Note: Descriptions are shown in the official language in which they were submitted.
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BLISTER FABRICS
WITH INTERNAL CONNECTING ELEMENTS
BACKGROUND
The present invention relates to fabrics having internal connecting elements
to
help stabilize the fabric construction.
Many methods have been used to stabilize the construction of a knit or woven
fabric. Coatings have been applied to prevent the yarns from moving. However,
coatings alone may not give the fabric the additional desired characteristics.
Recently, a process known as hydroentanglement has been employed to provide
stabilization to woven fabrics. Hydroentanglement uses fluid jets to force
fibers
extending from the main body of a yarn to entangle with fibers extending from
the
main body of another yarn. However, hydroentanglement can sometimes affect the
aesthetic characteristics of the fabric due to the large number of free fibers
needed
to create entanglements by the fluid jets. Therefore, there is a need for
fabrics that
have been stabilized by other methods, and the particular methods for
stabilizing the
fabrics.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top view of a blister fabric illustrating one embodiment of the
present invention;
FIG. 2 is an enlarged cross sectional view of the blister fabric from FIG. 1,
taken about the section lines 2-2.
FIG. 3 is an enlarged cross sectional view of another embodiment of the
present invention, using a composite of two separate layers of fabric.
FIG. 4 is an enlarged partial view of a needle used in the present invention.
FIGS. 5A and 5B are diagrams illustrating stitches used in one example of the
present invention.
DETAILED DESCRIPTION
Referring now to the figures, and in particular FIGS. 1-2, there is shown a
blister fabric 10 illustrating one embodiment of the present invention. The
blister
fabric 10 has alternating zones of blister zones 100 and base zones 200. The
blister
zones 100 have a lower blister layer 110 of a first material independent of an
upper
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blister layer 120 of a second material. The base zones 200 are a unified layer
of
material.
As illustrated, the blister fabric 10 is formed of base yarns 11 and blister
yarns
12. In one embodiment, the blister fabric 10 is formed from yarns having a
size of up
to about 600 denier. In another embodiment, the blister fabric 10 is formed
from
yarns having a size of at least about 15 denier. In one preferred embodiment,
the
fibers forming the base yarns 11 and the blister yarns 12 can both comprise
filament
yarns. As used herein, filament yarns includes multifilament yarns. In another
embodiment, the base yarns 11 and the blister yarns 12 can both comprise spun
yarns. In yet another embodiment, the base yarns 11 can comprise filament
yarns
and the blister yarns 12 can comprise spun yarns. In yet another embodiment,
the
base yarns 11 can comprise spun yarns and the blister yarns 12 can comprise
filament yarns. It is also contemplated that the present invention will work
with yarns
of combined filament and staple fiber. The combined filament and staple fiber
yarns
can be used in the base yarns 11 and/or the blister yarns 12 as a substitute
for either
the filament yarns and/or spun yarns in the above combinations. The fibers of
the
filament and/or spun yarns in the present invention can be formed from natural
or
manufactured material. For example, natural materials can include materials of
animals, vegetable, or mineral origin which are used as fibers. Manufactured
materials can include polymers synthesized from chemical compounds, modified
or
transformed natural polymers and minerals.
Still referring to FIGS. 1-2, as illustrated, the lower blister layer 110 of
the
blister fabric 10 is a jersey knit of the base yarns 11, and the upper blister
layer 120
of the blister fabric 10 is a jersey knit of the blister yarns 12. Also as
illustrated, the
base yarns 11 form a unified double layer jersey knit in the base zones 200,
and the
blister yarns 12 are sandwiched between the unified double layer jersey knit
of the
base yarns 11 in the base zones 200. Although the blister fabric 10 is
illustrated as
an all knitted fabric, it is contemplated that the blister fabric can be a
woven fabric, or
a combination of knit and woven fabric. Additionally, although the unified
base
zones 200 are illustrated as a knitted together section, it is contemplated
that the
unified base zones could be formed by processes such as weaving, stitching,
bonding, or the like.
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Referring now to FIG. 2, there is shown an enlarged cross sectional area of
the blister fabric 10. As illustrated, blister zone connections 130 are formed
between the lower blister layer 110 and the upper blister layer 120 by
portions of the
fibers from the yarns in one layer of the blister zone 100 passing from those
yarns
into, and/or between, the yarns of the other layer of the blister zone 110.
