U.S. patent application number 15/822125 was filed with the patent office on 2018-03-15 for composite structure having modifier material printed thereon.
This patent application is currently assigned to The Boeing Company. The applicant listed for this patent is The Boeing Company. Invention is credited to Christopher A. Howe, Samuel J. Meure.
Application Number | 20180073167 15/822125 |
Document ID | / |
Family ID | 54196887 |
Filed Date | 2018-03-15 |
United States Patent
Application |
20180073167 |
Kind Code |
A1 |
Meure; Samuel J. ; et
al. |
March 15, 2018 |
COMPOSITE STRUCTURE HAVING MODIFIER MATERIAL PRINTED THEREON
Abstract
A composite fiber may include at least one reinforcing filament
formed of a first material. A second material maybe systematically
deposited in a printed onto the at least one reinforcing filament
such that at least one of a length, a width, and a thickness of the
second material varies across a surface of the at least one
reinforcing filament. The printed pattern may alter one or more
properties of a composite structure containing the composite
fiber.
Inventors: |
Meure; Samuel J.;
(Fishermans Bend, AU) ; Howe; Christopher A.;
(Fishermans Bend, AU) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
The Boeing Company |
Chicago |
IL |
US |
|
|
Assignee: |
The Boeing Company
|
Family ID: |
54196887 |
Appl. No.: |
15/822125 |
Filed: |
November 25, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
14493364 |
Sep 23, 2014 |
9845556 |
|
|
15822125 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
D06P 1/00 20130101; B05D
2203/00 20130101; D04H 3/12 20130101; D04H 3/04 20130101; D06H 1/02
20130101; D02G 3/447 20130101; D06P 3/00 20130101; B05D 1/02
20130101; B05D 7/00 20130101; B05D 2256/00 20130101; D06M 11/83
20130101; D06P 5/30 20130101; D06M 23/16 20130101; B41M 5/0023
20130101; B05D 1/26 20130101; B41M 5/0041 20130101; B41M 5/0047
20130101; D02G 3/36 20130101; D06P 1/44 20130101; D10B 2505/02
20130101; B05D 7/24 20130101; D06M 11/79 20130101; B29C 70/58
20130101; D06M 11/74 20130101 |
International
Class: |
D02G 3/36 20060101
D02G003/36; B05D 1/02 20060101 B05D001/02; D06M 23/16 20060101
D06M023/16; D06P 1/44 20060101 D06P001/44; D06M 11/83 20060101
D06M011/83; D06M 11/79 20060101 D06M011/79; D06M 11/74 20060101
D06M011/74; D06P 5/30 20060101 D06P005/30; B29C 70/58 20060101
B29C070/58; D04H 3/12 20060101 D04H003/12; D04H 3/04 20060101
D04H003/04; B41M 5/00 20060101 B41M005/00; B05D 1/26 20060101
B05D001/26; B05D 7/24 20060101 B05D007/24; D06P 1/00 20060101
D06P001/00; D06P 3/00 20060101 D06P003/00; B05D 7/00 20060101
B05D007/00; D06H 1/02 20060101 D06H001/02; D02G 3/44 20060101
D02G003/44 |
Claims
1. A composite fiber, comprising: at least one reinforcing filament
formed of a first material and a second material systematically
deposited in a pattern onto the at least one reinforcing filament
such that at least one of a length, a width, and a thickness of the
second material varies across a surface of the at least one
reinforcing filament.
2. The composite fiber of claim 1, wherein: the reinforcing
filament includes a sizing applied in a uniform sizing thickness to
a filament surface of the at least one reinforcing filament; and
the second material systematically deposited onto the sizing of the
at least one reinforcing filament.
3. The composite fiber of claim 1, wherein: at least one of the
length, the width, and the thickness of the second material is
approximately 0.01 to 100 microns.
4. The composite fiber of claim 1, wherein: the second material is
comprised of any one or more of the following: inks, granules,
extrusion media, organic monomers, prepolymers, polymers, metallic
powders, inorganic fillers in an aqueous or solvent-based solution,
silica, block copolymers, graphene platelets, polymer
nanoparticles, and carbon nanotubes.
5. The composite fiber of claim 1, wherein: the second material is
applied onto the at least one reinforcing filament using a
deposition head of a printing device.
6. The composite fiber of claim 1, further comprising: one or more
additional materials including a third material systematically
deposited onto the at least one reinforcing filament.
7. The composite fiber of claim 1, wherein: the second material is
applied to at least two different surfaces associated with a bundle
of reinforcing filaments forming the composite fiber.
8. The composite fiber of claim 7, wherein: the surfaces include at
least one of a top surface, a bottom surface, and side surfaces of
the composite fiber.
9. The composite fiber of claim 1, wherein: the second material is
printed onto at least one reinforcing filament as pixels each
having a thickness of up to 100 microns.
10. The composite fiber of claim 1, wherein: the at least one
reinforcing filament comprises a plurality of reinforcing filaments
in at least one of the following forms: a fiber tow, unidirectional
tape, woven fabric, non-crimp fabric, a braid, a composite ply or
preform.
11. A composite structure, comprising: a resin; a plurality of
reinforcing filaments embedded in the resin and formed of a first
material; and a second material systematically deposited onto the
plurality of reinforcing filaments such that at least one of a
length, a width, or a thickness varies across a filament surface of
the plurality of reinforcing filaments.
12. The composite structure of claim 11, wherein: the composite
structure has at least one composite structure property that is
altered due to systematic deposition of the second material onto
the reinforcing filaments relative to the composite structure
property of a composite structure having reinforcing filaments that
are devoid of the second material.
13. The composite structure of claim 12, wherein: the altered
composite structure property includes at least one of the
following: toughness, volume fraction, permeability, modulus, cure
shrinkage, filament tack, flammability, and electrical
conductivity.
14. The composite structure of claim 12, further comprising: one or
more additional materials including a third material systematically
deposited onto the at least one reinforcing filament using a
deposition head of a printer; and the composite structure having at
least two different composite structure properties that are altered
due to printing of the respective second and third material to the
at least one reinforcing filament relative to the composite
structure properties of a composite structure having reinforcing
filaments that are devoid of the second and third material.
15. The composite structure of claim 12, wherein: the plurality of
reinforcing filaments each include a sizing applied in a uniform
sizing thickness to a filament surface of the plurality of
reinforcing filaments; and the second material systematically
deposited onto the sizing of the plurality of reinforcing
filaments.
16. The composite structure of claim 12, wherein: at least one of
the length, the width, and the thickness of the second material is
approximately 0.01 to 100 microns.
17. The composite structure of claim 12, wherein: the second
material is comprised of any one or more of the following: inks,
granules, extrusion media, organic monomers, prepolymers, polymers,
metallic powders, inorganic fillers in an aqueous or solvent-based
solution, silica, block copolymers, graphene platelets, polymer
nanoparticles, and carbon nanotubes.
18. The composite structure of claim 12, wherein: the second
material is applied onto the plurality of reinforcing filaments
using a deposition head of a printing device.
19. The composite structure of claim 12, wherein: the second
material is printed onto the plurality of reinforcing filaments as
pixels each having a thickness of up to 100 microns.
20. The composite structure of claim 12, wherein: the plurality of
reinforcing filaments are provided in at least one of the following
forms: fiber tows, unidirectional tape, woven fabric, non-crimp
fabric, a braid, a composite ply or preform.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a divisional application of and
claims priority to pending U.S. application Ser. No. 14/493,364
filed on Sep. 23, 2014, and entitled PRINTING PATTERNS ONTO
COMPOSITE LAMINATES, the entire contents of which is expressly
incorporated by reference herein.
FIELD
[0002] The present disclosure relates generally to composite
structures and, more particularly, to the printing of modifier
materials onto composite laminates.
