U.S. patent application number 15/039592 was filed with the patent office on 2016-11-03 for compositions and methods for fused filament fabrication.
This patent application is currently assigned to IMERYS TALC AMERICA, INC.. The applicant listed for this patent is IMERYS TALC AMERICA, INC.. Invention is credited to Saied KOCHESFAHANI.
Application Number | 20160318249 15/039592 |
Document ID | / |
Family ID | 53042112 |
Filed Date | 2016-11-03 |
United States Patent
Application |
20160318249 |
Kind Code |
A1 |
KOCHESFAHANI; Saied |
November 3, 2016 |
COMPOSITIONS AND METHODS FOR FUSED FILAMENT FABRICATION
Abstract
A composition for fused filament fabrication may include
polylactic acid resin and talc. The composition may range from 50%
by weight to 99% by weight polylactic acid resin, and from 7% by
weight to 40% by weight talc. The composition may be configured as
filaments or pellets adapted to be used in a fused filament
fabrication process. A method for generating a resin-based
structure may include providing a resin source that may include
polylactic acid resin and talc. The resin source may include from
50% by weight to 99% by weight polylactic acid resin, and from 7%
by weight to 40% by weight talc. The method may also include
heating the resin source to a temperature greater than the melting
temperature for semi-crystalline resins or significantly greater
than glass transition temperature for amorphous resins, and
depositing the heated resin source in a layered manner to form the
resin-based structure.
Inventors: |
KOCHESFAHANI; Saied; (San
Jose, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
IMERYS TALC AMERICA, INC. |
Roswell |
GA |
US |
|
|
Assignee: |
IMERYS TALC AMERICA, INC.
Roswell
GA
|
Family ID: |
53042112 |
Appl. No.: |
15/039592 |
Filed: |
November 7, 2014 |
PCT Filed: |
November 7, 2014 |
PCT NO: |
PCT/US14/64493 |
371 Date: |
May 26, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61902374 |
Nov 11, 2013 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B29C 64/118 20170801;
C08K 3/34 20130101; C08K 2201/002 20130101; B29C 64/106 20170801;
B32B 27/22 20130101; B29K 2067/046 20130101; B32B 27/20 20130101;
C08K 2201/006 20130101; B33Y 70/00 20141201; B29K 2995/004
20130101; C08K 2201/005 20130101; B33Y 10/00 20141201; B33Y 80/00
20141201; B29K 2105/0005 20130101; B32B 27/36 20130101; C08K
2201/018 20130101; B32B 27/08 20130101; B29K 2105/16 20130101; C08K
3/34 20130101; C08L 67/04 20130101 |
International
Class: |
B29C 67/00 20060101
B29C067/00; B33Y 80/00 20060101 B33Y080/00; B33Y 70/00 20060101
B33Y070/00; C08K 3/34 20060101 C08K003/34; B33Y 10/00 20060101
B33Y010/00 |
Claims
1. A composition for fused filament fabrication, the composition
comprising: polylactic acid resin and talc, wherein the composition
ranges from 50% by weight to 99% by weight polylactic acid resin,
wherein the composition ranges from 7% by weight to 40% by weight
talc, and wherein the composition is configured as a shape adapted
to be used in a fused filament fabrication process.
2. The composition of claim 1, wherein the talc has a median
particle size less than 12 microns.
3-7. (canceled)
8. The composition of claim 1, wherein the talc has a top particle
size less than 150 microns.
9-12. (canceled)
13. The composition of claim 1, wherein the talc has a Hegman
rating of 2 or greater.
14-16. (canceled)
17. The composition of claim 1, wherein the talc has a BET surface
area greater than 2 m.sup.2/g.
18-29. (canceled)
30. The composition of claim 1, wherein the talc has an oil
absorption less than 60 grams per 100 grams of talc.
31-34. (canceled)
35. The composition of claim 1, wherein the talc has a shape factor
greater than 10.
36-48. (canceled)
49. The composition of claim 1, wherein the composition ranges from
10% by weight to 30% by weight talc.
50-52. (canceled)
53. The composition of claim 1, further comprising at least one
additional mineral.
54. (canceled)
55. The composition of claim 1, wherein the composition further
comprises at least one of plasticizers, impact modifiers, pigments,
dyes, colorants, stabilizers, and other polymer additives or
processing aids, configured to modify resin properties.
56. (canceled)
57. A method for generating a resin-based structure, the method
comprising: providing a resin source comprising polylactic acid
resin and talc, wherein the resin source comprises from 50% by
weight to 99% by weight polylactic acid resin, and wherein the
resin source comprises from 7% by weight to 40% by weight talc;
heating the resin source to a temperature at least equal to the
glass transition temperature of the resin source; and depositing
the heated resin source in a layered manner to form the resin-based
structure.
58. An article having improved heat resistance, comprising: a
semi-crystalline polymer material having a heat deflection
temperature equal to or greater than about 70 C, wherein the
article comprises fused filaments of the semi-crystalline polymer
material.
59. The article of claim 58, wherein the semi-crystalline polymer
material comprises a functional mineral.
60. The article of claim 59, wherein the functional mineral
comprises talc.
61. The article of claim 59, wherein the functional mineral is
present in an amount ranging from 7% by weight to 40% by
weight.
63. The article of claim 59, wherein the functional mineral has a
shape factor greater than 10.
64. The article of claim 59, wherein the functional mineral has an
oil absorption less than 60 grams per 100 grams of mineral.
65. The article of claim 59, wherein the functional mineral has a
median particle size less than 12 microns.
66. The article of claim 58, wherein the semi-crystalline polymer
material comprises polylactic acid resin.
67. The article of claim 58, wherein the semi-crystalline polymer
material has a crystalline content of at least about 30%.
Description
CLAIM FOR PRIORITY
[0001] This PCT International Application claims the benefit of
priority of U.S. Provisional Patent Application No. 61/902,374,
filed Nov. 11, 2013, the subject matter of which is incorporated
herein by reference in its entirety.
DESCRIPTION
[0002] The present disclosure relates to compositions and methods
related to fused filament fabrication, and more particularly, to
polymer compositions including talc, mica, kaolin, bentonite,
montmorillonite, pyrophyllite, vermiculite, halloysite,
wollastonite, calcium carbonate, titania, perlite, diatomaceous
earth, combinations thereof, and/or the like. The present
disclosure may also relate to methods for generating resin-based
structures including providing polymer compositions including talc,
mica, kaolin, bentonite, montmorillonite, pyrophyllite,
vermiculite, halloysite, wollastonite, calcium carbonate, titania,
perlite, diatomaceous earth, combinations thereof, and/or the
like.
BACKGROUND
[0003] Solid objects having complex shapes may be manufactured by
additive manufacturing methods that are also sometimes referred to
as "three-dimensional printing." Three-dimensional printing may
generally refer to a process by which three-dimensional objects are
manufactured via an additive process, where successive layers of
material are laid down in different shapes to form the object. For
example, a digital or virtual blueprint of the object obtained from
computer-aided design software is sliced into digital
cross-sections of the object, and the three-dimensional printer
successively lays down the material according to the digital
cross-sections to form the object. Once completed, the
three-dimensional object has been "printed."
[0004] According to one example of three-dimensional printing
sometimes referred to as "fused filament fabrication" (e.g., FUSED
DEPOSITION MODELING.RTM.), polymer filament (or metal wire) is
unwound from a coil to supply material to an extrusion nozzle
configured to melt the filament and promote or stop the flow of
molten material used for additive manufacturing of the object on a
manufacturing surface or printing plate. The combination of nozzle
and printing plate are configured to move in horizontal and
vertical directions to control deposition of the molten material
using a computer-aided manufacturing or computer-aided design (CAD)
program. By forming the successive layers according to the
computer-aided design of the object, the object may be
"printed."