Lower
blister layer connections 131 are formed between the lower blister layer 110
and the
upper blister layer 120 by portions of the fibers from the yarns in the lower
blister
layer 110 passing from those yarns into, and/or between, the yarns of the
upper
blister layer 120. Upper blister layer connections 132 are formed between the
upper
blister layer 120 and the lower blister layer 110 by portions of fibers from
the yarns in
the upper blister layer 120 passing from those yarns into, and/or between, the
yarns
or of the lower blister layer 100. The lower blister layer connections 131 and
the
upper blister layer connections 132 provide a securing tie between the lower
blister
layer 110 and the upper blister layer 120.
Still referring to FIG. 2, a fiber forming one of the lower blister layer
connections 131 originates from a yarn in the lower blister layer 110 and then
projects into the upper blister layer 120. The fibers from the lower blister
layer 110
forming the lower blister layer connections 131 are secured by the fibers or
filaments
in the main body of the yarns in the upper blister layer 120. A portion of the
fibers
forming the lower blister layer connections 131 are secured between fibers
within the
main body of the yarns in the upper blister layer 120, the main body being the
group
of fibers which are oriented in about the same direction as the yarn itself.
Another
portion of the fibers forming the lower blister layer connections 131 are
secured
between yarns of the upper blister layer 120 by the fibers in the main body of
those
yarns. A fiber forming one of the upper blister layer connections 132
originates from
a yarn in the upper blister layer 120 and then projects into the lower blister
layer 110.
The fibers from the upper blister layer 120 forming the upper layer
connections 132
are secured by the fibers or filaments in the main body of the yarns in the
lower
blister layer 110. A portion of the fibers forming the upper blister layer
connections
132 are secured between fibers within the main body of the yarns in the lower
blister
layer 110, the main body being the group of fibers which are oriented in about
the
same direction as the yarn itself. Another portion of the fibers forming the
upper
blister layer connections 132 are secured between yarns of the lower blister
layer
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110 by the fibers in the main body of those yarns. These types of connections
contrast with connections formed between yarns and layers by the entanglement
of
fibers extending generally outward and at least partially radial from one yarn
with the
fibers extending in a direction generally outward and at least partially
radial from
another yarn, as experienced with many of the hydroentanglement methods of
treating a fabric.
Many of the lower blister layer connections 131 and the upper blister layer
connections 132 are loops of the fibers from the respective source layers that
insert
into the corresponding receiving layers. The loops of fibers create two
connections,
each of the connections being one half of the loop that originates in the same
yarn
and then project into the same receiving layer. In some instances, the upper
blister
layer connections 131 and/or the lower blister layer connections 132 can be
formed
by sections of the fibers that are attached at only one end to the respective
source
yarns. In some further instances, a fiber attached at only one end and forming
an
upper blister layer connection 131 or a lower blister layer connection 132 can
be
hooked, bent, or looped at the free end to further secure with the fibers of
the
corresponding layer to which the connection engages.
In one embodiment, the blister zone of a fabric incorporating the present
invention, has a total of at least about 275 total connections (the total of
both the
connections originating from a particular layer and the connections received
by that
particular layer) per square inch securing the lower blister layer to the
upper blister
layer, and a maximum of about 520,000 total connections per square inch,
depending on the stability needed and the construction of the fabric. In one
preferred embodiment, the blister zone has a total of from about 350 total
connections per square inch to about 1,050 total connections per square inch,
and
more preferably about 750 total connections per square inch.
Because the source of the connections comes from within yarns, and the
connections also secure yarns, it is helpful to understand the number of total
connections (the total of both connections originated from a particular yarn
and the
connections received by that particular yarn) per yarn distance. In one
embodiment,
the yarns that form the upper blister layer or the upper blister layer in the
blister zone
of the fabric incorporating the present invention, have a minimum of at least
about
1.1 total connections per yarn-inch securing the yarn, and a maximum of about
1,650
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total connections per yarn-inch. In one preferred embodiment, the yarns that
form
the lower blister layer or the upper blister layer of the blister zone of the
fabric
incorporating the present invention, have from about 1.4 total connections per
yarn-
inch to about 4.2 total connections per yarn-inch, and more preferably about
2.8 total
5 connections per yarn-inch.
Because the fibers of the yarn are the source of the connections, different
yarns will have different availability of fibers for the connection, and
different needs
for the amount of connections based on the fiber content of the yarn. A
measurement of filament-distance is length of a yarn having filaments)
multiplied by
the number of filaments in that yarn bundle. Therefore, it is helpful to
understand the
number of total connections (the total of both connections originated from a
particular
yarn and the connections received by that particular yarn) per filament
distance of
the yarns for the portion of the fabric incorporating the present invention.
