U.S. patent application number 11/175422 was filed with the patent office on 2007-02-15 for method for relofting a nonwoven fiber batt.
Invention is credited to Steven E. Ogle, Kenneth C. Thompson.
Application Number | 20070035058 11/175422 |
Document ID | / |
Family ID | 37741877 |
Filed Date | 2007-02-15 |
United States Patent
Application |
20070035058 |
Kind Code |
A1 |
Ogle; Steven E. ; et
al. |
February 15, 2007 |
Method for relofting a nonwoven fiber batt
Abstract
A method for relofting a nonwoven fiber product comprises
forming a high-loft nonwoven fiber batt, compressing the high-loft
nonwoven fiber batt to form a compressed fiber batt, securing the
compressed fiber batt with a restraint, such that the compressed
fiber batt will expand in the absence of the restraint, removing
the restraint from the compressed fiber batt, thereby allowing the
compressed fiber batt to expand into an expanded fiber batt, and
relofting the expanded fiber batt using heat, thereby increasing
the thickness of the expanded fiber batt to produce a relofted
fiber batt. In an embodiment, the high-loft nonwoven fiber batt has
a first thickness, the compressed fiber batt has a second thickness
less than the first thickness, the expanded fiber batt has a third
thickness greater than the second thickness, and the relofted fiber
batt has a fourth thickness greater than the third thickness.
Inventors: |
Ogle; Steven E.;
(Murphreesboro, TN) ; Thompson; Kenneth C.;
(Antioch, TN) |
Correspondence
Address: |
CONLEY ROSE, P.C.
5700 GRANITE PARKWAY, SUITE 330
PLANO
TX
75024
US
|
Family ID: |
37741877 |
Appl. No.: |
11/175422 |
Filed: |
July 6, 2005 |
Current U.S.
Class: |
264/113 |
Current CPC
Class: |
D04H 1/06 20130101 |
Class at
Publication: |
264/113 |
International
Class: |
D04H 1/16 20060101
D04H001/16 |
Claims
1. A method for relofting a nonwoven fiber product, the method
comprising: forming a high-loft nonwoven fiber batt; compressing
the high-loft nonwoven fiber batt to form a compressed fiber batt;
securing the compressed fiber batt with a restraint, such that the
compressed fiber batt will expand in the absence of the restraint;
removing the restraint from the compressed fiber batt, thereby
allowing the compressed fiber batt to expand into an expanded fiber
batt; and relofting the expanded fiber batt using heat, thereby
increasing the thickness of the expanded fiber batt to produce a
relofted fiber batt.
2. The method of claim 1: wherein the high-loft nonwoven fiber batt
has a first thickness; wherein the compressed fiber batt has a
second thickness less than the first thickness; wherein the
expanded fiber batt has a third thickness greater than the second
thickness; and wherein the relofted fiber batt has a fourth
thickness greater than the third thickness.
3. The method of claim 2 wherein the fourth thickness is greater
than the first thickness.
4. The method of claim 3 wherein the high-loft nonwoven fiber batt
is compressed without the use of heat.
5. The method of claim 4 wherein substantially all of the
compression occurs in the thickness direction of the high-loft
nonwoven fiber batt.
6. The method of claim 5 wherein the third thickness in inches is
greater than the weight per unit area in ounces per square foot of
the expanded fiber batt.
7. The method of claim 1 wherein the restraint is a band that
constricts the compressed fiber batt.
8. The method of claim 1 wherein the high-loft nonwoven fiber batt
comprises a plurality of binder fibers and a plurality of carrier
fibers.
9. The method of claim 8 wherein the binder fibers are sheath-core
bicomponent fibers and the carrier fibers are polyester fibers.
10. The method of claim 1 wherein a vacuum is used to compress the
high-loft nonwoven fiber batt.
11. A nonwoven fiber product relofted according to the method of
claim 1.
12. A method for relofting a nonwoven fiber product, the method
comprising: forming a high-loft nonwoven fiber batt; compressing
the high-loft nonwoven fiber batt without the use of heat, thereby
forming a compressed fiber batt; securing the compressed fiber batt
with a restraint, such that the compressed fiber batt will expand
in the absence of the restraint; removing the restraint from the
compressed fiber batt, thereby allowing the compressed fiber batt
to expand into an expanded fiber batt; and relofting the expanded
fiber batt using heat, thereby increasing the thickness of the
expanded fiber batt to produce a relofted fiber batt.