[0005] Due primarily to its favorable dimensional stability,
polylactic acid (PLA, (C.sub.3H.sub.4O.sub.2).sub.n) is a commonly
used polymer for fused filament fabrication processes. However, PLA
is a semi-crystalline polymer with slow crystallization kinetics
that normally forms an amorphous plastic with weak thermal
stability and a low glass transition temperature T.sub.g of about
50-60.degree. C. As a result, PLA may soften during storage,
transportation, or upon extended sun exposure. The weak thermal
stability of PLA becomes even more limiting for load bearing
applications where an improved heat deflection temperature (HDT) is
desired. It has been shown that increasing heat deflection
temperature of PLA requires achieving over 30% to 35% crystalline
content. This cannot be easily achieved in typical plastics
manufacturing techniques such as injection molding or extrusion
without some degree of in-process or post-process annealing.
[0006] In fused filament fabrication processed (e.g., FUSED
DEPOSITION MODELING.RTM.), in-process annealing is not possible
since it requires maintaining the printed object at temperatures
higher than the glass transition temperature T.sub.g for certain
period of time, which is not compatible with layer-by-layer
deposition of molten plastics according to this manufacturing
method. In addition, post-manufacturing annealing of PLA objects
made with fused filament fabrication is not possible, since free
form objects made with the additive manufacturing techniques would
not maintain their shape at temperatures higher than the glass
transition temperature T.sub.g that is required for annealing.
Therefore, it may be desirable to provide a PLA composition that
allows improving thermal stability of PLA objects made with fused
filament fabrication and/or makes post-fabrication annealing of
such objects possible to achieve durable and thermally stable
printed objects.
SUMMARY
[0007] According to one aspect, a composition for fused filament
fabrication may include polylactic acid resin and talc. The
composition may range from 50% by weight to 93% by weight
polylactic acid resin, and from 7% by weight to 40% by weight talc
and/or 0% by weight to 40% by weight of mica, kaolin, bentonite,
pyrophyllite, vermiculite, halloysite, wollastonite, perlite,
diatomaceous earth, combinations thereof, and/or the like. The
composition may be adapted to be used in a fused filament
fabrication process, and may include other materials, components,
or processing aids typically used to control or modify attributes
such as color, flexibility, flowability, processability, or the
like. According to some aspect, the composition is configured as
filament, bars, pellets, powder, or other shapes, adapted to be
used in a fused filament fabrication process.
[0008] According to some aspects, the composition (e.g., the
polylactic acid resin moiety) may contain plasticizers, impact
modifiers, pigments, dyes, colorants, stabilizers, and/or other
polymer additives or processing aids generally used to modify resin
properties including, for example, flexibility, brittleness, color,
and/or processability.
[0009] According to some aspects, the composition (e.g., the talc
moiety) may be supplemented or replaced with from 0% (e.g., greater
than 0%) to 40% of at least one mineral from the group consisting
of mica, kaolin, bentonite, montmorillonite, pyrophyllite,
vermiculite, halloysite, wollastonite, calcium carbonate, titania,
perlite, diatomaceous earth, and/or the like.
[0010] According to another aspect, a method for generating a
resin-based structure may include providing a resin source that may
include polylactic acid resin and talc, mica, kaolin, bentonite,
pyrophyllite, vermiculite, halloysite, wollastonite, perlite,
diatomaceous earth, sodium oxysulfate, combinations thereof, and/or
the like. The resin source may include from 50% by weight to 93% by
weight polylactic acid resin, and from 7% by weight to 40% by
weight talc, and/or 0% by weight to 40% by weight of mica, kaolin,
bentonite, pyrophyllite, vermiculite, halloysite, wollastonite,
perlite, diatomaceous earth, sodium oxysulfate, and/or the like.
The method may also include heating the resin source to a
temperature higher than the melting temperature for
semi-crystalline resins or significantly higher than the glass
transition temperature for amorphous resins, and depositing the
heated resin source in a layered manner to form the resin-based
structure.
[0011] According to another aspect, a method for generating a
resin-based structure method may include providing a resin source
comprising polylactic acid resin and talc, wherein the resin source
comprises from 50% by weight to 99% by weight polylactic acid
resin, and wherein the resin source comprises from 7% by weight to
40% by weight talc. The method may further include heating the
resin source to a temperature greater than melting temperature for
semi-crystalline resins or significantly greater than the glass
transition temperature for amorphous resins (e.g., from 180.degree.
C. to 220.degree. C. for polylactic acid) to allow flow in molten
state through a nozzle to produce a thin strand of molten resin
source. The method may also include depositing the heated resin
source in a layered manner based on a computer-aided design (CAD)
program to form a resin-based object or structure (e.g., according
to fused filament fabrication).
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is an exemplary embodiment of a test specimen for
testing relative thermal stability of compositions used in an
exemplary fused filament fabrication process.
[0013] FIGS. 2(a)-2(f) provide visual indications of the difference
in thermal stability of different specimens after oven heating at
temperatures above glass transition temperature of the resin: FIG.
2(a) a printed specimen prior to oven heating, FIG. 2(b) a specimen
printed using commercial unfilled PLA filament after oven heating
at 70.degree. C., FIG. 2(c) a specimen containing 10 wt % talc in
the PLA after oven heating at 70.degree. C., FIG. 2(d) a specimen
containing 30 wt % talc in the PLA after oven heating at 70.degree.
C., FIG. 2(e) a specimen containing 20 wt % talc in the PLA after
oven heating at 107.degree. C., and FIG. 2(f) a specimen containing
30 wt % talc in the PLA after oven heating at 107.degree. C.
[0014] FIG. 3 contains four graphs showing test results for four
examples of resin-based composition including polylactic acid used
to form four respective test specimens via fused filament
fabrication. The graphs show measured angles of 4 beams on each
test specimen after oven heating at 70.degree. C., where the
pre-heating angles of the beams were 10 degrees, 20 degrees, 30
degrees, and 45 degrees.
[0015] FIG. 4 is a graph showing the thermal stability of specimens
containing 0%, 10%, 20%, and 30% talc after oven heating at
different temperatures. Results are shown as the angle of the beam
after oven heating for the beam with a pre-heating angle of 30
degrees (from vertical position).
DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0016] Polylactic acid (PLA, (C.sub.3H.sub.4O.sub.2).sub.n), which
is a commonly used material in fused filament fabrication process,
such as, for example, FUSED DEPOSITION MODELING.RTM., has
relatively weak thermal stability and a low glass transition
temperature In order to improve the thermal stability of polylactic
acid when used, for example, in FUSED DEPOSITION MODELING.RTM., the
polylactic acid may be annealed either during processing or during
post-processing thermal treatment. Annealing generally refers to
maintaining the resin at a temperature above the polymer glass
transition temperate (T.sub.g) for a period of time required to
allow sufficient crystallization of the resin. Annealing may be
achieved during polymer processing by increasing the residence time
of manufactured objects, e.g., molded products, at elevated
temperatures. Alternatively, following processing, the manufactured
object may be annealed by placing it at elevated temperatures for a
certain period of time. This may enhance the thermal stability
and/or increase the heat deflection temperature of the formed
object. According to some embodiments, it has been surprisingly
discovered that the addition of talc to a resin-based composition
(e.g., including polylactic acid) may improve the thermal stability
of an object formed by fused filament fabrication (e.g., FUSED
DEPOSITION MODELING.RTM.) for non-loadbearing daily usage,
transportation or storage activities or to allow post-production
annealing at elevated temperatures to increase the heat deflection
temperature of the object for loadbearing applications. According
to some embodiments, it has been discovered that the addition of
talc and/or mica, kaolin, bentonite, montmorillonite, pyrophyllite,
vermiculite, halloysite, wollastonite, calcium carbonate, titania,
perlite, diatomaceous earth, sodium oxysulfate, and/or the like,
may also improve the printability of an object formed by fused
filament fabrication (e.g., FUSED DEPOSITION MODELING.RTM.) by:
[0017] increasing the tendency of PLA based resin source to attach
to the print surface (e.g., glass, painter's blue tape, etc.)
without the need for using special glues, a heated bed, or allowing
the use of lower print bed temperatures; and/or [0018] reducing the
tendency of objects formed (or printed) to warp or curl at the
edges of the shape to prevent detachment from the print surface,
maintaining the integrity of printed objects, or enhancing their
accuracy and appeal; and/or [0019] allowing the use of lower melt
temperatures, which reduces PLA degradation and improves
consistency and continuity of fused filament during printing;
and/or [0020] improving the resolution or appearance of objects
formed via controlling the flowability of molten resin source or
modifying physical and/or mechanical properties of the
material.
