than about 200 minutes. In an
illustrative example, the build material used to form the layers
306(1)-306(N) can have a crystallization half time from about 75
minutes to about 1000 minutes. In another illustrative example, the
build material used to form the layers 306(1)-306(N) can have a
crystallization half time from about 100 minutes to about 400
minutes. In a further illustrative example, the build material used
to form the layers 306(1)-306(N) can have a crystallization half
time from about 110 minutes to about 180 minutes. The
crystallization half time can be measured using a small angle light
scattering technique using a helium neon laser to measure the time
at which the intensity of transmitted light drops to half of the
maximum intensity achieved while cooling a sample to a
predetermined temperature.
[0065] Optionally, the build material used to form the layers
306(1)-306(N) can have a zero shear viscosity of at least about
1800 poise, at least about 1900 poise, at least about 2000 poise,
at least about 2100 poise, or at least about 2200 poise. Also, the
build material used to form the layers 306(1)-306(N) can have a
zero shear viscosity of no greater than about 7000 poise, no
greater than about 5000 poise, no greater than about 3000 poise, no
greater than about 2800 poise, no greater than about 2600 poise, or
no greater than about 2400 poise. In an illustrative example, the
build material used to form the layers 306(1)-306(N) can have a
zero shear viscosity from about 1750 poise to about 8000 poise. In
an additional illustrative example, the build material used to form
the layers 306(1)-306(N) can have a zero shear viscosity from about
1800 poise to about 4000 poise. In a further illustrative example,
the build material used to form the layers 306(1)-306(N) can have a
zero shear viscosity from about 1900 poise to about 3000 poise. The
zero shear viscosity can be measured using small amplitude
oscillatory shear techniques with a frequency sweep from about 1
rad/s to about 400 rad/s at 260.degree. C. using a 10% strain value
where the viscosity measured at 1 rad/s indicates the zero shear
viscosity.
[0066] The build material used to form the layers 306(1)-306(N) can
have a flexural modulus of at least about 1700 MPa, at least about
1750 MPa, at least about 1800 MPa, at least about 1850 MPa, or at
least about 1900 MPa. Further, the build material used to form the
layers 306(1)-306(N) can have a flexural modulus of no greater than
about 2100 MPa, no greater than about 2050 MPa, no greater than
about 2000 MPa, or no greater than about 1950 MPa. In an
illustrative example, the build material used to form the layers
306(1)-306(N) can have a flexural modulus from about 1700 MPa to
about 2100 MPa. In another illustrative example, the build material
used to form the layers 306(1)-306(N) can have a flexural modulus
from about 1775 MPa to about 1975 MPa. The flexural modulus can be
determined according to the ASTM D790 standard at the time of
filing of this patent application.
[0067] The build material used to form the layers 306(1)-306(N) can
have a notched Izod impact strength of at least about 60 J/m, at
least about 62 J/m, at least about 64 J/m, at least about 66 J/m,
or at least about 68 J/m. In addition, the build material used to
form the layers 306(1)-306(N) can have a notched Izod impact
strength of no greater than about 82 J/m, no greater than about 80
J/m, no greater than about 78 J/m, no greater than about 76 J/m, no
greater than about 74 J/m, or no greater than about 72 J/m. In an
illustrative example, the build material used to form the layers
306(1)-306(N) can have a notched Izod impact strength from about 60
J/m to about 85 J/m. In another illustrative example, the build
material used to form the layers 306(1)-306(N) can have a notched
Izod impact strength from about 65 J/m to about 75 J/m. The notched
Izod impact strength can be determined according to the ASTM D256
standard at 23.degree. C. at the time of filing of this patent
application.
[0068] Also, the build material used to form the layers
306(1)-306(N) can have a heat deflection temperature of at least
about 52.degree. C., at least about 54.degree. C., at least about
56.degree. C., at least about 58.degree. C., or at least about
60.degree. C. Further, the build material used to form the layers
306(1)-306(N) can have a heat deflection temperature of no greater
than about 72.degree. C., no greater than about 70.degree. C., no
greater than about 68.degree. C., no greater than about 66.degree.
C., no greater than about 64.degree. C., or no greater than about
62.degree. C. In an illustrative example, the build material used
to form the layers 306(1)-306(N) can have a heat deflection
temperature from about 50.degree. C. to about 72.degree. C. In
another illustrative example, the build material used to form the
layers 306(1)-306(N) can have a heat deflection temperature from
about 55.degree. C. to about 65.degree. C. The heat deflection
temperature can be determined according to the ASTM D648 standard
at about 264 psi at the time of filing of this patent
application.
[0069] The values of the physical properties of the build material
used to form the layers 306(1)-306(N) are conducive to forming
objects, such as the object 300, using an extrusion-based additive
manufacturing process. For example, build material used to form the
layers 306(1)-306(N) can have a crystallization half time of at
least 100 minutes to minimize or eliminate the formation of haze in
objects formed from the build materials and to minimize shrinkage
due to crystalline behavior in objects formed from the build
materials. Additionally, build materials used to form the layers
306(1)-306(N) can have values for zero shear viscosity that enable
the formation of objects using the build materials at relatively
low temperatures, such as less than 250.degree. C. Build materials
having values of zero shear viscosity as described herein can also
reduce an amount of pressure in the extrusion head, which can
facilitate the formation of objects using extrusion-based additive
manufacturing on less robust equipment, that is, on equipment that
is not fitted to be able to withstand processing conditions under
relatively high pressure. Furthermore, the values of the
glass-transition temperature and the values of the density of the
build materials used to form the layers 306(1)-306(N) impart
heating and cooling characteristics of the build material within
the extrusion head 304 and outside of the extrusion head 304 such
that the build material can flow through the extrusion head 304,
while solidifying once deposited onto the substrate 302 or another
layer such that defects of the object 300 are minimized. The build
material used to form the layers 306(1)-306(N) can also have an
elongation at break that causes the build material to have minimal
brittleness after extrusion. In addition, the build material used
to form the layers 306(1)-306(N) can have an inherent viscosity
that minimizes an amount of heat applied to the build material to
cause the build material to flow and be extruded. Extrusion of the
build material at minimized temperatures reduces degradation of the
build material during extrusion and minimizes shrinkage of the
build material after extrusion. The inherent viscosity of the build
material used to form the layers 306(1)-306(N) can also enable
appropriate flow of the build material through the extrusion head
304 and cause the object 300 to have a particular amount of
strength after being formed.
[0070] The substrate 302 can have a thickness 308 and a length 310.
The substrate 302 can also have a width that is perpendicular to
the length 310. The substrate 302 can be of various shapes,
including square, circular, rectangular, triangular, or any
suitable polygonal shape.
