U.S. patent application number 15/557052 was filed with the patent office on 2018-02-15 for systems and methods for the transfer of color and other physical properties to fibers, braids, laminate composite materials, and other articles.
The applicant listed for this patent is DSM IP Assets B.V.. Invention is credited to Christopher Michael Adams, Roland Joseph Downs, Jon Michael Holweger.
Application Number | 20180044852 15/557052 |
Document ID | / |
Family ID | 54783399 |
Filed Date | 2018-02-15 |
United States Patent
Application |
20180044852 |
Kind Code |
A1 |
Downs; Roland Joseph ; et
al. |
February 15, 2018 |
SYSTEMS AND METHODS FOR THE TRANSFER OF COLOR AND OTHER PHYSICAL
PROPERTIES TO FIBERS, BRAIDS, LAMINATE COMPOSITE MATERIALS, AND
OTHER ARTICLES
Abstract
A method of transferring a dye to a fiber, braid or composite
material comprising applying the dye to a transfer paper to create
a dye transfer paper, placing the colored transfer media into
contact with the fiber, braid or composite material over an
expandable rig or expanding structure such as a metal tube, and
applying at least one of heat, pressure, or vacuum to infuse the
dye to the fiber, braid or composite material, creating a colored
fiber, braid or composite material having minimal to no adverse
changes to the physical properties of the fiber, braid or composite
material.
Inventors: |
Downs; Roland Joseph; (Mesa,
AZ) ; Adams; Christopher Michael; (Mesa, AZ) ;
Holweger; Jon Michael; (Queen Creek, AZ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
DSM IP Assets B.V. |
Heerlen |
|
NL |
|
|
Family ID: |
54783399 |
Appl. No.: |
15/557052 |
Filed: |
March 25, 2016 |
PCT Filed: |
March 25, 2016 |
PCT NO: |
PCT/IB2016/000919 |
371 Date: |
September 8, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62138849 |
Mar 26, 2015 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
D06P 5/2033 20130101;
D06P 5/003 20130101; D06P 7/005 20130101; D06P 5/2005 20130101;
D06P 5/2066 20130101; D06P 5/2055 20130101; D06P 3/79 20130101;
D06P 5/004 20130101 |
International
Class: |
D06P 5/28 20060101
D06P005/28; D06P 5/20 20060101 D06P005/20; D06P 3/79 20060101
D06P003/79 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 1, 2015 |
EP |
15197399.7 |
Claims
1) A method of transferring a dye to a fiber, braid or composite
material, the method comprising: applying the dye to one side of a
transfer media to create a dye transfer media; wrapping the dye
transfer media onto an expandable rig or expanding structure such
that the dye side of the dye transfer media remains exposed;
wrapping said fiber, braid or composite material over the dye
transfer media; and applying at least one of heat, external force,
external pressure and vacuum pressure to infuse the dye to the
fiber, braid or composite material to create a colored fiber, braid
or composite material.
2) The method of claim 1, further comprising expanding the
expandable rig to pre-tension said fiber, braid or composite
material prior to said step of applying at least one of heat,
external force, external pressure and vacuum pressure.
3) The method of claim 1, wherein said expanding structure
comprises a tube having a coefficient of thermal expansion between
5.times.10.sup.-6/K and 30.times.10.sup.-6/K, whereby a temperature
increase of at least 10.degree. C. is applied in the method.
4) The method of claim 3, wherein said tube comprises glass, metal,
granite, concrete or quartz.
5) The method of claim 4, wherein said metal comprises aluminum,
copper, pure iron, cast iron, lead, nickel, palladium or stainless
steel.
6) The method of claim 1, wherein said fiber, braid or composite
material comprises UHMWPE fibers.
7) The method of claim 1, further comprising cooling the fiber,
braid or composite material to a temperature such that the fiber,
braid or composite material maintains a desired shape.
8) The method of claim 1, further comprising curing the dye, by
applying at least one ultraviolet or electron beam radiation, to
the fiber, braid or composite material.
9) The method of claim 1, further comprising adding a coating to
the fiber, braid or composite material.
10) The method of claim 1, further comprising adding a film to the
fiber, braid or composite material.
11) The method of claim 1, further comprising adding a nylon
coating and a urethane coating to the fiber, braid or composite
material.
12) The method of claim 1, wherein the composite material is at
least one of a non-woven and woven material.
13) The method of claim 1, wherein the transfer media is at least
one of transfer paper, transfer laminate, or transfer film.
14) The method of claim 1, wherein the dye is applied to the
transfer media in the shape of a pattern, graphic or logo, and
wherein the colored fiber, braid or composite material is infused
with a matching pattern, graphic or logo, respectively.
15) The method of claim 1, further comprising adding an additional
layer of dye transfer media onto said fiber, braid or composite
material prior to said step of applying at least one of heat,
external force, external pressure and vacuum pressure.
16) A method of transferring a dye to a fiber, the method
comprising: applying the dye to one side of a transfer media to
create a dye transfer media; wrapping the dye transfer media onto
an expandable rig such that the dye side of the dye transfer media
remains exposed; winding said fiber over the dye transfer media;
expanding said expandable rig to pre-tension said fiber at
20.degree. C. to a force of 1-30% of the break strength of said
fiber; and applying at least one of heat, external force, external
pressure and vacuum pressure to infuse the dye into the fiber to
create a colored fiber.
17) The method of claim 16, wherein said fiber comprises
UHMWPE.
18) The method of claim 17, wherein said step of applying at least
one of heat, external force, external pressure and vacuum pressure
comprises heating to between 275 and 280.degree. F.
19) A method of transferring a dye to a fiber, the method
comprising: applying the dye to one side of a transfer media to
create a dye transfer media; wrapping the dye transfer media onto a
tube such that the dye side of the dye transfer media remains
exposed, said tube having a coefficient of thermal expansion
between 5.times.10.sup.-6/K and 30.times.10.sup.-6/K and an ID
approximately 20 times the wall thickness; winding said fiber
around side tube over the dye transfer media; and applying at least
one of heat, external force, external pressure and vacuum pressure
to infuse the dye into the fiber to create a colored fiber, whereby
a temperature increase of at least 10.degree. C. is applied in the
method.
20) The method of claim 19, wherein said fiber comprises UHMWPE and
said tube comprises aluminum.
Description
BACKGROUND OF THE INVENTION
[0001] This invention relates to providing a system and method
relating to coloring individual fibers, braids and laminate
materials generally.
[0002] In the textile fibers industry, the coloration of fibers is
a requirement for a large number, if not a majority of military,
commercial, apparel, industrial, medical and aerospace
applications. However, laminated reinforced materials are plain in
color and not conducive to being dyed or colored. One known
technique for adding color to laminated material is to paint the
material. However, painting the material has the downside of the
paint flaking off through use and fading in sunlight over time.
These drawbacks can be very pronounced in flexible laminate
material. In another prior art embodiment, laminated reinforced
materials are combined with additional layers of films or other
materials to produce a fiber reinforced flexible fabric. The other
additional materials may include a more traditional woven cloth
that is capable of being dyed. Materials of this type are generally
found in applications requiring high performance and visual or
cosmetic appearance is secondary. The typical accepted appearance
is plain, as manufactured, and/or lacking visual coloration,
patterns, or graphics.
[0003] Ultra-high molecular weight polyethylene (UHMWPE) fibers
have been traditionally available in one and only one color, namely
translucent white. Such fibers are sold, for example, under the
brand names Dyneema.RTM. and Spectra.RTM.. Limitation of UHMWPE
fibers to only one shade of white has limited the suitability of
UHMWPE fibers in many areas where it otherwise has applicability
but cannot meet the requirements for an end use product that needs
a color other than white to meet necessary product requirements or
specifications.
[0004] Past attempts at dyeing or colorizing UHMWPE fibers, such as
Dyneema.RTM. or Spectra.RTM. fiber, have been largely unsuccessful
due to an inability to coat the fiber surface with a durable,
colorfast finish resistant to abrasion, environmental exposure,
washing, or chemical degradation. A lack of adhesion and/or
colorfastness of dye or colorant is especially problematic in
applications where the breakdown of the coloration and possible
transfer to other surfaces or to the environment can cause
contamination, discoloration or, in the case of medical
applications, toxicity, infection or a breakdown of engineered
surface properties such as surface tension, coefficient of
friction, lubricity and wettability.
[0005] Attempts to add colorant into the polyethylene polymer
precursor before spinning and drawing operations have also been
unsuccessful primarily due to a unacceptable drop in mechanical
properties of often greater than 50% due to chain scission and
polymer degradation or interaction effects between the polymer and
colorant, but also because of processing difficulties, supply chain
issues and manufacturing complexity of having to support multiple
colored variants of precursor polymers and cleaning and re-setup of
equipment for runs and different colored fibers. Even with
extensive down time for cleaning, it's very difficult to avoid
cross contamination between different runs of varying colors of
fibers.
