Note: Descriptions are shown in the official language in which they were submitted.
I 1819~B
DYED FLOCK FABRIC AND METHOD
_ OF MAKING _HE SAME
Background of the Invention
The inven-tion relat~s to dyed flock-coa-ted
- fabrics and to methods of making the same.
So far as I am aware, the dyeing of flock-
coated fabric has to date involved one of several
processes, each of which has its difficulties and
:limitations which impair product quality, or which
involve undue product waste, or which do not lend
themselves to as wide a variety of different ultimate
finishes, textures and colors as might be desired.
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According to one of these processes, the
manufacturer of the flock-coated substrate fabric
must tailor his production lot to what can be
accommoda-ted in a piece-dyeing operation, usually
a service performed other than by the flock-coatiny
house. The process involves scouring and rinsing
the goods, bringing the goods to temperature in a
dye bath, then introducing thc dyes for a time and
at a temperature appropriate to the class of dyes
and goods involved. The dye ba-th temperatures are
generally in the range 140 to 180 degrees ~ahrenheit.
This techni~ue has disadvantages which include
wastage of product at ends of the piece, great
difficulty of making uniform color in the finished
product, from one to the next piece, and the
economies of continuous-run production are simply
not available.
According to another process, a transfer-
printing dye is applied to so-calledgreige goods, i.e.,
to undyed flock-coated substrate fabric. A dye-bearing
transfer paper is faced against the gr-eigegoods in
oriented lay-down of the flock, and oil-heated steel
rolls apply contact hea-t and pressure by squeezing
the paper to the fabric, the steel rolls being at at
least 400 F., and the heat and pressure being applied
for at least 30 seconds. Although the process is not
as batch-limited as the piece-dyeing process, it is
nevertheless relatively expensive due to paper waste
and handling, and product texture and quality suffer
from the application of heat and pressure to layed-down
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flock. The process is also inheren-tly incapahle of dyeing the
substrate because the substrate materials are incapable of
withstanding the greater temperaturesand/or -times needed to
assure sufficient dye penetration via the flock.
Brief Statement of the Invention
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Therefore, this invention provides a method of pro-
ducing a dyed flocked fabric, which comprises selecting a suit-
able substra-te fabric, coating the substrate fabric with a wet
layer of flock adhesive, introducing a selected heat-sublimable
dye prior to applying flockr selecting flock of a material
capable of beiny dyed with a heat-sublimable dye, applying the
selected flock to the wet coating of flock adhesive, drying the
adhesive at a temperature less -than that at which said dye
sublimes, and then curing -the adhesive by exposing the dried
flocked substrate for a predetermined period of time to an
elevated curing temperature at which said dye substantially
fully sublimes.
By employing the aforementioned method the invention
provides a dyed flocked fabric, comprising a substrate fabric,
a cured flock adhesive coating on one side of said fabric,
and flock adhered to said substrate fabric via said cured ad
hesive coating, said flock being of a material capable of being
dyed with a heat-sublimable dye.
The invention seeks to eliminate any need to manufacture
a flock coated fabric prior to dyeing which now can be achieved
directly in the course of manufacture.
In its preferred embodiments the invention seeks to
provide a substantially increased variety of options for colour
development, colour contrast, pattern development and finish-
texture development.
Furthermore, the method of the invention can be carried
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out at a reduced cos-t with greater pxoduct quality.
In a preferred embodiment, a heat-sublimable dye is
employed as a component of flock adhesive that is wet-cvated
to the substrate fabric as a preliminary to applying flock to
the wet adhesive. The flocked adhesive coat is dried at less
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than adhesive-curiny temperature, and -the dried
coated fabric i5 then subjected to a curing time
and temperature which enables (a) color development
~ by sublimation and (b) adhesive curing. The
techniques may be embodied :in the otherwise-
conventional continuous-run production process
of the flock~coating house. The technique lends
itself to a variety of color-contrast, pattern-
contrast and surface-texturlng effects for whlch
illustrative examples are given.
Detailed Description
The invention will be described in detail
in eonjunction with the accompanying drawings, in
which:
Fig. 1 is a diagram which schematically depiets
suceessive steps in the method of the invention, for
producing dyed flock-coated fahrics; and
Figs. 2 to 7 are fragmentary diagrams, applicable
to various of the locations 2-2, 3-3, 4-4 and 6-6 in
Fig. l, to illustrate optional operative steps for
producing different appearance and texture variations
in the product of the method.
