U.S. patent application number 14/184010 was filed with the patent office on 2014-08-21 for reinforced fused-deposition modeling.
The applicant listed for this patent is Hemant Bheda. Invention is credited to Hemant Bheda.
Application Number | 20140232035 14/184010 |
Document ID | / |
Family ID | 51350641 |
Filed Date | 2014-08-21 |
United States Patent
Application |
20140232035 |
Kind Code |
A1 |
Bheda; Hemant |
August 21, 2014 |
REINFORCED FUSED-DEPOSITION MODELING
Abstract
An apparatus for manufacturing an object includes an extrusion
head having an extrusion needle for extruding thermoplastic
material associated with one or more fiber strands. The apparatus
may further include a turn-table, a more robotic arm for moving the
extrusion head and needle, thermoplastic filament and fiber strand
spools and thermoplastic filament and fiber strands. A controller
is provided for directing the robotic arm, extrusion head and the
turn-table. Further, a method for manufacturing an object includes
generating a design for the object that substantially satisfies
desired structural properties of the object and generating a
sequence for extruding one or more beads of thermoplastic material
to manufacture the object according to the design, in which the one
or more beads of thermoplastic material are associated with one or
more fiber strands. The one or more beads of thermoplastic material
and the associated one or more fiber strands are then extruded
according to the sequence.
Inventors: |
Bheda; Hemant; (Saratoga,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Bheda; Hemant |
Saratoga |
CA |
US |
|
|
Family ID: |
51350641 |
Appl. No.: |
14/184010 |
Filed: |
February 19, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61766376 |
Feb 19, 2013 |
|
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|
Current U.S.
Class: |
264/148 ;
264/308; 425/375 |
Current CPC
Class: |
B29C 64/321 20170801;
B29C 64/165 20170801; B29C 64/10 20170801; B33Y 50/02 20141201;
B29C 64/118 20170801; B29K 2105/06 20130101; B33Y 30/00 20141201;
B29C 64/106 20170801; B29C 64/40 20170801; B29C 64/307 20170801;
B29C 64/336 20170801; B33Y 10/00 20141201; B29C 64/112 20170801;
B29C 64/393 20170801 |
Class at
Publication: |
264/148 ;
425/375; 264/308 |
International
Class: |
B29C 67/00 20060101
B29C067/00 |
Claims
1. An apparatus for manufacturing an object, the apparatus
comprising an extrusion head for extruding thermoplastic material
associated with one or more fiber strands.
2. The apparatus of claim 1, further comprising a spooled filament
of thermoplastic material for feeding to the extrusion head, the
filament of thermoplastic material containing one or more fiber
strands.
3. The apparatus of claim 1, further comprising a spooled filament
of thermoplastic material for feeding to the extrusion head.
4. The apparatus of claim 1, further comprising a spooled fiber
strand for feeding to the extrusion head.
5. The apparatus of claim 1, wherein the extrusion head includes an
extrusion needle through which the thermoplastic material and the
associated one or more fiber strands are extruded from the
extrusion head.
6. The apparatus of claim 5, wherein the extrusion needle has a
length equal to at least the longest dimension of the object.
7. The apparatus of claim 1, wherein the extrusion head includes a
blade element for cutting the one or more fiber strands.
8. The apparatus of claim 7, wherein the extrusion head includes an
extrusion needle and wherein the blade element is disposed at a
dispensing tip of the extrusion needle.
9. The apparatus of claim 1, wherein the extrusion head includes an
extrusion needle and further comprising a positioning assembly for
placing a dispensing tip of the extrusion needle at any location in
a build volume of the object from any approach angle.
10. The apparatus of claim 9, wherein the positioning assembly
provides at least three degrees of freedom.
11. The apparatus of claim 9, wherein the positioning assembly
comprises a six or seven axes robotic arm.
12. The apparatus of claim 9, wherein the extrusion head moves
along a Z axis in any direction, along an X axis in any direction,
along the a Y axis in any direction, and any combination
thereof.