[0021] According to some embodiments, this may be achieved with or
without reduced amounts of other additives, such as, for example,
plasticizers, pigments/dyes, processing aids, and/or nucleating
agents (i.e., chemical and/or mineral nucleating agents). According
to some embodiments, other additives (e.g., plasticizers,
pigments/dyes, processing aids, and/or nucleating agents) may be
added to the resin to improve flexibility, processing, or other
properties, or to further improve the thermal stability and/or
increase the heat deflection temperature of the formed object.
[0022] While not wishing to be bound by theory, it is believed that
when added to a resin or polymer used in fused filament fabrication
(e.g., polylactic acid), talc is an effective nucleating agent for
crystallization of the polymer. For example, polylactic acid is
known to have a slow crystallization rate. As a result, polylactic
acid objects produced by many polymer processing techniques contain
no or very small amounts of crystalline structure and behave like
amorphous polymers. Such polylactic acid objects soften at
temperatures above the glass transition temperature T.sub.g, which
is about 55.degree. C., and thus, may deform or suffer a change in
appearance under minimal load, for example, during storage,
transportation, or prolonged exposure to the sun. However, the
presence of a crystalline phase within the polymer structure may
reduce the mobility of polymer chains at temperatures greater than
the glass transition temperature T.sub.g, thereby enhancing the
thermal stability of the polymer. It is believed that a minimum of
about 30% to 35% crystalline content may be required to
significantly increase thermal stability of polylactic acid, such
that its heat deflection temperature is about 70.degree. C. or
higher, as measured according to Standard ASTM or ISO
standards.
[0023] While not wishing to be bound by theory, it is believed that
the addition of talc significantly reduces the crystallization
half-time of polymers such as polylactic acid, perhaps from a few
hours to only a few minutes or less, for example, with isothermal
annealing. While annealing at temperatures higher than the glass
transition temperature T.sub.g to achieve crystalline contents of
30%-35% or higher and heat deflection temperatures exceeding
70.degree. C. may be possible for some polymer processing methods,
for example, injection molding, it may not be feasible for most
objects produced by additive manufacturing or fused filament
fabrication (e.g. FUSED DEPOSITION MODELING.RTM.), since such
free-form processing methods do not use a mold or other support to
prevent deformation of the manufactured object when they soften at
annealing temperatures above the glass transition temperature
T.sub.g. Using nucleating and/or reinforcing mineral additives,
e.g., talc, in the polymer compound may allow printed objects to
keep their shape and integrity during annealing, which may be
required for improving their thermal stability, HDT, and/or
mechanical properties.
[0024] According to some embodiments, the addition to, for example,
polylactic acid resin, of talc and/or one or more other minerals,
such as, for example, mica, kaolin, bentonite, montmorillonite,
pyrophyllite, vermiculite, halloysite, wollastonite, calcium
carbonate, titania, perlite, diatomaceous earth, sodium oxysulfate,
and/or the like, may improve one or more of the following
characteristics of an object formed by fused filament fabrication
relative to objects formed via conventional polylactic acid:
warpage (i.e., reduced warpage), impact resistance (i.e., increased
impact resistance), and tensile elongation at break (i.e.,
increased tensile elongation at break). According to some
embodiments, the improvements in one or more of these
characteristics may be further improved by the addition of
plasticizers, such as, for example, polyethylene glycol.
[0025] For example, with respect to warpage, the solidification
shrinkage and thermal contraction upon cooling of an object
produced by fused filament fabrication may result in curling at the
edges and warpage of the base of printed shapes. Larger printed
objects normally have higher tendencies to warp. For this reason
"Flat Bar" and Test Box" shapes may be selected as two internal
standards for studying the warpage and detachment of shapes printed
with fused filament fabrication printers. For example, warpage may
be measured as follows: "flat bar" warpage in millimeters (mm) is
the height of one end of a printed bar from a horizontal surface,
when the bar is laid flat on the horizontal surface, and its other
end is pressed and held parallel onto the horizontal surface; and
"test box" in mm is the maximum height measured (as explained above
for the flat bar warpage), when the test box is laid flat on its
base on a horizontal surface, and one edge is pressed against and
held parallel onto the surface and the height of opposing edge is
measured. The measurement is repeated for all two edges and the
maximum reading is used as warpage indicator.
[0026] According to some embodiments, at mineral loading of, for
example, from about 5% to about 30% (e.g., from about 10% to about
20%) warpage may be reduced relative to conventional PLA. For
example, flat bar warpage may be reduced by, for example, from
about 5% to about 60%, from about 5% to about 50%, from about 5% to
about 40%, from about 5% to about 30%, from about 5% to about 25%,
from about 5% to about 20%, from about 5% to about 15%, or from
about 5% to about 10%. According to some embodiments, test box
warpage may be reduced by, for example, from about 5% to about 60%,
from about 5% to about 50%, from about 5% to about 40%, from about
5% to about 30%, from about 5% to about 25%, from about 5% to about
20%, from about 5% to about 15%, or from about 5% to about 10%.
[0027] According to some embodiments, at mineral loading of, for
example, from about 5% to about 30% (e.g., from about 10% to about
20%) impact resistance may be increased relative to conventional
PLA. For example, impact resistance may be increased by, for
example, from about 10% to about 150%, from about 10% to about
125%, from about 10% to about 100% (i.e., doubled), from about 10%
to about 75%, from about 10% to about 50%, from about 10% to about
40%, from about 10% to about 30%, or from about 10% to about
20%.
[0028] According to some embodiments, at mineral loading of, for
example, from about 5% to about 30% (e.g., from about 10% to about
20%) tensile elongation at break may be increased relative to
conventional PLA. For example, tensile elongation at break may be
increased by, for example, from about 10% to about 150%, from about
10% to about 125%, from about 10% to about 100% (i.e., doubled),
from about 10% to about 75%, from about 10% to about 50%, from
about 10% to about 40%, from about 10% to about 30%, or from about
10% to about 20%.
[0029] According to some embodiments, at mineral loading of, for
example, from about 5% to about 30% (e.g., from about 10% to about
20%) impact resistance may be increased relative to conventional
PLA. For example, impact resistance may be increased by, for
example, from about 10% to about 150%, from about 10% to about
125%, from about 10% to about 100% (i.e., doubled), from about 10%
to about 75%, from about 10% to about 50%, from about 10% to about
40%, from about 10% to about 30%, or from about 10% to about
20%.
[0030] According to some embodiments, a composition for fused
filament fabrication includes polylactic acid resin and talc. The
composition ranges from 50% by weight to 93% by weight polylactic
acid resin, and from 7% by weight to 40% by weight talc. In other
embodiments, less talc may be present in the composition when other
minerals are present. According to some embodiments, the
composition is configured to be adapted for use in a fused filament
fabrication process.