Referring to Fig. l, the method of the invention
illustratively utilizes flock-coating equipment
comprising means for processing a continuous length
of substrate fabric lO, from a supply roll ll on a
suitable stand l~ at one end, to a driven take up
roll 13 for finished product on a suitable stand 14
at the other end. The substrate fabric lO is shown
first to pass an appllcator station A, where a coating
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applicator 15 extends the full coating wldth of
the web of fabric 10 and is continuous]y supplied
with a suitably regulated flow of liquid flock
adhesive from a supply means 16. In similar fashion,
at a downstream-oEfset flocking station B, a flock
applicator 17 extends the full adhesive~coated
width of -the fabric 10 and is continuously supplied
with a suitably regulated flow of flock material
from a supply means 18. After flock application to
the wet adhesive coat, the continuous-production
equipment is shown to include a first oven 19 or
ovens set to dry the adhesive but no-t to cure the
same. Thereafter, the flocked fabric wi-th dried
adhesive is subjected to conditions of curing
temperature and time as it passes through a curing
oven 20. After curing at 20, the finished product
is wound upon take-up roll 13, for storage or ship-
ment, as re~uired.
The means 15 of adhesive coating and the means
17 of flock application and orientation, including
their respective supply means 16-18 are existing,
well-known devices, and need no further description
for present purposes; also, the ovens 19-20 including
festoons therein (not shown) and various drive and
support rolls (not shown) along the length of web
under treatment are well-understood and require no
present description.
In accordance with one mode of the invention, a
heat-sublimable dye is an essential additive component
of the liquid adhesive supply at 16. The quantity of
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such adhesive mix-ture may be sufficient Eor an
entire run, or it may be adquate to serve only
a fraction of an entire continuous run, it being
in the latter case necessary for an opera-tor to
monitor the current supply level at 16 and to
replenlsh with fresh mixture as needed. The
proportions of dye material and adhesive components
may be so readily maintained to sufficiently close
tolerances that color in the resulting product is
not degraded by the fact tha-t a given run uses
batch-mixed replenishment of the dye compounded
liquid adhesive.
At the drying oven or ovens 19-19', the wet
flocked fabric web is exposed for a time and at
temperature (e.g., 200 F.) to achieve adhesive
drying without curing. Then in the curing oven 20,
the web passes through successive zones (e.g., three)
of progressively greater temperature. Illustratively,
curing at 20 may proceed at temperatures of 275 F.
in a first oven zone, 350 F. in a second oven zone,
and 400 F. in the third oven zone. A total ime of
12 to 14 minutes is shared in roughly equal fractions
at the respective curing-oven zones, and it has been
found with materials thus-far employed that a final
curing time of four minutes at 400 F. is desirable,
for best heat-development of the sublimable dye
components used, as well as for curing of the adhesive.
Stated in other words, a greater length of time at 400 F.
curing temperature has not thus far established any
improvement in dye-color development, but a different
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oven, such as a multiple-pass curing oven would
pro~ably permit a shorter overall curing time at
400F., for both the adhesive and i-ts dye component.
In another rnode of the invention, the greige
substrate fabric is gravure or otherwise printed
with heat-sublimable dye prior to the adhesive-
coating step. The coating-adhesive may be colorless
or it may contain a heat-sublimable dye selected for
ultimate color contrast wi-th that which had been
prlnted on the substrate fabric. Flock application,
drying and curing then prcceed as before, to produce
a finished product, wound upon the take-up roll 13.
Examples of different product, made by variously
combined steps of the indicated methods will be
specifically described.
Example I
Starting with a woven cotton substrate, a wet
layer of flock adhesive was applied before flocking
with natural 3-Denier Trilobal* nylon, cut to 80-mils
length. The substrate was 100 percent cotton, being
unnapped, soft-filled sheeting. Adhesive was applied
at approximately 3 ounces/square yard, and flock was
also applied at approximately 3 ounces/square yard.
The adhesive was a commercially available acrylic
water-based flocking adhesive, in which a 3 percent
addition of heat-sublimable dye had been mixed. The
dye materials were those intended for heat-transfer
inks and were products of Verona Dyestuff Division of
Mobay Chemical Corporation, Union, New Jersey, being
their dyes known as Resiren yellow T-4G~WN Liqùid
and Resiren blue TGL-WN Liquid, in the proportions:
A trademark of the DuPont Company.