In one
embodiment, the yarns that form the lower blister layer or the lower blister
layer in
the blister zone, have at least about 0.02 total connections per filament-
inch, and a
maximum of about 6.4 total connections per filament-inch. In one preferred
embodiment, the yarns that form the upper blister layer or the lower blister
layer of
the blister zone have from about 0.022 total connections per filament-inch to
about
0.07 total connections per filament-inch, and more preferably about 0.04 total
connections per filament-inch.
Referring again to FIG. 2, the base zone 200 is a unitary construction with a
lower base layer portion 210, an upper base layer portion 220, and trapped
yarns
230 passing between the upper base layer portion 210 and the upper base layer
portion 220. In the embodiment illustrated, the lower base layer portion 210
and the
upper base layer portion 220 are formed by the base yarns 11, and the blister
yarns
12 form the trapped yarns 230 between the two layers. As illustrated, base
layer
connections 240 are formed between the lower base layer portion~210 and the
upper
base layer portion 220. Also, trapped yarn connections 250 are formed between
the
lower base layer 210 and the trapped yarn 230 and the upper base layer portion
220
and the trapped yarn portion 230.
Referring still to FIG. 2, similar to the blister zone connections 230, the
base
layer connections 240 are formed between the lower base layer 210 and the
upper
base layer 220 by portions of the fibers from the yarns in one layer of the
base zone
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200 passing from those yarns into the other layer of the base zone 200. Lower
base
layer connections 241 are formed by fibers that originate from a yarn in the
lower
base layer 210 and then project into. and/or between, the yarns of the upper
base
layer 220. The fibers from the lower base layer 210 forming the lower base
layer
connections 241 are secured by the fibers or filaments in the main body of the
yarns
in the upper base layer 220. A portion of the fibers forming the lower base
layer
connections 241 are secured between fibers within the main body of the yarns
in the
upper base layer 220, the main body being the group of fibers which are
oriented in
about the same direction as the yarn itself. Another portion of the fibers
forming the
lower base layer connections 241 are secured between yarns of the upper base
layer 220 by the fibers in the main body of those yarns. Upper base layer
connections 242 are formed by fibers that originate from a yarn in the upper
base
layer 220 and then project into the lower base layer 210. The fibers from the
upper
base layer 220 forming the upper base layer connections 242 are secured by the
fibers or filaments in the main body of the yarns in the lower base layer 210.
A
portion of the fibers forming the upper base layer connections 242 are secured
between fibers within the main body of the yarns in the lower base layer 210,
the
main body being the group of fibers which are oriented in about the same
direction
as the yarn itself. Another portion of the fibers forming the upper base layer
connections 242 are secured between yarns of the lower base layer 210 by the
fibers in the main body of those yarns. The lower base layer connections 241
and
the upper base layer connections 242 provide a securing tie between the lower
base
layer 210 and the upper base layer 220.
As with the lower blister layer connections 131 and the upper blister layer
connections 132, many of the lower base layer connections 241 and the upper
base
layer connections 242 are loops of the fibers in the respective source yarns
that
insert into the corresponding receiving layer. In some instances, the lower
base
layer connections 241 and/or the upper blister layer connections 242 can be
formed
by sections of the fibers that are attached at only one end to the respective
source
yarns. In some further instances, a fiber attached at only one end and forming
a
lower base layer connection 241 or an upper base layer connection 242 can be
hooked, bent, or looped at the free end to further secure with the fibers of
the
corresponding receiving layer to which the connection engages. The base layer
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connections 240 provide a securing tie between the lower base layer 210 and
the
upper base layer 220, thereby giving the base zone 200 a more stabilized and
abrasion resistant fabric.
In one embodiment, the base zone of a fabric incorporating the present
invention has a total of at least about 57 total connections (the total of
both the
connections originating from a particular layer and the connections received
by that
particular layer) per square inch securing the lower base layer to the upper
base
layer, and a maximum of about 109,110 total connections per square inch, and
more
preferably about 150 total connections per square inch, depending on the
stability
needed and the construction of the fabric. In one embodiment, the yarns that
form
the lower base layer of the upper base area of the base zone of the fabric
incorporating the present invention, have a minimum of at least about 0.6
total
connections per yarn-inch securing the yarn, and a maximum of about 11.61
total
connections per inch, and more preferably about 1.6 total connections per yarn-
inch.