13. The method of claim 12 wherein substantially all of the
compression occurs in the thickness direction of the high-loft
nonwoven fiber batt.
14. The method of claim 13: wherein the high-loft nonwoven fiber
batt has a first thickness; wherein the compressed fiber batt has a
second thickness less than the first thickness; wherein the
expanded fiber batt has a third thickness greater than the second
thickness; and wherein the relofted fiber batt has a fourth
thickness greater than the third thickness.
15. The method of claim 14 wherein the fourth thickness is greater
than the first thickness.
16. A method for relofting a nonwoven fiber product, the method
comprising: forming a high-loft nonwoven fiber batt; compressing
the fiber batt without the use of heat to form a compressed fiber
batt, wherein substantially all of the compression occurs in the
thickness direction of the fiber batt; expanding the compressed
fiber batt into an expanded fiber batt; relofting the expanded
fiber batt using heat, thereby increasing the thickness of the
expanded fiber batt to produce a relofted fiber batt.
17. The method of claim 16 further comprising: securing the
compressed fiber batt with a restraint, such that removal of the
restraint expands the fiber batt; and removing the restraint from
the compressed fiber batt, thereby producing the expanded fiber
batt.
18. The method of claim 16 wherein a vacuum is used to compress the
fiber batt.
19. The method of claim 16: wherein the high-loft nonwoven fiber
batt has a first thickness; wherein the compressed fiber batt has a
second thickness less than the first thickness; wherein the
expanded fiber batt has a third thickness greater than the second
thickness; and wherein the relofted fiber batt has a fourth
thickness greater than the third thickness.
20. The method of claim 19 wherein the fourth thickness is greater
than the first thickness.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
REFERENCE TO A MICROFICHE APPENDIX
[0003] Not applicable.
BACKGROUND
[0004] Manufacturers are constantly seeking new ways to reduce
their production costs, which thereby decreases the price of their
products and/or increases their profits. For nonwoven fiber batt
manufacturers, production costs include shipping costs to transport
their products to the customer. Fiber batt manufacturers generally
transport their products by commercial freight carrier using a
ship, train, aircraft, or truck, such as an 18-wheeler. Commercial
freight carriers typically charge for their services by volume of
product transported, such as by the trailer load. If the
manufacturer could reduce the volume of each individual nonwoven
fiber batt, then the quantity of nonwoven fiber batts that could be
loaded into each trailer would increase, thereby reducing the per
batt transportation cost. Thus, a need exists for a method of
reducing the volume of a nonwoven fiber batt to thereby reduce
transportation costs.
[0005] However, some methods of reducing the volume of a fiber batt
tend to destroy the loft and resilient memory of the batt. For
example, it is possible to compress a high-loft fiber batt until it
becomes a densified fiber batt in which the air spaces therein are
substantially reduced or eliminated. Doing so destroys the
advantageous properties of loft and resilient memory inherent in
the high-loft fiber batt such that the batt will not expand
sufficiently when the compressive force is released. Accordingly,
while such compression methods succeed in reducing volume, they are
unsuitable for high-loft fiber batts. Therefore, a need exists for
a method of reducing the volume of a high-loft fiber batt such that
the loft and resilient memory of the fiber batt is not
destroyed.
[0006] Another problem encountered when reducing the volume of
high-loft fiber batts is that the uncompressed thickness of the
fiber batt may be permanently decreased when the fiber batt has
been compressed for an extended period of time. For example, a
two-inch thick, high-loft nonwoven fiber batt that is compressed to
one-inch thick and stored for an extended period of time may only
expand to a thickness of one and three-quarters inches when the
compressive force is removed. Although such a decrease in thickness
appears marginal, in applications where there is a small tolerance
for thickness variations, the decrease can render the fiber batt
unsuitable for its intended purpose. One solution to this problem
is to store uncompressed fiber batts or transport uncompressed
fiber batts to the customers. However, for the reasons disclosed
herein, it is not preferable to store or transport the fiber batt
without first compressing it. Consequently, a need exists for a
method of compressing a high-loft fiber batt for transportation
and/or storage without destroying its loft and resilient memory. A
need also exists for a method of returning the high-loft fiber batt
to its original thickness after the compressive force has been
released.