BACKGROUND
[0003] Composite structures typically include continuous
reinforcing fibers embedded in a resin matrix. A composite laminate
is a type of composite structure comprising a layup of composite
plies arranged in a stack. The individual composite plies of a
composite layup may be pre-impregnated with resin (e.g., prepreg
plies) prior to stacking. The stack of prepreg plies may be
arranged such that the continuous reinforcing fibers in each ply
are oriented in a specific direction. Heat may be applied to the
stack to reduce the viscosity of the resin in each ply to allow the
resin to intermingle with the resin of adjacent plies while the
stack is consolidated under pressure to remove voids and volatiles
from within the composite layup. The resin may be cured or
solidified into a hardened state and passively or actively cooled
resulting in a composite structure. Alternatively, instead of using
prepreg plies, the composite plies may be provided as dry fiber
preforms arranged in a stack. Liquid resin may be infused into the
stack while heat and/or pressure are applied to consolidate and
cure the resin after which the layup may be passively or actively
cooled to result in a composite structure.
[0004] The ability to tailor the direction of the reinforcing
fibers in each ply of a composite layup results in a composite
structure with significant performance advantages. Such performance
advantages include a high specific strength and high specific
modulus of elasticity relative to the specific strength and modulus
of metallic structures. Unfortunately, conventional composite
laminates possess several characteristics that may detract from
their performance advantages. For example, conventional composite
laminates may be susceptible to separation at the resin-fiber
interface due to the absence of crack-arresting features within the
composite laminate. In addition, a conventional composite assembly
may have relatively low mode II interlaminar shear strength or peel
strength at the interface between co-bonded or co-cured composite
laminates that make up the composite assembly.
[0005] A conventional composite laminate may also possess
relatively low electrical conductivity which may present challenges
in transporting and distributing electrical current through a
composite structure such as in the event of a lightning strike. In
addition, composite laminates that interface with metallic
components may be susceptible to corrosion as a result of oxidation
or reduction reactions that may occur between the composite
laminate and metallic material. Furthermore, conventional dry fiber
composite plies may lack sufficient tack to enable the dry fiber
plies to stick together to allow for controlled stacking of the dry
fiber plies into a preform.
[0006] Attempts to resolve the issue of separation at the
resin-fiber interface of conventional composite laminates include
randomly distributing thermoplastic material in bulk throughout a
composite layup. Although the random distribution of thermoplastic
material may improve the mode II interlaminar strength, the lack of
control at the resin-fiber interface in conventional composite
laminates results in low mode I interlaminar strength which may
present challenges in preventing crack propagation within fiber
tows. Attempts to address low mode II interlaminar shear strength
at the interface between composite laminates of a conventional
composite assembly include the addition of tougheners in the resin.
Unfortunately, resin tougheners may have a relatively high
molecular weight that may undesirably increase the viscosity of the
resin which may inhibit resin flow during infusion of fiber
preforms. Attempts to address the issue of low electrical
conductivity in conventional composite laminates include the
addition of metallic meshes or foils across the surface of
composite plies. Unfortunately, the addition of separate metallic
meshes or foils increases the cost, complexity, and production time
of a composite structure.
[0007] Attempts to prevent corrosion at the interface between a
composite laminate and a metallic part include adding a separate
layer of fiberglass at the interface to act as a barrier ply
against corrosion. Unfortunately, the addition of fiberglass
increases the cost and complexity of manufacturing a composite
laminate. The problem of low tack in conventional dry fiber
composite plies has been addressed by adding epoxy binders or
nylons in the resin, or by using soldering irons to locally heat
and tack composite plies together. Unfortunately, epoxy binders or
nylons have finite properties that limit the range of temperatures
and pressures required to form a ply stack of dry fiber preforms.
The local tacking together of composite plies using soldering irons
is a time-consuming process that adds to the production time of a
composite structure.
[0008] As can be seen, there exists a need in the art for a
composite laminate and manufacturing method that provides
performance improvements such as improved crack-resistance,
improved interlaminar shear strength, increased electrical
conductivity and corrosion resistance, and improved tack in a broad
range of temperatures.
SUMMARY
[0009] The above-noted needs associated with composite laminates
are specifically addressed by the present disclosure which provides
a composite fiber that may include at least one reinforcing
filament formed of a first material. A second material may be
systematically deposited in a printed pattern onto the reinforcing
filament such that a length, a width, and/or a thickness of the
second material varies across a surface of the reinforcing
filament. The printed pattern may have the effect of altering one
or more properties of a composite structure containing the
composite fiber.
[0010] In a further embodiment, disclosed is a composite structure
which may include a resin and a plurality of reinforcing filaments
embedded in the resin. The reinforcing filaments may be formed of a
first material. The composite structure may include a second
material which may be systematically deposited onto the reinforcing
filaments such that a length, a width, and/or a thickness of the
second material varies across the surface of the reinforcing
filaments.
[0011] Also disclosed is a method of producing a composite fiber.
The method may include providing a plurality of reinforcing
filaments formed of a first material. The method may additionally
include printing a second material onto the plurality of
reinforcing filaments using a deposition head of a printer or
printing device.
[0012] The features, functions and advantages that have been
discussed can be achieved independently in various embodiments of
the present disclosure or may be combined in yet other embodiments,
further details of which can be seen with reference to the
following description and drawings below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] These and other features of the present disclosure will
become more apparent upon reference to the drawings wherein like
numbers refer to like parts throughout and wherein:
[0014] FIG. 1 is a block diagram of a composite structure
incorporating one or more materials printed onto the reinforcing
fibers formed of a first material and which may be configured as
fiber tows, unidirectional tape, and/or woven fabric;
[0015] FIG. 2 is a perspective view of a composite layup including
a stack of unidirectional plies upon which one or more materials
may be printed to improve the properties of the composite
structure;
[0016] FIG. 3 is a top view of a portion of a length of a
unidirectional tape taken along line 3 of FIG. 2 and illustrating a
printed pattern of a second material (and/or a third material, a
fourth material, etc.) printed onto the unidirectional tape in the
form of an array of dots to improve the tack of the unidirectional
ply;
[0017] FIG. 4 is a top view of a portion of a length of a
unidirectional tape showing an example of a second material printed
onto the unidirectional tape in the form of perpendicular lines
oriented transverse to a lengthwise direction of the unidirectional
tape and facilitating anisotropic conductivity in the composite
structure and/or to facilitating crack termination in the composite
structure;
[0018] FIG. 5 is a top view of a portion of a length of a
unidirectional tape showing an example of a second material printed
onto the unidirectional tape in the form of cross-hatch patterns to
facilitate crack arresting in the composite structure;
[0019] FIG. 6 is a top view of a portion of a length of a
unidirectional tape showing an example of a second material (and/or
a third material, a fourth, material, etc.) printed onto the
unidirectional tape in the form of a combination of curves;
[0020] FIG. 7 is a perspective view of a portion of a length of a
reinforcing filament of a fiber tow and illustrating a sizing
(e.g., a surface coating) that may be optionally included with the
reinforcing filament;
[0021] FIG. 8 is a cross-sectional view of a unidirectional tape
taken along line 8 of FIG. 3 and showing an example of the
distribution of a second material printed onto a top surface of the
unidirectional tape;
[0022] FIG. 9 is a cross-sectional view of a unidirectional tape
showing an example of the distribution of a second material printed
onto the top surface and the bottom surface of the unidirectional
tape;
[0023] FIG. 10 is a cross-sectional view of a unidirectional tape
showing an example of a second material of a printed pattern
directly contacting both of the adjacent composite plies of a
composite structure;
[0024] FIG. 11 is a cross-sectional view of the composite layup
illustrating a pair of adjacent composite plies of unidirectional
tape having the same fiber orientation and showing an example of
contact between the printed pattern of second material on each one
of the composite plies;
[0025] FIG. 12 is a cross-sectional view of a unidirectional tape
of adjacent composite plies and showing a printed pattern of second
material directly contacting on one composite ply and mechanically
engaging the printed pattern of second material on an adjacent
composite ply;
[0026] FIG. 13 is a cross-sectional view of a portion of a
composite layup illustrating several adjacent composite plies of
unidirectional tape having different fiber orientations and showing
a second material directly contacting the adjacent composite plies
and further showing a second material deposited between the sides
of adjacent unidirectional tapes;
[0027] FIG. 14 is a schematic illustration of an example of a
system for printing a printed pattern of second material onto a
fiber tow;
[0028] FIG. 14A is a schematic illustration of print media taken
along line 14A of FIG. 14 and showing the print media made up of
particulates;
[0029] FIG. 14B is a schematic illustration of the print media made
up of filament strands;
[0030] FIG. 14C is an enlarged view of a tip of the deposition head
taken along line 14C of FIG. 14 and showing pixels being formed on
a fiber tow;
[0031] FIG. 15 is a schematic illustration of an example of a
robotic device for automated printing of a printed pattern of
second material onto a composite layup;
[0032] FIG. 16 is a schematic illustration of an example of a
system for printing a printed pattern of second material onto a
woven fabric or unidirectional tape;
[0033] FIG. 17 is a schematic illustration of an example of a
robotic device for automated printing of a printed pattern of
second material onto a woven fabric, and/or unidirectional tape
[0034] FIG. 18 is a flowchart illustrating one or more operations
that may be included in a method of applying a printed pattern of
second material onto a fiber tow, woven fabric, and/or
unidirectional tape;
[0035] FIG. 19 is a flowchart illustrating one or more operations
that may be included in a method of printing a printed pattern
using a system shown in FIGS. 14-17;
[0036] FIG. 20 is a flowchart illustrating one or more operations
that may be included in a method of printing a printed pattern onto
one or more composite plies during layup on a preform tool.