[0006] Thus, it is desirable to produce colored fibers, braids and
laminated reinforced materials that are colored or colorable,
patterned, or enriched with other physical properties, such as
resistance to fading.
SUMMARY OF THE INVENTION
[0007] In various embodiments of the present disclosure, dye
sublimation coloring techniques are used for the coloration of
UHMWPE materials. In various aspects, the UHMWPE material comprises
any one of a fiber, a braid, and a laminate composite material. For
example, the UHMWPE material colored per the methods herein may
comprise drawn UHMWPE fibers made through gel spun technology, such
as Dyneema.RTM. fibers. Coloration methods in accordance with the
disclosure allow infusion of colorant into gel spun UHMWPE fibers
themselves under controlled conditions of heat and pressure. In
addition to being an effective method of fiber coloration, various
embodiments of the dye sublimation coloration method herein can be
implemented after the fibers are spun from the polymer solution, at
many points in the fiber or braid manufacturing process, using a
wide number of readily available coating or transfer methods in a
wide range of colors. This processing flexibility enhances the
utility, practicality and economic efficiency of the process while
allowing the color to be applied at a point in the product stream
that streamlines and simplifies inventory and process flow.
[0008] More importantly, while other coloration techniques can
adversely reduce the mechanical properties of UHMWPE fibers by 50%
or more, infusion of colorant into the fibers themselves via the
dye sublimation method herein can be accomplished without
significant changes to the mechanical properties of the fibers,
such as Strength and Engineering Young's Modulus, both of which are
critical for UHMWPE fibers and a primary selling point of the
fibers.
[0009] In various embodiments of the present disclosure, UHMWPE
fibers and braids were colored with two (2) or more colors, in
multiple sections along each fiber or fiber braid, (a) without
reducing the tensile strength of the fiber/braid by more than 10%;
(b) without excessive colorant residue; and (c) using no surface
coating (just colorant/dye). In various embodiments, the method
comprises wrapping fibers around an expandable mandrel and allowing
the mandrel to expand and tension the fibers during the coloration
process.
[0010] In various aspects, a method of transferring a dye to a
composite material comprises: applying the dye to a transfer media
to create a colored transfer media; placing the colored transfer
media into contact with the composite material; and applying, such
as by using an autoclave, at least one of heat, external pressure,
and vacuum pressure to infuse the dye to the composite material to
create a colored composite material. The method may further
comprise cooling the composite material to a temperature such that
the composite material maintains a desired shape. In various
aspects, the method may further comprise curing the dye, by
applying at least one ultraviolet or electron beam radiation, to
the composite material. Also, the method may further comprise
adding a coating, (such as a polyimide), to the composite material.
Additionally, the method may further comprise adding a polyvinyl
fluoride (PVF) film to the composite material and/or nylon and/or
urethane coating to the composite material. In various embodiments,
a film is used as a color transfer medium remaining as a film
coating on a composite material after the colorization process.
[0011] In various embodiments, the composite material comprises a
non-woven material or a woven material. In various embodiments, the
composite material comprises at least one layer of woven material
and at least one layer of non-woven material. The transfer media
may comprise at least one of transfer paper, transfer laminate, or
transfer film. The dye may be applied to the transfer media in the
shape of a pattern, graphic or logo, and wherein the composite
material is infused with a matching pattern, graphic or logo,
respectively. In addition, the dye may be applied to the transfer
media using direct printing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 illustrates an exemplary embodiment of a rotary color
transfer system;
[0013] FIGS. 2A and 2B illustrate an exemplary embodiment of a
heated press color transfer system and corresponding pressure
graph;
[0014] FIG. 3 illustrates a flow chart of an exemplary heat press
process;
[0015] FIGS. 4A and 4B illustrate an exemplary embodiment of an
autoclave color transfer system and corresponding pressure
graph;
[0016] FIG. 5 illustrates a flow chart of an exemplary autoclave
process;
[0017] FIG. 6 illustrates an exemplary embodiment of a linear color
transfer system;
[0018] FIG. 7 illustrates an exemplary embodiment of a multilayered
color transfer stack;
[0019] FIG. 8 illustrates an embodiment of an expandable structure
in accordance with the present disclosure;
[0020] FIG. 9 illustrates an embodiment of an autoclave cure
schedule for fiber and braid specimens, plotted as temperature
versus time for both the autoclave temperature (.degree. F.) and
the part temperature (.degree. F.);
[0021] FIG. 10 illustrates an embodiment of an autoclave cure
schedule for fiber and braid specimens, plotted as pressure/vacuum
versus time for both the autoclave pressure (psi) and the vacuum
(psi);
[0022] FIG. 11 illustrates Spectra.RTM. fiber braid tensile test
results for as-received material;
[0023] FIG. 12 illustrates Spectra.RTM. fiber braid tensile test
results for as-received material, in plotted form;
[0024] FIG. 13 illustrates Spectra.RTM. fiber 1740 dtex braid
tensile test results on dyed material;
[0025] FIG. 14 illustrates Spectra.RTM. fiber 1740 dtex braid
tensile test results on dyed material, in plotted form;
[0026] FIG. 15 illustrates a plot of Tenacity versus Tensile Strain
for as-received Spectra.RTM. 1000, 400 denier fibers; and
[0027] FIG. 16 illustrates a plot of Tenacity versus Tensile Strain
for dyed Spectra.RTM. 1000, 400 denier fibers.
DETAILED DESCRIPTION OF THE INVENTION
[0028] While exemplary embodiments are described herein in
sufficient detail to enable those skilled in the art to practice
the invention, it should be understood that other embodiments may
be realized and that logical material, electrical, and mechanical
changes may be made without departing from the spirit and scope of
the invention. Thus, the following detailed description is
presented for purposes of illustration only.
[0029] Materials
[0030] In various embodiments, fibers, braids, fabrics, and
laminated materials are colored in accordance with the present
disclosure. Various types of fibers and braids include, for
example, Dyneema.RTM. or Spectra.RTM. brand UHMWPE materials. In
various embodiments, UHMWPE fibers are colorized and modified by
the methods according to the present disclosure. UHMWPE is a type
of polyolefin made up of extremely long chains of polyethylene.
Trade names include Dyneema.RTM. and Spectra.RTM.. UHMWPE is also
referred to in the industry as either high-modulus polyethylene
(HMPE) or high-performance polyethylene (HPPE). The molecular
weight (MW) of UHMWPE is often expressed as "Intrinsic Viscosity"
(IV), which is typically at least 4 dl/g and preferably at least 8
dl/g. Generally, the IV for UHMWPE is less than about 50 dl/g, and
preferably less than about 40 dl/g. In various embodiments, the
UHMWPE fibers comprise extruded polymer chains. In various
embodiments, the UHMWPE fibers comprise pultruded polymer
chains.
[0031] Various types of composite materials include both woven
materials and non-woven materials. In an exemplary embodiment,
woven materials comprise many low denier tows (i.e., light weight
fibers). Woven materials comprise fibers passing over and under
each other in a weave pattern that can result in some degree of
crimp in the fibers. Also, in woven materials, tensile loading
induces transverse loads at fiber overlap sections as crimped
fibers attempt to straighten. The transverse loads reduce the
translation of fiber strength to fabric strength, and decrease
long-term fatigue and creep rupture performance. In an exemplary
embodiment, higher performance engineering fibers have more
pronounced crimp-related reduction properties. This is particularly
pronounced in fibers with optimization of axial filament properties
and reduced transverse properties of the filaments.
[0032] As used herein, a composite material is defined as one or
more layers of unidirectional fiber and polymer matrix plies
oriented in one or more directions. For example, unidirectional
fibers in adjacent plies may be offset at an angle between their
directions. In contrast, in an exemplary embodiment, non-woven
composite materials use high denier tows for easier
manufacturability. Non-woven composite materials, such as felts,
comprise fibers that do not pass over and under each other and thus
do not have crimp. An advantage of non-woven composite materials is
unlimited fiber areal weights, which is the weight of fiber per
unit area. In other words, thicker fibers can be used in non-woven
materials versus woven materials. Another advantage of non-woven
composites is the ability to form composite materials from multiple
layers of fibers oriented at any angle relative to fibers in other
layers. Furthermore, in an exemplary embodiment, a non-woven
composite material is designed with optimal weight, thickness, and
strength at particular locations or along predetermined load paths
as desired. In addition, non-woven composite materials constructed
from high modulus fibers can have predictable and linear properties
for engineering designs.
[0033] In accordance with an exemplary embodiment, a composite
material is infused with color during the manufacturing process. In
various embodiments, the composite material comprises one or more
layers of thinly spread high strength fibers such as, for example,
UHMWPE, (commercially available as, e.g. Dyneema.RTM.),
Vectran.RTM.; aramid; polyester; carbon fiber; Zylon PBO, or other
materials, coated and/or embedded in a resin or other material, or
any combination thereof. A particular preferred embodiment of the
present invention relates to colorization of composite material
comprising one or more layers of thinly spread high strength UHMWPE
fibers.