13. The apparatus of claim 12, further comprising a controller for
directing at least one of the positioning assembly and the
extrusion head.
14. The apparatus of claim 9, further comprising a controller for
directing at least one of the positioning assembly and the
extrusion head.
15. The apparatus of claim 1, further comprising a platform on
which the object is built.
16. The apparatus of claim 15, wherein the platform includes a
drive mechanism for rotating the platform around a Z axis in any
direction, moving the platform along the Z axis in any direction,
moving the platform along an X axis in any direction, moving the
platform along a Y axis in any direction, or any combination
thereof.
17. The apparatus of claim 16, further comprising a controller for
directing the drive mechanism.
18. The apparatus of claim 1, further comprising a controller for:
generating a design for the object that substantially satisfies
desired structural properties of the object; generating a sequence
for extruding the thermoplastic material and the associated one or
more fiber strands to manufacture the object according to the
design; and directing the extrusion head to extrude the
thermoplastic material and the associated one or more fiber strands
according to the sequence.
19. The apparatus of claim 18, wherein the controller includes a
list of structural properties of the thermoplastic material and the
associated one or more fiber strands, the list being used by the
controller for generating the design and the sequence.
20. A method for manufacturing an object, the method comprising:
generating, in a computer process, a design for the object that
substantially satisfies desired structural properties of the
object; generating, in a computer process, a sequence for extruding
one or more beads of thermoplastic material to manufacture the
object according to the design, wherein the one or more beads of
thermoplastic material are associated with one or more fiber
strands; and extruding the one or more beads of thermoplastic
material and the associated one or more fiber strands according to
the sequence.
21. The method of claim 20, wherein the one or more fiber strands
are disposed within the one or more beads, partially within the one
or more beads, adjacent to the one or more beads, or any
combination thereof.
22. The method of claim 20, wherein the one or more fiber strands
and the one or more beads are extruded together or separately in
any order.
23. The method of claim 20, wherein the length of any of the one or
more fiber strands is short, medium, or long.
24. The method of claim 20, wherein the one or more fiber strands
are made of the same material or different materials or some of the
one or more fiber strands are made of the same material and some of
the one or more fiber strands are made of different materials.
25. The method of claim 20, wherein the one or more fiber strands
have the same modulus of elasticity or different modulus of
elasticity, or some of the one or more fiber strands have the same
modulus of elasticity and some of the one or more fiber strands
have different modulus of elasticity.
26. The method of claim 20, wherein at least one of the one or more
fiber strands comprises a bundle of fiber strands.
27. The method of claim 20, wherein the one or more fiber strands
are oriented parallel to a longitudinal axis of the one or more
beads, at an angle to the longitudinal axis of the one or more
beads, or parallel to a longitudinal axis of the one or more beads
and at an angle to the longitudinal axis of the one or more
beads.
28. The method of claim 20, wherein the one or more fiber strands
are cut to a desired length in accordance with the design prior to
being extruded, after being extruded, or prior to being extruded
and after being extruded.
29. The method of claim 20, wherein the extruding step is performed
with an extrusion head, and wherein after the sequence generating
step and prior to the extruding step, further comprising feeding
one or more filaments of the thermoplastic material to the
extrusion head to be melted therein, wherein the one or more beads
of the thermoplastic material are extruded from the melted
filaments of the thermoplastic material.
30. The method of claim 29, wherein at least one of the one or more
filaments of the thermoplastic material includes at least one of
the one or more fiber strands.
31. The method of claim 29, further comprising feeding at least one
of the one or more fiber strands to the extrusion head and
associating the at least one of the one or more fiber strands with
the one or more beads of the thermoplastic material.
32. The method of claim 31, wherein at least one of the one or more
filaments of the thermoplastic material includes at least another
one of the one or more fiber strands.
33. The method of claim 20, wherein the extruding step is performed
with an extrusion head, and further comprising moving the extrusion
head along a Z axis in any direction, along an X axis in any
direction; along a Y axis in any direction; or any combination
thereof, as the sequence progresses.