[0031] According to some embodiments, the composition may include,
for example, plasticizers, impact modifiers, pigments, dyes,
colorants, stabilizers, and/or other additives or processing aids.
For example, the composition may include plasticizers, impact
modifiers, pigments, dyes, colorants, stabilizers, and/or other
additives or processing aids used in polymer processing known to
those skilled in the art. According to some embodiments, the
composition (e.g., the talc moiety) may be supplemented or replaced
with from 0% (e.g., greater than 0%) to 40% of at least one mineral
from the group consisting of mica, kaolin, bentonite,
montmorillonite, pyrophyllite, vermiculite, halloysite,
wollastonite, calcium carbonate, titania, perlite, diatomaceous
earth, and/or the like.
[0032] According to some embodiments, the talc has a median
particle size less than 18 microns, a median particle size less
than 12 microns, a median particle size less than 10 microns, a
median particle size less than 8 microns, a median particle size
less than 6 microns, a median particle size less than 4 microns, a
median particle size less than 2 microns, or a median particle size
less than 1 micron.
[0033] "Median particle size," as used herein, for example, in the
context of particle size distribution (psd), is measured in terms
of equivalent spherical diameter (esd). Sometimes referred to as
the "d.sub.50" value, median particle size and other particle size
properties referred to in the present application may be measured
in a well-known manner, for example, by sedimentation of the
particle material in a fully-dispersed condition in an aqueous
medium using a SEDIGRAPH 5100.RTM. machine, as supplied by
Micromeritics Corporation. Such a machine may provide measurements
and a plot of the cumulative percentage by weight of particles
having a size, referred to in the art as "equivalent spherical
diameter" (esd), less than the given esd values. The median
particle size (d.sub.50) is the value that may be determined in
this manner of the particle esd at which there are 50% by weight of
the particles that have an esd less than the indicated median
particle size (the d.sub.50 value).
[0034] According to some embodiments, the talc has a top particle
size (d.sub.90) less than 150 microns, a top particle size less
than 100 microns, a top particle size less than 50 microns, a top
particle size less than 20 microns, a top particle size less than
10 microns, or a top particle size less than 6 microns. "Top
particle size," or "d.sub.90," as used herein, for example, in the
context of particle size distribution (psd), is defined as the size
for which 90 percent of the volume of the particles have an esd
smaller than the indicated top particle size (the d.sub.90 value).
According to some embodiments, the non-talc minerals identified
herein may have the same (or similar) particle size distributions
(e.g., d.sub.50 and d.sub.90) as the particle size distributions
identified herein for talc.
[0035] According to some embodiments, the talc has a Hegman rating
of 2 or greater, a Hegman rating of 3 or greater, a Hegman rating
of 4 or greater, a Hegman rating of 5 or greater, a Hegman rating
of 6 or greater, a Hegman rating of 7 or greater, or a Hegman
rating of 7.5 or greater. According to some embodiments, the talc
has a BET surface area greater than 2 m.sup.2/g, a BET surface area
greater than 4 m.sup.2/g, a BET surface area greater than 6
m.sup.2/g, a BET surface area greater than 8 m.sup.2/g, or a BET
surface area greater than 10 m.sup.2/g. According to some
embodiments, the talc has a BET surface area less than 20
m.sup.2/g, a BET surface area less than 15 m.sup.2/g, a BET surface
area less than 12 m.sup.2/g, or a BET surface area less than 10
m.sup.2/g. According to some embodiments, the talc has a BET
surface area ranging from 2 m.sup.2/g to 20 m.sup.2/g, a BET
surface area ranging from 4 m.sup.2/g to 15 m.sup.2/g, a BET
surface area ranging from 4 m.sup.2/g to 10 m.sup.2/g, or a BET
surface area ranging from 10 m.sup.2/g to 15 m.sup.2/g.
[0036] According to some embodiments, the talc has an oil
absorption less than 60 grams per 100 grams of talc, less than 50
grams per 100 grams of talc, or less than 40 grams per 100 grams of
talc. According to some embodiments, the talc has an oil absorption
ranging from 20 grams per 100 grams of talc to 60 grams per 100
grams of talc, or ranging from 25 grams per 100 grams of talc to 55
grams per 100 grams of talc
[0037] According to some embodiments, the talc has a shape factor
greater than 10, greater than 20, greater than 30, greater than 40,
greater than 50, greater than 75, or greater than 100. "Shape
factor," as used herein, is a measure of the ratio of particle
diameter to particle thickness for a population of particles of
varying size and shape as measured using the electrical
conductivity methods, apparatuses, and equations described in U.S.
Pat. No. 5,576,617 ("the '617 patent"), which is incorporated
herein by reference. As the technique for determining shape factor
is further described in the '617 patent, the electrical
conductivity of a composition of an aqueous suspension of
orientated particles under test is measured as the composition
flows through a vessel. Measurements of the electrical conductivity
are taken along one direction of the vessel and along another
direction of the vessel transverse to the first direction. Using
the difference between the two conductivity measurements, the shape
factor of the particulate material under test is determined.
[0038] According to some embodiments, the talc has a shape factor
less than 200, less than 150, or less than 100. According to some
embodiments, the talc has a shape factor ranging from 10 to 200,
ranging from 15 to 150, ranging from 15 to 50, or ranging from 15
to 100.
[0039] According to some embodiments, the composition ranges from
7% by weight to 40% by weight talc. For example, the composition
ranges from 10% by weight to 30% by weight talc, from 10% by weight
to 25% by weight talc, from 10% by weight to 20% by weight talc,
from 20% by weight to 30% by weight talc, or from 15% by weight to
25% by weight talc.
[0040] According to some embodiments, the composition may use at
least one other mineral by itself or in addition to talc, for
example, from the group consisting of kaolin, bentonite,
montmorillonite, mica, pyrophyllite, vermiculite, halloysite,
wollastonite, calcium carbonate, titania, perlite, diatomaceous
earth, combinations thereof, or the like. According to some
embodiments, these minerals may have the same (or similar) particle
size distributions (e.g., d.sub.50 and d.sub.90) as the particle
size distributions identified herein for talc.
[0041] According to some embodiments, a method for generating a
resin-based structure includes providing a resin source including
polylactic acid resin and talc. The resin source includes from 50%
by weight to 99% by weight polylactic acid resin, and from 7% by
weight to 40% by weight talc. The method includes heating the resin
source to a temperature higher than the melting temperature for
semi-crystalline resins or significantly higher than glass
transition temperature for amorphous resins, and depositing the
heated resin source in a layered manner to form the resin-based
structure.
[0042] According to some embodiments, the talc of the resin source
has a median particle size less than 18 microns, a median particle
size less than 12 microns, a median particle size less than 10
microns, a median particle size less than 8 microns, a median
particle size less than 6 microns, a median particle size less than
4 microns, a median particle size less than 2 microns, or a median
particle size less than 1 micron.
[0043] According to some embodiments, the talc or the resin source
has a top particle size (d.sub.90) less than 150 microns, a top
particle size less than 100 microns, a top particle size less than
50 microns, a top particle size less than 20 microns, a top
particle size less than 10 microns, or a top particle size less
than 6 microns.