[0034] In the context of the present invention, "high strength"
means a tensile strength of at least 1.5 GPa; preferably 2.5 GPa;
more preferably at least 3.6 GPa and most preferably at least 4.2
GPa. Fibers subject to colorization according to the methods
disclosed herein may be characterized by various physical
properties, in addition to characterization by particular chemical
composition. These properties, for example, relate to stretch and
strength of the fibers. Tensile properties (measured at 25.degree.
C.): tensile strength (or strength), tensile modulus (or modulus)
and elongation at break (or EAB) are defined and determined on
multifilament yarns as specified in ASTM D885M, using a nominal
gauge length of the fiber of 500 mm, a crosshead speed of 50%/min.
On the basis of the measured stress-strain curve, the modulus is
determined as the gradient between about 0.3 and 1% strain. For
calculation of the modulus and strength, the tensile forces
measured are divided by the titre, as determined by weighing 10
meters of fiber; values in GPa are calculated assuming a density of
0.97 g/cm.sup.3.
[0035] Polymers such as used for fibers, generally have an
"Intrinsic Viscosity" (IV) that can be determined according to ASTM
D1601-2004 (at 135.degree. C. in decalin), the dissolution time
being 16 hours, with DBPC as anti-oxidant in an amount of 2 g/l
solution, by extrapolating the viscosity as measured at different
concentrations to zero concentration.
[0036] Linear polymers also may be characterized by the amount of
side chains present. For example, the number of side chains in a
UHMWPE sample is determined by FTIR on a 2 mm thick compression
molded film, by quantifying the absorption of infrared radiation at
a wavelength of 1375 cm.sup.-1 using a calibration curve based on
NMR measurements (as e.g. disclosed in EP 0269151).
[0037] The infused color may appear as a solid color, a pattern, or
any type of graphic such as a picture or logo on one or both sides
of the composite material. Other possibilities include
manufacturing the composite materials to have stripes, polka dots,
figures, shapes, and the like. In an exemplary embodiment, the
laminate films and/or fabrics can also have other tints sublimating
or non-sublimating, color bases, modifiers or ultra-violet or color
stabilizers pre-incorporated to interact with, synergize, or modify
the color process.
[0038] A colorant usable for sublimation/diffusion in accordance
with the present disclosure may comprise a dye or a pigment or
combinations thereof. For example, sublimation dyes that find use
herein typically range from the following class of dyes: Acid, Vat,
Pigment, Disperse, Direct and Reactive Dyes. In various
embodiments, Disperse and Direct Dyes are preferred. These dyes are
prepared from the chemical class of organic systems that is known
as azo, anthroquinone and phthalocyanine dye systems. In other
aspects, color possibilities include pigments such as titanium
dioxide, carbon black, phthalo blue, quinacridone red, organic
yellow, phthalo green, dark yellow ocher, ercolano orange, venetian
red, burnt umber, viridian green, ultramarine blue and pewter grey.
In some embodiments of fiber, braid and composite coloring, Royal
Blue, Aqua Blue, Black, Steelhead Grey, Process Yellow, Fire Red,
Scarlet Red, Process Red, Rubine Red, Magenta, Navy Blue, Process
Blue, and Kelly Green sublimation dyes are useful, and can be used
singly or in various combinations for colored patterns. The terms
"dye" and "pigment" are used interchangeably herein to refer
generally to a colorant for the method.
[0039] In other various embodiments, composite materials can also
have various coatings added to alter various surface properties of
the material. The various coatings can be in addition to, or as
alternative to, color dyes added to the material. In a first
exemplary embodiment, a film coating is added to the material. The
specific film coating can be used to increase or decrease the
composite's tensile strength, toughness, chemical and dimensional
stability, weld-ability, gas barrier properties, electrical
properties, high temperature resistance, ultra-violet or infrared
radiation performance, and/or reduce the coefficient of friction.
In a second exemplary embodiment, a polyimide coating is added to
the composite material. The polyimide coating can alter the
electric and dielectric properties of the material. Furthermore,
the polyimide coating may be configured to increase the stability
of the material properties over a wide range of temperature. In a
third exemplary embodiment, a film, such as polyvinyl fluoride
(PVF) film (Tedlar.RTM.), is added to the composite material. Film
such as PVF film facilitates added weather durability, long term
durability, and environmental stability. Similarly, in a fourth
exemplary embodiment, nylon and urethane coatings both increase
toughness and are flexible, along with lower mechanical and
permeability properties. In other aspects, a dye transfer medium
comprises a dye coated film, which remains behind as a layer of the
composite material after the colorization process.
[0040] In accordance with an exemplary embodiment, a composite
material may be layered with woven coatings to create a composite
material hybrid. The woven coatings can be incorporated to increase
abrasion resistance. For example, a woven coating on a composite
material may comprise a Nylon woven layer. Furthermore, in an
exemplary embodiment, the composite material hybrid may be designed
to combine the various material properties of the composite
material and the coatings to result in a high strength,
dimensionally stable flexible composite material. Exemplary
applications of composite material hybrids include military
applications, such as advanced visual camouflage and/or infrared
signature reduction. Another example is use in a ballistic armor
vest.
[0041] In an exemplary embodiment, sublimation infusion is
implemented to achieve various additions to composite materials.
The additions may include, for example, color, pattern, and gloss
application, specular or infrared reflectivity modification,
anti-microbial or medicines, surface adhesion modifiers,
nano-material infusion, dielectric modifiers, the printing of
conductive metal or polymer materials to add electrical/dielectric
conductivity features or electrical circuit patterns, and/or
incorporation of fire retardant materials or synergistic components
for fire retardant materials in the laminate, surface films, or
surface fabrics. In an exemplary embodiment, ultra-violet
stabilizing or curing additives are incorporated into the material.
These additives can extend the useful life of the composite
material.
[0042] Furthermore, in various embodiments, a fire retardant
adhesive or polymer is used with the composite materials.
Furthermore, fire retardants may be added to a flammable matrix or
membrane to improve the flame resistance of the composite material.
Fire retardants may function in several ways, such as endothermic
degradation, thermal shielding, dilution of gas phase or gas phase
radical quenching. Examples of fire retardant additives include:
DOW D.E.R. 593 Brominated Resin, Dow Corning 3 Fire Retardant
Resin, and polyurethane resin with Antimony Trioxide (such as
EMC-85/10A from PDM Neptec Ltd.), although other fire retardant
additives may also be suitable as would be known to one skilled in
the art. Additional examples of fire retardant additives that may
be used to improve flame resistance include Fyrol FR-2, Fyrol HF-4,
Fyrol PNX, Fyrol 6 and SaFRon 7700, although other additives may
also be suitable as would be known to one skilled in the art. In
various embodiments, fire retardancy and self-extinguishing
features can also be added to the fibers either by using fire
retardant fibers, ceramic or metallic wire filaments, inherent fire
retardant fibers, or by coating the fibers. Examples of fire
retardant fibers include Nomex.RTM. or Kevlar.RTM.. Inherent fire
retardant fibers include fibers that have had fire retardant
compounds added directly to the fiber formulation during the fiber
manufacturing process. Furthermore, fibers may be coated with a
sizing, polymer or adhesive incorporating fire retardant compounds,
such as those described herein or other suitable compounds as would
be known to one skilled in the art. In additional various
embodiments, any woven or scrim materials used in the composite
material may be either be pretreated for fire retardancy by the
supplier or coated and infused with fire retardant compounds during
the manufacturing process. In an exemplary embodiment, ultra-violet
stabilizing or curing additives are incorporated into the composite
material. These additives can extend the useful life of the
material.
[0043] In various embodiments, the composite materials are
assembled as a multilayer composite of outer surface layers, which
may be colorized or textured, via any of the various application
methods set forth herein. The outer surface layers may be
unidirectional plies, films, non-woven fabric or felt, woven cloth,
weldable thermoplastic membranes, waterproof breathable membranes
and fabric scrims. These outer surface materials may have initial
coloring or patterning complementary to the various methods of
infusion transfer, sublimation transfer or roll transfer in order
to obtain the desired cosmetic or visual effect. Additionally, in
order to adjust the saturation, hue, opacity or light transmission
of the finished colorized materials various powder tints, colored
dyes or sublimation colorants can also be added to the bonding
adhesives or the laminating resin component of the unidirectional
ply layers. In order to further adjust the saturation, hue, opacity
or light transmission of the finished colorized materials one or
more tinted, opaque or light blocking film may be added between one
or more laminate ply interfaces.
[0044] There are several applications suitable for the composite
materials in industrial and technical textiles, apparel, sporting
goods, water sports, boating and sailing materials, sail cloth,
hunting and fishing, Balloon and Lighter Than Air vehicles,
commercial fabric, upholstery, inflatable structure, military
apparel, gear, medical or protective articles or devices, tension
structures, seismic structural reinforcement materials, banner and
signage and other flexible material or fabric applications where
the high performance, light weight, high strength, rip and tear
resistance, high flexibility, flex life, durability, weatherability
and unique characteristics of flexible composite materials are very
desirable but cosmetic or visual coloration, patterns, graphics and
other visual properties or effects are also a significant component
of the intended purpose of the material or product. Properties such
as absorption or reflection of various wavelengths of the
ultraviolet, visual, infrared or other regions of the
electromagnetic spectrum and/or surface texture or shape, gloss or
sheen, opaqueness, light transmission or blocking, or colorfastness
and fade resistance are also desirable.