In one embodiment, the yarns forming the connections have from about 28.8
connections per filament-inch to about 557 connections per filament-inch.
Still Referring to FIG. 2, the trapped yarn connections 250 are formed
between the trapped yarns 230 and the lower base layer 210 and the upper base
layer 220, by portions of the fibers from the trapped yarn 230 passing into,
and/or
between, the main body of the yarns in the lower base layer 210 or the upper
base
layer 220, and/or fibers from yarns in the lower base layer 210 or the upper
base
layer 200 passing into the trapped yarn 230. Lower base trapped yarn
connections
251 are formed between the trapped yarns 230 and the lower base layer 210 by
portions of the fibers from the yarns in the lower base layer 210 passing from
those
yarns into the main body of the trapped yarns 230, and by fibers from the
trapped
yarns passing from the trapped yarns 230 into, and/or between the maih body of
the
yarns of the lower base layer 210. Upper base trapped yarn connections 252 are
formed between the trapped yarns 230 and the upper base layer 220 by portions
of
the fibers from the yarns in the upper base layer 220 passing from those yarns
into
the main body of the trapped yarns 230, and by fibers from the trapped yarns
230
passing from the trapped yarns 230 into, and/or between, the main body of the
yarns
of the upper base layer 220.
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As with the lower base layer connections 241 and the upper base layer
connections 242, many of the lower base trapped yarn connections 251 and the
upper base trapped yarn connections 252 are loops of the fibers in the
respective
source yarns that insert into the corresponding receiving yarns or layer. In
some
instances, the lower base trapped yarn connections 251 and/or the upper base
trapped yarn connections 252 can be formed by sections of the fibers that are
attached at only one end to the respective source yarns. In some further
instances,
a fiber attached at only one end and forming an lower base trapped yarn
connection
251 or an upper base trapped yarn connection 252 can be hooked, bent, or
looped
at the free end to further secure with the fibers of the corresponding
receiving yarn or
layer to which the connection engages.
The trapped yarn connections 250 provide a securing tie between the trapped
yarn 230 and the lower base layer 210, and the trapped yarn 230 and the upper
base layer 220, thereby giving the base zone 200 a more stabilized and
abrasion
resistant fabric. In one embodiment, the yarns that form the trapped yarns of
the
base zone of the fabric incorporating the present invention, have a minimum of
at
least about 0.6 total connections per yarn-inch securing the yarn, a maximum
of
about 11.61 total connections per yarn-inch, and more preferably about 1.6
total
connections per yarn-inch. In one embodiment, the trapped yarns have from
about
28.8 connections per filament-inch to about 557 connections per filament-inch.
In one embodiment, the needled blister fabric 10 also includes a back coating
disposed on the back side of the lower blister layer 110 and the lower base
layer
210. It has been found that a backcoating further improves the abrasion
resistance
of the opposite side of the needled blister fabric 10. The back coating can be
any
polymeric material, such as latex, polyvinylacetate, or the like. The back
coating can
be applied at a level of from about 0.25 oz/yd2 to about 5 oz/yd2.
Referring now to FIG. 3, there is shown an enlarged cross section of a fabric
composite 20 illustrating another embodiment of the present invention. The
fabric
composite 20 is a multiple layered cloth, such as a double cloth, a triple
cloth, etc.
The fabric comprises at least a first layer 21 and a second layer 22. At least
one of
the first layer 21 and the second layer is a knitted fabric. In the embodiment
illustrated in FIG. 3, the first layer 21 is formed from first layer yarns 23,
and the
second layer 22 is formed from second layer yarns 24. In one embodiment, the
first
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layer yarns 23 and/or the second layer yarns 24 have a yarn size of up to
about 600
denier. In another embodiment, the first layer yarns 23 and/or the second
layer
yarns 24 have a yarn size of at least about 15 denier. In one preferred
embodiment,
both the first layer yarns 23 and the second layer yarns 24 comprise
filaments. In
another embodiment, the first layer yarns 23 are filament yarns and the second
layer
yarns 24 are spun yarns. In yet another embodiment, both the first layer yarns
23
and the second layer yarns 24 are spun yarns. Additionally, it is contemplated
that
first layer yarns 23 and/or the second layer yarns 24 can include yarns formed
of the
combination of filaments and staple fibers.