34. The method of claim 20, wherein the extruding step is performed
on a platform, and further comprising rotating the platform around
a Z axis in any direction or along the Z axis in any direction, or
any combination thereof, as the sequence progresses.
35. The method of claim 20, wherein the extruding step is performed
on a platform with an extrusion head, and further comprising moving
the extrusion head along the a axis in any direction, moving the
extrusion head along an X axis in any direction, moving the
extrusion head along a Y axis in any direction, rotating the
platform around the Z axis in any direction, moving the platform
along the Z axis in any direction, or any combination thereof, as
the sequence progresses.
Description
RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Application Ser. No. 61/766,376, filed Feb. 19, 2013, entitled
"REINFORCED FUSED-DEPOSITION MODELING" (Attorney Docket
3019-001PR1), which is incorporated herein by reference. If there
are any contradictions or inconsistencies in language between this
application and the case that has been incorporated by reference
that might affect the interpretation of the claims in this case,
the claims in this case should be interpreted to be consistent with
the language in this case.
FIELD
[0002] The present disclosure relates to manufacturing, and, more
particularly, to fused-deposition modeling.
BACKGROUND
[0003] Fused-deposition modeling is a technique for building a
three-dimensional object from a mathematical model of the object.
In general, the object is built by feeding a thermoplastic filament
into a heated extrusion head. The heated extrusion head melts and
deposits the molten thermoplastic material as a series of beads.
Each bead is roughly spherical or cylindrical in shape--and is much
like the toothpaste that is squeezed from a tube--but much smaller
than a grain of rice. Typically, a bead is between 0.001.sup.th to
0.010.sup.th of an inch thick. When a bead is deposited, it is just
slightly above its melting point. After it is deposited, the bead
quickly solidifies and fuses with the beads that are next to and
below it.
[0004] Perhaps the greatest advantage of fused-deposition modeling
is that it can build an object of any shape. To accomplish this,
however, there are constraints on the sequence in which the beads
can be deposited. First, each bead must be supported. In other
words, a bead cannot be deposited on air. Therefore, each bead must
be deposited on: [0005] (i) a platform that is not part of the
object, or [0006] (ii) one or more previously-deposited beads that
will be part of the object, or [0007] (iii) a temporary scaffold of
support material that is not part of the object, or [0008] (iv) any
combination of i, ii, and iii. Second, when a three-dimensional
surface is sealed with beads, it is no longer possible to deposit a
bead inside of that surface. This is analogous to the situation in
which once you close a box, you can't put anything into the
box.
[0009] There is a general methodology that is used in
fused-deposition modeling that satisfies these constraints and
enables the building of an object of any shape. The
three-dimensional model of the object is modeled as thousands of
thin layers in the X-Y plane. Each layer is modeled as thousands of
beads and voids. The object is then built, one bead at a time, one
layer at a time, only in the +Z direction.
[0010] There are, however, costs and disadvantages associated with
traditional fused-deposition modeling.
SUMMARY
[0011] One of the disadvantages of traditional fused-deposition
modeling is that the resulting objects are not strong enough for
many applications. That is why the objects are often used only as
models or prototypes of "real" objects.
[0012] Embodiments of the present disclosure address this
deficiency by combining fiber strands with fused-deposition
modeling to create fiber-reinforced objects. In general,
fiber-reinforced objects are much stronger than unreinforced
objects.
[0013] A fiber-reinforced object is built by depositing one or more
fiber strands in association with one or more beads of
thermoplastic material. A fiber strand and a bead can be associated
in which: [0014] (i) the fiber strand is wholly within the bead, or
[0015] (ii) the fiber strand is partially within the bead, or
[0016] (iii) the fiber strand is adjacent to the bead, or [0017]
(iv) any combination of i, ii, and iii. A fiber strand and an
associated bead can be deposited together or separately. The fiber
strand can be deposited first and then the bead can be deposited.
Alternatively, the bead can be deposited first and then the fiber
strand can be deposited. One fiber strand can be associated with
one or more beads, and one bead can be associated with one or more
fiber strands.