[0045] Since many of these potential applications are consumer
oriented such as the apparel, outdoor, sporting goods, hunting and
fishing, water sports, boating and sailing, or medical fabrics or
textiles, which have special requirements or features such as fire
retardancy or fire resistance, anti-odor, anti-mildew or
anti-microbial resistance, water resistance and/or breathability,
chemical resistance or abrasion resistance, any combination of the
methods and materials are contemplated to fulfill the desirable
characteristics for the intended application.
Methods of Application of Color
[0046] Various methods may be implemented to facilitate the
transfer of dye to a composite material. These methods generally
are of two types of processes: continuous process and batch
process. A continuous process is one where material is unrolled at
a steady web speed or at steady stepwise stop-and-start rate. The
material is assembled, consolidated, colorized, textured and then
rewound onto a rewind roll. In batch process, the composite
material constituents and colorants are loaded into a press, vacuum
bag or autoclave and then subjected to a heating/curing
process.
[0047] In accordance with exemplary embodiments, the various
methods of dye transfer may include heat transferring from a
printed or saturated carrier; direct printing onto laminate or
surface films via ink jet or dye sublimation printer; incorporation
of dye, tint, or sublimating color or pattern directly onto or into
the composite material or matrix; heat transfer onto a composite
material or film; and bath or dipping infusion. In an exemplary
embodiment, sublimating ink is used for more resistant and
permanent coloring.
[0048] In accordance with an exemplary method, color is applied to
a composite material using a transfer carrier substrate. As an
initial step, the transfer carrier is selected, such as a film or
paper. The color applied may be a solid color or may be a pattern
or graphic, which is placed on the transfer carrier. The transfer
carrier coloring process may use at least one of an inkjet printer,
a gravure roll coater, a slot die coating head, dip bar bath
coating, anilox roll coating, knife over roll coater, reverse roll
coater, and an air knife coater. In various exemplary embodiments,
application of a solid color to the composite material may be
facilitated through direct printing or transfer onto an intended
surface, layer, or interface of the laminated material with an
autoclave, belt press, vacuum oven, and the like.
[0049] In various exemplary embodiments of direct printing,
application of a pattern or graphic to the composite material may
be facilitated through use of at least one of an inkjet printer, a
sublimation printer, flexo printer process, anilox roll printing,
and offset printing.
[0050] Whether a solid color or a pattern/graphic is transferred,
the transfer carrier substrate is in proximity to the composite
material, such that heat applied through various methods and
systems if a separate carrier is used to transfer, infuse, or
sublimate the color or pattern onto the composite material.
[0051] The various systems and processes applied to achieve the
color transfer to composite materials include a heated rotary
system, a heated press system, an autoclave system, a dye infusion
system, a heated linear color transfer system, vacuum oven and
matrix pigment tint coloring.
[0052] Heated Rotary System
[0053] In one exemplary embodiment and with reference to FIG. 1, a
rotary color transfer system 100 comprises a rotating heated roll
110, a tensioned belt 120, a roll of material to receive color 130,
and a color transfer carrier 140. Rotary color transfer system 100
is a continuous roll-to-roll process for applying color or graphics
to materials 130. The material 130 that receives the color may be
fabric, cloth, film, or laminated material. The film or fabric can
then be used in the manufacture of composite materials. For
example, rolls of finished composite materials, film or fabric
precursor may be run through rotary color transfer system 100 to
set or infuse the colors. In an exemplary embodiment, material 130
may be pre-coated or pre-printed with color before being fed
through the belt press portion of rotary color transfer system
100.
[0054] In other embodiments, color transfer carrier 140 may be film
or paper. The color transfer carrier 140 can be fed from rolls on
an unwind and processed through rotary color transfer system 100 to
transfer colors or patterns to material 130, such as film, fabrics,
and composite materials. Accordingly, tensioned belt 120 is in
contact with rotating heated roll 110. Furthermore, material 130
and color transfer carrier 140 are processed in contact with each
other and rolled between rotating heating roll 110 and tensioned
belt 120. The color can be applied to material 130 via direct
printing either in-line or off-line. An in-line process includes
applying or coating the colors or patterns to composite material,
film or fabrics, or color carrier 140 as part of the belt press
portion of rotary color transfer system 100. An off-line process
includes applying or coating the colors or patterns to laminate,
film or fabrics, or color carrier 140 as part of a separate batch
process before being set up onto the belt press portion of rotary
color transfer system 100. In an exemplary embodiment, heated
rotary belt 120 can be used in-line with a lamination process.
Moreover, the color can be transferred from color transfer carrier
140. In an exemplary embodiment, a vacuum is established between
rotating heated roll 110 and tensioned belt 120 to facilitate color
infusion and transfer. Various methods may be used to create the
vacuum as would be known to one skilled in the art.
[0055] In an exemplary embodiment, and as illustrated in FIG. 1,
color transfer carrier 140 is closest to rotating heated roll 110
and material 130 is closest to tensioned belt 120. In other
exemplary embodiment, material 130 is closest to rotating heated
roll 110 and color transfer carrier 140 is closest to tensioned
belt 120. In an exemplary embodiment, material 130 and color
transfer carrier 140 are both individual rolls that are unwound,
processed through the rotary belt process as described above, and
then rewound onto individual rolls.
[0056] Heated Press System
[0057] In accordance with an exemplary embodiment and with
reference to FIGS. 2A and 2B, a heated press color transfer system
200 comprises two plates 210 or other similar hard surface, a
material to receive the color 220, and a color carrier 230. In
another embodiment, heated press color transfer system 200 further
comprises a pressure intensifier layer 240 made from natural or
synthetic rubber. By way of example, suitable caul rubbers are
produced by Torr Technologies or Airtech International. The
pressure intensifier layer 240 is coupled to the inside at least
one of two plates 210 such that pressure intensifier layer 240 in
between two plates 210 and in contact with composite material 220
and/or color carrier 230. In an exemplary embodiment, pressure
intensifier layer 240 has at least some ability to compress. The
compression facilitates additional pressure to be applied to two
plates 210 and transferred to material 220 and color carrier 230.
In various embodiments, pressure intensifier layer 240 may have a
combination of one or more smooth mirror surfaces, smooth matte
surface, and a textured or pattern surface to provide a desired
surface gloss or texture that complements the colorants.
[0058] In an exemplary process and with reference to FIG. 3, a heat
press process 300 includes four primary steps. First, apply a color
tint/dye transfer to the color carrier, which may include composite
material with a surface film or cloth surface on one or both sides,
or may include transfer paper/film carrier (310). In various
embodiments, the film or cloth surface may incorporate a
complementary color or pre-printed pattern, image or design on one
or both sides of the laminate. Furthermore, transfer paper/film
carrier may contain solid color, one or more color patterns or
printed graphics to form an image, design, or picture.
Additionally, the transfer media may also include a smooth or
textured surface to impart a surface with a desired degree of gloss
or smoothness texture pattern on one or both sides of the colorized
surface. Second, position the color tint/dye transfer in contact
with the composite material (320). Third, apply heat and pressure
to transfer, sublimate, and/or infuse the color, graphics, textures
or patterns to the materials (330). Temperatures typically range
from about 70.degree. F. to about 650.degree. F., and pressures
range from the minimum to keep materials in intimate contact,
typically 2 psi, to a maximum of 10,000 psi. The temperature and
pressure applied depend on the particular colorant used, the
substrates the colorant is applied to, and the degree of lamination
or consolidation required. Fourth, cool the material to a
temperature such that the finished article remains flat or in the
desired shape, and such that there is no damage, distortion, or
delamination of the finished colorized material. Once the system is
at or below the removal temperature, the material and color carrier
are removed from the heated press (340).
[0059] In yet another exemplary embodiment, the heated press color
transfer system further comprises a vacuum to increase the pressure
in the process. The exemplary vacuum may be created either by
enclosing the press platens within a sealable vacuum chamber or by
enclosing the laminate in a vacuum bag system. The applied vacuum
can range from about 5 to about 29 inches of mercury (Hg). Once the
vacuum has been applied, the assembly is placed into the press such
that the press platens apply the appropriate pressure profile
during the profile of the heating cycle and cooling cycle.
[0060] Implementing a vacuum is beneficial to assist in the
sublimation colorant into the substrate, to lower the temperature
at which sublimation colorant transfer occurs, to remove any
trapped air or bubbles from the materials, and to prevent
oxidization at higher temperatures. If appropriate, the material
may be exposed to ultraviolet or electron beam radiation to cure or
set curable tints or dyes.