[0044] According to some embodiments, the talc of the resin source
has a Hegman rating of 2 or greater, a Hegman rating of 3 or
greater, a Hegman rating of 4 or greater, a Hegman rating of 5 or
greater, a Hegman rating of 6 or greater, a Hegman rating of 7 or
greater, or a Hegman rating of 7.5 or greater. According to some
embodiments, the talc of the resin source has a BET surface area
greater than 2 m.sup.2/g, a BET surface area greater than 4
m.sup.2/g, a BET surface area greater than 6 m.sup.2/g, a BET
surface area greater than 8 m.sup.2/g, or a BET surface area
greater than 10 m.sup.2/g. According to some embodiments, the talc
of the resin source has a BET surface area less than 20 m.sup.2/g,
a BET surface area less than 15 m.sup.2/g, a BET surface area less
than 12 m.sup.2/g, or a BET surface area less than 10 m.sup.2/g.
According to some embodiments, the talc of the resin source has a
BET surface area ranging from 2 m.sup.2/g to 20 m.sup.2/g, a BET
surface area ranging from 4 m.sup.2/g to 15 m.sup.2/g, a BET
surface area ranging from 4 m.sup.2/g to 10 m.sup.2/g, or a BET
surface area ranging from 10 m.sup.2/g to 15 m.sup.2/g.
[0045] According to some embodiments, the talc of the resin source
has an oil absorption less than 60 grams per 100 grams of talc,
less than 50 grams per 100 grams of talc, or less than 40 grams per
100 grams of talc. According to some embodiments, the talc of the
resin source has an oil absorption ranging from 20 grams per 100
grams of talc to 60 grams per 100 grams of talc, or ranging from 25
grams per 100 grams of talc to 55 grams per 100 grams of talc.
[0046] According to some embodiments, the talc of the resin source
has a shape factor greater than 10, greater than 20, greater than
30, greater than 40, greater than 50, greater than 75, or greater
than 100. According to some embodiments, the talc of the resin
source has a shape factor less than 200, less than 150, or less
than 100. According to some embodiments, the talc of the resin
source has a shape factor ranging from 10 to 200, ranging from 15
to 150, ranging from 15 to 50, or ranging from 15 to 100.
[0047] According to some embodiments, the resin source ranges from
7% by weight to 40% by weight talc. For example, the resin source
ranges from 10% by weight to 30% by weight talc, from 10% by weight
to 25% by weight talc, from 10% by weight to 20% by weight talc,
from 20% by weight to 30% by weight talc, or from 15% by weight to
25% by weight talc.
[0048] According to some embodiments, the resin source may use at
least one other mineral by itself or in addition to talc, for
example, from the group consisting of kaolin, bentonite,
montmorillonite, mica, pyrophyllite, vermiculite, halloysite,
wollastonite, calcium carbonate, titania, perlite, diatomaceous
earth, combinations thereof, and/or the like.
[0049] According to some embodiments, a method for generating a
resin-based structure method may include providing a resin source
comprising polylactic acid resin and talc, wherein the resin source
comprises from 50% by weight to 99% by weight polylactic acid
resin, and wherein the resin source comprises from 7% by weight to
40% by weight talc. The method may further include heating the
resin source to a temperature greater than melting temperature for
semi-crystalline resins or significantly greater than the glass
transition temperature for amorphous resins (e.g., from 180.degree.
C. to 220.degree. C. for polylactic acid) to allow flow in molten
state through a nozzle to produce a thin strand of molten resin
source. The method may also include depositing the heated resin
source in a layered manner based on a computer-aided design (CAD)
program to form a resin-based object or structure (e.g., according
to fused filament fabrication).
EXAMPLES
[0050] Several examples of resin-based compositions were tested to
examine the thermal behavior of the exemplary compositions
including polylactic acid. In particular, an angled beam test
method was developed to examine the stability of resin-based
structures including, for example, polylactic acid, formed by fused
filament fabrication, upon exposure to high temperatures during
normal day-to-day use or during post-fabrication annealing. The
following test method is designed specifically to examine the
temperature stability of resin-based structures, such as those
formed of a resin including polylactic acid, which tends to soften
above its glass transition temperature (T.sub.g) of about
55.degree. C. The method is suitable for examining structures or
objects formed by additive manufacturing techniques, such as, for
example, fused filament deposition (e.g., FUSED DEPOSITION
MODELING.RTM.), because such structures or objects may be defined
by a computer-aided design program and formed layer-by-layer as
free-formed structures, which are not protected or confined within
a mold, support, etc. Other test methods are contemplated.
[0051] According to the exemplary test, a resin-based beam specimen
for each example composition tested was formed or "printed" by
fused filament fabrication, and each of the formed beam specimens
was subjected to controlled heating to examine the thermal
stability of the resulting, resin-based specimens. As shown in FIG.
1, the beam specimen selected for this exemplary test method was
composed of a set of ten beams attached at the bottom to a support
at different angles in a cantilever manner. The entire beam
specimen sits on a thin square base measuring with 5
centimeters.times.5 centimeters in dimension. The beams are
arranged such that they extend from the base at angles ranging from
10 to 70 degrees from a vertical orientation, such that the
70-degree beam is closest to the horizontal orientation, and the
10-degree beam is closest to the vertical orientation. All of the
exemplary beams are 3 centimeters in length. The digital data to
form the beam specimen tested is available on the Makerbot
Thingiverse website at www.thingiverse.com, and more specifically
at http://www.thingiverse.com/thing:100934. The computer-aided
design for fused filament fabrication printing of the beam specimen
may also be available for download from the same web-link.
[0052] As the angle of the beams increase, the load applied to the
base of the beams increase. When the material of the beam structure
becomes soft, it may deform under the load due to gravity. In
particular, deformation occurs when the applied load is higher than
the material's strength or stiffness. Deformation may also occur
only if the material has reached or exceeded its softening point
(e.g., at the glass transition temperature (T.sub.g) in the case of
an amorphous polymer such as, for example, polylactic acid).
However, the presence of a crystalline structure, minerals, or
other solids within the amorphous polymer may reduce the mobility
of polymer chains or physically reinforce and strengthen the
material. Thus, the exemplary beam specimen and testing method may
provide a practical measure of relative stability of different
shapes and compositions at each temperature.
[0053] According to the testing method, the beam specimens were
"printed" with a selected infill amount based on the printer
software. "Infill" is defined as the portion of the printed shape
that is filled with printing material, with the balance being void
fraction (e.g., 100% infill has zero void fraction, i.e., filaments
of the fused filament deposition process are positioned next to
each other, and 80% infill has a 20% void fraction). All of the
tested beam specimens were printed with the same infill ratio and
compared together in order to obtain a relative measure of material
heat stability. Although, the method attempts to quantify the
difference in heat stability, the results are still considered
relative because the mechanical properties of the printed beam
structures may vary from one fused filament fabrication printer to
another, and with the selection of infill ratio and other
processing parameters that are not standardized.
[0054] Once the beam specimens for each of the example compositions
were formed or "printed," the printed specimens were placed in an
oven at a target temperature. The target temperatures started from
50.degree. C. (i.e., just below T.sub.g for polylactic acid) and
were increased up to greater than 100.degree. C., based on the
stability of the material tested. Since heat history may affect
crystallization and thermal stability of polylactic acid, each
printed object was placed in the oven only once. In addition,
temperature variations were minimized by placing the test specimens
at the same location for the same duration in the oven to minimize
variation in temperature exposure. Care was taken to also minimize
the amount of time taken to place the objects in the oven and to
minimize the temperature drop that occurs when the oven door is
opened for this purpose. To ensure sufficient exposure to target
temperature, the beam structures were placed in the oven for 20 to
30 minutes. FIGS. 2(a)-2(f) show pictures of several beam specimens
after oven heating, indicating the effect of material on
temperature stability of the specimen.