[0071] The thickness 308 of the substrate 302 can be at least about
0.5 mm, at least about 1 mm, or at least about 2 mm. Additionally,
the thickness 308 of the substrate 302 can be no greater than about
5 mm, no greater than about 4 mm, or no greater than about 3 mm. In
an illustrative example, the thickness 308 of the substrate 302 can
be included in a range of about 0.7 mm to about 4 mm. In another
illustrative example, the thickness 308 of the substrate 302 can be
included within a range of about 1 mm to about 2 mm.
[0072] The length 310 of the substrate 302 can be at least about 40
mm, at least about 80 mm, at least about 120 mm, or at least about
150 mm. Additionally, the length 310 of the substrate 302 can be no
greater than about 500 mm, no greater than about 400 mm, no greater
than about 300 mm, no greater than about 250 mm, or no greater than
about 200 mm. In an illustrative example, the length 310 of the
substrate 302 can be included in a range of about 30 mm to about
600 mm. In another illustrative example, the length 310 of the
substrate 302 can be included in a range of about 40 mm to about
250 mm. In an additional illustrative example, the length 310 of
the substrate 302 can be included in a range of about 50 mm to
about 200 mm.
[0073] Further, a width of the substrate 302 can be at least about
35 mm, at least about 75 mm, at least about 125 mm, or at least
about 160 mm. The width of the substrate 302 can also be no greater
than about 480 mm, no greater than about 390 mm, no greater than
about 310 mm, no greater than about 250 mm, or no greater than
about 210 mm. In an illustrative example, the width of the
substrate 302 can be included in a range of about 30 mm to about
600 mm. In another illustrative example, the width of the substrate
302 can be included in a range of about 40 mm to about 250 mm. In
an additional illustrative example, the width of the substrate 302
can be included in a range of about 50 mm to about 200 mm. In some
examples, a square-shaped substrate 302 can have a width of from
about 100 mm to about 200 mm and have the length 312 of from about
100 mm to about 200 mm.
[0074] The thickness (in the Z-direction of FIG. 3), of each of the
layers 306(1)-(N) of the object 300, such as a thickness 312, can
be a value that provides a specified resolution to the object 300.
That is, layers having relatively greater values for thickness can
result in a noticeably rigid or jagged outer surface of the object
300 (i.e., lower resolution object), while layers having relatively
lower values for thickness can make the separate layers
inconspicuous and the object 300 can have a smoother outer surface
in both appearance and feel (i.e., a higher resolution object).
Furthermore, each of the layers 306(1)-(N) can be of substantially
uniform thicknesses or of varying thicknesses.
[0075] A representative layer of the layers 306(1)-306(N), such as
the layer 306(N-1), can have a thickness 312 that is from about 5
micrometers to about 2000 micrometers. In some cases, the thickness
312 can be from about 10 micrometers to about 1000 micrometers.
Additionally, the thickness 312 can be from about 25 micrometers to
about 500 micrometers. The thickness 312 can also be from about 35
micrometers to about 250 micrometers.
[0076] The material of the substrate 302 and the build material of
the layers 306(1)-306(N) are selected to provide adhesion between
the respective layers. For example, the material of the substrate
302 and the material of the layer 306(1) can be selected to provide
sufficient adhesion between the substrate 302 and the layer 306(1)
such that the layer 306(1) remains on the substrate 302 during the
formation of the object 300 while being removed from the substrate
302 with minimal, if any, damage to the object 300 or the substrate
302. Additionally, the build material of the layers 306(1)-306(N)
can be selected such that any movement of the layers 306(1)-306(N)
is minimized to avoid or reduce any deformation of the object
300.
[0077] FIG. 4 is a flow diagram of an example process 400 of
forming an object on a substrate by depositing a plurality of
layers of a polymeric material onto a substrate and removing the
object from the substrate. The process 400 is illustrated as a
collection of blocks in a logical flow graph, which represent a
sequence of operations that can be implemented, at least in part,
by an extrusion-based additive manufacturing system, such as the
additive manufacturing system 100 of FIG. 1, the additive
manufacturing system 200 of FIG. 2, or both. The order in which the
operations are described is not intended to be construed as a
limitation, and any number of the described blocks can be combined
in any order and/or in parallel to implement the process.
[0078] At 402, a substrate 404 can be provided for forming thereon
an object using an additive manufacturing process. The substrate
404 can be the same as or similar to the substrate 104 of FIG. 1,
the substrate 204 of FIG. 2, or the substrate 302 of FIG. 3. In
some examples, the providing the substrate 404 at 402 can comprise
removably mounting or attaching a preformed substrate 404 to a
platform, such as the platform 106 of FIG. 1. In other examples,
providing the substrate 404 at 402 can further comprise producing
the substrate 404 by a suitable manufacturing technique, such as
injection-molding, extrusion, blow-molding, compression molding,
casting, or any other suitable method of making the substrate
402.
[0079] At 406, a filament 408 formed from a polymeric material
including units of an acid component and units of a glycol
component can be provided. In some cases, providing the filament
408 at 406 can include combining a diacid component and a glycol
component to form the polymeric material. For example, one or more
diacids and one or more glycols can be mixed together. In some
cases, the one or more diacids and the one or more glycols can be
in the form of pellets, powder, or some combination thereof. In a
particular example, pellets of at least one of the diacid component
or the glycol component can be subjected to a grinding operation
before being combined. The units of the acid component can be
derived from one or more acids and the units of the glycol
component can be derived from one or more glycols. In a particular
example, the polymeric material can be produced via a condensation
reaction between one or more acids and one or more glycols.
[0080] In some cases, the acid component of the polymeric material
can include units derived from one or more dibasic acids. For
example, the acid component can include units derived from a
terephthalic acid, units derived from an isophthalic acid, units
derived from a cyclohexanedicarboxylic acid, units derived from a
naphthalene dicarboxylic acid, units derived from a
stilbenedicarboxylic acid, or combinations thereof. Optionally, the
acid component can be comprised of from about 40 mole % to about 60
mole % of units derived from a first acid and from about 40 mole %
to about 60 mole % of units derived from a second acid. In a
particular example, the acid component can be comprised of from
about 45 mole % to about 55 mole % of units derived from
terephthalic acid and from about 45 mole % to about 55 mole % of
units derived from isophthalic acid.
[0081] Additionally, the glycol component can include units derived
from cyclohexamedimethanol. Further, the glycol component can
include units derived from one or more additional glycols, such as
ethylene glycol, 1,2-propanediol, 1,3-propanediol, neopentyl
glycol, 1,4-butanediol, 1,5-pentatnediol, 1,6-hexanediol, p-xylene
glycol, 2,2,4,4-Tetramethyl-1,3-cyclobutanediol, or combinations
thereof. In some cases where the polymeric material includes units
derived from multiple glycols, the glycol component can include
from about 75 mole % to about 98 mole % of units derived from a
first glycol and from about 2 mole % to about 25 mole % of units
derived from one or more second glycols.