[0018] The length of a fiber strand can be: [0019] (i) "short," or
[0020] (ii) "medium," or [0021] (iii) "long."
[0022] A "short-length" fiber strand has a maximum length that is
less than twice the minimum dimension of a bead. The angular
orientation of the longitudinal or neutral axis of a short-length
fiber strand associated with a bead is generally correlated with
the longitudinal or neutral axis of the bead. Although the ends of
a short-length fiber strand can extend beyond the wall of a
bead--like a spine on a cactus--a short-length fiber strand
intersects only one bead and its immediate neighbors. In accordance
with some embodiments of the present disclosure, short-length fiber
strands are cut before being deposited, but in other embodiments
the short-length fiber strands are cut while being deposited.
[0023] A "long-length" fiber strand has a length that is
approximately equal to the length of a bead. The angular
orientation of a long-length fiber strand associated with a bead is
generally parallel to the longitudinal or neutral axis of the bead.
In accordance with some embodiments of the present disclosure,
long-length fiber strands are cut while being deposited, but in
other embodiments the long-length fiber strands are cut before
being deposited.
[0024] A "medium-length" strand has a length longer than a
short-length fiber strand and shorter than a long-length fiber
strand. The angular orientation of a medium-length fiber strand
associated with a bead is generally parallel to the longitudinal or
neutral axis of the bead. In accordance with some embodiments of
the present disclosure, short-length fiber strands are cut before
being deposited, but in other embodiments the short-length fiber
strands are cut while being deposited.
[0025] In accordance with embodiments of the present disclosure, a
bead can be associated with a fiber strand made of glass, carbon,
aramid, cotton, wool, or any other fibrous material.
[0026] A bead can be associated with one or more bundles of fiber
strands. A bundle of fiber strands can be grouped as a tow, a yarn,
or a braid. The cross section of a bundle of fiber strands can be
flat, cylindrical, rectangular, triangular, or irregular. A bundle
of fiber strands can comprise fiber strand made of one or more
materials (e.g., glass and carbon, glass and aramid, carbon and
aramid, glass and carbon and aramid, etc.).
[0027] An object that is built in accordance with present
disclosure can comprise: [0028] (i) beads that are not associated
with a fiber strand, or [0029] (ii) beads that are associated with
"short" strands, or [0030] (iii) beads that are associated with
"medium" strands, or [0031] (iv) beads that are associated with
"long" strands, or [0032] (v) any combination of i, ii, iii, and
iv.
[0033] In accordance with some embodiments of the present
disclosure, the thermoplastic filament comprises one or more fiber
strands (or one or more bundles of fiber strands) prior to being
fed into the extrusion head. In some alternative embodiments, one
or more fiber strands (or one or more bundles of fiber strands) are
combined with the thermoplastic material during deposition.
[0034] Some embodiments of the present disclosure comprise a
plurality of thermoplastic filaments in which at least one of the
filaments does not comprise a fiber strand and at least one of the
filaments does comprise a fiber strand. Furthermore, some
embodiments of the present disclosure comprise a plurality of
thermoplastic filaments that each comprise: [0035] (i) a fiber
strand of different length, or [0036] (ii) a fiber strand of
different material, or [0037] (iii) a fiber strand of different
modulus, or [0038] (iv) a different bundle of fiber strands, or
[0039] (v) any combination of i, ii, iii, and iv.
[0040] Some embodiments of the present disclosure can deposit
multiple beads and fiber strands (or bundles of fiber strands) in
parallel.
[0041] Some embodiments of the present disclosure can deposit:
[0042] (i) a bead of thermoplastic material, or [0043] (ii) a fiber
strand, or [0044] (iii) both a bead of thermoplastic material and a
fiber strand in a substantially straight segment whose longitudinal
or neutral axis is: [0045] (a) in the X-Y plane and parallel to the
X axis, or [0046] (b) in the X-Y plane and parallel to the Y axis,
or [0047] (c) in the X-Y plane and at an acute angle to the X axis,
or [0048] (d) at a right angle to the X-Y plane, or [0049] (e) at
an acute angle to the X-Y plane.