`t/-R ~ r,- a ~ ~
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1 perCerlt Resiren~yellow T-4G-WN Liquid
2 percent Resiren`~blue TGL-WN Liquid
Upon drying the flocked adhesive-coated substrate,
the treated surface was light gray in color (being
the color of the uncured adhesive), but after curing
in the manner indicated, iOe.~ concluding with four
minutes at 40~F., the dye had been developed by
sublimation to a uniform rela-tively dark green at
the adhesive-coat, beiny visible over the entire
flocked surface as what I would call an apple green,
modulated only by bright flock highlights of lighter
green, as a func-tion of light-incidence upon the
flocke~ fabric. It is my belief that, except or
the above-noted highlighting effect, the rela-tively
dark overall appearance of the fabric is in important
degree attributable to the somewhat fiber-optic nature
of the individual pieces of flock, in relatively
uniform stand-up adjacent array, and of course it i5
possible that to the degree that dye had bled into
the flock, the strength of the coloring is enhanced.
The finishe~d fabric has a soft uniform velvet-like
feel or hand and is highly resistive to fading.
Example IT
Starting with a knitted polyester substrate, the
2~ same procedures were followed as with Example I, the
only difference being as to the selection of heat-
sublimable dye mixed in -the adhesive. The selected
dye proportions in the adhesive were:
1 percent Resiren~yellow T-4G-~L~
2 percent Resirerr~red TFB-WN Liquid
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Results of drying and curing in the rnanner of
Example I produced a uniform sof-t rust color
in the flocked side of the fabric, with a hand
and fastness as for Example I.
Exam~
Starting with the cotton sheeting, adhesive-
coating, and dye-content of Example I, the flocked
coated substrate fabric was subjected to precisely
the same drying and curing procedures as in Example I,
except that at location 2-2 of Fig. 1, i.e~, between
the location of flock-application and entry to drying
oven 19, the 10cked and still-wet adhesive-coated side
of the fabric was subjected to an air-embossing step,
for which operative mechanism is schematically shown
in Fig. 2.
The mechanism of Fig. 2 comprises two elongate
manifolds 25-26 in the form of tubular pipes drilled
and fitted at spaced locations to define downwardly
directed air jets, symboliæed by downward arrows at
spaced locations. The manifolds 25-26 are supplied
at one end by a suitable source of pressurized airflow,
and they are-closed at their other end. Manifolds
25-26 are held in fixed pa.rallel relation, at longi-
tudinal spacing D, above the coated and flocked surface
of web 10 and are oriented transverse to the direction
of web movement. The means for holding manifolds 25-26
at their spacing D includes (a) a yoke 27 at their
closed ends and (b) guide means (not shown) whereby
oscillatory displacement may be imparted to manifolds
25-26 in the direction transverse to the direction of
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web movement, a motor 23 being shown with crank
29 and link 30 connection to yoke 27 for imparting
such motion.
In the air-embossing use of the device of
Fig. 2 in Example III, the air jets along each
manifold 25-26 were at 1.5-inch spacing, the
amplitude of transverse oscillation impar-ted by
means 28-29-30 was 2.2~ inches, and the distance
D was so se~cted in relation to the speed of web
displacement and to the oscillation cycle that
sinusoidal air-embossments on the web 10 due -to
jet action from the upstream manifold 25 were at
180 degrees phase~offset from the corresponding
sinusoidal air-embossments on the web due to jet
action from the downstream manifold. The full
; cycle of transverse oscillation repeated at 8-inch
intervals in the direction of web movement.
The finished product was green as in Example I,
except that surface texture had been characterized
`by a permanent pattern of entwined 180-displaced
sinusoids, whexein each sinusoid due to manifold 25
lapped the adjacent three 180-displaced sinusoids of
manifold 26, and vice versa The air blasts from
manifolds 25-26 locally incline affected flock, and
curing retains -the inclination. The result is not
only a highlighted appearance effect, in accordance
with the entwined-sinusoid pattern, but also a
textured feel akin to velvet which has had similarly
29 tex-tured shearing.
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Example_IV
Starting wi-th a woven polyester-cotton osnaburg
fabric, the side to be flocked was first screen-printed
with a non-adhesive print paste wherein the dye
ingredient was again of the heat-sublimable variety,
the print dye being of a heat-developable first
color A, and -the thus-prin-ted surface of the web
10 was then adhesive-coa-ted with adhesive containing
a second dye of heat-developable color B. Flocking,
drying and curing were otherwise as described for
Example I.