[0082] The polymeric material of the filament 408 can also include
additives, such as stabilizers, antioxidants, fillers, branching
agents, pigments, dyes, combinations thereof, and the like.
[0083] Optionally, the polymeric material can have an intrinsic
viscosity from about 0.55 dL/g to about 0.7 dL/g, a density no
greater than about 1.25 g/cm.sup.3, a glass transition temperature
of at least about 80.degree. C., and a crystallization half-time no
greater than about 300 minutes. Also, the polymeric material can
have a zero shear viscosity no greater than about 3000 Poise.
Further, the polymeric material can have an elongation at break of
at least about 75%.
[0084] After combining the diacid component and the glycol
component to form the polymeric material, the polymeric material
can be extruded to form the filament 408. In some cases, the
polymeric material can be fed into the extruder in the form of
pellets, while in other cases, the polymeric material can be fed
into the extruder as a powder. In particular, the filament 408 of
the build material can be produced using an extruder, such as a
single screw extruder, in some instances, or a twin screw extruder,
in other instances. In some cases, the extruder can include a melt
pump, while in other cases, a melt pump can be absent from the
extruder. When a single screw extruder or a twin screw extruder is
used to produce the filament 408, the screw(s) of the extruders can
be operated at a speed from about 50 rotations per minute to about
200 rotations per minute. In an illustrative example, the speed of
the single screw extruder or the twin screw extruder can be from
about 75 rotations per minute to about 175 rotations per minute. In
another illustrative example, the speed of the single screw
extruder or the twin screw extruder can be from 60 rotations per
minute to 85 rotations per minute. In addition, a feed rate into
the extruder of one or more materials used to form the filament 408
can be from 10 grams/minute to 40 grams/minute, from 15
grams/minute to 35 grams/minute, from 20 grams/minute to 30 grams
per minute, or from 15 grams/minute to 25 grams/minute.
[0085] The extruder can include one or more chambers and the
mixture of materials used to form the filament 408 can be heated in
one or more chambers of the extruder. For example, heat can be
applied to the polymeric material in a first chamber of the
extruder at a first temperature from 100.degree. C. to 180.degree.
C., from 110.degree. C. to 160.degree. C., or from 120.degree. C.
to 140.degree. C. Also, heat can be applied to the polymeric
material used to form the filament 408 in a second chamber of the
extruder at a second, different temperature, such as from
160.degree. C. to 260.degree. C., from 190.degree. C. to
250.degree. C., from 200.degree. C. to 240.degree. C., or from
210.degree. C. to 230.degree. C. When the extruder includes more
than two chambers, heat can be applied to the polymeric material
used to form the filament 408 in one or more additional chambers of
the extruder at the first temperature or the second temperature. In
an illustrative example, heat can be applied to the polymeric
material used to form the filament 408 in one or more chambers of
the extruder at a temperature from about 210.degree. C. to about
240.degree. C.
[0086] The filament 408 can have a diameter from about 1 mm to
about 5 mm and a length of at least about 3 cm. In some cases, the
filament 408 can have a length of at least about 5 cm. In some
cases, the filament 408 can have a length of at least about 30 cm.
In some cases, the filament 408 can have a length from about 3 cm
to about 5 m. In some cases, the filament 408 can have a length
from about 30 cm to about 5 m. Additionally, the filament 408 can
have a length that is greater than 5 m. In a particular example,
the filament 408 can have a body with a diameter from about 1.5 mm
to about 3 mm and a length of at least about 2 m.
[0087] At 410, a plurality of layers of the polymeric material can
be deposited onto the substrate 404 to produce an object 412. For
example, the one or more layers of the polymeric material can be
extruded onto the substrate 404 via an extrusion head according to
a predetermined design to form the object 412. To illustrate, the
depositing of the one or more layers of the polymeric material onto
the substrate 404 can occur based on a predetermined design to
build the object 412 in a layer-by-layer fashion according to 3D
model data processed by an additive manufacturing system. In some
cases, an amount of the polymeric material can be heated at a
temperature from about 190.degree. C. to about 270.degree. C.
before depositing the amount of the polymeric material onto the
substrate 404.
[0088] In addition, in depositing the plurality of layers of the
filament 408 onto the substrate 404, the polymeric material can be
deposited at a specified rate. In some cases, the filament 408 can
be extruded onto the substrate 404 to produce the plurality of
layers of the object. In these cases, the rate at which the
filament 408 is extruded can be referred to as the "rate of
extrusion." In an illustrative example, the rate at which the
filament 408 is deposited onto the substrate 404 during the
formation of the object 412 can be from about 5.5 mm.sup.3/s to
about 9.5 mm.sup.3/s. In another illustrative example, the rate at
which the filament 408 is deposited onto the substrate 404 during
the formation of the object 412 can be from about 6.5 mm.sup.3/s to
about 9.0 mm.sup.3/s. In an additional illustrative example, the
rate at which the filament 408 is deposited onto the substrate 404
during the formation of the object 412 can be from about 7.6
mm.sup.3/s to about 8.7 mm.sup.3/s.
[0089] The object 412 can have an inherent viscosity of at least
about 0.4 dL/g, at least about 0.45 dL/g, at least about 0.50 dL/g,
at least about 0.55 dL/g, or at least about 0.60 dL/g.
Additionally, the object 412 can have an inherent viscosity of no
greater than about 0.90 dL/g, no greater than about 0.85 dL/g, no
greater than about 0.80 dL/g, no greater than about 0.75 dL/g, no
greater than about 0.70 dL/g, or no greater than about 0.65 dL/g.
In an illustrative example, the object 412 can have an inherent
viscosity from about 0.35 dL/g to about 1.00 dL/g. In another
illustrative example, the object 412 can have an inherent viscosity
from about 0.50 dL/g to about 0.80 dL/g. In an additional
illustrative example, the object 412 can have an inherent viscosity
from about 0.55 dL/g to about 0.70 dL/g. The inherent viscosity of
the object 412 can be measured in approximately a 60/40 solution of
phenol/tetrachloroethane at a concentration of about 0.5 g/100 ml
at about 25.degree. C.
[0090] In some cases, the object 412 can have a minimal loss of
inherent viscosity relative to an inherent viscosity of the
polymeric material used to produce the object 412. In particular,
an inherent viscosity loss with inherent viscosity abbreviated as
I.V. in the equation below can be expressed as:
I . V . loss = polymeric material I . V . - object I . V .
polymeric material I . V . .times. 100 ##EQU00001##
In particular, the object 412 can have an inherent viscosity loss
of no greater than about 6%, no greater than about 5%, no greater
than about 4%, no greater than about 3%, no greater than about 2%,
no greater than about 1.5%, no greater than about 1.3%, no greater
than about 1.1%, no greater than about 1%, no greater than about
0.9%, no greater than about 0.7%, or no greater than about 0.5%. In
some cases, the object can have substantially no inherent viscosity
loss. In an illustrative example, the object 412 can have an
inherent viscosity loss from about 0.01% to about 10%. In another
illustrative example, the object 412 can have an inherent viscosity
loss from about 0.05% to about 8%. In an additional illustrative
example, the object 412 can have an inherent viscosity loss from
about 0.10% to about 5%. In a further illustrative example, the
object 412 can have an inherent viscosity loss from about 0.5% to
about 2%.