SUMMARY
[0007] In one aspect, the invention is a method for relofting a
nonwoven fiber product, the method comprising: forming a high-loft
nonwoven fiber batt; compressing the high-loft nonwoven fiber batt
to form a compressed fiber batt; securing the compressed fiber batt
with a restraint, such that the compressed fiber batt will expand
in the absence of the restraint; removing the restraint from the
compressed fiber batt, thereby allowing the compressed fiber batt
to expand into an expanded fiber batt; and relofting the expanded
fiber batt using heat, thereby increasing the thickness of the
expanded fiber batt to produce a relofted fiber batt. In an
embodiment, the high-loft nonwoven fiber batt has a first
thickness; the compressed fiber batt has a second thickness less
than the first thickness; the expanded fiber batt has a third
thickness greater than the second thickness; and the relofted fiber
batt has a fourth thickness greater than the third thickness. In
embodiments the fourth thickness is greater than the first
thickness, the high-loft nonwoven fiber batt is compressed without
the use of heat, substantially all of the compression occurs in the
thickness direction of the high-loft nonwoven fiber batt, and/or
the third thickness in inches is greater than the weight per unit
area in ounces per square foot of the expanded fiber batt.
Variously, the restraint is a band that constricts the compressed
fiber batt, the high-loft nonwoven fiber batt comprises a plurality
of binder fibers and a plurality of carrier fibers, the binder
fibers are sheath-core bicomponent fibers and the carrier fibers
are polyester fibers, and/or a vacuum is used to compress the
high-loft nonwoven fiber batt. The invention includes a nonwoven
fiber product relofted according to the method.
[0008] In another aspect, the invention includes a method for
relofting a nonwoven fiber product, the method comprising: forming
a high-loft nonwoven fiber batt; compressing the high-loft nonwoven
fiber batt without the use of heat, thereby forming a compressed
fiber batt; securing the compressed fiber batt with a restraint,
such that the compressed fiber batt will expand in the absence of
the restraint; removing the restraint from the compressed fiber
batt, thereby allowing the compressed fiber batt to expand into an
expanded fiber batt; and relofting the expanded fiber batt using
heat, thereby increasing the thickness of the expanded fiber batt
to produce a relofted fiber batt. In an embodiment, substantially
all of the compression occurs in the thickness direction of the
high-loft nonwoven fiber batt. In another embodiment, the high-loft
nonwoven fiber batt has a first thickness; the compressed fiber
batt has a second thickness less than the first thickness; the
expanded fiber batt has a third thickness greater than the second
thickness; and the relofted fiber batt has a fourth thickness
greater than the third thickness. Variously, the fourth thickness
is greater than the first thickness, the restraint is a band that
constricts the compressed fiber batt, the high-loft nonwoven fiber
batt comprises a plurality of binder fibers and a plurality of
carrier fibers, the binder fibers are sheath-core bicomponent
fibers and the carrier fibers are polyester fibers, and/or a vacuum
is used to compress the high-loft nonwoven fiber batt. The
invention includes a nonwoven fiber product relofted according to
the method.
[0009] In a third aspect, the invention is a method for relofting a
nonwoven fiber product, the method comprising: forming a high-loft
nonwoven fiber batt; compressing the fiber batt without the use of
heat to form a compressed fiber batt, wherein substantially all of
the compression occurs in the thickness direction of the fiber
batt; expanding the compressed fiber batt into an expanded fiber
batt; relofting the expanded fiber batt using heat, thereby
increasing the thickness of the expanded fiber batt to produce a
relofted fiber batt. In an embodiment, the method further
comprises: securing the compressed fiber batt with a restraint,
such that removal of the restraint expands the fiber batt; and
removing the restraint from the compressed fiber batt, thereby
producing the expanded fiber batt. In embodiments, the restraint is
a band that constricts the compressed fiber batt and/or a vacuum is
used to compress the fiber batt. In yet another embodiment, the
high-loft nonwoven fiber batt has a first thickness; the compressed
fiber batt has a second thickness less than the first thickness;
the expanded fiber batt has a third thickness greater than the
second thickness; and the relofted fiber batt has a fourth
thickness greater than the third thickness. Variously, the fourth
thickness is greater than the first thickness, the fiber batt
comprises a plurality of binder fibers and a plurality of carrier
fibers and/or the binder fibers are sheath-core bicomponent fibers
and the carrier fibers are polyester fibers. The invention includes
a nonwoven fiber product relofted according to the method.