[0055] Following heating in the oven, the beam structures are
observed, and the angles of beams are measured by determining the
vertical and horizontal position of the suspended end of each beam
relative to the base. Typically, the most deformed beams are those
with the larger vertical angle (i.e., 70 degrees), and the heating
effect decreases as the angle of the beams decreases (i.e., the
10-degree beam shows the least deformation as it is closest to a
vertical orientation, resulting in less bending stress). According
to this exemplary testing method, a single test creates multiple
(up to ten) results that are indicative of the temperature
stability of the tested beam specimen under different loads that
are representative of what a typical printed plastic object could
experience in daily usage or during post-fabrication annealing. The
difference in load is experienced at the base of each beam, which
results in the bending or deformation of the beam and an increased
angle (compared to its original angle), depending on the heat
stability of the material used to form the tested beam specimens.
In this exemplary manner, the relative thermal stability of example
compositions used to form the tested beam specimens may be
evaluated and compared.
[0056] While the beam structure used in the test method was
printed, for example, using fused filament fabrication (FFF), and
its properties including thermal stability may vary depending on
the material used and processing conditions employed, the test
method developed could be used to evaluate the thermal stability of
the final printed object (beam structure) regardless of variations
in materials or processing conditions. Thus, it provides a method
for investigating the effect of such variables as materials and
operating conditions on the results.
[0057] The software for forming the beam specimens was loaded into
the FFF printer, and the infill ratio was selected. The infill
ratio was kept constant for all specimens tested to allow a direct
comparison of the material performance. Thereafter, the beam
structures of the test specimens were printed. During printing,
care was taken to ensure that the CAD program follows the same
manufacturing pattern for each sample, and the shape of the beam
structures was free of defects, especially at the base. Once
printing was completed, the beam structures were allowed to cool to
below 40.degree. C. before removing them, and care was taken to
avoid damage as the beam structures were removed from the support
on which they were formed. This exemplary procedure was repeated to
form a beam specimen for each sample composition being tested.
[0058] The testing oven was pre-heated to the desired temperature
and maintained at a steady temperature. Care was taken to avoid or
reduce temperature variations in the oven, so that the test
specimens (the beam structures) were exposed to similar
temperatures in the oven. A forced circulation oven was used to
minimize temperature variation with sample position and radiation
from the walls. The test specimens for comparison were all placed
in the same tray, the oven door was quickly opened, the tray was
quickly placed in a pre-selected position, and the oven door was
quickly closed. The tray of specimens was allowed to remain in the
oven for 20 minutes. Different oven exposure times are contemplated
(e.g., 20 to 30 minutes). Once heating for the desired duration was
completed, the tray of specimens was removed and allowed to
cool.
[0059] Following cooling, the amount of deformation was observed
and compared, by measuring the horizontal (X) and vertical (Y)
positions of the suspended ends of the beams relative to their
respective bases. Using the X and Y values measured for each beam,
one can calculate the beam angle after oven heating using the
following equation:
Angle of beam (from vertical position in
degrees)=90-180.times.(tan.sup.-1(Y/X))/.pi..
[0060] FIG. 3 shows the temperature stability of four example
compositions tested: (1) a composition including a commercial pure
polylactic acid (Naturework's Ingeo.RTM. 4043D); (2) a composition
including the same polylactic acid (Ingeo.RTM. 4043D) and 10% talc
by weight ("10% Talc)"; (3) a composition including polylactic acid
and 20% talc by weight ("20% Talc)"; and (4) a composition
including polylactic acid and 30% talc by weight ("30% Talc)."
[0061] As shown in FIG. 3, the thermal stability of FFF-printed
objects formed using resin-based material (i.e., polylactic
acid-based material) increased significantly as talc was added to
the polylactic acid. In addition, increasing the talc content of
formulation (e.g., from 10% by weight up to 30% by weight) resulted
in further improving the thermal stability of the tested beam
structures. In particular, the tested beam structures having a
higher percentage of talc added to the polylactic acid exhibited
less beam deflection when heated (i.e., the ends of the beams
remained higher). This is shown in FIG. 3 by the lower angle of the
beam from vertical position after the test specimens were placed in
an oven at 70.degree. C. for 20 minutes. Further investigation
tests indicated that specimens showing improved thermal stability
at 70.degree. C. were also stable at higher oven temperatures of
75.degree. C., 85.degree. C., 95.degree. C., and 107.degree. C.
(see FIG. 4). Variation observed in values shown in FIG. 4 for
these temperatures represent the standard deviation of the test
method caused by factors such as printing defect, oven temperature
control, and accuracy of measuring the angle of the beam (from X
and Y values). Otherwise, a reduction in thermal stability of the
specimen would result in a clear increase in the angle of the beam
(i.e., the beam would tend to lean downward toward a horizontal
position, as shown in FIG. 3 for unfilled, standard polylactic
acid).
[0062] Without wishing to be bound by theory, it is believed that
the combination of polylactic acid and talc loading increases the
crystallization speed and crystalline content of the polylactic
acid in combination with providing physical reinforcement from
rigid talc structure. It is also believed that this phenomenon may
be unique to processing polylactic acid-based materials via fused
filament fabrication (e.g., via FUSED DEPOSITION MODELING.RTM.),
and that other types of polymer processing (e.g., injection
molding) may not exhibit this level of improved thermal stability
by the addition of talc to polylactic acid.
[0063] For the avoidance of doubt, the present application is
directed to the subject matter described in the following numbered
paragraphs (i.e., numbered paragraphs 1-110 (also denoted by
[0060]-[00169])).
[0064] 1. A composition for fused filament fabrication, the
composition comprising: polylactic acid resin and talc, wherein the
composition ranges from 50% by weight to 99% by weight polylactic
acid resin, wherein the composition ranges from 7% by weight to 40%
by weight talc, and wherein the composition is configured to be
used in a fused filament fabrication process.
[0065] 2. The composition according to numbered paragraph 1 (also
denoted by [0060]), wherein the talc has a median particle size
less than 18 microns or less than 12 microns.
[0066] 3. The composition according to any preceding numbered
paragraph (i.e., paragraphs 1 and 2 (also denoted by [0060] and
[0061])), wherein the talc has a median particle size less than 10
microns.
[0067] 4. The composition according to any preceding numbered
paragraph, wherein the talc has a median particle size less than 8
microns.
[0068] 5. The composition according to any preceding numbered
paragraph, wherein the talc has a median particle size less than 6
microns.
[0069] 6. The composition according to any preceding numbered
paragraph, wherein the talc has a median particle size less than 4
microns.
[0070] 7. The composition according to any preceding numbered
paragraph, wherein the talc has a median particle size less than 2
microns, or a median particle size less than 1 micron.
[0071] 8. The composition according to any preceding numbered
paragraph, wherein the talc has a top particle size (d.sub.90) less
than 150 microns.
[0072] 9. The composition according to any preceding numbered
paragraph, wherein the talc has a top particle size (d.sub.90) less
than 100 microns.
[0073] 10. The composition according to any preceding numbered
paragraph, wherein the talc has a top particle size (d.sub.90) less
than 50 microns.
[0074] 11. The composition according to any preceding numbered
paragraph, wherein the talc has a top particle size (d.sub.90) less
than 20 microns or less than 10 microns.
[0075] 12. The composition according to any preceding numbered
paragraph, wherein the talc has a top particle size (d.sub.90) less
than 6 microns.
[0076] 13. The composition according to any preceding numbered
paragraph, wherein the talc has a Hegman rating of 2 or
greater.
[0077] 14. The composition according to any preceding numbered
paragraph, wherein the talc has a Hegman rating of 3 or
greater.
[0078] 15. The composition according to any preceding numbered
paragraph, wherein the talc has a Hegman rating of 4 or
greater.
[0079] 16. The composition according to any preceding numbered
paragraph, wherein the talc has a Hegman rating of 5 or greater, a
Hegman rating of 6 or greater, a Hegman rating of 7 or greater, or
a Hegman rating of 7.5 or greater.