Connections 25 are formed between the first layer 21 and the second layer 22
by filaments of the yarns in the two layers. First layer connections 26 are
formed by
portions of the fibers in the first layer 21 that project into the second
layer 22. The
first layer connections 25 are secured by the fibers of the main body of the
second
layer yarns 24. Second layer connections 27 are formed by portions of the
fibers in
the second layer 22 that project into the first layer 21. The second layer
connections
27 are secured by fibers of the main body of the first layer yarns 23. It is
contemplated that the connections 25 of the present invention can be formed
across
the entire composite fabric 20, or in discrete zones.
Many of the first layer connections 26 and the second layer connections 27
are loops of the fibers from the respective source layers that insert into the
corresponding receiving layers. The loops of fibers create two connections,
each of
the connections being one half of the loop that originates in the same yarn
and then
project into the same receiving layer. In some instances, the first layer
connections
26 and/or the second layer connections 27 can be formed by sections of the
fibers
that are attached at only one end to the respective source yarns. In some
further
instances, a fiber attached at only one end and forming a first layer
connection 26 or
a second layer connection 27 can be hooked, bent, or looped at the free end to
further secure with the fibers of the corresponding layer to which the
connection
engages.
In one embodiment, the composite fabric, or zone of the composite fabric
incorporating the present invention, has a total of at least about 275 total
connections (the total of both the connections originating from a particular
layer and
the connections received by that particular layer) per square inch securing
the first
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layer to the second layer, and a maximum of about 520,000 total connections
per
square inch, depending on the stability needed and the construction of the
fabric. In
one preferred embodiment, there is a total of from about 350 fiotal
connections per
square inch to about 1,050 total connections per square inch, and more
preferably
5 about 750 total connections per square inch.
In one embodiment, the yarns that form the first layer or the second layer of
the composite fabric incorporating the present invention, have a minimum of at
least
about 1.1 total connections per yarn-inch securing the yarn, and a maximum of
about
1,650 total connections per yarn-inch. In one preferred embodiment, these
yarns
10 have from about 1.4 total connections per yarn-inch to about 4.2 total
connections
per yarn-inch, and more preferably about 2.3 total connections per yarn-inch.
In one embodiment, the yarns that form the first layer or the second layer of
the composite fabric incorporating the present invention, have at least about
0.02
total connections per filament-inch, and a maximum of about 6.4 total
connections
per filament-inch. In one preferred embodiment, these yarns have from about
0.022
total connections per filament-inch to about 0.07 total connections per
filament-inch,
and more preferably about 0.04 total connections per filament-inch.
In one method of making the present invention, the fabric to be further
processed is formed and then subjected to a needling process. In one
embodiment,
the fabric can be a blister fabric which is formed by standard knitting or
weaving
techniques of filament yarns. The blister fabric includes areas with two
separated
layers of knitted material, and areas of a double layer jersey knit with yarns
from one
of the two separated layers sandwiched between the layers of the double layer
jersey knit. In another embodiment, the fabric two be processed is two layers
that are
to be joined in the subsequent processing. At least one of the layers in a
multilayer
fabric to be processed is a knitted fabric, and both layers could be a knitted
fabric. In
a preferred embodiment, the yarns forming the fabric to be processed are
filament
yarns. However, it is contemplated that the yarns could include shorter fibers
or
could be spun fiber yarns with, or without, filaments.
The formed fabric to be processed is fed into a needling machine that needles
the fabric by the insertion of a bed of needles into the fabric. Typically,
the needling
machine inserts the needles into the fabric, and withdraws the needles, at a
direction
generally perpendicular to the surface of the fabric. Backing plates provide
support
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to the fabric on the opposite side of the needle bed, and have openings to
allow the
needles to pass completely through the fabric. The needles can be inserted and
withdrawn from either side of the fabric, or both sides of the fabric. By
inserting the
needles from only one side, connections will only be generated by the side of
the
fabric to be processed that the needles are inserted. If more needle
insertions per
square area are required than can be provided by a single insertion of the bed
of
needles, then the bed of needles can be inserted more than once in a
particular area
of the fabric, or multiple beds of needles can be used to be inserted into the
same
area.
In one embodiment, the needling machine inserts the needles into the fabric
in a manner that produces little to no relative motion between the beds of
needles
and the fabric in the linear direction (the machine direction) as the fabric
moves into,
through, and exits needling machine. The relative linear motion between the
needle
beds and the fabric can be accomplished by moving the needle beds with the
direction of travel of the fabric as the needles are inserted into the fabric
and
removed from the fabric. After the fabric is needled, a backcoating can be
applied to
the fabric by various known methods, such as knife coating, foam coating,
lamination, spray coating, or other similar methods.