[0050] Some embodiments of the present disclosure can deposit:
[0051] (i) a bead of thermoplastic material, or [0052] (ii) a fiber
strand, or [0053] (iii) both a bead of thermoplastic material and a
fiber strand in a two-dimensional curvilinear segment (e.g., an
arc, substantially a circle, a parabola, a sinewave, a spiral, a
cissoid, a Folium of Descartes, a planar spring, etc.) that lies in
a plane that is: [0054] (a) parallel to the X-Y plane, or [0055]
(b) at a right angle to the X-Y plane, or [0056] (c) at an acute
angle to the X-Y plane.
[0057] Some embodiments of the present disclosure can deposit:
[0058] (i) a bead of thermoplastic material, or [0059] (ii) a fiber
strand, or [0060] (iii) both a bead of thermoplastic material and a
fiber strand in a helical segment (e.g., a circular helix, a
conical helix, a cylindrical or general helix, a left-handed helix,
a right-handed helix, etc.) whose axis is: [0061] (a) in the X-Y
plane, or [0062] (b) at a right angle to the X-Y plane, or [0063]
(c) at an acute angle to the X-Y plane. The helix can be regular or
irregular (like the windings of rope on a spool).
[0064] Some embodiments of the present disclosure can deposit:
[0065] (i) a bead of thermoplastic material, or [0066] (ii) a fiber
strand, or [0067] (iii) both a bead of thermoplastic material and a
fiber strand in a polygon (e.g., a triangle, a rectangle, etc.)
that lies in a plane that is: [0068] (a) parallel to the X-Y plane,
or [0069] (b) at a right angle to the X-Y plane, or [0070] (c) at
an acute angle to the X-Y plane. The polygon can be regular or
irregular, simple or not simple, concave or non-concave, convex or
non-convex.
[0071] In general, some embodiments of the present disclosure can
deposit beads of thermoplastic material and fiber strands in many
topologies (e.g., a toroid, a cage, etc.).
[0072] The fact that some embodiments of the present disclosure can
deposit a fiber strand at a non-zero angle to the X-Y plane can
create a situation in which the general methodology of depositing
beads in a strict layer-by-layer sequence are not possible.
Therefore, some embodiments of the present disclosure generate an
sequence for depositing the beads and fiber strands that is
manufacturable. Such sequences can iteratively progress in both the
+X, -X, +Y, -Y, +Z, and -Z directions.
[0073] The location of the fiber strands in the object and their
geometry and orientation can affect the structural properties of
the object. Furthermore, the structural properties of the object
can be predicted based on the location of the fiber strands in the
object and their geometry. Therefore, some embodiments of the
present disclosure accept both a mathematical model of the object
and a list of the desired structural properties of the object, and
generate a design for: [0074] (i) the number of fiber strands in
the object, and [0075] (ii) the bundling of the fiber strands in
the object, and [0076] (iii) the material of the fiber strands in
the object, and [0077] (iv) the Young's modulus of the fiber
strands in the object, and [0078] (v) the location of the fiber
strands in the object, and [0079] (vi) the geometry of the fiber
strands in the object, and [0080] (vii) the orientation of the
fiber strands in the object, and [0081] (viii)an sequence for
depositing the beads and fiber strands that: [0082] (1) attempt to
satisfy the desired structural properties of the object, and [0083]
(2) can be actually be built.
[0084] The latter condition is especially important because there
are many arrangements of fibers that cannot be manufactured using
fused-deposition modeling.
[0085] Some embodiments of the present disclosure are capable of
depositing support material at a location and removing the support
material and re-depositing the support material at the same
location and of removing the re-deposited support material. This is
to enable the support of a bead and fiber strand at one moment and
then after the bead has hardened to enable another bead and fiber
strand to be deposited under the first.
[0086] Some embodiments of the present disclosure comprise a
turntable that supports the object while it is built and that spins
under the control of the embodiment's CAD/CAM controller. This
facilitates the deposition of circular and helical beads and fiber
strands on the object. This also facilitates the ability of the
embodiments to deposit beads and fiber strands at any location in
the build volume from any approach angle.