[0091] Optionally, inherent viscosity loss can depend on a
temperature at which the polymeric material of the filament 408 is
heated as the layers of the polymeric material are deposited onto
the substrate 404 during the formation of the object 412. To
illustrate, when the object 412 is formed at a temperature of about
225.degree. C., an inherent viscosity loss of the object 412
relative to the polymeric material of the filament 408 can be no
greater than about 2.5%, no greater than about 2.1%, no greater
than about 1.7%, no greater than about 1.5%, no greater than about
1.3%, no greater than about 1.1%, no greater than about 0.9%, no
greater than about 0.7%, no greater than about 0.5%, no greater
than about 0.3%, or no greater than about 0.1%. In some cases, when
the object 412 is formed at a temperature of about 225.degree. C.,
there can be substantially no inherent viscosity loss of the object
412 relative to the polymeric material of the filament 408. In an
illustrative example, when the object 412 is formed at a
temperature of about 225.degree. C., an inherent viscosity loss of
the object 412 relative to the polymeric material of the filament
408 can be from about 0.01% to about 3%. In another illustrative
example, when the object 412 is formed at a temperature of about
225.degree. C., an inherent viscosity loss of the object 412
relative to the polymeric material of the filament 408 can be from
about 0.04% to about 2.50%. In an additional illustrative example,
when the object 412 is formed at a temperature of about 225.degree.
C., an inherent viscosity loss of the object 412 relative to the
polymeric material of the filament 408 can be from about 0.1% to
about 2%.
[0092] Additionally, when the object 412 is formed at a temperature
of about 230.degree. C., an inherent viscosity loss of the object
412 relative to the polymeric material of the filament 408 can be
no greater than about 5.5%, no greater than about 5.0%, no greater
than about 4.5%, no greater than about 4%, no greater than about
3.5%, no greater than about 3%, no greater than about 2.5%, no
greater than about 2.0%, no greater than about 1.5%, no greater
than about 1.0%, no greater than about 0.9%, no greater than about
0.7%, no greater than about 0.5%, no greater than about 0.3%, or no
greater than about 0.1%. In some cases, when the object 412 is
formed at a temperature of about 230.degree. C., there can be
substantially no inherent viscosity loss of the object 412 relative
to the polymeric material of the filament 408. In an illustrative
example, when the object 412 is formed at a temperature of about
230.degree. C., an inherent viscosity loss of the object 412
relative to the polymeric material of the filament 408 can be from
about 0.01% to about 6%. In another illustrative example, when the
object 412 is formed at a temperature of about 230.degree. C., an
inherent viscosity loss of the object 412 relative to the polymeric
material of the filament 408 can be from about 0.04% to about
2.50%. In an additional illustrative example, when the object 412
is formed at a temperature of about 230.degree. C., an inherent
viscosity loss of the object 412 relative to the polymeric material
of the filament 408 can be from about 0.1% to about 2%.
[0093] Further, when the object 412 is formed at a temperature of
about 240.degree. C., an inherent viscosity loss of the object 412
relative to the polymeric material of the filament 408 can be no
greater than about 6%, no greater than about 5.5%, no greater than
about 5%, no greater than about 4.5%, no greater than about 4%, no
greater than about 3.5%, no greater than about 3%, no greater than
about 2.5%, no greater than about 2%, no greater than about 1.9%,
no greater than about 1.7%, no greater than about 1.5%, no greater
than about 1.3%, no greater than about 1.1%, or no greater than
about 0.9%. In an illustrative example, when the object 412 is
formed at a temperature of about 240.degree. C., an inherent
viscosity loss of the object 412 relative to the polymeric material
of the filament 408 can be from about 0.8% to about 6%. In another
illustrative example, when the object 412 is formed at a
temperature of about 240.degree. C., an inherent viscosity loss of
the object 412 relative to the polymeric material of the filament
408 can be from about 1% to about 4%. In an additional illustrative
example, when the object 412 is formed at a temperature of about
240.degree. C., an inherent viscosity loss of the object 412
relative to the polymeric material of the filament 408 can be from
about 1.1% to about 2.1%.
[0094] Also, when the object 412 is formed at a temperature of
about 250.degree. C., an inherent viscosity loss of the object 412
relative to the polymeric material of the filament 408 can be no
greater than about 7.5%, no greater than about 7%, no greater than
about 6.5%, no greater than about 6%, no greater than about 5.5%,
no greater than about 5%, no greater than about 4.5%, no greater
than about 4%, no greater than about 3.5%, no greater than about
3%, no greater than about 2.5%, no greater than about 2%, no
greater than about 1.9%, no greater than about 1.7%, or no greater
than about 1.5%. In an illustrative example, when the object 412 is
formed at a temperature of about 250.degree. C., an inherent
viscosity loss of the object 412 relative to the polymeric material
of the filament 408 can be from about 2.3% to about 7.5%. In
another illustrative example, when the object 412 is formed at a
temperature of about 250.degree. C., an inherent viscosity loss of
the object 412 relative to the polymeric material of the filament
408 can be from about 2.7% to about 6.1%. In an additional
illustrative example, when the object 412 is formed at a
temperature of about 250.degree. C., an inherent viscosity loss of
the object 412 relative to the polymeric material of the filament
408 can be from about 2.8% to about 5.1%.
[0095] Furthermore, inherent viscosity loss can depend on a rate at
which the polymeric material of the filament 408 is deposited onto
the substrate 404 during the formation of the object 412. For
example, when the filament 408 is deposited onto the substrate 404
during the formation of the object 412 at a rate from about 7
mm.sup.3/s to about 8 mm.sup.3/s, an inherent viscosity loss of the
object 412 relative to the polymeric material of the filament 408
can be no greater than about 5%, no greater than about 4.5%, no
greater than about 4%, no greater than about 3.5%, no greater than
about 3%, no greater than about 2.5%, no greater than about 2%, no
greater than about 1.5%, no greater than about 1%, no greater than
about 0.9%, no greater than about 0.7%, no greater than about 0.5%,
no greater than about 0.3%, or no greater than about 0.1%. In some
cases, when the filament 408 is deposited onto the substrate 404
during the formation of the object 412 at a rate from about 7
mm.sup.3/s to about 8 mm.sup.3/s, there can be substantially no
inherent viscosity loss of the object 412 relative to the polymeric
material of the filament 408. In an illustrative example, when the
filament 408 is deposited onto the substrate 404 during the
formation of the object 412 at a rate from about 7 mm.sup.3/s to
about 8 mm.sup.3/s, an inherent viscosity loss of the object 412
relative to the polymeric material of the filament 408 can be from
about 0.01% to about 6%. In another illustrative example, an
inherent viscosity loss of the object 412 relative to the polymeric
material of the filament 408 can be from about 0.7% to about 4.3%.