The non-adhesive print paste was a water-diluted
mixture comprising a 4-percerlt addition of Resiren blue
TGL-I~il Liquid in a stock solution of carrier in water,
the latter being a 4 percent solution of stock print
thickener (specifically, Chemloid Auxiliary 0155M) in
water. And the printed surface of the web was dried
before application of the flock adhesive. The dye
selected for mixing in the adhesive was Resiren red
TF~-WN Liquid, added as a 2 percent component of the
liquid adhesive.
; As indicated, flocking, drying and curing steps
proceeded as in Example I, but the curing step was
operative upon the hea-t-sublimable dye components of
both the print paste and the adhesive. The resulting
product had the texture and feel of the product of
Example I, but the color appearance was in accordance
with the striped print pattern, wherein soft purple
alternates with soft red. The stripes had been printed
1/8-inch wide, at 1/8-inch spacing, and so at moderate
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viewing distance from the product, e.g., five or
more feet away, the appearance was -that of a soft
red-modulated mayenta. The hand and fastness oE
the product were as described for Example I.
Example V
Using a 284 polyester-cotton osnaburg substrate
and applying the adhesive mix of Example I (i.e.,
wi.th the potential for heat-development to green),
a fixedly mounted gouging comb 35 (Fig. 3) was
applied to the surface of the adhesive, just prior
to flocking with natural flock; this location is
designated 3-3 in Fig. 1. The flock was also as
described for Example I except that i-t was a random-
Cllt nylon, of ~ mils maximum length. The gouging
1~ comb had teeth at 1/8-inch spacing, across the
adhesive-coated width of the substrate, thereby
producing parallel elongate ribs and valleys to
which the flock was applied. Upon drying and curing
as described for Example I, the product was green
; 20 and had the àppearance and feel of a corduroy,
combined with the feel of a short-cropped velvetO
Ribs are highlighted, and valleys are darker.
Example VI
Adopting the substrate, adhesive mix and short
flock material of Example V, the gouging step was
omitted, and therefore the flock was applied to the
smooth surface of the wet adhesi~e coat. The wet
adhesive of the flocked substrate was then dried in
oven 19; but at location 4-4 ~Fig. 1), the flocked
surface of the substrate was subjected to eI~ossing
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pressures by passage be-tween an embossing roll 40
and its associated backing-pressure roll 41 (Flg. 4).
The embossing pattern had been engraved in the
cylindrical surface of roll 40, in the form of
intersecting finite longitudinal and transverse
lines, the engraving being to 30-mil depth, i.e.,
to a depth exceeding the cut ]ength of the flock.
The rolls 40-41 were heated to 400 F. so that
primary initial heat transfer to the dye components
of the adhesive could be at valley regions of the
flocked goods. Adhesive curing required less than
the four minutes desired for full color development,
and the exposure at curing oven 20 was limited to the
one minute (at 400 F.) required for adhesive curing.
The finished goods had cleanly and clearly defined
embossment faithful to the engraving pattern, with
background valley regions of darker blue-green and
with lighter, almost gray, blue-green at the ribs of
the embossment, reflecting in the embossment regions
less than the more complete color development which
was accomplished in the background or valley regions.
The produci lends itself admirably to richly textured
wall-covering application.
Example VII
Starting with the woven-cotton substrate of
Example I, but dyed to a light-blue color~ a flock
adheslve was applied through a stencil pattern which
characterized the cylindrical surface of an adhesive-
application rotary screen or roll 15' ~Fig. 5), in
place of the means 15 of Fig. 1. Surface motion of
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3 ~8190~
roll 15l at contact with the substrate web 10
matched that of web 10, and a regulated flow of
adhesive was supplied to roll 15' via suitable
non-rotating end-fitting means 50. The adhesive
had as an essential component a 3 percent addition
of Resiren blue TGL-~ Liquid. The flock was again
the 80-mil cut 'rrilobal natural nylon of Example I,
but of course it adhered to the adhesive-coated
substrate only in accordance with the stenci]. pattern
of adhesive coating. Upon drying and cur.ing, w.ith
full four-minute exposure at 400~F., the finished
product was an overall dark blue, characterized by
fine light-blue where substrate was exposed between
the larger tufts of dark-blue velvet which dominated
the appearance.