Referring now to FIG. 4, there is shown an enlarged partial view of one
embodiment of one of the needles 400 used in the present invention. The needle
400 has a pointed end 410 and notches 420 along the length of the needle 400.
The
pointed end 410 of the needle 400 facilitates the passage of the needle 400
through
the yarns and the fabric layers. The notches 420 of the needle 400 pick up or
"hook"
fibers of the yarns as the needle 400 passes through the yarns and fabric
layers. As
the needle 400 continues to pass through adjacent yarns and/or fabric layers,
the
fibers previously hooked by the notches 420 of the needle 400 are moved into
the
main body of the adjacent yarns and/or fabric layers. The movement of the
fibers by
the needle 400 will stretch or pull the fibers from the originating yarns. For
fibers
with free ends near the needle 400, the fiber will follow the notch 420 of the
needle
400 until the free end of the fiber passes through the notch 420 or the needle
400
reaches the end of its travel, and fiber is deposited into the adjacent yarn
and/or
fabric layer. For other fibers, the fiber will pass into the adjacent yarn
and/or layer
until the needle 400 reaches the end of its travel, or the tension in the
fiber causes
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the fiber to come free from the notch 420, or the fiber breaks. The portion of
the fiber
that follows the needle and becomes free from the needle, or breaks, will
deposit that
portion of the fiber into the adjacent yarn and/or layer.
The result is a positive movement of a portion of the fibers and/or filaments
of
the yarn directly into the main body of the adjacent yarns and/or fabric
layers where
those fibers and/or filaments create an anchor directly within the main body
of the
adjacent yarns and/or fabric layers. The fiber and/or filament left in the
adjacent yarn
forms the connection between the fabric layers or the yarns of a fabric layer.
In
contrast, methods such as hydroentanglement force fibers external to the main
body
of a yarn to entangle with fibers external to another yarn, providing a less
direct
connection between the two components. Additionally, hydroentanglement has a
limited ability to provide stability to a filament yarn fabric because there
are no or few
free ends of the filaments that can be broken free from the main body of the
yarn
and/or fabric layer to entangle with the free ends of filaments from other
yarns and/or
layers.
EXAMPLE 1
The present invention can be better understood with reference to the following
Example. The fabric is a blister fabric formed of two 1/200/48 yarns of
difFerent color
for the base yarns and 2/150/50 yarns for the blister yarns. The blister
fabric is
formed on a two bed circular knitting machine with the knitting pattern as
shown in
FIGS. 5A and 5B. On the back of the fabric, the two base yarns are used to
make
two different colors knitted in alternate courses, each yarn having about 18
courses
per inch each (combined making about 36 courses per inch) and about 13 wales
per
inch (combined making about 26 wales per inch). The blister yarn does not get
knitted in the back of the fabric. On the face of the fabric in the blister
zone, the
blister yarn forms a jersey knit with about 32 courses per inch and about 28
wales
per inch. Also on the face, but in the base area, the two base yarns are
knitted in
alternate courses, each yarn having about 18.25 courses per inch each
(combined
making about 36.5 courses per inch) and about 14 wales per inch (combined
making about 28 wales per inch).
The blister fabric was then subjected to a needling process to form the
connections in the fabric. A Dilo Hyperpunch Double Needle Loom (Dilo
Manufacturing Co.) was used to needle the fabric with a needling motion that
had
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little to no relative motion in the machine direction between the fabric and
the needle
bed. The needle bed contained Groz-Beckert F222 needles, which are a
triangular
needle with six notches (2 per corner edge of the needle). The needle bed was
inserted into the fabric sufficient times that about 900 needle insertions
were made
per square centimeter of the fabric. It was found that this needling process
resulting
in about 350 connections per square inch of the fabric in the blister zone,
which was
about 1.4 connections per yarn inch and about 0.022 connections per filament
inch.
The needled fabric was then backcoated with about 3 oz/yd2 of latex.
The face of the fabric was subjected to the Taber snag testing according to
SAE J948, using H-13 wheels with 1000 grams weight for 200 cycles for samples
that were not needled, and samples that were needled. For fabric that was not
needled, the face of the fabric received a rating of 3Ø For fabric that was
needled,
the face of the fabric obtained a rating of 3.5.