[0061] Autoclave System
[0062] In accordance with an exemplary embodiment and with
reference to FIGS. 4A and 4B, an autoclave color transfer system
400 comprises a rigid or reinforced elastomeric tool plate 410 and,
optionally, a rigid or elastomeric caul plate 420 inside a vacuum
bag 430. In various embodiments, tool plate 410 is typically a
stiff plate having a smooth surface while caul plate 420 may be
thinner and/or more compliant than tool plate 410. Vacuum bag 430
is made of flexible, impermeable material, or may be a flexible,
impermeable elastomeric diaphragm. Alternatively, vacuum bag 430
may be sealed to the side or outer surface of first caul plate 410.
Vacuum bag 430 is typically 0.001-0.015 inch thick nylon or other
film that is sealed with a tape or strip of tacky high temperature
caulk. Suitable bag and sealant materials include Airtech Securelon
L500Y nylon vacuum bag and TMI Tacky Tape or Aerotech AT-200Y
sealant tape. Moreover, if a diaphragm is used in place of a vacuum
bag, the diaphragms are typically low durometer, high temperature
resistant silicone rubber, and generally have a thickness of
0.032-0.060 inches.
[0063] In place of direct printing or color transferring to
material, autoclave system 400 further comprises one or more color
transfer carriers 440 and a colorant receiving material or laminate
450. Color transfer carrier 440 is placed in contact with receiving
material 450, where both are between tool plate 410 and caul plate
420. For embodiments with high pressure and temperature operations
or with large areas, a permeable felt or non-woven breather
material may be included on top of the caul to allow air to flow
freely under vacuum bag 430 in order to provide uniform compaction
pressure. One example of a suitable breather material is Airtech
Airweave 10. The air inside the vacuum bag 430 is removed via a
vacuum tap 460, which creates a pressure differential in system 400
to provide compaction pressure on the part inside the vacuum bag
430. In exemplary embodiments, vacuum bag 430 may be placed inside
a pressurized autoclave 470, such that the hyperbaric pressure
inside autoclave 470, external to vacuum bag 430, is raised to a
predetermined level. The predetermined level may be ambient
atmospheric pressure up to 1000 psi to provide compaction force
while the pressure under vacuum bag 430 is maintained at a vacuum
of less than 2 to up to about 29 inch Hg.
[0064] In an exemplary embodiment, heat is more easily produced in
a high-pressure environment and facilitates the transfer of dye to
receiving material 450. The temperature inside the autoclave may be
set to a predetermined heating rate profile, temperature hold and
cool down profile. Typical temperature ramp rates vary from
2-50.degree. F. per minute, to temperatures ranging from 70.degree.
F. to 600.degree. F., with cool down rates ranging from
2-20.degree. F. per minute. For the cooling profile, cool the
material to a temperature such that the finished article remains
flat or in the desired shape and such that there is no damage,
distortion or delamination of the finished colorized material. Once
the system is at or below the removal temperature, the material and
color carrier are removed from the autoclave and removed from the
bag. In an exemplary embodiment, autoclave color transfer system
400 is very effective and can be incorporated into a composite
material manufacturing process.
[0065] In an exemplary process and with reference to FIG. 5, an
autoclave process 500 comprises four primary steps:
[0066] (1) applying a color tint/dye transfer to the color carrier,
which may include laminate with surface films or cloth surface on
one or both sides, or transfer paper/film carrier (510). The film
or cloth surface may incorporate a complementary color or
preprinted pattern, image or design on either or both sides of the
laminate. The transfer paper or media may contain a single color in
an uninterrupted area, a single or multi-color pattern, or printed
graphics of any color combination to form an image, design or
picture. The transfer media may also include a smooth or textured
surface to impart a surface with given degree of gloss, smoothness
texture pattern on one or both sides of the colorized;
[0067] (2) placing the color tint/dye transfer in contact with the
composite material (520);
[0068] (3) applying heat and pressure, and vacuum to transfer
and/or infuse or sublimate the color, graphics, textures, or
patterns to the materials (530). Temperatures typically range from
about 70.degree. F. to about 650.degree. F., and pressures range
from the minimum to keep materials in intimate contact, typically
ambient atmospheric pressure to a maximum of 1000 psi. The
temperature and pressure applied depend on the particular colorant
used, the substrates the colorant is applied to, and the degree of
lamination or consolidation required; and
[0069] (4) cooling the material to a temperature such that the
finished article remains flat or in the desired shape, and such
that there is no damage, distortion, or delamination of the
finished colorized material. Once the system is at or below the
removal temperature, the material and color carrier are removed
from the vacuum bag tool assembly (540). In various appropriate
embodiments, the material may be exposed to ultraviolet or electron
beam radiation to cure or set curable tints or dyes.
[0070] Linear Color Transfer System
[0071] In one exemplary embodiment and with reference to FIG. 6, a
linear color transfer system 600 comprises a rotating horizontal
belt press 610, a film or membrane 620, and color transfer carrier
630. The endless rotating belts form a continuous process capable
of applying a uniform, continuous consolidation pressure to a
Composite Material 650, and color transfer film or paper carrier
630 to maintain intimate contact for infusion or sublimation color
transfer. The materials are heated to a sufficient temperature to
perform the color infusion in the pressurized heating zone and then
cooling the composite material and color transfer media to a
temperature that is at or below the safe removal temperature for
the composite material. The linear color transfer system 600 may be
a continuous roll-to-roll process for applying color or graphics to
composite material 650. The composite material 650 that receives
the color may be fabric, cloth, film, or laminated material. The
film or fabric 620 can then be used in the manufacture of composite
materials. For example, a web of assembled layers of rolls of
finished Composite Material, film or fabric 620 precursors may be
run through linear color transfer system 600 to set or infuse the
colors. In an exemplary embodiment, material 650 may be pre-coated
or pre-printed with color before being fed through the belt press
portion 610 of the linear color transfer system by means of
printer, coater or treater 660.
[0072] The colorized composite material may then be optionally run
through a set of calendar or embossing rolls 670 to apply a smooth
shiny or matt surface to the composite material or to apply a
texture to one or both outer surfaces. The optional rolls 670 may
be heated, chilled, or left at room temperature, depending upon the
desired surface finish, surface texture, the exit temperature of
the composite material from the belt portion of the press or the
specific materials. Typical running speed for the composite
material web ranges from 2-250 feet per minute. The rolls 670 and
belt sections of the press 610 can be set either for a
predetermined gap or a for a preset pressure to the preset roll
gaps or with the gaps set to zero with a preset pressure to ensure
full consolidation with a given pressure distribution. Typical gap
settings range from 0.0002'' up to 0.125'' and typical pressures
range from 5 to 1000 lbf per linear inch of width. The rolls and
belt system can be heated to consolidate the materials and/or
transfer, infuse or sublimate into one or both sides of the
composite material. Individual plies of the composite may be
unwound from a roll, laid up on the composite web by hand layup, by
automated tape layup or by an automated robotic pick and place
operation. Typical heating temperature set points range from
70.degree. F. to 550.degree. F.
[0073] Furthermore, typical heating temperature set points range
from 70.degree. F. to 550.degree. F.
[0074] Radiation curing systems such as an E-beam or UV lamp array
can be located in-line. One advantage of the linear system is that
it can integrate the assembly of unidirectional fiber ply layers
into a structural reinforcement, the application of the colorant,
the incorporation of the various arbitrary internal or surface film
layers, non-woven cloth layers and woven layers into a multi-step
integrated manufacturing process where base unidirectional fiber
plies are converted to finished, colorized roll goods.
Multilayer Composite Material Color Infusion
[0075] In an exemplary embodiment, multilayer composite material
color infusion can be performed using either a heated press color
transfer system, such as system 200 or an autoclave color transfer
system, such as system 400. In either process and with reference to
FIG. 7, a multilayered stack comprising multiple caul plates 710,
barrier/breather layers 720, color carriers 730 and laminates 740
may be substituted for the single stack of composite material and
color carrier described in system 200 and system 400.
[0076] Batch Dye Infusion
[0077] In an exemplary embodiment, composite material, surface
films and surface fabrics can also have colors incorporated via
batch dying or infusion. In this process, rolls of composite
material, film or fabrics are saturated with color media or tint
and placed in a vessel and exposed to an appropriate heat, pressure
or vacuum profile to apply to infuse color media. The films or
fabrics treated in this manner may then be incorporated into
laminates.
[0078] Matrix Pigment and Tint Coloring
[0079] In an alternative to dye sublimation/diffusion into fibers
and braids, pigment may be added to the adhesive resin used in the
unidirectional fiber ply manufacturing process, thereby resulting
in a color infused unidirectional tape subsequently used in the
manufacture of the composite material. For example, materials that
can be added directly into the adhesive resin include, but are not
limited to, titanium dioxide, carbon black, phthalo blue,
quinacridone red, organic yellow, phthalo green, dark yellow
orcher, ercolano orange, venetian red, burnt umber, viridian green,
ultramarine blue and pewter grey. In an exemplary embodiment the
colored composite material that results from the use of the colored
unidirectional fiber plies may be additionally colored using the
before-mentioned processes, namely Heated Rotary System 100, Heated
Press System 200/300, Autoclave System 400/500, Linear System 600,
Multilayer Laminate Color Infusion 700, and/or Batch Dye
Infusion.