Conclusion
It wili be seen that the described inventi.on
meets all stated objects and introduces a new
dimension to the variety of fabric colors, patterns
and textures which the flock-coa-ting house may provide
to its customers. Not only is the variety of product
increased, but this is done at great economy as
compared to prior techniques which required batch
handling, dye-transfer paper, piece-dyeing and other
operations which are no-longer necessary. In other
words, the desired end result of a finished product
is achieved without the need for any after-finishing,
liquid or mechanical. Morecver, uniformly superior
quality of the end product is much more rèadily
controlled and assured, without introducing any
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undesired surface di.stor-tions (coloring or texture)
in the finished product. The process of the invention
provides tremendous savlngs by avoiding or subs-tantially
reducing the need for large inventories of raw rnaterials
or in~process goods, in that one or a few possible
substrates and merely natural flock can well serve
for the production of a wide variety of differently
dyed proclucts, the only needed change-over being in
the cleaning and mixing of correct heat-sublimable dye
additive to the wet adhesive mixture. Further savings
are realized in raw material (water, scouring agents,
softeners and chemicals) and in energy and labor7
through the one-pass technique of the invention, as
compared to conventional dyeing procedures, including
pre~dyeing of substrate and/or flock, and the
; pig~enting of adhesives in conventional colored
flocking.
In the case of Example IV, it should be noted
that a velvety stand-up look was uniform over the
entire flocked surface of the product, and this
represents a product that, to my knowledge, is also
new. In the past, print-transfer printing techniques
applied to flocked fabric have required (a) steam-
aging to develop color, and (b) washing; the resulting
products is characterized by wring marks, "rope" marks
and the like, all without assurance of a uniform velvety
stand-up of the flock. It is also to be noted that in
any print-transfer of dye to flocked fabric, the dyed
region is only skin deep, for example, there is not
enough dye penetration into the substrate to permit
9 ~ 6
use of the flocked fabric alone as a drape, a
lining being required for thus~printed fabrics.
On the other hand, with dye as an integral part
of the full adhesive coat, an opacity is achieved
which enables drape functions to be well served,
in solid color or patterned colors, without requiring
a lining.
While the invention has been described in
detail for preferred method steps and structures,
it will be understood that the specific disclosures
and examples given are merely illustrative and are
not limiting, in that modifications may be made
without departing from the scope of the invention.
For example, instead of pre-printing the substrate,
as described in Example IV, the pre-printing step
may be incorporated in continuous-run production
of the ultimate fabrics, such pre-printing being for
example through use of gravure-prin~ing rolls 60-61
and subsequent oven-drying at 62 (Fig. 6), applied
at location 6-6 of FigO 1, i.e., prior to adhesive
coating; in Fig. 6, a doctor blade 63 assures a
uniformly clean gravure-roll surface for continuous
fresh application of printing paste at 64, the paste
being as described in Example IV, namely including
one or more heat-sublimable dyes as an essential
component.
Also, while embossing may be of the high-pressure
steel-die delineated variety described for Example VI,
it will be understood that other embossing techniques
may be employed. A "soft" embossing technique may
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for example employ a pa-tterned relief in the
cylindrical surface of a large-diameter soft
roll 70 of foamed polyurethane which is either
driven to match the surface speed of wet-adhesive
coat or is alloed to ligh-tly drag its contact
with the adhesive coat of passing web 10. Such
a step would occur just after flocking, e.g., at
2-2 in ~ig. 1, wherein the "soft" embossing is
seen at 10' to have been the cause of locally
"laying down" the flock, or at least modulating
its otherwise stand-up orientation.
Still further, although the recited specific
examples have involved use of woven cotton fabric
and woven polyester fabric, the invention is clearly
not so limited, in that the fabric may be knitted
or non-woven, and the fiber or blend may be selected
from the wide variety of those available as long as
it can withstand the temperature exposures indicated
for curing of flock adhesive and heat-sublimable dye.
Thus, the fabric may be selected from polye~ter, nylon,
acrylic, polyrayon and acetate varie-ties; the fabric
may also be a blend of one or more of such fibers with
or without cotton; and the flock need not be Trilobal
bu~, rather, for example, may be a selected one of the
nylon, acrylic and polyester varieties available.
Still further, the flock adhesive may be solvent-based
and therefore not necessarily the water-based adhesive
28 mentionecl in the present specific examples.
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