[0080] 17. The composition according to any preceding numbered
paragraph, wherein the talc has a BET surface area greater than 2
m.sup.2/g.
[0081] 18. The composition according to any preceding numbered
paragraph, wherein the talc has a BET surface area greater than 4
m.sup.2/g.
[0082] 19. The composition according to any preceding numbered
paragraph, wherein the talc has a BET surface area greater than 6
m.sup.2/g.
[0083] 20. The composition according to any preceding numbered
paragraph, wherein the talc has a BET surface area greater than 8
m.sup.2/g.
[0084] 21. The composition according to any preceding numbered
paragraph, wherein the talc has a BET surface area greater than 10
m.sup.2/g.
[0085] 22. The composition according to any preceding numbered
paragraph, wherein the talc has a BET surface area less than 20
m.sup.2/g.
[0086] 23. The composition according to any preceding numbered
paragraph, wherein the talc has a BET surface area less than 15
m.sup.2/g.
[0087] 24. The composition according to any preceding numbered
paragraph, wherein the talc has a BET surface area less than 12
m.sup.2/g.
[0088] 25. The composition according to any preceding numbered
paragraph, wherein the talc has a BET surface area less than 10
m.sup.2/g.
[0089] 26. The composition according to any preceding numbered
paragraph, wherein the talc has a BET surface area ranging from 2
m.sup.2/g to 20 m.sup.2/g.
[0090] 27. The composition according to any preceding numbered
paragraph, wherein the talc has a BET surface area ranging from 4
m.sup.2/g to 15 m.sup.2/g.
[0091] 28. The composition according to any preceding numbered
paragraph, wherein the talc has a BET surface area ranging from 4
m.sup.2/g to 10 m.sup.2/g.
[0092] 29. The composition according to any preceding numbered
paragraph, wherein the talc has a BET surface area ranging from 10
m.sup.2/g to 15 m.sup.2/g.
[0093] 30. The composition according to any preceding numbered
paragraph, wherein the talc has an oil absorption less than 60
grams per 100 grams of talc.
[0094] 31. The composition according to any preceding numbered
paragraph, wherein the talc has an oil absorption less than 50
grams per 100 grams of talc.
[0095] 32. The composition according to any preceding numbered
paragraph, wherein the talc has an oil absorption less than 40
grams per 100 grams of talc.
[0096] 33. The composition according to any preceding numbered
paragraph, wherein the talc has an oil absorption ranging from 20
grams per 100 grams of talc to 60 grams per 100 grams of talc.
[0097] 34. The composition according to any preceding numbered
paragraph, wherein the talc has an oil absorption ranging from 25
grams per 100 grams of talc to 55 grams per 100 grams of talc.
[0098] 35. The composition according to any preceding numbered
paragraph, wherein the talc has a shape factor greater than 10.
[0099] 36. The composition according to any preceding numbered
paragraph, wherein the talc has a shape factor greater than 20.
[0100] 37. The composition according to any preceding numbered
paragraph, wherein the talc has a shape factor greater than 30.
[0101] 38. The composition according to any preceding numbered
paragraph, wherein the talc has a shape factor greater than 40.
[0102] 39. The composition according to any preceding numbered
paragraph, wherein the talc has a shape factor greater than 50.
[0103] 40. The composition according to any preceding numbered
paragraph, wherein the talc has a shape factor greater than 75.
[0104] 41. The composition according to any preceding numbered
paragraph, wherein the talc has a shape factor greater than
100.
[0105] 42. The composition according to any preceding numbered
paragraph, wherein the talc has a shape factor less than 200.
[0106] 43. The composition according to any preceding numbered
paragraph, wherein the talc has a shape factor less than 150.
[0107] 44. The composition according to any preceding numbered
paragraph, wherein the talc has a shape factor less than 100.
[0108] 45. The composition according to any preceding numbered
paragraph, wherein the talc has a shape factor ranging from 10 to
200.
[0109] 46. The composition according to any preceding numbered
paragraph, wherein the talc has a shape factor ranging from 15 to
150.
[0110] 47. The composition according to any preceding numbered
paragraph, wherein the talc has a shape factor ranging from 15 to
50.
[0111] 48. The composition according to any preceding numbered
paragraph, wherein the talc has a shape factor ranging from 15 to
100.
[0112] 49. The composition according to any preceding numbered
paragraph, wherein the composition ranges from 10% by weight to 30%
by weight talc, from 10% by weight to 25% by weight talc, or 10% by
weight to 20% by weight talc.
[0113] 50. The composition according to any preceding numbered
paragraph, wherein the composition ranges from 15% by weight to 30%
by weight talc.
[0114] 51. The composition according to any preceding numbered
paragraph, wherein the composition ranges from 20% by weight to 30%
by weight talc.
[0115] 52. The composition according to any preceding numbered
paragraph, wherein the composition ranges from 15% by weight to 25%
by weight talc.
[0116] 53. The composition according to any preceding numbered
paragraph, further comprising at least one additional mineral or a
mineral replacing the talc.
[0117] 54. The composition according to any preceding numbered
paragraph, wherein the at least one additional mineral is selected
from the group consisting of kaolin, bentonite, montmorillonite,
pyrophyllite, vermiculite, halloysite, wollastonite, mica, calcium
carbonate, titania, perlite, sodium oxysulfate, and diatomaceous
earth.
[0118] 55. A method for generating a resin-based structure, the
method comprising: providing a resin source comprising polylactic
acid resin and talc, wherein the resin source comprises from 50% by
weight to 99% by weight polylactic acid resin, and wherein the
resin source comprises from 7% by weight to 40% by weight talc;
heating the resin source to a temperature greater than melting
temperature for semi-crystalline resins and significantly greater
than the glass transition temperature for amorphous resins; and
depositing the heated resin source in a layered manner to form the
resin-based structure.
[0119] 56. The method according to numbered paragraph 55 (also
denoted by [00114]), wherein the talc has a median particle size
less than 18 microns or less than 12 microns.
[0120] 57. The method according to any preceding numbered paragraph
beginning with paragraph 55 (i.e., paragraphs 55 and 56), wherein
the talc has a median particle size less than 10 microns.
[0121] 58. The method according to any preceding numbered paragraph
beginning with paragraph 55, wherein the talc has a median particle
size less than 8 microns.
[0122] 59. The method according to any preceding numbered paragraph
beginning with paragraph 55, wherein the talc has a median particle
size less than 6 microns.
[0123] 60. The method according to any preceding numbered paragraph
beginning with paragraph 55, wherein the talc has a median particle
size less than 4 microns.
[0124] 61. The method according to any preceding numbered paragraph
beginning with paragraph 55, wherein the talc has a median particle
size less than 2 microns, or a median particle size less than 1
micron.
[0125] 62. The method according to any preceding numbered paragraph
beginning with paragraph 55, wherein the talc has a top particle
size (d.sub.90) less than 150 microns.
[0126] 63. The method according to any preceding numbered paragraph
beginning with paragraph 55, wherein the talc has a top particle
size (d.sub.90) less than 100 microns.
[0127] 64. The method according to any preceding numbered paragraph
beginning with paragraph 55, wherein the talc has a top particle
size (d.sub.90) less than 50 microns.
[0128] 65. The method according to any preceding numbered paragraph
beginning with paragraph 55, wherein the talc has a top particle
size (d.sub.90) less than 20 microns or a top particle size less
than 10 microns.
[0129] 66. The method according to any preceding numbered paragraph
beginning with paragraph 55, wherein the talc has a top particle
size (d.sub.90) less than 6 microns.
[0130] 67. The method according to any preceding numbered paragraph
beginning with paragraph 55, wherein the talc has a Hegman rating
of 2 or greater.
