Note: Descriptions are shown in the official language in which they were submitted.
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Background of the Invention
Woven synthetic scrims are now widely used as the primary
backing material for tufted carpeting, and scrims woven from
polypropylene ribbon fllaments are probably the most common.
While such scrims have a number of desirable characteristics,
they also present some problems. The finished product may not,
for example, have sufficient dimensional stability, it may not
have desirable stiffness, or it may not meet current standards
for flame retardance. Another problem is that woven synthetic
scrims can be difficult to tuft through because the scrim
filaments are likely to slide over one another during the
tufting process.
To provide the desired dimensional stability and
stiffness for products of the type contemplated, it is common to
provide a secondary backing such as jute or a foam layer, but
this presents several disadvantages. First, the use of a
secondary backing obviously increases material and manufacturing
costs. Further, conventional secondary backings reduce the
porosity of the finished product so that it holds more liquid
and is, for example, less desirable for outdoor use. Still
further, conventional secondary backings tend to reduce the
flame retardance of the finished product, at least as measured
by tunnel test.
Non-woven staple fibers have been used with synthetic
scrims, or to form primary backing materials, but have not
heretofore been used in the way contemplated by this invention.
In U.S. patent No. 3,605,666, dated September 20, 1971, for
example, a relatively thin non-woven layer is applied to the top
of a woven synthetic scrim; but it serves primarily an esthetic
function by providing a dyeable subface. In U.S. patent No.
3,817,817, dated June 18, 1974, a needlebonded layer is applied
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to the underside of a woven synthetic scrim to make a secondary
- backlng material. ln ~.S. patent No. 2,706,324, dated April lY,
1955, staple fibers are needled onto the bottom surface of a
tufted carpet after tufting. In U.S. patents Nos. 2,810,95~,
dated October 29, l9S7, and 2,866,206, dated December 30, 1958,
needled staple fibers are applied to a fabric, but the fabric
appears to serve primarily as a carrier for the fibers, as
opposed to providing substantial dimensional stability in its
own right, so that the resulting product is essentially a non-
woven backing.
~ummary or the Invention
.
~ l~he inventlon comprehends a ribbon scrim tufted carpet
and method of manufacturing same which has a unitary backing
with two staple faces that does the job of both a primary -
backing and secondary backing. The carpet includes a unitary
backing with two staple faces having a woven ribbon scrim with a
first scrim slde and a second scrim side, and a deposit layer of
staple fibers needled through the scrim to form a bottom fiber
layer on one of the scrlm sides and a subface fiber layer on the :
other scrim side, the bottom fiber layer being thicker than the
subface fiber layer. The carpet also has yarn tufted through
the unitary backing from the side having the bottom fiber layer ~ ,
to develop tufts, the tufts so developed being partially
- surrounded by fibers of bottom fiber layer to provide better
tuft lock and extending above the subface fiber layer.
The method of manufacturing the carpet comprises the ~ -
steps of provi~ing a unitary backing with two staple faces which ~' " .'
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is provided by providing a woven ribbon scrim having a first
scrim side and a second scrim side, depositing a deposit layer
of staple fibers on the first scrim side, and needling a portion
of the deposit layer through the scrim to form a bottom fiber
layer on one of the scrim sides and a subface fiber layer on the
other scrim side, the bottom fiber layer being thicker than the
subface fiber layer. The method then provides for tufting yarn
through the unitary backing from the side having the bottom
fiber layer to develop tufts, the tufts so developed being
partially surrounded by fibers of the bottom fiber layer to
provide better tuft lock and extending above the subface fiber
layer.
In the preferred embodiment, staple fibers are selected
that can be dyed with the same dye system to be used for the
tufts, and the fibers are needled through the scrim to also
provide a dyeable subface on the face side, thus additionally
affording the esthetic advantages referred to in the aforesaid
U.S. patent No. 3,605,666 without great increases in -~
manufacturing expense.
~O The foregoing are illustrative only, and additional
features, objects and advantages will appear from the
description to follow.
Brief Description of the Drawing
Fig. l is a schematic representation of a manufacturing
line for performing a preferred embodiment of the process and -
manufacturing a preferred embodiment of the product of the
invention,
Fig. ~ is an enlarged, somewhat schematic, fragmentary -
view in cross section showing a preferred embodiment of the
unitary needle-bonded backing material of the invention, as
manufactured in accordance with Fig. l, before tufting~ -
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Fig. 3 is a view similar to Fig. 2 but showing the
product after tufting,
Fig. 4 is a view similar to Figs. 2 and 3 but showing the
. . .
material after dyeing and sizing, and
Fig. 5 is a view similar to Fig. 2 but illustrating a
different embodiment.
Description of the Preferred Embodiment
The scrim used in the preferred embodiment is a generally
conventional, woven polypropylene scrim with rib~on filaments.
It is designated generally by the reference numeral l; and as
can be seen in Figs. 2 - 4 it has warp ribbons 2 (only one of
which can be seen) and weft or fill ribbons 3. The preferred
scrim is a 30 x 11 construction - meaning that there are thirty
warp ribbons and eleven fill ribbons to the inch - and weighs
approximately 3.3 ounces per square yard. The warp ribbons are
approximately .045 inches wide (which means that there is some ~ -
overlapping and/or bending to have thirty filaments per inch) and -
.0022 inches thick; and the fill ribbons are about .09 inches
wide and .0036 inches thick. While this construction is
preferred, other scrim constructions can be substituted.