In an additional illustrative example, when the filament 408 is
deposited onto the substrate 404 during the formation of the object
412 at a rate from about 7 mm.sup.3/s to about 8 mm.sup.3/s, an
inherent viscosity loss of the object 412 relative to the polymeric
material of the filament 408 can be from about 0.9% to about
2.5%.
[0096] In addition, when the filament 408 is deposited onto the
substrate 404 during the formation of the object 412 at a rate from
about 8 mm.sup.3/s to about 9 mm.sup.3/s, an inherent viscosity
loss of the object 412 relative to the polymeric material of the
filament 408 can be no greater than about 5%, no greater than about
4.5%, no greater than about 4%, no greater than about 3.5%, no
greater than about 3%, no greater than about 2.5%, no greater than
about 2%, no greater than about 1.5%, no greater than about 1%, no
greater than about 0.9%, no greater than about 0.7%, no greater
than about 0.5%, no greater than about 0.3%, or no greater than
about 0.1%. In some cases, when the filament 408 is deposited onto
the substrate 404 during the formation of the object 412 at a rate
from about 8 mm.sup.3/s to about 9 mm.sup.3/s, there can be
substantially no inherent viscosity loss of the object 412 relative
to the polymeric material of the filament 408. In an illustrative
example, when the filament 408 is deposited onto the substrate 404
during the formation of the object 412 at a rate from about 8
mm.sup.3/s to about 9 mm.sup.3/s, an inherent viscosity loss of the
object 412 relative to the polymeric material of the filament 408
can be from about 0.01% to about 4%. In another illustrative
example, when the filament 408 is deposited onto the substrate 404
during the formation of the object 412 at a rate from about 8
mm.sup.3/s to about 9 mm.sup.3/s, an inherent viscosity loss of the
object 412 relative to the polymeric material of the filament 408
can be from about 0.1% to about 3.3%. In an additional illustrative
example, when the filament 408 is deposited onto the substrate 404
during the formation of the object 412 at a rate from about 8
mm.sup.3/s to about 9 mm.sup.3/s, an inherent viscosity loss of the
object 412 relative to the polymeric material of the filament 408
can be from about 0.2% to about 0.9%.
[0097] In a particular example, when the object 412 is formed at a
temperature of about 230.degree. C. and when the filament 408 is
deposited onto the substrate 404 during the formation of the object
412 at a rate from about 7 mm.sup.3/s to about 8 mm.sup.3/s, an
inherent viscosity loss of the object 412 relative to the polymeric
material of the filament 408 can be no greater than about 5.5%,
such as from about 0.7% to about 5.3%. In another particular
example, when the object 412 is formed at a temperature of about
240.degree. C. and when the filament 408 is deposited onto the
substrate 404 during the formation of the object 412 at a rate from
about 7 mm.sup.3/s to about 8 mm.sup.3/s, an inherent viscosity
loss of the object 412 relative to the polymeric material of the
filament 408 can be no greater than about 5.5%, such as from about
1.5% to about 5.3%. In an additional particular example, when the
object 412 is formed at a temperature of about 250.degree. C. and
when the filament 408 is deposited onto the substrate 404 during
the formation of the object 412 at a rate from about 7 mm.sup.3/s
to about 8 mm.sup.3/s, an inherent viscosity loss of the object 412
relative to the polymeric material of the filament 408 can be no
greater than about 7.1%, such as from about 2.7% to about 6.8%.
[0098] Also, when the object 412 is formed at a temperature of
about 230.degree. C. and when the filament 408 is deposited onto
the substrate 404 during the formation of the object 412 at a rate
from about 8 mm.sup.3/s to about 9 mm.sup.3/s, an inherent
viscosity loss of the object 412 relative to the polymeric material
of the filament 408 can be no greater than about 2.5%, such as from
about 0.1% to about 2.3%. Additionally, when the object 412 is
formed at a temperature of about 240.degree. C. and when the
filament 408 is deposited onto the substrate 404 during the
formation of the object 412 at a rate from about 8 mm.sup.3/s to
about 9 mm.sup.3/s, an inherent viscosity loss of the object 412
relative to the polymeric material of the filament 408 can be no
greater than about 3.5%, such as from about 0.9% to about 3.3%.
Further, when the object 412 is formed at a temperature of about
250.degree. C. and when the filament 408 is deposited onto the
substrate 404 during the formation of the object 412 at a rate from
about 8 mm.sup.3/s to about 9 mm.sup.3/s, an inherent viscosity
loss of the object 412 relative to the polymeric material of the
filament 408 can be no greater than about 6.1%, such as from about
2.5% to about 5.7%.
[0099] Inherent viscosity loss can indicate an amount of
degradation of a material that occurs during an additive
manufacturing process. The loss of inherent viscosity can cause a
change in mechanical properties of a material. In some case, the
change in mechanical properties can result in an object produced
using an additive manufacturing process being brittle.
[0100] Further, the object 412 can have a notched Izod test value
from about 35 kJ/m.sup.2 to about 60 kJ/m.sup.2. In another
example, the object 412 can have a notched Izod test value from
about 40 kJ/m.sup.2 to about 55 kJ/m.sup.2. In an additional
example, the object 412 can have a notched Izod test value from
about 45 kJ/m.sup.2 to about 50 kJ/m.sup.2. The notched Izod test
value of the object 412 can be measured according to the ASTM D256
standard at the time of filing of this patent application.
[0101] At 414, the object 412 can be removed from the substrate
404. In some cases, a machine, such as a robotic arm, can be used
to remove the object 412 from the substrate 404. In other cases, an
individual can remove the object 412 from the substrate 404 by
using a hand or tool.
[0102] Other architectures can be used to implement the described
functionality, and are intended to be within the scope of this
disclosure. Furthermore, although specific distributions of
responsibilities are defined above for purposes of discussion, the
various functions and responsibilities might be distributed and
divided in different ways, depending on circumstances.
[0103] The concepts described herein will be further described in
the following examples with reference to the following figures,
which do not limit the scope of the disclosure described in the
claims.
EXAMPLES
Example 1
[0104] Samples of polymeric materials were prepared having the
compositions described in Table 1. Samples 1 and 2 were formed
according to techniques described herein and Samples 3 and 4 were
prepared as comparative examples. In addition to the components
shown in Table 1, Sample 4 also included a trimellitic anhydride
branching agent. The composition of the samples was determined
using proton nuclear magnetic resonance spectroscopy (NMR).