DETAILED DESCRIPTION
[0037] Referring now to the drawings wherein the showings are for
purposes of illustrating various embodiments of the disclosure,
shown in FIG. 1 is a block diagram of a composite structure 100.
The composite structure 100 may be formed as a composite layup 102
or composite laminate 104 including a plurality of composite plies
106. The composite plies 106 may include reinforcing fibers 114
embedded within resin 112. The reinforcing fibers 114 may be made
up of a plurality of reinforcing filaments 116. In some examples,
the reinforcing filaments 116 may include a sizing 138 (see, e.g.,
FIG. 7) or protective coating which may be applied to the filament
surface 118 of the reinforcing filaments 116 during manufacturing
of the reinforcing filaments 116. The sizing 138 may be a surface
finish that may be deposited in a uniform or non-uniform sizing
thickness 140 (FIG. 7) onto the reinforcing surface along the
length of the reinforcing filament 116. The sizing 138 may improve
the adhesion between the reinforcing filaments 116 and the resin
112 and/or may protect the reinforcing filaments 116 from breakage
during processing such as during weaving and/or prepregging
operations. The reinforcing filaments 116 may be formed of a first
material 120 such as carbon material or non-carbon material.
[0038] Advantageously, in the present disclosure, one or more
modifier materials (e.g., a second material, a third material, a
fourth material, etc.) may be applied to one or more reinforcing
filaments 116, fiber tows 114, unidirectional tapes 132 (FIG. 2),
unidirectional sheet, woven fabric 134 (FIG. 16), braided fabric,
non-crimp fabrics, composite plies or preforms, or any one of a
variety of other fiber forms, as a means to alter the properties of
the composite structure 100. The modifier material or second
material 202 (FIG. 4) or any number of other materials (a second
material, a third material, a fourth material, etc.) may be
systematically deposited in a predetermined printed pattern 200
along a length or width of a reinforcing filament, fiber tow 114,
unidirectional tape 132, unidirectional sheet, woven fabric 134,
composite ply 106, or other fiber form such that at least one of a
length 204, a width 206, and a thickness 208 of the second material
202 varies across a surface of the reinforcing filament, fiber tow
114, unidirectional tape 132, unidirectional sheet, woven fabric
134, or other fiber form.
[0039] In some examples, the second material 202 may be applied to
fiber forms (e.g., tows, tape, fabric) containing reinforcing
filaments 116 (FIG. 2) that lack sizing 138. In other examples, the
second material 202 may be applied over the sizing 138 of the
reinforcing filaments 116, fiber tows 114, tape, woven fabric 134
(FIG. 16), or other fiber forms. The printed modifier material or
second material 202 may be different than the first material 120 of
the reinforcing filaments 116. The second material 202 (e.g., the
modifier material) may be systematically deposited (e.g.,
three-dimensionally printed) in a precisely-controlled printed
pattern 200 along a length and/or width of one or more reinforcing
filaments 116, fiber tows 114 (FIG. 2), unidirectional tape 132,
woven fabric 134, or other fiber forms of a composite layup 102 to
alter the properties of a composite structure 100. The second
material 202 may be printed as print media 264 (FIG. 14A) in the
form of inks, granules, particulates 266, filament strands 268, and
extrusion media.
[0040] The second material 202 may be applicable to or printed by
other manufacturing techniques including, but not limited to, hand
application/printing, spray coating, fused deposition molding,
lithography, stereolithography, flexography, dry transfer, laser
sintering, selective heat sintering, plaster-based 3D printing,
layer-by-layer deposition, inkjet printing, chemical/thermal
binding and extrusion to position. The second material 202 (FIG. 4)
may include one or more of organic monomers, prepolymers, polymers,
metallic powders, inorganic fillers, and an aqueous or
solvent-based solution. The second material 202 may also include
fillers or secondary phases such as nano-silica, block copolymers,
graphene platelets, carbon nanotubes, and other types of material.
Advantageously, the printed pattern 200 may be provided in a
hierarchical structure within the composite laminate 104 (FIG. 2)
to achieve specific functionality or performance improvements in
the composite structure 100.
[0041] In one example, a second material 202 may contain polymer
nanoparticles (not shown) that provide at least one of increased
toughness, increased flammability resistance, increased electrical
conductivity, reduced cure-shrinkage-related distortion, reduced
heat-of-reaction-related distortion, and/or reduced
heat-of-reaction-related resin degradation. The polymer
nanoparticles may be made from the same materials as the resin or
at least one of thermoplastic material, acrylics, fluorocarbons,
polyamides, polyolefins, polyesters, polycarbonates, polyurethanes,
polyaryletherketones, polyetherimides, thermosetting material,
polyurethanes, phenolics, polyimides, sulphonated polymer
(polyphenylene sulphide), a conductive polymer (e.g., polyaniline),
benzoxazines, bismaleimides, cyanate esthers, polyesters, epoxies,
and silsesquioxanes. The polymer nanoparticles may also have at
least one of the following properties: be at least partially
soluble, have a core-sheath configuration, have a nanoparticle cure
shrinkage less than the resin cure shrinkage, a nanoparticle CTE
different than the resin CTE, a nanoparticle heat of reaction lower
than the resin heat of reaction, a greater distortion capability
than the resin, release either a catalyst or a hardener during a
resin curing process, and the catalyst or hardener may alter a
reaction rate of the resin 112.
[0042] Any number of modifier materials (e.g., a second material
202, a third material 212, a fourth material. etc.) may be printed
onto any one of a variety of the above-mentioned fiber forms (e.g.,
filaments, fiber tows, tape, and/or woven fabric, etc.) in a
highly-controlled manner. For example, a second material 202 (FIG.
4) may be printed on the nano-scale to meso-scale (e.g., 10.sup.-9
mm to 10.sup.-3 mm) onto one or more fibers 114 forms as a
precisely-defined structural and/or functional modifier or additive
for a fiber-reinforced composite laminate structure. Printing of
the second material 202 allows for a relatively high degree of
positional accuracy and hierarchical control of the print media 264
(e.g., the second material 202). In some examples, the second
material 202 may be printed such that the length 204, the width 206
(FIG. 4), and/or the thickness 208 of the second material 202 is
within the range of approximately 0.01 to 100 microns.