[0131] 68. The method according to any preceding numbered paragraph
beginning with paragraph 55, wherein the talc has a Hegman rating
of 3 or greater.
[0132] 69. The method according to any preceding numbered paragraph
beginning with paragraph 55, wherein the talc has a Hegman rating
of 4 or greater.
[0133] 70. The method according to any preceding numbered paragraph
beginning with paragraph 55, wherein the talc has a Hegman rating
of 5 or greater, a Hegman rating of 6 or greater, a Hegman rating
of 7 or greater, or a Hegman rating of 7.5 or greater.
[0134] 71. The method according to any preceding numbered paragraph
beginning with paragraph 55, wherein the talc has a BET surface
area greater than 2 m.sup.2/g.
[0135] 72. The method according to any preceding numbered paragraph
beginning with paragraph 55, wherein the talc has a BET surface
area greater than 4 m.sup.2/g.
[0136] 73. The method according to any preceding numbered paragraph
beginning with paragraph 55, wherein the talc has a BET surface
area greater than 6 m.sup.2/g.
[0137] 74. The method according to any preceding numbered paragraph
beginning with paragraph 55, wherein the talc has a BET surface
area greater than 8 m.sup.2/g.
[0138] 75. The method according to any preceding numbered paragraph
beginning with paragraph 55, wherein the talc has a BET surface
area greater than 10 m.sup.2/g.
[0139] 76. The method according to any preceding numbered paragraph
beginning with paragraph 55, wherein the talc has a BET surface
area less than 20 m.sup.2/g.
[0140] 77. The method according to any preceding numbered paragraph
beginning with paragraph 55, wherein the talc has a BET surface
area less than 15 m.sup.2/g.
[0141] 78. The method according to any preceding numbered paragraph
beginning with paragraph 55, wherein the talc has a BET surface
area less than 12 m.sup.2/g.
[0142] 79. The method according to any preceding numbered paragraph
beginning with paragraph 55, wherein the talc has a BET surface
area less than 10 m.sup.2/g.
[0143] 80. The method according to any preceding numbered paragraph
beginning with paragraph 55, wherein the talc has a BET surface
area ranging from 2 m.sup.2/g to 20 m.sup.2/g.
[0144] 81. The method according to any preceding numbered paragraph
beginning with paragraph 55, wherein the talc has a BET surface
area ranging from 4 m.sup.2/g to 15 m.sup.2/g.
[0145] 82. The method according to any preceding numbered paragraph
beginning with paragraph 55, wherein the talc has a BET surface
area ranging from 4 m.sup.2/g to 10 m.sup.2/g.
[0146] 83. The method according to any preceding numbered paragraph
beginning with paragraph 55, wherein the talc has a BET surface
area ranging from 10 m.sup.2/g to 15 m.sup.2/g.
[0147] 84. The method according to any preceding numbered paragraph
beginning with paragraph 55, wherein the talc has an oil absorption
less than 60 grams per 100 grams of talc.
[0148] 85. The method according to any preceding numbered paragraph
beginning with paragraph 55, wherein the talc has an oil absorption
less than 50 grams per 100 grams of talc.
[0149] 86. The method according to any preceding numbered paragraph
beginning with paragraph 55, wherein the talc has an oil absorption
less than 40 grams per 100 grams of talc.
[0150] 87. The method according to any preceding numbered paragraph
beginning with paragraph 55, wherein the talc has an oil absorption
ranging from 20 grams per 100 grams of talc to 60 grams per 100
grams of talc.
[0151] 88. The method according to any preceding numbered paragraph
beginning with paragraph 55, wherein the talc has an oil absorption
ranging from 25 grams per 100 grams of talc to 55 grams per 100
grams of talc.
[0152] 89. The method according to any preceding numbered paragraph
beginning with paragraph 55, wherein the talc has a shape factor
greater than 10.
[0153] 90. The method according to any preceding numbered paragraph
beginning with paragraph 55, wherein the talc has a shape factor
greater than 20.
[0154] 91. The method according to any preceding numbered paragraph
beginning with paragraph 55, wherein the talc has a shape factor
greater than 30.
[0155] 92. The method according to any preceding numbered paragraph
beginning with paragraph 55, wherein the talc has a shape factor
greater than 40.
[0156] 93. The method according to any preceding numbered paragraph
beginning with paragraph 55, wherein the talc has a shape factor
greater than 50.
[0157] 94. The method according to any preceding numbered paragraph
beginning with paragraph 55, wherein the talc has a shape factor
greater than 75.
[0158] 95. The method according to any preceding numbered paragraph
beginning with paragraph 55, wherein the talc has a shape factor
greater than 100.
[0159] 96. The method according to any preceding numbered paragraph
beginning with paragraph 55, wherein the talc has a shape factor
less than 200.
[0160] 97. The method according to any preceding numbered paragraph
beginning with paragraph 55, wherein the talc has a shape factor
less than 150.
[0161] 98. The method according to any preceding numbered paragraph
beginning with paragraph 55, wherein the talc has a shape factor
less than 100.
[0162] 99. The method according to any preceding numbered paragraph
beginning with paragraph 55, wherein the talc has a shape factor
ranging from 10 to 200.
[0163] 100. The method according to any preceding numbered
paragraph beginning with paragraph 55, wherein the talc has a shape
factor ranging from 15 to 150.
[0164] 101. The method according to any preceding numbered
paragraph beginning with paragraph 55, wherein the talc has a shape
factor ranging from 15 to 50.
[0165] 102. The method according to any preceding numbered
paragraph beginning with paragraph 55, wherein the talc has a shape
factor ranging from 15 to 100.
[0166] 103. The method according to any preceding numbered
paragraph beginning with paragraph 55, wherein the composition
ranges from 10% by weight to 30% by weight talc, from 10% by weight
to 25% by weight talc, or from 10% by weight to 20% by weight
talc.
[0167] 104. The method according to any preceding numbered
paragraph beginning with paragraph 55, wherein the composition
ranges from 15% by weight to 30% by weight talc.
[0168] 105. The method according to any preceding numbered
paragraph beginning with paragraph 55, wherein the composition
ranges from 20% by weight to 30% by weight talc.
[0169] 106. The method according to any preceding numbered
paragraph beginning with paragraph 55, wherein the composition
ranges from 15% by weight to 25% by weight talc.
[0170] 107. The method according to any preceding numbered
paragraph beginning with paragraph 55, further comprising at least
one additional mineral or another mineral replacing the talc.
[0171] 108. The method according to any preceding numbered
paragraph beginning with paragraph 55, wherein the at least one
additional mineral is selected from the group consisting of kaolin,
bentonite, montmorillonite, pyrophyllite, vermiculite, halloysite,
wollastonite, mica, calcium carbonate, titania, perlite, sodium
oxysulfate, and diatomaceous earth.
[0172] 109. The composition or method according to any preceding
numbered paragraph beginning with paragraph 1, wherein the
composition further comprises at least one of plasticizers, impact
modifiers, pigments, dyes, colorants, stabilizers, nucleating
agents, and other polymer additives or processing aids, configured
to modify resin properties.
[0173] 110. The composition or method according to any preceding
numbered paragraph beginning with paragraph 1, wherein the
composition further comprises at least one mineral from the group
consisting of mica, kaolin, bentonite, montmorillonite,
pyrophyllite, vermiculite, halloysite, wollastonite, calcium
carbonate, titania, perlite, and diatomaceous earth, and wherein
the composition comprises from greater than 0% by weight to 40% by
weight of the at least one mineral.
[0174] Other embodiments will be apparent to those skilled in the
art from consideration of the specification and practice of the
embodiments disclosed herein. It is intended that the specification
and examples be considered as exemplary only.
* * * * *
References