TABLE-US-00001 TABLE 1 Compositions for Samples 1-4 Sample 1 Sample
2 Sample 3 Sample 4 Cyclohexanedi- 100 mole % 31 mole % 31 mole %
31 mole % methanol Ethylene 0 mole % 69 mole % 69 mole % 69 mole %
Glycol Terephthalic 52 mole % 100 mole % 100 mole % 100 mole % Acid
Isophthalic 48 mole % 0 mole % 0 mole % 0 mole % Acid
[0105] Some of the characteristics of the samples were measured
according to ASTM D standards. The results of the sample
measurements are shown in Table 2.
TABLE-US-00002 TABLE 2 Physical Property Measurements for Samples
1-4 Sample 1 Sample 2 Sample 3 Sample 4 Density (g/cm.sup.3) 1.20
1.28 1.28 1.27 Inherent Viscosity (dL/g) 0.64 0.59 0.75 0.75 Glass
Transition Temperature (.degree. C.) 84 78 78 78 Crystallization
Half-Time (minutes) 128 >1500 >1500 >1500 Zero Shear
Viscosity (Poise) 2750 2810 -- -- Heat Deflection Temperature
(.degree. C.) 63 62 62 62 Tensile Strength at Yield (MPa) 50 51 51
50 Elongation at Break (%) 193 33 33 110 Flexural Modulus (MPa)
1814 2007 2007 2100 Notched Izod Impact Strength 70 69 98 95
(J/m)
[0106] The density of the samples was measured using the ASTM D 792
standard at the time of filing of this patent application. In
addition, the inherent viscosity of the samples was measured in
approximately a 60/40 solution of phenol/tetrachloroethane at a
concentration of about 0.5 g/100 ml at about 25.degree. C. In
addition, the glass transition temperature of the samples was
measured using a TA Instruments differential scanning calorimeter
(DSC) at a scan rate of about 20.degree. C.
[0107] The crystallization half-time of the samples was measured
using a small angle light scattering (SALS) technique with a
helium-neon laser. In particular, the sample was melted at about
280.degree. C. to remove preexisting crystallinity. The sample was
then rapidly cooled to a predetermined crystallization temperature
from about 140.degree. C. to about 160.degree. C. and the
transmitted light intensity was recorded as a function of time. The
time at which the light intensity drops to half the original value
denotes the crystallization half-time.
[0108] The zero shear viscosity of the samples was measured using
small amplitude oscillatory shear (SAOS) rheology conducted with
RDA II from Rheometrics Scientific. A frequency sweep from about 1
to about 400 rad/s was performed at about 260.degree. C. using
about a 10% strain value. The samples exhibited a Newtonian-like
plateau in the 1-10 rad/s shear rate regime. The viscosity measured
at about 1 rad/s was reported as the zero-shear viscosity.
[0109] For the remaining tests, an ASTM test bar was molded on a
Toyo 90 injection molding machine. The pellets of the samples were
first dried at about 70.degree. C. for about 3-6 hours. The molding
melt temperature was about 260.degree. C. and the mold temperature
was about 30.degree. C. The heat deflection temperature of the
samples was measured at about 264 psi according to the ASTM D 648
standard at the time of filing this patent application. In
addition, the flexural modulus was measured according to the ASTM D
790 standard at the time of filing this patent application.
Further, the tensile strength at yield and the elongation at break
were measured according to the ASTM D 638 standard at the time of
filing of this patent application. Also, the notched Izod impact
strength of the samples were measured at about 23.degree. C.
according to the ASTM D 256 standard at the time of filing of this
patent application.
Example 2
[0110] Objects were produced using filaments formed from samples
1-4 of Table 1 and inherent viscosity of the objects was measured
in approximately a 60/40 solution of phenol/tetrachloroethane at a
concentration of about 0.5 g/100 ml. The solution was heated to
about 150.degree. C. to mix and dissolve the material in the
solution. The solution was then cooled to about 25.degree. C. The
inherent viscosity was determined by measuring the pressure used to
force the solution down a narrow bore stainless steel tube relative
to the pressure used to force the 60/40 phenol/tetrachoroethane
solution without the material down the tube.
[0111] Table 3 shows the process conditions and inherent viscosity
(I.V.) measurements for objects made from filaments of polymeric
materials corresponding to samples 1-4 of Table 1 with the
extrusion head having a first rate of extrusion of about 7.6
mm.sup.3/s for sample 1, about 7.4 mm.sup.3/s for sample 2, about
4.4 mm.sup.3/s for sample 3, and about 4 mm.sup.3/s for sample 4.
Table 4 shows the process conditions and inherent viscosity
measurements for objects made from filaments of polymeric materials
corresponding to samples 1-4 of Table 1 with the extrusion head
having a second rate of extrusion of about 8.7 mm.sup.3/s for
sample 1, about 8.8 mm.sup.3/s for sample 2, about 4.8 mm.sup.3/s
for sample 3, and about 4.1 mm.sup.3/s for sample 4. The inherent
viscosity loss was calculated in Tables 3 and 4 based on a first
inherent viscosity of the polymeric material before the objects
were produced and a second inherent viscosity of the completed
objects. The first inherent viscosity for sample 1 was about 0.619
dL/g, the first inherent viscosity for sample 2 was about 0.588
dL/g, the first inherent viscosity for sample 3 was about 0.720
dL/g, and the first inherent viscosity for sample 4 was about 0.735
dL/g. The second inherent viscosity measurements of the completed
objects are shown in Tables 3 and 4.
TABLE-US-00003 TABLE 3 Inherent viscosity and inherent viscosity
loss for objects produced using additive manufacturing at a first
rate of extrusion. Sample 2 Sample 1 I.V. Sample 3 Sample 4 Temp.
I.V. (dL/g)/I.V. (dL/g)/I.V. I.V. (dL/g)/I.V. I.V. (dL/g)/
(.degree. C.) Loss (%) Loss (%) Loss (%) I.V. Loss (%) 220 0.612/1
0.572/3 0.676/6 0.689/6 225 0.611/1 0.562/4 0.672/7 0.668/9 230
0.611/1 0.555 6 0.651/10 0.662/10 235 0.606/2 0.552/6 0.632/12
0.631/14 240 0.606/2 0.554/6 0.619/14 0.618/16 245 0.604/2 0.549/7
0.613/15 0.602/18 250 0.601/3 0.544/7 0.607/16 0.602/18 255 0.599/4
0.538/9 0.605/16 0.596/19 260 0.599/4 0.543/8 0.597/17 0.592/19
TABLE-US-00004 TABLE 4 Inherent viscosity and inherent viscosity
loss for objects produced using additive manufacturing at a second
rate of extrusion. Sample 2 Sample 1 I.V. Sample 3 Sample 4 Temp.