Advantageously, the length 204, the width 206, and the thickness
208 of the second material 202 may be controlled in a highly
precise manner to provide the desired functionality improvements to
specific locations of a composite structure 100 (FIG. 1). For
example, the deposition (e.g., the printing) of the second material
202 may improve the crack-resistance, interlaminar shear strength,
electrical conductivity, and/or corrosion resistance of a composite
structure, and/or the second material 202 may increase the tack of
the composite plies 106 in a composite layup 102, as described in
greater detail below.
[0043] FIG. 2 shows an example of a composite structure 100 formed
as a laminated stack of unidirectional plies 110. Each one of the
unidirectional plies 110 may include a plurality of parallel fiber
tows 114 laid side-by-side. In the example shown, the fibers 114 in
one composite ply 106 may be oriented non-parallel to the fibers
114 in an adjacent composite ply 106 (e.g., above or below) in the
stack. However, one or more of the composite plies 106 may include
fibers 114 that are oriented parallel to the fibers 114 in an
adjacent composite ply 106. As indicated above, the reinforcing
filaments 116 or fibers 114 may be formed of a first material 120.
In one example, the first material 120 (FIG. 1) may be carbon or
graphite. However, in other examples, the reinforcing filaments 116
or fibers 114 may be formed of non-carbon material. For example,
the fibers 114 may be formed of boron, glass, ceramic, metallic
material, and/or any other type of fiber material.
[0044] The fibers 114 in each one of the unidirectional plies 110
may be provided as parallel fibers 114 of unidirectional tape 132
or unidirectional sheet (not shown). Each one of the composite
plies 106 (FIG. 2) may include a plurality of continuous fiber tows
114. A single fiber tow 114 may include a bundle of several
thousand reinforcing filaments 116 (e.g., 1000 to 100,000 or more
reinforcing filaments) bundled together. In some examples, a
reinforcing filament may have a filament cross-sectional width or
diameter of 5-30 microns. For example, a carbon reinforcing
filament may have a filament cross-sectional width of approximately
5-7 microns. Glass reinforcing filaments may have a filament
cross-sectional width of 10-25 microns. Although not shown,
composite fibers 114 in the present disclosure may also encompass
chopped fibers 114 as may be incorporated into a fiber mat. In this
regard, composite fibers 114 of the present disclosure may also be
provided in any one of a variety of other fiber configurations, and
are not limited to the fiber configurations disclosed herein. In
the present disclosure, the terms reinforcing filament, fiber,
fiber tow, and composite fiber may be used interchangeably.
[0045] In some examples, a composite structure 100 may be formed of
composite plies 106 that may be pre-impregnated with resin 112
(e.g., prepreg composite plies) which may be formed of prepreg
fiber tows 114 (FIG. 2), prepreg unidirectional tape 132, and other
forms of prepreg. Alternatively, a composite structure 100 may be
formed as a dry fiber preform 136. For example, a composite
structure 100 (FIG. 2) may be formed by laying up dry composite
plies 106, fiber tows 114, dry unidirectional tape 132 (FIG. 4),
dry fiber sheets, dry woven cloth, fabric, and/or other forms of
dry fiber. The dry fiber forms may be arranged in a stack of
composite plies 106 onto which the second material 202 may be
printed after which resin 112 may be infused in a wet layup
process.
[0046] In any one of the examples disclosed herein, the resin 112
and/or the reinforcing filaments 116 may be formed from
thermoplastic material or thermosetting material. Thermoplastic
material may include at least one of the following: acrylics,
fluorocarbons, polyamides, polyethylenes, polyesters,
polypropylenes, polycarbonates, polyurethanes, polyarylether
ketones, polyetheretherketone, polyetherketoneketone, and
polyetherimides. Thermoset material may include one of the
following: polyurethanes, phenolics, polyimides, bismaleimides,
polyesters, epoxies, cyanate esters, polysolfones, and
silsesquioxanes. In addition, in any one of the examples disclosed
herein, the resin 112 (FIG. 2) and/or the reinforcing filaments 116
or fibers 114 (FIG. 2) may be formed from materials such as
carbons, silicon carbide, and boron. The reinforcing filaments 116
or fibers 114 may also be formed from glass such as E-glass
(alumino-borosilicate glass), S-glass (alumino silicate glass),
pure silica, borosilicate glass, optical glass, and other glass
compositions.
[0047] FIG. 3 is a top view of a portion of a length of a fiber tow
114 or unidirectional tape 132 having a printed pattern 200 in the
form of an array of dots 214 printed onto the fiber tow 114 or
unidirectional tape 132. As indicated above, the fiber tow 114 or
unidirectional tape 132 may be comprised of a bundle 122 of
continuous reinforcing filaments 116. The reinforcing filaments 116
may or may not include sizing 138 (see, e.g., FIG. 7) covering the
reinforcing filaments 116. The fiber tows 114 or unidirectional
tape 132 may be provided as dry fibers 114 or the fiber tows 114 or
unidirectional tape 132 may be provided as prepreg. The array of
dots 214 may be formed of one or more modifier materials that may
be different than the first material 120 from which the reinforcing
filaments 116 are formed. For example, the array of dots 214 may be
formed of a second material 202 which may be different than the
first material 120. Some of the dots 214 in an array of dots may be
formed of a third material 212 which may be a different composition
than the first material 120 and/or the second material 202. The
third material 212 may be printed in the same or different size
(e.g., length, width, thickness) and in the same or different
printed pattern than the second material 202. A fourth material
(not shown), a fifth material (not shown), or any number of other
materials may be printed to provide different functionality. For
example, such additional functionalities that may be provided by
the different materials may include, but are not limited to,
improved crack resistance, improved interlaminar shear strength,
increased electrical conductivity and corrosion resistance, and
improved tack in a broad range of temperatures. It should be noted
that any one of the second, third, fourth, and/or fifth or more
materials may provide any one of the above-noted functionalities.
In this regard, any number of materials may be combined in any
number of ways to provide any one or more of the above-noted
functionalities.
[0048] The array of dots 214 or any one of a variety of other
geometric configurations of one or more modifier materials may be
arranged in a printed pattern 200 (FIG. 3) to provide one or more
of a variety of different functionalities. For example, a printed
pattern 200 may be configured to provide improved tack to the
composite plies 106. One or more modifier materials may be provided
in a printed pattern 200 that may provide chemical bonding between
adjacent composite plies 106 (FIG. 2) and/or mechanical and/or
physical interlocking between adjacent composite plies 106. For
example, a modifier material may be printed on a fiber form (e.g.,
a fiber tow, unidirectional tape, woven fabric) and may bond with
the reinforcing filaments 116 as the modifier material is applied
or printed onto the fiber form by a printer 260 (FIG. 14). The
modifier material may have a tackiness that allows the modifier
material to stick to an adjacent composite ply 106. In some
examples, modifier materials may be printed with mechanical
features formed on the printed pattern 200 such as teeth 224 (not
shown) or notches that may be engageable to the reinforcing
filaments 116 (FIG. 3) of an adjacent composite ply 106. In a
further embodiment, a printed pattern 200 on one composite ply 106
may be printed with mechanical features for engaging the printed
pattern 200 of an adjacent composite ply 106, as described
below.
[0049] Furthermore, modifier materials may be selected to be
compatible with the processing temperatures of the composite layup
102. For example, modifier materials may be selected to provide
tack between composite plies 106 (FIG. 2) within a range of
temperatures from room temperature to elevated temperatures
associated with consolidation and curing of the resin 112 (FIG. 2).
The improved tack may enable dry fiber composite plies or prepreg
plies to stick together to allow for controlled handling and
stacking of the composite fiber plies into a composite layup 102
(FIG. 2). In this regard, the improved tack provided by the printed
pattern 200 may stabilize the composite plies 106 against relative
movement during stacking, vacuum bagging, resin infusion,
consolidation, and other composite processing operations.