[0080] Fiber and Braid Coloring Under Tensioning
Conditions--General Considerations
[0081] In various embodiments, fibers or braids are under tension
during colorization. Tensioning during colorization is believed to
draw the fibers to some extent, counteracting the shrinkage of the
fibers and negating the added weight of the colorant added per
linear length of fiber. Not wishing to be bound by any particular
theory, it is believed that controlling the inherent shrinking of
fibers by tensioning during heating minimizes disturbances of the
extended polymer chains in the fibers. Tensioning may be held
relatively constant during colorization, or tensioning may vary
(increasing or decreasing) during colorization. Also, pre-tensioned
fibers, when subsequently exposed to heat during colorization, may
relax to some extent, meaning the tension of fibers during
colorization may be less than the pre-tensioning applied prior to
colorization.
[0082] In one variation, fibers or braids are wrapped around an
adjustable rig and pre-tensioned to a desired tension (i.e. force)
prior to the start of the colorization process. Such an expandable
structure may comprise an expandable tubular construct such as an
expansion cylinder having circumferentially arranged segments that
are driven apart from one another by the action of, for example, a
bolt having a larger diameter than the inside diameter (ID) of the
unexpanded segments. Such rigs are sometimes referred to as
"expansion clamps for ID holding." More elaborate variations of the
rig can include a ratcheting mechanism that pushes paired elements
(such as rods) in opposite directions, increasing the distance
between the pair, and thus increasing the tension on the fibers or
braids wrapped around them. Pre-tensioning of fibers or braids can
be to any level of tensioning that is numerically less than the
breaking point of the fiber or braid. That is, fibers or braids may
be pre-tensioned to a percentage (<100%) of their break
strength. For example, for colorizing UHMWPE fibers having a
tensile strength of about 3.6 GPa, a pre-tensioning of the fibers
at 20.degree. C. to 1-30% of their break strength would equate to
pre-tensioning the fibers prior to colorization to a force of 36
MPa to about 0.36 GPa. In various embodiments, fibers are
pre-tensioned around a suitable rig at 20.degree. C. to a force
equal to 1-30% of the break strength of the fibers. In other
embodiments, fibers are pre-tensioned at 20.degree. C. to a force
equal to 2-20% of the break strength of the fibers. In other
embodiments, fibers are pre-tensioned at 20.degree. C. to a force
equal to 3-10% of the break strength of the fibers. Dye transfer
paper may be placed on the rig prior to winding of the fibers over
the paper and prior to the pre-tensioning by the expansion bolt or
ratcheting mechanism. In various embodiments, another layer of dye
transfer paper is placed over the pre-tensioned fibers. Then the
assembled rig with the one or more dye transfer papers on either or
both sides of the wound and pre-tensioned fibers is heated to
sublime and diffuse the colorant from the transfer paper(s) into
the fibers. In other embodiments, fibers are pre-tensioned on a
tensioning rig and then the rig is simply submerged in a heated
vessel of dye until the tensioned fibers are colored.
[0083] In another variation, fibers or braids are wrapped around a
structure that expands during the colorization process, in which
case the tensioning of the fibers or braids increases from little
to no tension at the start of the colorization process up to a
desired tension during the colorization process. Such a structure
may expand at a measureable and predictable rate when heated at
least about 10.degree. C. above ambient. For example, the diameter
of an aluminum tube or mandrel expands at a known rate when heated
based on the known coefficient of thermal expansion (CTE) of
aluminum. The gradual increase in diameter of for example an
aluminum tube causes an increase in the tensioning of fibers
wrapped around the tube when the tube is heated to an increase in
temperature of at least 10.degree. C. during colorization of the
fibers.
[0084] UHMWPE fibers, such as Dyneema.RTM. fibers, have a negative
CTE. That is, these types of fibers shrink when heated. The CTE of
UHMWPE fibers is about -12.times.10.sup.-6/K. Given this known
contraction, it is preferred that an expanding structure, such as a
metal tube, be chosen to have approximately the opposite CTE of the
fibers, such that the expanding structure counteracts or negates
the contraction of the fibers during the colorization process when
at least a 10.degree. C. temperature increase occurs. Aluminum, for
example, has a CTE of 22.2.times.10.sup.-6/K, and thus can be seen
to be of the order of magnitude necessary to offset the shrinkage
of UHMWPE fibers during the same heating. The CTE of copper is
16.6.times.10.sup.-6/K, pure iron 12.0.times.10.sup.-6/K and cast
iron 10.4.times.10.sup.-6/K, and therefore structures, such as
tubes, made from these metals are expected to tension UHMWPE fibers
during the colorization process wherein at least a 10.degree. C.
increase in temperature occurs.
[0085] In various embodiments, the expandable structure comprises a
tube made from a material having a CTE of from about
5.times.10.sup.-6/K to about 30.times.10.sup.-6/K. In various
embodiments, the expandable structure is a tube made of glass,
metal, granite, concrete or quartz. In various embodiments, the
metal is chosen from the group consisting of aluminum, copper, pure
iron, cast iron, silver, lead, nickel, palladium, and stainless
steel. In various embodiments, the expandable structure is a glass,
metal, granite, concrete or quartz tube having an ID approximately
20 times the wall thickness. The length of the tube is chosen
primarily on the basis of practicality, such as the size of the
autoclave or other system to be used for applying at least one of
heat, pressure, force and vacuum, the scale of the colorization
process (e.g. how many meters of fiber to be colored), the width of
composite material to be colored, cost of a tube, and the like.
[0086] For the indirect coating of tensioned fibers, dye
sublimation colorant saturated commercial transfer papers with
solid and patterned colors may be used as the dye transfer medium.
Although these transfer papers are suitable for smaller-scale
processes, for production applications, the dye sublimation
colorant could be applied directly to the tooling mandrels or
process equipment via a wide range of coating methods such as
gravure coating.
[0087] In various embodiments, a method of transferring a dye to a
fiber, braid or composite material comprises: a) wrapping said
fiber, braid or composite material onto an expandable structure; b)
applying the dye to a transfer media to create a colored transfer
media; c) placing the colored transfer media into contact with the
fiber, braid or composite material; and, d) applying at least one
of heat, external force, external pressure and vacuum pressure to
infuse the dye to the a fiber, braid or composite material to
create a colored a fiber, braid or composite material. Temperatures
for this process typically range from about 70.degree. F. to about
650.degree. F., and pressures range from the minimum to keep
materials in intimate contact, typically ambient atmospheric
pressure to a maximum of 1000 psi. In preferred embodiments, the
temperature of the colorization process is close to, but below, the
melting point of the fibers. In various embodiments, the colored
transfer media is a dye transfer paper with dye on one side. In
other embodiments, an autoclave can be used in conjunction with the
application of heat, force, pressure, and/or vacuum. In various
embodiments, the expandable structure comprises an adjustable rig
that can be expanded at 20.degree. C. to pre-tension the fibers at
preferably 1-30%, more preferably 2-20% or most preferably 3-10% of
the breaking strength of the fibers prior to colorization. In other
embodiments, the expandable structure is a tube, e.g. glass, metal,
granite, concrete or quartz, which gradually expands when
temperature is increased at least 10.degree. C. to tension the
fibers during the colorization process and offset the shrinkage of
the fibers that would have occurred from the heating.
[0088] In various embodiments, a method of transferring a dye to a
fiber, braid or composite material comprises: a) applying the dye
to a transfer media to create a dye transfer media; b) wrapping the
dye transfer media onto an expandable structure leaving the dye
coated side of the dye transfer media exposed; c) wrapping said
fiber, braid or composite material onto the expandable structure
over the top of and in contact with the dye transfer media; and d)
applying at least one of heat, external force, external pressure
and vacuum pressure to infuse the dye to the a fiber, braid or
composite material to create a colored a fiber, braid or composite
material. In various embodiments, the colored transfer media is a
dye transfer paper with dye on one side. In various embodiments, an
autoclave can be used in conjunction with the application of heat,
pressure, and/or vacuum. In various embodiments, the material to be
dyed can be directly wound against the expandable structure, (e.g.
winding fiber around a metal tube or expandable rig), or
alternatively the dye transfer media can be wrapped against the
expandable structure, and then fiber, braid or composite wrapped
around the dye transfer media such that the dye transfer media is
between the expandable structure and the fiber, braid or composite
to be dyed. Temperatures for this process typically range from
about 70.degree. F. to about 650.degree. F., and pressures range
from the minimum to keep materials in intimate contact, typically
ambient atmospheric pressure to a maximum of 1000 psi. In preferred
embodiments, the temperature of the colorization process is close
to the melting point of the fibers. In various embodiments, the
expandable structure comprises an adjustable rig that can be
expanded at 20.degree. C. to pre-tension the fibers at preferably
1-30%, more preferably 2-20% or most preferably 3-10% of the
breaking strength of the fibers prior to colorization. In other
embodiments, the expandable structure is a tube, e.g. a metal tube
such as aluminum, copper, pure iron or cast iron, which gradually
expands when heated to tension the fibers during the colorization
process and offset the shrinkage of the fibers that would have
occurred from the heating.