I.V. (dL/g)/I.V. (dL/g)/I.V. I.V. (dL/g)/I.V. I.V. (dL/g)/
(.degree. C.) Loss (%) Loss (%) Loss (%) I.V. Loss (%) 220 0.616/0
0.581/1 0.708/2 0.712/3 225 0.616/0 0.573/3 0.698/3 0.711/3 230
0.618/0 0.572 3 0.686/5 0.698/5 235 0.613/1 0.567/4 0.676/6 0.692/6
240 0.612/1 0.563/4 0.666/7 0.676/8 245 0.610/1 0.556/5 0.657/9
0.660/10 250 0.602/3 0.551/6 0.637/12 0.649/13 255 0.601/3 0.551/6
0.622/14 0.619/16 260 0.604/4 0.552/6 0.610/15 0.608/17
[0112] Table 5 shows a summary of process conditions and inherent
viscosity change between the inherent viscosity of a polymeric
material before being used to produce an object using
extrusion-based additive manufacturing and the inherent viscosity
of a completed object produced from the polymeric material. The
maximum temperature and the minimum temperature of Table 5 indicate
the maximum and minimum temperatures at which adhesion between the
layers of the object are sufficient. The objects produced from the
polymeric material of sample 1 had values for the inherent
viscosity drop that were less than that of objects produced using
polymeric materials of samples 2-4. Additionally, the temperature
range at which the objects produced using the polymeric material of
sample 1 was greater than that of objects produced using polymeric
materials of samples 2-4.
TABLE-US-00005 TABLE 5 Process conditions and inherent viscosity
change between the inherent viscosity of a polymeric material
before being used to produce an object and the inherent viscosity
of a completed object produced from the polymeric material. Rate
Temp. (.degree. C.) Delta (mm.sup.3/s) I.V. Drop Min Max (.degree.
C.) Min Max Min Max Sample 1 230 245 15 7.6 8.7 0% 2% Sample 2 225
235 10 7.4 8.8 3% 7% Sample 3 235 245 10 4.4 4.8 6% 14% Sample 4
235 245 10 4 4.1 6% 18%
[0113] Adhesion was tested by using an Ultimaker 2 extrusion based
additive manufacturing system to produce layers of objects at
different temperatures while holding the speed relatively constant.
A Python script was used to direct the system to form the layers of
the objects. The adhesion was then tested at the different
temperatures through a manual test of the amount of force exerted
by a human hand to separate the layers. The minimum and maximum
temperatures shown in Table 5 were recorded when the layers could
not be readily separated by the use of a human hand.
[0114] FIG. 5 shows an example object produced at an extrusion rate
of about 1 mm.sup.3/s where the filament is heated at different
temperatures before extruding the filament to form the object. In
particular, the object shown in FIG. 5 is produced from a polymeric
material according to the composition of Sample 4. When a different
temperature was used to heat the filament prior to extrusion, a
layer having a diameter that was less than the diameter of a
previously formed layer was produced to aid in demarcating the
transition between temperatures. The object shown in FIG. 5
includes demarcation lines indicating layers formed at 220.degree.
C., 225.degree. C., 230.degree. C., 235.degree. C., and 240.degree.
C. FIG. 5 also shows that visual degradation of the object takes
place when the layers of the object are produced at temperatures
above 240.degree. C. As the object shown in FIG. 5 was produced,
adhesion was tested at each temperature transition point. For
example, adhesion between the layers produced at 220.degree. C. and
adhesion between layers produced at 225.degree. C. was tested by
trying to separate the respective layers at the ring indicated in
FIG. 5. Subsequent tests were performed for each of the temperature
transitions. The same procedure was followed to test adhesion
between layers produced at different temperatures for polymeric
materials having compositions corresponding to Sample 1, Sample 2,
and Sample 3. FIG. 6 shows an object produced using a polymeric
material having a composition corresponding to Sample 1 at an
extrusion rate of about 2 mm.sup.3/s, where the filament is heated
at different temperatures before extruding the filament to form the
object. FIG. 6 shows that visual degradation of the object occurs
at temperatures above 245.degree. C. Table 6 shows visual
degradation temperatures for objects produced using compositions of
Sample, 1, Sample 2, Sample 3, and Sample 4. The first extrusion
rate measurements are taken at a rate of extrusion of about 1
mm.sup.3/s and the second extrusion rate measurements are taken at
a rate of extrusion of about 2 mm.sup.3/s.
TABLE-US-00006 TABLE 6 Temperatures at which visual degradation is
observed in .degree. C. Second Extrusion First Extrusion Rate Rate
Sample 1 245 260 Sample 2 235 250 Sample 3 245 260 Sample 4 245
265
[0115] FIG. 7 shows an object produced using the composition of
Sample 4 at a temperature of about 235.degree. C. using an
extrusion based additive manufacturing apparatus. The extrusion
rate at which the layers of the object were formed increased with
increasing height of the object. Additionally, FIG. 8 shows an
object produced using the composition of Sample 1 at a temperature
of about 235.degree. C. using an extrusion based additive
manufacturing apparatus, where the extrusion rate at which the
layers of the object were formed increased with increasing height
of the object. The initial extrusion rate was about 1 mm.sup.3/s.
The extrusion rates recorded in Table 5 were calculated by
measuring a height of an object formed according to the composition
corresponding to the respective sample before degradation occurred
using the following formula:
Extrusion Rate in mm 3 / s = height measured s + initial extrusion
rate ##EQU00002##
[0116] The constant "5" in the formula indicates that the extrusion
rate increases by 1 mm.sup.3/s for every 5 mm of the object
produced. The height of the tower shown in FIG. 8 versus the height
of the tower shown in FIG. 7 shows that the polymeric material used
to produce the tower of FIG. 8 can be used to form objects over a
greater range of extrusion rates indicating physical properties
that are more conducive to extrusion-based additive manufacturing
processes than the polymeric material used to form the tower of
FIG. 7.
[0117] Notched Izod testing was performed on objects produced from
polymeric materials related to samples 1-4 and the results are
shown in Table 7. The highest and lowest values in Table 6 for the
notched Izod test results are measured in KJ/m.sup.2. The notched
Izod tests were carried out according to the ASTM D256 standard at
the time of filing of this patent application. The objects produced
from the polymeric material corresponding to sample 1 had the least
variability in the notched Izod test results.
TABLE-US-00007 TABLE 7 Notched Izod test results. Max Min Delta
Variability Sample 1 47 46.5 0.5 0.03 Sample 2 47.3 46.7 0.6 0.06
Sample 3 47.4 46.4 1 0.1 Sample 4 47.9 45.7 2.2 0.22
Conclusion
[0118] In closing, although the various implementations have been
described in language specific to structural features and/or
methodological acts, it is to be understood that the subject matter
defined in the appended representations is not necessarily limited
to the specific features or acts described. Rather, the specific
features and acts are disclosed as example forms of implementing
the claimed subject matter.