[0050] Any one or more of a variety of printed patterns 200 may
also provide functionally in the form of improved ply bridging
between adjacent plies in a composite laminate 104 (FIG. 10). For
example, a printed pattern 200 (FIG. 10) of one or more modifier
materials may provide crack prevention or crack-arresting features
in the composite structure 100. For example, one or more modifier
materials may improve the adhesive bond between the reinforcing
filaments 116 and the resin 112 (FIG. 10). In addition, a printed
pattern 200 of one or more modifier materials may act as a
toughening mechanism which may inhibit or prevent crack initiation
or crack growth within the composite structure 100. One or more
modifier materials may be printed onto the fiber tows 114 or
unidirectional tape 132 in a precisely controlled length 204, width
206, and/or thickness 208 to bridge across the interlaminar region
108 (see e.g., FIGS. 10-13) between an adjacent pair of composite
plies 106 as described in greater detail below. The bridging of
adjacent composite plies 106 may distribute localized stress
concentrations within the composite laminate 104 and thereby
minimize and prevent crack initiation or crack growth within the
composite laminate 104.
[0051] In some examples, the printing of a modifier material in the
form of an array of dots 214 or other geometric configuration may
improve the toughness of a composite laminate 104. For example, a
printed pattern 200 (FIG. 3) of modifier material may induce a
controlled pullout, release, or detachment of modifier material
particles from reinforcing filaments 116 (FIG. 3) as a stress
release mechanism to inhibit or prevent crack formation and/or
crack growth. In another example, a modifier material may have a
composition or mechanical properties that allow for a controlled
amount of deformation of the modifier material when the composite
laminate 104 (FIG. 2) is subjected to certain types of loads (e.g.,
loads of a certain magnitude and/or direction).
[0052] In the present disclosure, a second material 202, a third
material 212, and/or any number of other modifier materials may be
systematically printed onto a fiber form (e.g., fiber tows,
unidirectional tape, woven fabric, etc.) using a deposition head
262 (e.g., see FIGS. 14-17) of a printer 260 such as a
three-dimensional ink jet printer or other printer configuration.
The process of applying one or more modifier materials onto a fiber
form may take advantage of the precision in size (e.g., length,
width, thickness) and position with which the printer deposition
head 262 may print pixels 210 (FIG. 14C) of modifier material in an
additive process to form a predetermined printed pattern 200 on a
fiber form.
[0053] A deposition head 262 of a printer 260 may be configured to
print the materials (e.g., the second material 202, third material
212, etc.) in pixels 210 (FIG. 14C) of up to 100 microns in
diameter and at a thickness of up to 100 microns. In some examples,
the size of each pixel 210 may be between approximately 0.1 to 10
microns in diameter. In other examples, each one of pixels 210 may
be applied to a fiber tow, tape, or fabric in a thickness of the
each pixel of at least approximately 0.01 microns. A succession of
pixels 210 may be printed using a printer 260 deposition head 262
(FIG. 14C) to build up a printed pattern 200 onto a fiber tow 114
or other fiber form such that the final printed pattern 200 (FIG.
13) has a precisely-controlled length 204, width 206, and thickness
208.
[0054] FIG. 4 shows a length of a unidirectional tape 132 having a
second material 202 printed in a printed pattern 200 of
perpendicular lines 216 oriented transverse to a lengthwise
direction of the unidirectional tape 132. The printed pattern 200
of perpendicular lines 216 may facilitate anisotropic electrical
conductivity along a direction parallel to the perpendicular lines
216 of the printed pattern 200. The arrangement of perpendicular
lines 216 may facilitate the transportation and/or distribution of
electrical charge through a composite structure 100 such as in the
event of a lightning strike on an aircraft. The printed pattern 200
of perpendicular lines 216 may also facilitate crack termination or
prevent crack propagation in the composite structure 100. For
example, the perpendicular lines 216 may prevent propagation of
cracks that may form in the resin 112 between reinforcing filaments
116 when a load is applied perpendicular to the lengthwise
direction (e.g., the load-carrying direction) of the reinforcing
filaments 116.
[0055] FIG. 5 shows a length of a fiber tow 114 with a printed
pattern 200 in the form of cross-hatch patterns 218 along the
length of the fiber tow 114. Similar to the perpendicular lines 216
shown in FIG. 4, a cross-hatch pattern 218 may also facilitate
crack termination or prevent crack propagation that may form and
the resin 112 (FIG. 2) of a composite structure 100. The
cross-hatch patterns 218 may also provide a pathway to assist in
distributing electrical charge through a composite structure 100.
One or more of cross-hatch patterns 218 may be printed using one or
more of the modifier materials. For example, a cross-hatch pattern
218 may be formed of a second material 202 and a third material 212
which may be different than the first material 120 from which the
reinforcing filaments 116 may be formed. The second material 202
may provide one type of functionality such as providing a
toughening mechanism to prevent crack initiation or crack growth in
the composite structure 100 (FIG. 2) during thermal cycling and/or
during certain loading conditions on the composite structure 100.
The third material 212 may provide another type of functionality to
the composite structure 100 such as improving the electrical
conductivity of the composite structure 100.
[0056] FIG. 6 shows a length of a unidirectional tape 132 with a
printed pattern 200 in the form of a combination of curves 220. The
curves 220 may be formed of one or more modifier materials as
indicated above. In this regard, the printed pattern 200 may vary
in length and width to include a combination of a variety of sizes,
shapes and configurations. For example, a printed pattern 200 may
include any combination of dots 214, lines 216 (FIG. 4),
cross-hatches 218 (FIG. 5), and/or curves 220, or any one of a
variety of other printed pattern 200 configurations.
[0057] In any example disclosed herein, any one or more modifier
materials (e.g., a second material 202, a third material 212, etc.)
may be printed onto a fiber form (e.g., reinforcing filaments,
fiber tows, unidirectional tape, woven fabric, etc.) in any one of
a variety of different printed patterns 200. A modifier material
such as a second material 202 may be systematically deposited such
that at least one of a length 204, a width 206 (FIG. 3), and a
thickness 208 (FIG. 8) of the second material 202 varies across a
surface of one or more filaments or one or more fibers 114. For
example, a second material 202 may be systematically deposited in a
printed pattern 200 along any portion of a length of a fiber tow
114, unidirectional tape 132, or woven fabric 134 (FIG. 16). In
some examples, a printed pattern 200 may be repeated along a
portion of a length of a fiber tow 114, unidirectional tape 132
(FIG. 5), or woven fabric 134. In other examples, a printed pattern
200 may be printed in a random spacing along the length of a fiber
tow 114, unidirectional tape 132, or woven fabric 134.
[0058] As may be appreciated, any one or more of a variety of
different modifier materials may be incorporated into the printed
pattern 200 (FIG. 6) to provide one or more desired functionalities
for the composite structure 100 (FIG. 2). In this regard, the
systematic deposition of the modifier material onto a fiber form of
a composite laminate may result in a composite structure 100 that
has at least one composite structure property that is altered
relative to the properties of a composite structure having
reinforcing filaments that are devoid of the modifier material. The
altered composite structure property may include toughness, volume
fraction, permeability, modulus, cure shrinkage, heat of reaction,
filament tack, flammability, and electrical conductivity, and other
types of functionalities. In some examples, a third material 212
may be systematically deposited onto one or more reinforcing
filaments 116 or other fiber forms using a deposition head 262
(FIG. 14A) of a printer 260. The result of depositing a second
material 202 and a third material 212 may be a composite structure
100 that has at least two (2) different composite structure
properties that are altered relative to the properties of a
composite structure having reinforcing filaments that are devoid of
the second and third material.
[0059] In an embodiment, one or more modifier materials may be
applied or printed onto a fiber form in one or more printed
patterns 200 (FIG. 6) to improve the interlaminar shear strength
and/or peel strength of the composite structure 100 (FIG. 2) at the
interfaces between mating composite components (not shown). For
example, a modifier material may be applied to a fiber form in a
printed pattern 200 to improve the interlaminar shear strength
and/or peel strength at an interface between a composite skin and a
composite stiffener of a resin-infused laminate structure. In
another example, one or more modifier materials may be printed onto
one or more of the fiber tows 114, unidirectional tapes 132 (FIG.