Referring now to Fig. 1, the scrim 1 is fed from a supply
roll 4 to a conventional lapper 5 which deposits, on what will
be the back or bottom surface, a layer 6 of garnetted staple
fibers. The fibers are preferably nylon, 15 - 20 denier,
1.5 - 3 inches in length and are deposited at the rate of 5.5
ounces per square yard. As will be apparent to those skilled in
the art, other fibers, fiber speciflcations, and application
rates, methods and apparatus may be used.
m e product then moves through a conventional needle loom
7 where the layer is needled through the scrim 1 to develop a
backing layer 8 on the back surface and a subface 9 on the face
side. As can be seen most clearly in Fig. ~, the backing layer
8 is relatively thicker, having a weight of approximately 3.5
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ounces per square yard, and the subface 9 is relatively thinner,
with the weight of about 2 ounces per square yard. The needle
loom / preferably uses 15 x 18 x 20 x 3 dye pressed needles, 195
punches per square inch with a punching depth of 0.625 inches.
A11 of these specifications can of course be varied to meet
specific requirements, and for the preferred embodiment it would
be possible to needle from either the top or bottom.
It is important to note that it is not necessary to
needle the fibers through the scrim 1 to develop the subface 9.
The same or a lesser or greater amount of fibers can simply be
needled onto the bottom surface to develop a backing layer, and
this construction is illustrated by Fig. 5 where the backing
layer is identified by the reference numeral 8'. Needling onto
the back surface only as illustrated by Fig. 5 will of course
result in some fibers extending up through the scrim 1, as
shown, but not enough to develop the visually continuous layer ~ `
9 .
The backing as seen in Fig. 2, or as illustrated by ;~
Fig. 5, has a number of advantages over the woven scrim 1
itself. The layer 8, or 8', gives the backing significantly
greater weight, stiffness and dimensional stability. The
filaments 2 and 3 are held against relative sliding motion, and
thus the backing i9 easier to tuft through. Further, the
increased density and compaction provided by the fibers of the
layer 8 or 8' gives the backing significantly improved flame
retardance characteristics; flame retardance can be enhanced
even more by using flame retardant fibers, such as wool, for the
backing layer, but there is improvement even where less flame
retardant fibers are used because of the compaction.
The backing then passes through a conventional tufter 10,
where suitable yarn is tufted through from what will be the back
side of the carpeting to provide tufts 11 which can be seen in
Figs. 3 and 4. The tufts 11 have bases 12 which are below the
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scrim 1 and partially surrounded by the fibers of the backing
layer 8, the tufts 11 thus being held more securely in place
than if the scrim 1 were used alone - in the terminology of the
art, there is a better "tuft lock~. The specifications for the
product can be altered so that the degree to which the tuft
bases 12 are surrounded by the fibers of the layer 8 is greater
or less than that shown in Figs. 3 and 4, but the tuft bases 12
shoùld be surrounded at least partially to provide for the
desired tuft lock.
In the preferred embodiment, nylon yarn is used for the
tufting operation, but other materials could be used. Where
there is a subface 9, the tuft material is preferably compatibly
dyeable with the staple fibers - i.e. they are dyeable using the
same dye system as set forth in the aforesaid U.S. patent No.
3,605,666 - but it would be possible to use pre-dyed staple
fibers instead. The tufts can be looped as shown or cut, and
may be of any suitable height and spacing.
After tufting, the material preferably passes through a
suitable dyer 13, although dyeing can be accomplished after the
sizing operation to be described, or may not be necessary at all
to the extent that pre-dyed materials are used. Vat dyeing,
printing, or other known methods can be used, and suitable ovens
or other drying apparatus (not shown) can be used after the
dyeing step. In the preferred embodiment, the staple fibers and
tufts are dyed simultaneously by the same dye system, the
subface 9 then serving ton~sk the scrim 1 and provide a more
attractive appearance, again as set forth in the aforesaid U.S.
patent No. 3,605,666. ~he re~ulting fiber and tuft coloration
are indicated by stippling in Fig. 4, from which it can be seen
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that the dye preferably extends below the scrim 1 to color the
tuft bases 12 and backing layer 8 as well as the tufts 11 and
subface 9.
A suitable latex or other sizing is then applied to the
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back side of the carpeting, using a spray apparatus 14, or
conventional roll coating or other suitable means. In the
preferred embodiment, a carboxylated ssR (styrene butadiene
rubber) based compound is used and it is applied at the rate of
3 - 30 ounces per s~uare yard, depending on the method of
application. As can be seen in Fig. 5, the sizing material,
which is indicated by the reference numeral 15, is dispersed to
some extent throughout the backing layer 8, but is not above the
scrim 1. The greatest concentration is on the bottom surface,
but it is not necessary to use sufficient sizing material to
develop an actual continuous skin on the back surface of the ~ :
carpeting. After application, the sizing 15 is dried by passing ~
the carpeting through a conventional oven 16, or drying can be -
accomplished using a can dryer or other suitable means. After ~ ,
drying, the product is complete and is wound on a storage roll
17.
The final carpeting, illustrated in Fig. 4, has excellent
stiffness, dimensional stability and flame retardance, and it is
unnecessary to provide a conventional secondary backing material
such as jute or a layer of foam. The dyeable subface 9, if
provided, gives the improved esthetic characteristics noted
above. At the same time, the product and the process for
manufacturing it are relatively simple and inexpensive.
While preferred embodiments of the invention have been
2~ shown and described, various changes in materials and
specifications can be made as noted above or otherwise. The
invention is not, therefore, intended to be limited by the
showing or description herein, or in any other manner, except
insofar as may specifically be required.
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