Illustrative Examples of Inventive Concepts
[0119] While Applicant's disclosure includes reference to specific
implementations above, it will be understood that modifications and
alterations may be made by those practiced in the art without
departing from the spirit and scope of the inventive concepts
described herein. All such modifications and alterations are
intended to be covered. As such the illustrative examples of the
inventive concepts listed below are merely illustrative and not
limiting.
Example 1
[0120] An article comprising: a plurality of layers of a polymeric
material that includes units of a diacid component and units of a
glycol component, wherein the units of the diacid component are
derived from a first diacid and a second diacid.
Example 2
[0121] The article of example 1, wherein the plurality of layers
are arranged according to a design.
Example 3
[0122] The article of any one of examples 1-2, wherein the first
diacid is terephthalic acid and the second diacid is isophthalic
acid, a cyclohexanedicarboxylic acid, a naphthalenedicarboxylic
acid, a stilbenedicarboxylic acid, or a combination thereof.
Example 4
[0123] The article of any one of examples 1-3, wherein the diacid
component includes from about 40 mole % to about 60 mole % of units
derived from the first diacid and from about 40 mole % to about 60
mole % of units derived from the second diacid.
Example 5
[0124] The article of any one of examples 1-3, wherein the diacid
component includes from about 45 mole % to about 55 mole % of units
derived from terephthalic acid and from about 45 mole % to about 55
mole % of units derived from isophthalic acid.
Example 6
[0125] The article of any one of examples 1-5, wherein the units of
the glycol component are derived from cyclohexanedimethanol.
Example 7
[0126] The article of any one of examples 1-6, wherein the glycol
component includes from about 75 mole % to about 98 mole % of units
derived from a first glycol and from about 2 mole % to about 25
mole % of units derived from one or more second glycols.
Example 8
[0127] The article of example 7, wherein the first glycol includes
cyclohexanedimethanol and the one or more second glycols include
ethylene glycol, a propanediol, neopentyl glycol, a butanediol, a
pentanediol, a hexanediol, p-xylene glycol, or a combination
thereof.
Example 9
[0128] The article of any one of examples 1-8, wherein the
polymeric material has an inherent viscosity from about 0.55 dL/g
to about 0.7 dL/g, a density no greater than about 1.25 g/cm.sup.3,
a glass transition temperature of at least about 80.degree. C., and
a crystallization half-time no greater than about 300 minutes.
Example 10
[0129] An article comprising: a body comprised of a polymeric
material that includes units of a diacid component and units of a
glycol component, wherein: the body has a diameter from about 1 mm
to about 5 mm and a length of at least about 3 cm; and an inherent
viscosity loss of an object formed from the polymeric material
relative to the polymeric material before forming the object is no
greater than about 0.9%.
Example 11
[0130] The article of example 10, wherein the polymeric material
has a zero shear viscosity no greater than about 3000 Poise.
Example 12
[0131] The article of any one of examples 10-11, wherein the
polymeric material has an elongation at break of at least about
75%.
Example 13
[0132] The article of any one of examples 10-12, wherein the
polymeric material has a density no greater than about 1.25
g/cm.sup.3.
Example 14
[0133] The article of any one of examples 10-13, wherein the
polymeric material has a glass transition temperature of at least
about 80.degree. C.
Example 15
[0134] The article of any one of examples 10-14, wherein the body
has a length of at least about 3 cm.
Example 16
[0135] The article of any one of examples 10-15, wherein the body
has a diameter from about 1.5 mm to about 3 mm and a length of at
least about 2 m.
Example 17
[0136] The article of any one of examples 10-16, wherein the units
of the glycol component are derived from cyclohexanedimethanol,
from about 40 mole % to about 60 mole % of the units of the diacid
component are derived from terephthalic acid, and from about 40
mole % to about 60 mole % of the units of the diacid component are
derived from isophthalic acid.
Example 18
[0137] A process comprising: heating a polymeric material at a
temperature from about 225.degree. C. to about 250.degree. C., the
polymeric material including units of a diacid component and units
of a glycol component; extruding a plurality of layers of the
polymeric material onto a substrate to form an object, where a rate
of extrusion is from about 7 mm.sup.3/s to about 9 mm.sup.3/s;
wherein an inherent viscosity loss of the object relative to the
polymeric material before forming the object is no greater than
about 5% when the polymeric material is heated at a temperature of
about 250.degree. C.
Example 19
[0138] The process of example 18, wherein the plurality of layers
of the polymeric material are deposited onto the substrate
according to a predetermined design.
Example 20
[0139] The process of any one of examples 18-19, wherein depositing
the plurality of layers of the polymeric material onto the
substrate includes extruding the polymeric material onto the
substrate via an extrusion head.
Example 21
[0140] The process of any one of examples 18-20, wherein the units
of the glycol component are derived from cyclohexanedimethanol,
from about 40 mole % to about 60 mole % of the units of the diacid
component are derived from terephthalic acid, and from about 40
mole % to about 60 mole % of the units of the diacid component are
derived from isophthalic acid.
Example 22
[0141] The process of any one of examples 17-21, wherein the
polymeric material has an inherent viscosity from about 0.55 dL/g
to about 0.7 dL/g, a density no greater than about 1.25 g/cm.sup.3,
a glass transition temperature of at least about 80.degree. C., and
a crystallization half-time no greater than about 300 minutes.
Example 23
[0142] The process of any one of examples 17-22, wherein the
inherent viscosity loss is no greater than about 2%.
Example 24
[0143] A process comprising: combining a diacid component and a
glycol component to form a polymeric material, wherein the diacid
component includes a first diacid and a second diacid; extruding
the polymeric material to form a filament, the filament having a
body with a diameter from about 1 mm to about 5 mm and a length of
at least about 3 cm.
Example 25
[0144] The process of example 24, wherein the extruding the
polymeric material to form the filament is performed by an extruder
having a single screw or a twin screw.
Example 26
[0145] The process of example 25, wherein a screw speed of the
extruder is from about 60 rotations per minute (rpm) to about 85
rpm.
Example 27
[0146] The process of example 25, wherein at least one chamber of
the extruder is heated at a temperature from about 210.degree. C.
to about 240.degree. C.
Example 28
[0147] The process of any one of examples 24-27, further comprising
grinding pellets of at least one of the diacid component or the
glycol component before combining the diacid component and the
glycol component.
Example 29
[0148] The process of any one of examples 24-28, wherein the
filament has a length of at least about 30 cm.
Example 30
[0149] The process of any one of examples 24-29, wherein the
filament has a length from about 30 cm to about 5 m.
Example 31
[0150] The process of any one of examples 24-30, further
comprising: depositing a plurality of layers of the filament onto a
substrate according to a predetermined design to produce an object;
and removing the object from the substrate.
[0151] Example 32
[0152] The process of any one of examples 24-31, wherein the units
of the glycol component are derived from cyclohexanedimethanol and
the units of the diacid component are derived from terephthalic
acid and isophthalic acid.
* * * * *