6), and/or woven fabric 134 (FIG. 16) of a laminated composite
structure 100 in a manner to locally increase or decrease the
fracture toughness, elastic modulus, and/or or strain-to-failure of
the composite structure 100 in anticipation of predicted
environmental and/or mechanical loading conditions to which the
composite structure 100 may be subjected during its service
life.
[0060] In another example, one or more modifier materials may be
applied to a fiber form in a printed pattern 200 that functions as
a corrosion barrier between a laminated composite structure and a
metallic part. In this regard, the printed pattern 200 (FIG. 6) may
act as a corrosion barrier against oxidative and/or a reduction
reactions that may occur between a carbon fiber laminate and a
metallic component such as an aluminum component. In a further
example, one or more modifier materials may be printed onto a fiber
formed to improve the flammability, smoke, and/or toxicity
characteristics of a composite structure 100 (FIG. 2).
Advantageously, in any of the examples disclosed herein, modifier
materials may be printed onto a fiber form to locally tailor the
properties of the composite laminate 104 (FIG. 2) in correspondence
with the anticipated service environment and/or loading conditions.
For example, modifier materials may be printed in a manner to alter
the modulus of elasticity at different locations within the
composite laminate 104 to accommodate the loading conditions of the
composite laminate 104. In this regard, by printing of one or more
different types, quantities, and geometric configurations of
modifier materials on fiber tows, tapes, plies, and/or woven fabric
in specific regions of a layup 102, the performance of a composite
structure 100 may be tailored to the anticipated service conditions
and operating environment of the composite structure 100.
[0061] FIG. 7 shows a portion of a length of a reinforcing filament
116 of a fiber tow 114 (FIG. 5) and illustrating a sizing 138
(e.g., a surface coating) that may be optionally included with the
reinforcing filament 116. As indicated above, the sizing 138 may be
applied during manufacturing of a reinforcing filament 116. The
sizing 138 may protect the reinforcing filament 116 from damage
such as breakage during manufacturing and/or during later
processing such as during weaving and/or layup of composite plies
106.
[0062] FIG. 8 shows a cross section of a fiber tow 114 and/or
unidirectional tape 132 formed of the plurality of reinforcing
filaments 116 of a first material 120. Also shown is a printed
pattern 200 of modifier material (e.g., a second material 202)
printed onto an outer portion of the bundle 122 of reinforcing
filaments 116. The modifier material is shown printed on a top
surface 128 of the fiber tow 114 and/or unidirectional tape 132. As
indicated above, the modifier material may be printed in a desired
thickness 208. For example, modifier material may be printed in a
thickness 208 of up to 100 microns of greater.
[0063] FIG. 9 shows a cross section of a fiber tow 114 and/or
unidirectional tape 132 formed of a plurality or bundle 122 of
reinforcing filaments 116. A modifier material (e.g., a second
material 202) may be printed in a printed pattern 200 on at least
two (2) different planes 124 associated with the bundle 122 of
reinforcing filaments 116. For example, a printed pattern 200 may
be applied to both a top surface 128 and a bottom surface 130 of
the unidirectional tape 132. The modifier material may be printed
in a distributed pattern and at a desired thickness 208 to enable
ply bridging with composite plies 106 adjacent to the top surface
128 and bottom surface 130. In addition, a printed pattern may be
applied to one or more sides of unidirectional tape (see e.g., FIG.
13).
[0064] FIG. 10 is a cross-sectional view of a composite layup 102
(FIG. 2) showing a printed pattern 200 bonding together the
unidirectional tape 132 of adjacent composite plies 106 of a
composite structure 100. The printed pattern 200 of modifier
material may be applied to the reinforcing filaments 116 of one or
both of the composite plies 106 at a depth that enables mechanical
interlocking and/or chemical interaction of the composite plies
106. In FIG. 10, the printed pattern 200 of modifier material
directly contacts and may provide improved tack with or may
adhesively bond with both of the composite plies 106. Although the
unidirectional plies 110 in FIG. 10 have the same fiber
orientation, the modifier material may directly bond adjacent
composite plies 106 having different fiber orientations. In one
example, a printed pattern 200 may vary in length, width, and
height to include any combination of geometric features (not shown)
for mechanical interlocking of plies including, but not limited to,
ball and sockets, hooks and loops, dovetail wedges and grooves,
curved peaks and troughs, bionic interlocking features, irregular
three-dimensional shapes, and any other type of geometric
feature.
[0065] FIG. 11 is a cross-sectional view of a composite layup 102
(FIG. 2) including a pair of adjacent composite plies 106 of
unidirectional tape 132. Modifier material may be printed onto each
one of the composite plies 106. The modifier material of one
composite ply 106 may be in contact with the modifier material of
the adjacent composite ply 106. The modifier materials may be
mechanically and/or chemically interlocked with one another. In any
of the examples disclosed herein, the composition of modifier
materials may be selected such that contact between the modifier
materials result in an interface with miscible or immiscible
interaction between the modifier materials.
[0066] Furthermore, any one or more modifier materials may be
soluble, partially soluble, or insoluble in the resin 112 (FIG. 2).
A soluble or partially soluble modifier material may be configured
to release catalyst or hardener during curing of the resin to
locally alter the cure properties (e.g., cure time and/or cure
temperature) of the resin. In this regard, a modifier material may
at least partially dissolve in the resin when the soluble material
reaches a predetermined temperature causing the modifier material
to progressively release catalyst or hardener into the resin, and
thereby reduce the resin cure time relative to the cure time of
resin lacking the modifier material. In addition, any one or more
modifier materials may have a heat of reaction that is lower than
the resin heat of reaction which may have the effect of locally
reducing the cure temperature to thereby reduce local thermal
distortion in the composite laminate as a result of differences in
the coefficient of thermal expansion (CTE) of the resin relative to
the CTE of the fibers 114. In a further example, any one or more
modifier materials may be porous to locally increase the strain
capability of the resin along at least one direction when the
composite structure is subjected to an external load or force.
[0067] FIG. 12 is a cross-sectional view of a composite layup 102
(FIG. 2) wherein a modifier material may be printed on each one of
the composite plies 106 to facilitate interlocking of the modifier
material of each composite ply 106. The printed pattern 200 of
modifier material on each one of the composite plies 106 may be
printed with mechanical interlocking features 222. For example, the
printed pattern 200 on one of the composite plies 106 may include
teeth 224, hooks, or other mechanical features for physically
engaging and interlocking with corresponding mechanical
interlocking features 222 that may be printed on the modifier
material of the opposing composite ply 106. In some examples, the
modifier material of one composite ply 106 in FIG. 12 may be
configured to chemically interlock with the modifier material of
the adjacent composite ply 106.
[0068] FIG. 13 is a cross-sectional view of a composite layup 102
(FIG. 2) showing several adjacent composite plies 106 of
unidirectional tape 132 having different fiber orientations.
Printed patterns 200 of modifier material may be printed on the
composite plies 106 to facilitate or enable improved tack and/or
ply bridging between the adjacent composite plies 106. A printed
pattern 200 may also be applied between the side surfaces 131 of
adjacent unidirectional tapes 132. In any one of the examples
disclosed herein, modifier materials may be printed onto one or
more fiber forms to provide any number of desired functionalities
for the composite laminate 104. For example, modifier materials may
be printed to improve the tack, electrical conductivity, corrosion
resistance, interlaminar shear strength and fracture toughness,
crack-arresting capability, thermal properties, and other
functionalities. Advantageously, the ability to precisely control
the material, size, geometry, and position of each printed pattern
200 with micro-scale accuracy in a repeatable manner may result in
an improvement of the specific performance of composite
laminates.