BRIEF DESCRIPTION OF THE DRAWINGS
[0087] FIG. 1 depicts a front view of manufacturing system 100 in
accordance with the illustrative embodiment of the present
disclosure.
DETAILED DESCRIPTION
[0088] FIG. 1 depicts a front view of manufacturing system 100 in
accordance with the illustrative embodiment of the present
disclosure. Manufacturing system 100 may comprise: [0089] CAD/CAM
controller 101, [0090] build chamber 102, [0091] turn-table 110,
[0092] one or more robotic arms 121, each comprising an extrusion
head 122 with an extrusion needle 123, [0093] thermoplastic
filament spool 130-1 and thermoplastic filament 131-1, [0094]
thermoplastic filament spool 130-2 and thermoplastic filament
131-2, and [0095] fiber strand spool 130-3 and fiber strand 131-3.
The purpose of manufacturing system 100 is to build a
three-dimensional object--depicted as object 151 in FIG. 1.
[0096] CAD/CAM controller 101 directs the building of object 151
based on a mathematical model of object 151. In accordance with the
illustrative embodiment, the mathematical model of object 151 is
created with CAD/CAM controller 101, but it will be clear to those
skilled in the art, after reading this disclosure, how to make and
use alternative embodiments of the present disclosure in which the
model is created elsewhere and imported into CAD/CAM controller
101.
[0097] CAD/CAM controller 101 may comprise a list of the desired
structural properties of object 151. This list may include, but is
not limited to: [0098] 1. the desired compression strength
characteristics of object 151, and [0099] 2. the desired tensile
strength characteristics of object 151, and [0100] 3. the desired
resonance characteristics of object 151.
[0101] In accordance with the illustrative embodiment,
thermoplastic filament 131-1 comprises a continuous tow of 5
low-modulus carbon-fiber strands, and thermoplastic filament 131-2
does not comprise a fiber strand. Thermoplastic filament 131-2 is
used as support material in building object 151.
[0102] CAD/CAM controller 101 may also comprise a list of the
structural properties of thermoplastic filament 131-1. This list
may include, but is not limited to: [0103] 1. the compression
strength of the thermoplastic and tow of carbon fibers (after
deposition and in object 151), and [0104] 2. the tensile strength
of the thermoplastic and tow of carbon fibers (after deposition and
in object 151), and [0105] 3. the thermal expansion of the
thermoplastic and tow of carbon fibers (after deposition and in
object 151), and [0106] 4. the Young's modulus of the thermoplastic
and tow of carbon fibers (after deposition and in object 151).
[0107] CAD/CAM controller 101 may also comprise a list of the
structural properties of thermoplastic filament 131-2 and/or fiber
strand 131-3.
[0108] CAD/CAM controller 101 generates a design for object 151
that: [0109] (1) attempts to satisfy the desired structural
properties of object 151, and [0110] (2) a sequence for depositing
beads of thermoplastic material and support material. The design
for object 151 includes, but is not limited to: [0111] (i) the
location of fiber strands in the object, and [0112] (ii) the
geometry of the fiber strands in the object.
[0113] Build chamber 102 is an enclosed environment in which object
151 is built.
[0114] Turn-table 110 comprises a platform on which object 151 is
built. Turn-table 110 may be driven by a drive mechanism 110-1 that
is directed by CAD/CAM controller 101. The drive mechanism 110-1
may comprise a motor arrangement including, but not limited to one
or more stepper and/or servo motors. Some embodiments may also
include a transmission or gear arrangement for controlled
transmission of the rotational movement of the motor(s) to the
turn-table 110. The transmission or gear arrangement may include
without limitation one or more gears, belts, chains, and
combinations thereof.
[0115] Various embodiments of the drive mechanism 110-1 may be
configured to rotate the turn-table 110 in clockwise and
counterclockwise directions around the Z axis under the direction
of CAD/CAM controller 101. The drive mechanism 110-1, in various
other embodiments, may also be configured to raise and lower the
turn-table 110 in the +Z and the -Z directions under the direction
of CAD/CAM controller 101. In various other embodiments, the drive
mechanism 110-1 may also be configured to move the turn-table 110
in the +X direction, the -X direction, the +Y direction the -Y
direction, or any combination thereof.