[0089] In various embodiments, a method of transferring a dye to a
fiber, braid or composite material comprises: a) applying the dye
to a transfer media to create a dye transfer media; b) wrapping the
dye transfer media onto an expandable structure; c) wrapping said
fiber, braid or composite material onto the expandable structure
over the top of and in contact with the dye transfer media; d)
wrapping additional dye transfer media over said fiber, braid or
composite material with the dye coated side in contact with the
fiber, braid or composite, and e) applying at least one of heat,
external force, external pressure and vacuum pressure to infuse the
dye to the fiber, braid or composite material to create a colored
fiber, braid or composite material. In other words, two layers of
dye transfer media may be used to sandwich the fiber, braid or
composite material to be dyed, all of which is wound around an
expandable structure in layers. Temperatures for this process
typically range from about 70.degree. F. to about 650.degree. F.,
and pressures range from the minimum to keep materials in intimate
contact, typically ambient atmospheric pressure to a maximum of
1000 psi. In preferred embodiments, the temperature of the
colorization process is close to, but below, the melting point of
the fibers. In various embodiments, the expandable structure
comprises an adjustable rig that can be expanded at 20.degree. C.
to pre-tension the fibers at preferably 1-30%, more preferably
2-20% or most preferably 3-10% of the breaking strength of the
fibers prior to colorization. In other embodiments, the expandable
structure is a glass, metal, granite, concrete or quartz tube,
(e.g. a metal like aluminum, copper, pure iron or cast iron), which
gradually expands when increased in temperature at least 10.degree.
C. to tension the fibers during the colorization process and offset
the shrinkage of the fibers that would have occurred from the
heating.
[0090] Exemplary Procedure for Colorization of Fibers Under
Tension
[0091] In the example, tension is provided by the differential (and
opposite) thermal expansion between the fibers and the expandable
structure as they are both heated up together. Metal is typically
the material of construction for expandable structures suitable for
use in accordance with the present method, with a metal tube being
ideally preferred. In various embodiments, the expandable structure
comprises a metal tube having any wall thickness, diameter and
length. In various embodiments, the metal tube comprises aluminum,
copper, pure iron or cast iron. In various embodiments, the
expandable structure comprises an aluminum tube having an ID about
20 times the wall thickness. In various embodiments, the expandable
structure comprises a 10 inch ID aluminum tube having 0.5 inch wall
thickness.
[0092] FIG. 8 depicts the expandable structure used in this
example. Tubing 890 is an aluminum mandrel having 0.5 inch wall
thickness and 10 inch ID. The fibers used in this example were
Spectra.RTM. UHMWPE fibers. As mentioned, UHMWPE fibers have a
negative coefficient of thermal expansion (CTE), which causes the
fibers to contract as they are heated up, while the aluminum
mandrel 890 has a positive CTE, which causes the mandrel to expand
as it is heated. The combined action of the Spectra.RTM. fiber's
contraction and the aluminum mandrel's expansion helps prevent loss
of mechanical properties in the fibers caused by disturbances of
the extended polymer chain configuration in the fibers.
[0093] Before application of the dye sublimation transfer paper to
the surface of the aluminum mandrel, the mandrel was cleaned by
scrubbing the surface with a solvent wipe saturated with methyl
ethyl ketone (MEK) or other solvent to remove any oils or
contaminants. The MEK was subsequently flashed off using a hand
held heated air gun, and dye sublimation transfer paper was tightly
wound around the outer surface of the mandrel with the dye
sublimation side pointing outwards in order to be used as the
contact surface with the fiber and braid being colorized. Both
solid color and patterned dye sublimation transfer paper were
utilized for this study with the solid pattern being used when a
solid color is to be transferred to the fiber or braid and with the
patterned transfer paper used when a multi-color sectioned pattern
of colors is to be applied along the length of the fiber or braid.
The transfer paper was secured to the mandrel with tape.
[0094] Once the transfer paper was secured to the mandrel the
mandrel was mounted to a tension controlled winder using an
inflatable core chuck and the fiber or braid spool was mounted on
tension controlled let off. The Spectra.RTM. braid or fiber was
then wrapped over the dye-sub paper at a predetermined tension such
that each wrap of the braid was tightly wound in intimate contact
with the coloration surface of the transfer paper and abutting but
preferably not overlapping the adjoining wrap of braid or fiber.
After the Spectra.RTM. braid or fiber was completely wound onto the
mandrel a second sheet of dye sublimation transfer paper was
overwrapped onto the fiber or braid layer, with the dye sublimation
transfer surface pointing inwards, such that the dye transfer
surface was in intimate contact with the outer surface of the
Spectra.RTM. fiber or braid and the paper was secured with tape to
prevent shifting of the transfer paper on the mandrel. In this way
the fiber or braid layer is sandwiched between dye transfer paper
layers, with each of the dye transfer paper layers arranged such
that the dye side faces against the fiber or braid to be
colored.
[0095] The outer layer of the transfer paper on the mandrel was
covered with a layer of non-porous 2 mil thick Teflon.RTM. film to
prevent migration of the colorant gases away from the Spectra.RTM.
fiber or braid during the sublimation process. Also, a layer of
Airweave N-10 was applied as a breather layer. The mandrel was then
covered with a layer of Airtech 5 mil nylon vacuum bag sealed to
the caul with Airtech tacky tape. An Airtech vacuum tap was
inserted under the nylon film vacuum bag. The vacuum tap was locked
in place to seal it against the nylon bag film and a vacuum hose
connected to a high volume vacuum pump evacuate the air from under
the vacuum bag.
[0096] A vacuum of 27 inches Hg was applied to the bagged assembly
using a liquid ring vacuum pump in order to check for leaks in bag
or sealing system.
[0097] The completed mandrel assembly was maintained under vacuum
and placed into an autoclave. Once in the autoclave the vacuum tap
on the mandrel was connected to the autoclave's internal vacuum
system. The autoclave was pressurized to 5 psi with dry nitrogen to
keep the bag from shifting, and the under bag vacuum on the mandrel
was vented to the atmosphere to maintain atmospheric pressure on
the sublimation paper during the autoclave heating process to
prevent premature sublimation of the dye sublimation colorant
before the Spectra.RTM. fiber had reached a sufficiently high
temperature to allow the colorant to be infused into the
Spectra.RTM. fiber filaments. This temperature was close to, but
below, the melting point of the fibers, between about 275 and
280.degree. F.
[0098] The autoclave temperature was ramped up to the sublimation
transfer temperature of 275-280.degree. F. and held at that
temperature until the lagging tool and Spectra.RTM. fiber layer
reached the transfer temperature. When the Spectra.RTM. material
reached the transfer temperature the pressure of the autoclave was
released to prevent damage to the Spectra.RTM. filaments while a
vacuum of 28 in Hg was pulled under the vacuum bag to initiate the
sublimation of the colorant off of the dye transfer paper and
facilitate the colorant's infusion into the Spectra.RTM. fiber
filaments. The Spectra.RTM. fibers were held at the 275-280.degree.
F. infusion temperature under vacuum for 15 minutes to allow the
colorant to infuse into the Spectra.RTM. material. At the end of
the 15 minute dwell period, the autoclave was cooled down to
150.degree. F. while full vacuum was held under the mandrel vacuum
bag.
TABLE-US-00001 TABLE 1 Autoclave cure schedule for fiber and braid
specimens. Time Autoclave Part Autoclave Vacuum (hours) Temp
(.degree. F.) Temp (.degree. F.) Pressure (psi) (inHg) 0 71 73 0 28
0.5 208 146 5 0 1 257 225 5 0 1.08 275 243 5 0 1.75 279 275 0 28 2
278 275 0 28 2.25 150 150 0 28
[0099] FIGS. 9 and 10 are plots of the data from TABLE 1. FIGS. 9
and 10 provide the autoclave dye sublimation infusion time,
temperature, autoclave pressure, and mandrel under bag pressure
schedule for the coloration cycle.
[0100] At the end of the infusion cycle, the mandrel assembly was
removed from the autoclave, and the vacuum bag, breather cloth,
Teflon.RTM. film and outer layer of transfer paper were each
removed from the aluminum mandrel. The resulting colorized
Spectra.RTM. fiber or braid was inspected for quality and
uniformity of the colorization.
[0101] The mandrel was re-mounted onto the tension-controlled
winder using an inflatable core chuck, and the fiber or braid was
re-spooled onto a suitable core. The colorized fibers and braid
were then subjected to tensile testing in a suitably equipped
testing lab.