[0069] FIG. 14 is a schematic illustration of an example of a
system for printing a printed pattern 200 of second material 202
onto a fiber tow 114 or unidirectional tape 132 or form. In the
example shown, the system includes a bobbin 282 of fiber tow 114.
The fiber tow 114 (FIG. 13) may be dry fiber or the fiber tow 114
may be pre-impregnated with resin 112 (FIG. 2). The fiber tow 114
may be fed via feed rollers 270 into a printer bed 256. The printer
bed 256 may include a printer 260 having a deposition head 262 for
printing modifier material in a printed pattern 200 onto the fiber
tow 114. In some examples, the printer 260 may be movable along a
guide track 258 along a left-to-right direction relative to the
plane the paper as may be desirable for a pulse-printing operation
wherein a length of the fiber tow 114 may be moved into the printer
bed 256 and stopped to allow the printer 260 to apply the printed
pattern 200 onto the length of fiber tow 114. The printer 260 may
also be movable in a direction in and out of the plane of paper
while the tow is stationary within the printer bed 256. In other
examples, the printer 260 may be stationary and the fiber tow 114
may be continuously movable through the printer bed 256 while the
printer 260 continuously prints the printed pattern 200 onto the
fiber tow 114.
[0070] In FIG. 14, the printer 260 may operate in response to a
computer-readable print program 254 instructions (e.g., code) based
on a digital model 252 of the printed pattern 200. In some
examples, the digital model 252 of the printed pattern 200 may be
based on a computer-aided-design (CAD) model of the printed pattern
200 which may be generated on a computer 250 and which is shown
displayed on the screen of the computer 250. The print program 254
may provide positional control of the deposition head 262 and may
also control the size, shape, and general configuration of the
printed pattern 200 that may be printed using print media 264
(e.g., the modifier material). In some examples, the printer bed
256 may include a display 274 for observation of the progress of
printing the printed pattern 200 on a fiber tow 114 (FIG. 13).
After printing the printed pattern on a fiber tow 114, the printed
fiber tow 276 may be wound on a bobbin 282. Although not shown, the
bobbin 282 of printed fiber tow 276 may be transported to a
composite layup area wherein the fiber tow 114 may be laid up into
a composite laminate 104 in a manually layup process and/or by
using an automated tape laying machine (not shown).
[0071] FIG. 14A is a schematic illustration of an example of print
media 264 made up of particulates 266. The particulates 266 may be
provided in a generally spherical shape. However other shapes are
contemplated. FIG. 14B is a schematic illustration of print media
264 made up of filament strands 268. As indicated above, the print
media 264 (e.g., the modifier material) may include organic
monomers, pre-polymers, polymers metallic powders, inorganic
fillers, and other modifier materials. FIG. 14C is an enlarged view
of a tip of the deposition head 262 showing pixels 210 being formed
on a fiber tow 114. As mentioned above, each pixel 210 may have a
diameter of up to 100 microns or larger and may have a thickness
208 of at least approximately 0.1 microns. The deposition head 262
may print a succession of pixels 210 in order to build up a printed
pattern 200 of desired thickness 208, length 204, width 206, and
geometry.
[0072] FIG. 15 is a schematic illustration of an example of a
robotic device 272 for printing a printed pattern 200 of modifier
material onto a fiber form. In the example shown, the robotic
device 272 may include articulated arms for positioning the
deposition head 262 of the printer 260 relative to a composite
laminate 104 of unidirectional tape 132 (FIG. 13). The robotic
device 272 may control the printer 260 to print a predetermined
printed pattern 200 of modifier material on successive composite
plies 106 in a stack of a composite laminate 104. The robotic
device 272 may be operated in response to computer-readable print
program 254 instructions (e.g., code) based on a digital model 252
of the printed pattern 200, similar to the arrangement described
for the printer bed 256 of FIG. 14.
[0073] FIG. 16 is a schematic illustration of an example of a
printer bed 256 for printing a printed pattern 200 of modifier
material onto a woven fabric 134 or unidirectional tape 132 or
sheet. In the example shown, the system includes a roll 284 of
woven fabric 134 which may be dry fabric or prepreg fabric. The
woven fabric 134 may be continuously fed via feed rollers 270 into
a printer bed 256 having a printer 260 with a deposition head 262
for printing modifier material in a printed pattern 200 onto the
woven fabric 134. The printer 260 may be stationary or the printer
260 may be movable in any one of a variety of different directions
relative to the printer bed 256 similar to the above-described
arrangement of FIG. 14. After printing the printed pattern 200 onto
the woven fabric 134, the printed fiber tow 278 may be wound onto a
roll 286.
[0074] The system of FIG. 16 may optionally be operated in a pulse
mode arrangement wherein a section or length of the woven fabric
134 may be moved into the printer 260 head and the printer 260 may
be moved while depositing a printed pattern 200 on the length of
woven fabric 134, after which the printed woven fabric 278 may be
wound on a roll 286. A new length of the woven fabric 134 may be
fed into the printer bed 256 for printing. The fiber tow 114
printing system illustrated in FIG. 14 may also be operated in a
pulse mode arrangement.
[0075] FIG. 17 shows an example of a robotic device 272 for
automated printing of a printed pattern 200 of modifier material
onto a woven fabric 134 and/or unidirectional tape 132 (FIG. 16) or
sheet. The robotic device 272 may be operated in a manner similar
to that described above for FIG. 16. In this regard, the print
program 254 may cause a robotic device 272 to position the printer
260 relative to the composite layup 102 while the deposition head
262 is controlled to print the predetermined printed pattern
200.
[0076] FIG. 18 is a flowchart illustrating one or more operations
that may be included in a method 300 of applying a pattern of
second material 202 (FIG. 4) onto a fiber tow 114 (FIG. 4), woven
fabric 134 (FIG. 16), and/or unidirectional tape 132 (FIG. 4). Step
302 of the method 300 may include providing a plurality of
reinforcing filaments 116 (FIG. 4) formed of a first material 120.
As indicated above, the plurality of reinforcing filaments 116 may
be provided as fiber tows, unidirectional tape, woven fabric, or
other fiber forms.
[0077] Step 304 of the method 300 may include printing a second
material 202 onto the plurality of reinforcing filaments 116 using
a deposition head 262 of a printer 260. For example, FIGS. 14 and
16 illustrate a system including a printer 260 of a printer bed 256
for positioning the deposition head 262 relative to the fiber form.
FIGS. 15 and 17 illustrate a robotic device 272 having articulated
arms for positioning the deposition head 262 of a printer 260
relative to a composite laminate 104. In some examples, the
deposition head 262 may be moved or positioned based on
programmable code of a print program 254 that may be derived from a
digital model 252 (computer-aided-design model) of a predetermined
printed pattern 200 generator on a computer 250.
[0078] As may be appreciated, alternative systems may be
implemented for printing a modifier material onto a fiber form. The
printing of the modifier material may occur during fabrication of
one or more forms a reinforcing filament 116 (FIG. 8) such as
during fabrication of fiber tows 114 (FIG. 8), unidirectional tape
132 (FIG. 9), woven fabric 134, and/or fiber preforms 136. The
printing of the modifier material may be performed by moving a
printer deposition head 262 relative to a fiber preform 136 (FIG.
2) containing the plurality of reinforcing filaments 116 and/or by
printing the second material 202 (FIG. 13) onto the fiber perform
during layup of the fiber preform 136.
[0079] In some examples, the printed pattern 200 may be formed of a
modifier material that has a length 204, a width 206, and/or a
thickness 208 of approximately 0.01 to 500 microns. In some
examples, the second material 202 may be printed in a predetermined
printed pattern 200 on an outer portion 126 of the plurality of
reinforcing filaments 116. For example, FIGS. 8-13 illustrate a
printed pattern 200 deposited onto a top surface 128 and/or a
bottom surface 130 of fiber tows 114, unidirectional tape 132. As
indicated above, the modifier material (e.g., print media) may be
provided in any one of a variety of different sizes, shapes,
materials, and configurations, including, but not limited to,
particulates 266 and/or filament strands 268 as respectively shown
in FIGS. 14A and 14B.