[0116] The one or more robotic arms 121 may be configured to place
the dispensing end of the extrusion needle 123 at any location in
the build volume of object 151, from any approach angle. This
enables manufacturing system 100 to lay fiber strands on the inside
an enclosure such as a closed sphere through a hole in the
enclosure (e.g., sphere) just large enough for extrusion needle
123. The robotic arms 121, in various embodiments, may be powered
by electric motors, hydraulic actuators, or combinations thereof,
and configured to provide three or more axes or degrees of freedom
so that the extrusion head/needle can move in the +X direction, the
-X direction, the +Y direction, the -Y direction, the +Z direction,
the -Z direction, or any combination thereof. In one illustrative
embodiment, the robotic arm 121 may be configured as a six-axis
robotic arm. In another illustrative embodiment, the robotic arm
121 may be configured as a seven-axis robotic arm. Any other
suitable positioning assembly capable of placing the dispensing end
of the extrusion needle 123 at any location in the build volume of
object 151, from any approach angle, may be used in place of the
robotic arms 121.
[0117] The extrusion head 122 is configured to melt the
thermoplastic and extrude the molten thermoplastic (which may
partially or wholly contain one or more fiber strands) via the
extrusion needle 123. Various embodiments of the extrusion head 122
may define an interior chamber 122-1 for receiving the
thermoplastic material. The extrusion head 122 may include a heater
or heating element 122-2 for melting the thermoplastic material
within the chamber for extrusion through the extrusion needle in
liquid form. The extrusion head 122 may include a motor (not shown)
or any other suitable mechanism for pushing the thermoplastic
material through the chamber 122-2 and out the extrusion needle
123. In some embodiments, the extrusion head 122 may also be
configured with a cutting mechanism 122-4 to cut the one or more
fiber strands to the appropriate length. The cutting mechanism
122-4 may include a blade or other suitable cutting member for
cutting the one or more fiber strands. In one illustrative
embodiment, the cutting mechanism 122-4 may be disposed at the
dispensing end or tip 123-1 of extrusion needle 123.
[0118] Extrusion needle 123 may comprise a hollow tube or nozzle
having a first open end that communicates with the chamber of the
extrusion head 122 and a second open end (dispending end or tip
123-1) that dispenses the thermoplastic, which may partially or
wholly contain one or more fiber strands. The opening of the tip
123-1 may be circular, oval, square, slotted or any other suitable
shape that is capable of extruding the thermoplastic material in a
desired cross-sectional shape. In various embodiments, the
extrusion needle 123 may have a length equal to at least the
longest dimension of object 151 so that the tip of 123-1 extrusion
needle 123 can deposit material at any location in the build volume
of object 151 from any approach angle.
[0119] In operation, according to one illustrative embodiment, one
or more motors may be used for feeding the filament(s) of
thermoplastic material 131-1, 131-2 (and fiber strand(s) 131-3)
into the chamber 122-1 of the extrusion head 122 from the spools
130-1, 130-2, 130-3. The thermoplastic material entering the
chamber 122-1 is melted by the heater 122-2, and extruded from the
extrusion head 122 via the extrusion needle 123. The CAD/CAM
controller 101 may control the rate of the one or more feed motors,
the temperature of the heater 122-2, and/or the other process
parameters mentioned earlier, so that the thermoplastic material
and fiber strand(s) can be extruded in a manner that to attempts to
satisfy the desired structural properties of object 151.
[0120] Although the manufacturing system, methods, thermoplastic
filaments, fiber strands, and other associated elements have been
described in terms of exemplary embodiments, they are not limited
thereto. Rather, the appended claims should be construed broadly to
include other variants and embodiments of same, which may be made
by those skilled in the art without departing from the scope and
range of equivalents of the device, tray and their elements.
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