[0102] For the testing, an Instron 5667 Universal Test load frame
controlled by Instron's Blue Hill mechanical test control and data
collection system was used. A 500 Newton Instron load cell was
mounted onto the load frame along with a set of Instron pneumatic
grip fixtures optimized for the testing of Spectra.RTM. fibers and
the grip length for the test fixtures was set to 250 mm. The
colorized Spectra.RTM. fiber and braid were tested to failure at
crosshead speed of 127 mm/min, with the load and displacement data
collected for each sample test for calculation of tenacity and
modulus. The test results for the colorized Spectra.RTM. braid and
fiber were compared to un-colorized (i.e. "as-received")
Spectra.RTM. fiber and braid using the identical test set up and
parameters. The test results for the colorized and un-colorized
Spectra.RTM. fiber and braid were compared to evaluate the impact
of the colorization process on tenacity and modulus.
[0103] FIG. 11 is a tabular summary of the test results on the
Spectra.RTM. material in an "as-received" state, (i.e., prior to
the colorization process). FIG. 12 is a plot of tenacity versus
tensile strain for the un-colorized Spectra.RTM. material.
[0104] In comparison, FIG. 13 is a tabular summary of the test
results on the colorized Spectra.RTM. material obtained from the
process described immediately above. FIG. 14 is a plot of tenacity
versus tensile strain for the colorized Spectra.RTM. material from
the colorization process above. The material used was Spectra.RTM.
fiber 1740 dtex braid.
[0105] Results
[0106] The averagelure load of the Royal Blue colored 1740 dtex
braid was measured at 89.1 lbs., which gives a corresponding
average strength of 22.78 cN/dtex. The average failure load of
"as-received," in the white grey goods uncolored 1740 dtex braid
was 90.9 lbs., which gives a corresponding average strength of
23.24 cN/dtex. Compare FIG. 11 versus FIG. 13 to compare test
results in tabular form, and compare FIG. 12 to FIG. 14 to compare
Tenacity versus Strain plots of the colored and uncolored 1740 dtex
braid samples. Recalculation of the percentage strength difference
drops to reduction in tensile strength for the colored braid to
1.1% when the outlier in the test data is excluded.
[0107] From the test results, it was determined that the tenacity
of the colored 1740 dtex Spectra.RTM. braid is 1.9% lower than the
average tenacity of the uncolored material, (i.e. the white
Spectra.RTM. 1740 dtex braid as tested directly off the factory
roll). Inspection of the tabular data for failure strength of the
colored braid showed an outlier in the data on Test #5 due to
gripping error that resulted in a premature failure of the test
sample. If the one outlier of Test #5 in the colored test sample is
excluded from the data set, then the average failure strength for
the colored samples increases to 89.8 lbs., and the average
strength increases to 22.95 cN/dtex. Recalculation of the
percentage strength difference drops to reduction in tensile
strength for the colored braid to 1.1% when the outlier in the test
data is excluded.
[0108] The average modulus of the colored 1740 dtex braid is 126.67
cN/dtex, which is actually slightly higher by 1.2% than the average
modulus for the uncolored, in the white 1740 dtex braid, which
tested at 125.07 cN/dtex. Although not wishing to be bound by any
particular theory, this improvement in the modulus for the colored
braid is believed to be attributed to some degree to heat setting
and fiber alignment of the braid under tension induced during
coloration heat and pressure cycle. Examination of the Tenacity vs
Strain plots of the tensile test results in FIGS. 12 and 14 tend to
support the improvement of tensile stretch propertied as a result
of heat setting hypothesis.
[0109] As can be seen from the plots, the colored braids have a
tighter, more reproducible load/displacement relationship, most
likely due to the heat setting of the braid. TABLE 2 summarizes the
average strength and average modulus for the Spectra.RTM. fiber
braid "as received" and Spectra.RTM. fiber braid dyed, in
accordance to the process herein.
TABLE-US-00002 TABLE 2 Average Strength and Average Modulus Avg Avg
Strength Modulus (cN/dtex) (cN/dtex) As-received Fiber Braid 23.24
125 Dyed Fiber Braid 22.78 127 Difference -1.9% +1.2%
Spectra.RTM. 1000, 400 Denier Fiber Test Results and Comparison
[0110] The average failure load of the Royal Blue colored
Spectra.RTM. 1000 400 denier (425 dtex) fiber was 28.23 lbs., which
gives a corresponding average tenacity of 29.51 cN/dtex. The
average failure load of as-received, in the white uncolored 400
denier (425 dtex) Spectra.RTM. 1000 fiber is 29.94 lbs., which
gives a corresponding average strength of 31.29 cN/dtex. TABLE 3
sets out these test results in tabular form.
TABLE-US-00003 TABLE 3 Average strength and average modulus for 400
denier fiber Avg Avg Strength Modulus (cN/dtex) (cN/dtex)
As-received Spectra .RTM. Fiber 400 denier 29.94 1098 Dyed Spectra
.RTM. Fiber 400 denier 29.51 1115 Difference -1.5% 1.5%
[0111] FIGS. 15 and 16 are Tenacity versus Strain plots of the
uncolored (FIG. 15) and colored (FIG. 16) 400 denier (425 dtex)
Spectra.RTM. 1000 fiber samples.
[0112] The test results show that the Tenacity of the colored 400
denier (425 dtex) Spectra.RTM. 1000 fiber is 1.5% lower than the
average Tenacity of the uncolored, in the white 400 denier (425
dtex) Spectra.RTM. 1000 fiber as tested directly off the factory
roll.
[0113] The average modulus of the colored 400 denier (425 dtex)
Spectra.RTM. 1000 fiber is 1098.04 cN/dtex, which is slightly lower
by 1.5% than the average modulus for the uncolored, in the white
400 denier (425 dtex) Spectra.RTM. 1000 fiber, which tested at
1115.07 cN/dtex. Although not wishing to be bound by any particular
theory, this drop in the modulus for the colored braid is believed
to be attributed to some degree due to the disruption of the
catenary pattern in the fibers that drops the measured modulus due
to non-uniformity of filament engagement. Examination of the
scatter in Tenacity Vs Strain plots of the tensile test results in
FIGS. 15 and 16 tend to support the notion that the drop in tensile
stretch properties of the colored fibers is a result of the
disruption of the fiber catenary uniformity. This disruption of the
fiber catenary uniformity may also account for a significant
portion of the 2.4% drop in strength for the colored fiber, which
would reduce the component of strength reduction caused by the drop
in the Spectra.RTM. material's properties as a direct consequence
of the coloration.
Indirect Application of Multiple Colors to Braid Using Printed
Pattern Dye Sublimation Transfer Paper.
[0114] In a multi-color exemplary embodiment, a sample of
Spectra.RTM. 435 Denier Braid simulated fishing line was colored
using the multiply colored "Aqua Blue/Black Stripe/Steelhead Grey"
color pattern dye sublimation transfer sample. The colorization
process resulted in a fully infused coloration of the fibers in the
braid. The color and pattern itself appeared highly suitable as
camouflaged fishing line, and likely suitable for other
applications where a blue/grey camouflage color pattern is desired.
Due to the inhomogeneity, non-uniformity and presence of defects
and knots in the braid, the braid was used only for coloration
demonstration purposes and no mechanical testing results were
reported for this braid sample.
[0115] Additional details with regards to material, process,
methods and manufacturing, refer to U.S. Pat. No. 5,470,062,
entitled "COMPOSITE MATERIAL FOR FABRICATION OF SAILS AND OTHER
ARTICLES," which was issued on Nov. 28, 1995, and U.S. Pat. No.
5,333,568, entitled "MATERIAL FOR THE FABRICATION OF SAILS," which
was issued on Aug. 2, 1994, and U.S. patent application Ser. No.
13/168,912, entitled "WATERPROOF BREATHABLE COMPOSITE MATERIALS FOR
FABRICATION OF FLEXIBLE MEMBRANES AND OTHER ARTICLES," which was
filed Jun. 24, 2011; the contents of which are hereby incorporated
by reference for any purpose in their entirety.
[0116] Benefits, other advantages, and solutions to problems have
been described above with regard to specific embodiments. However,
the benefits, advantages, solutions to problems, and any element(s)
that may cause any benefit, advantage, or solution to occur or
become more pronounced are not to be construed as critical,
required, or essential features or elements of any or all the
claims. As used herein, the terms "includes," "including,"
"comprises," "comprising," or any other variation thereof, are
intended to cover a non-exclusive inclusion, such that a process,
method, article, or apparatus that comprises a list of elements
does not include only those elements but may include other elements
not expressly listed or inherent to such process, method, article,
or apparatus. Further, no element described herein is required for
the practice of the invention unless expressly described as
"essential" or "critical."
[0117] Although applicant has described applicant's preferred
embodiments of this invention, it will be understood that the
broadest scope of this invention includes modifications such as
diverse shapes, sizes, and materials. Such scope is limited only by
the below claims as read in connection with the above
specification. Further, many other advantages of applicant's
invention will be apparent to those skilled in the art from the
above descriptions and the below claims
* * * * *