[0080] In one example, the printing of the second material 202
(FIG. 1) may include the targeted placement of the second material
202 in resin-rich pockets (not shown) at divots and/or
intersections of the fiber tows of woven fabric or between plies
and/or tapes. In one embodiment, during the process of laying up
composite plies of a woven fabric or prepreg, polymer nanoparticles
(not shown) may be placed into the resin-rich pockets such as at
the divots and/or intersections of the fiber tows of the woven
fabric to prevent microcracking or stress cracking resulting from
changes in temperature of the composite structure 100.
[0081] FIG. 19 is a flowchart illustrating one or more operations
that may be included in a method 400 of printing a printed pattern
200 onto a fiber form using one of the systems schematically
illustrated in FIG. 14-17. Step 402 of the method may include
providing the fiber form to be printed such as fiber tow 114, woven
fabric 134, or unidirectional tape 132. Step 404 may include
loading the fiber tow 114 onto a bobbin, or loading woven fabric
134 or unidirectional tape 132 on a roll. Step 406 may include
transferring the fiber tow 114 or woven fabric 134 to a printer bed
256 as shown in FIGS. 14 and 16, or positioning a printer 260 of a
robotic device 272 over the fiber tow 114, unidirectional tape 132,
or woven fabric 134 as shown in FIGS. 15 and 17.
[0082] Step 408 of the method 400 may include providing print media
264 for printing onto the fiber tow 114, woven fabric 134, or
unidirectional tape 132. Step 410 may include loading the print
media 264 into a printer 260 as shown in FIGS. 14-17. Step 412 may
include designing a printed pattern 200 to be printed onto a fiber
form. For example, a computer 250 may be used to create a digital
model 252 of a printed pattern 200. Step 416 may include creating a
numerical control (N/C) three-dimensional print program 254 (e.g.
code) based on the digital model 252. The print program 254 may
include instructions regarding the length, width, height, and/or
geometry with which the modifier material is to be printed onto the
fiber form.
[0083] Step 418 may include running the print program 254 to
operate a printer of a printer bed 256 (FIGS. 14 and 16) or a
robotic device 272 (FIGS. 15 and 17). Step 420 may include printing
the printed pattern 200 onto the fiber tow 114, woven fabric 134,
or unidirectional tape 132. As indicated above, the fiber form may
be passed through the fiber bed on a continuous basis or on a pulse
basis while the deposition head 262 prints the printed pattern 200
onto the fiber form. Alternatively, the fiber form may be
stationary as shown in FIGS. 15 and 17, and the robotic device 272
may move the deposition head 262 to print the printed pattern 200
onto a composite laminate 104. Step 422 may include loading the
printed fiber tow/tape or printed woven fabric 134 onto a
respective bobbin 282 or roll 286.
[0084] The method may include transporting the bobbin 282 or roll
286 to a layup area (not shown) and laying up the printed fiber
form into a composite laminate 104. The printed fiber form may
include prepreg fibers containing the printed pattern 200 (FIG. 14)
and arranged in a stack. Heat may be applied to the stack to reduce
the viscosity of the prepreg resin causing the resin of adjacent
composite plies 106 (FIG. 13) to intermingle. The resin may be
allowed to cure and/or harden into a solidified state after which
the resin may be passively or actively cooled to form the composite
structure 100. Alternatively, the printed fiber form may be dry
fibers containing the printed pattern 200 and which may be arranged
in a stack. Liquid resin may be infused into the stack and heat
and/or pressure may be applied to consolidate and cure and/or
harden into a solidified state after which the resin 112 (FIG. 2)
may be passively or actively cooled to form the composite structure
100.
[0085] FIG. 20 is a flowchart illustrating one or more operations
that may be included in a method 500 of printing one or more
printed patterns 200 onto one or more composite plies 106 during
layup on a preform tool (not shown). Step 502 of the method may
include providing print media 264 and a print program 254 to one or
more robotic devices 272 in a manner similar to that described with
regard to FIG. 19. For example, the print media 264 may be loaded
into the deposition head 262 of a robotic device 272 similar to the
robotic device 272 shown in FIG. 17. A printed pattern 200 may be
designed such as by using a computer aided design program to create
a digital model 252 (FIG. 17) of the printed pattern 200 which may
be transformed into a numerical control (N/C) three-dimensional
print program 254 (e.g. code) and loaded into the robotic device
272.
[0086] Step 504 of the method 500 may include providing a preform
tool (not shown) upon which one or more composite plies 106 may be
laid up. For example, prepreg or dry fiber composite plies 106 may
be precut to the approximate shape of a final composite structure
100 to be manufactured. One or more of the composite plies 106 may
be laid up onto the preform tool during Step 506 of the method
500.
[0087] Step 508 of the method 500 may include activating the
robotic device 272 to cause the deposition head 262 to print the
printed pattern 200 onto the composite ply 106. As indicated above,
the deposition head 262 may be configured to apply or print any
number of different materials in any number of different patterns
200 onto any portion of a composite ply 106. For example, a second
material may be printed onto the composite ply 106 to provide a
specific functionality such as increased toughness for improved
crack resistance in the final composite structure. A third
material, fourth material, and any number of additional materials
may be printed onto a composite ply 106 in any number of printed
patterns 200 to provide specific functionalities such as improved
interlaminar shear strength, increased electrical conductivity and
corrosion resistance, improved tack in a broad range of
temperatures, or any number of other functionalities, without
limitation.
[0088] After completing the printing onto a composite ply 106, one
or more additional composite plies 106 may be laid up over a
previously-printed composite ply 106, and the deposition head 262
of the robotic device 272 may print another printed pattern 200
onto the newly-laid composite ply 106. Step 510 of the method may
include repeating the layup Step 506 and the printing Step 508
until the desired number of composite plies 106 have been laid up
and/or printed. Advantageously, the above-method allows for a high
degree of precision and flexibility in applying printed patterns
200 to specific regions of a composite layup 102 using any number
of different types of printed media or material (e.g., a second
material, a third material, etc.).
[0089] Illustrative embodiments of the disclosure may be described
in the context of a method (not shown) of manufacturing and/or
servicing an aircraft, spacecraft, satellite, or other aerospace
component. Pre-production, component manufacturing, and/or
servicing may include specification and design of aerospace
components and material procurement. During production, component
and subassembly manufacturing, and system integration of aerospace
components takes place. Thereafter, the aircraft, spacecraft,
satellite, or other aerospace component may go through
certification and delivery in order to be placed in service.
[0090] In one example, aerospace components produced by the
manufacturing and servicing method may include an airframe with a
plurality of systems and an interior. Examples of the plurality of
systems may include one or more of a propulsion system, an
electrical system, a hydraulic system, and an environmental system.
Any number of other systems may be included. Although an aerospace
example is shown, different illustrative embodiments may be applied
to other industries, such as the automotive industry.
[0091] Apparatuses and methods embodied herein may be employed
during at least one of the stages of an aerospace component
manufacturing and/or servicing method. In particular, a composite
structure 100 (e.g., FIG. 1), a coating, an injection-molded
plastic, and/or an adhesive may be manufactured during any one of
the stages of the aerospace component manufacturing and servicing
method. For example, without limitation, a composite structure may
be manufactured during at least one of component and subassembly
manufacturing, system integration, routine maintenance and service,
or some other stage of aircraft manufacturing and servicing. Still
further, a composite structure may be used in one or more
structures of aerospace components. For example, a composite
structure may be included in a structure of an airframe, an
interior, or some other part of an aircraft, spacecraft, satellite,
or other aerospace component.
[0092] Additional modifications and improvements of the present
disclosure may be apparent to those of ordinary skill in the art.
Thus, the particular combination of parts described and illustrated
herein is intended to represent only certain embodiments of the
present disclosure and is not intended to serve as limitations of
alternative embodiments or devices within the spirit and scope of
the disclosure.
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