[0010] In a fourth aspect, the invention is a method for relofting
a nonwoven fiber product, the method comprising: forming a
high-loft nonwoven fiber batt; compressing the high-loft nonwoven
fiber batt to produce a compressed fiber batt, wherein
substantially all of the compression occurs in the thickness
direction of the fiber batt; securing the compressed fiber batt
with a restraint, such that the compressed fiber batt will expand
in the absence of the restraint; removing the restraint from the
compressed fiber batt, thereby allowing the compressed fiber batt
to expand into an expanded fiber batt; and relofting the expanded
fiber batt using heat, thereby increasing the thickness of the
expanded fiber batt to produce a relofted fiber batt. In
embodiments, the restraint is a band that constricts the fiber
batt, a vacuum is used to compress the high-loft nonwoven fiber
batt, and/or the fiber batt is compressed without the use of heat.
In another embodiment, the high-loft nonwoven fiber batt has a
first thickness; the compressed fiber batt has a second thickness
less than the first thickness; the expanded fiber batt has a third
thickness greater than the second thickness; and the relofted fiber
batt has a fourth thickness greater than the third thickness.
Variously, the fourth thickness is greater than the first
thickness, the high-loft nonwoven fiber batt comprises a plurality
of binder fibers and a plurality of carrier fibers, and/or the
binder fibers are sheath-core bicomponent fibers and the carrier
fibers are polyester fibers. The invention includes a nonwoven
fiber product relofted according to the method.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] For a more complete understanding of the present invention,
and for further details and advantages thereof, reference is now
made to the accompanying drawings, in which:
[0012] FIG. 1 is a block diagram showing the Method for Relofting a
Nonwoven Fiber Batt;
[0013] FIG. 2 is a plan view of an embodiment of an apparatus for
forming a nonwoven fiber batt in accordance with the method of FIG.
1;
[0014] FIG. 3A is a side view of an embodiment of a thermal bonding
apparatus used in forming a nonwoven fiber batt in accordance with
the method of FIG. 1;
[0015] FIG. 3B is a side view of an alternative embodiment of a
thermal bonding apparatus used in forming a nonwoven fiber batt in
accordance with the method of FIG. 1;
[0016] FIG. 4A is a side view of an embodiment of an apparatus for
compressing and securing a nonwoven fiber batt in accordance with
the method of FIG. 1;
[0017] FIG. 4B is a perspective view of an alternative embodiment
of an apparatus for compressing and securing a nonwoven fiber batt
in accordance with the method of FIG. 1;
[0018] FIG. 5A is a side view of an embodiment of an apparatus for
removing the restraint from a compressed nonwoven fiber batt in
accordance with the method of FIG. 1;
[0019] FIG. 5B is a perspective view of an alternative embodiment
of an apparatus for removing the restraint from a compressed
nonwoven fiber batt in accordance with the method of FIG. 1;
and
[0020] FIG. 6 is a side view of an embodiment of an apparatus for
relofting the nonwoven fiber batt in accordance with the method of
FIG. 1.
DETAILED DESCRIPTION
[0021] As depicted in FIG. 1, in general, one method 70 for
relofting a nonwoven fiber batt comprises: forming a nonwoven fiber
batt at step 72, compressing the fiber batt at step 74, securing
the fiber batt in its compressed state with a restraint at step 76,
transporting the fiber batt at step 78, removing the restraint to
expand the compressed fiber batt at step 80, and optionally
relofting the fiber batt at step 82.
[0022] In more detail, the method 70 generally commences by forming
a nonwoven fiber batt per step 72 of method 70. It will be well
recognized that the methods disclosed herein are not limited to the
specific composition of the nonwoven fiber batt. However, for
purposes of illustration, the nonwoven fiber batt may comprise a
homogeneous blend of binder fibers and carrier fibers. The binder
fibers and the carrier fibers may be either natural fibers or
synthetic fibers. For example, thermoplastic polymer fibers such as
polyester or polypropylene are suitable synthetic carrier fibers.
Wool, cotton, and silk are examples of suitable natural carrier
fibers. Other fibers can be used depending upon the precise
processing limitations imposed and the desired characteristics of
the nonwoven batt. For purposes of illustrating the formation of a
nonwoven fiber batt, and not by way of limitation, the carrier
fibers may be KoSa Type 209, 6 to 15 denier, 2 to 3 inches in
length, round, hollow, cross-section polyester fibers.
Alternatively, the carrier fibers may be KoSa Type 295, 6 to 15
denier, 1/5 to 4 inches in length, pentalobal, cross-section
polyester fibers. As one of the ordinary skill in the art will
readily recognize, other nonwoven fibers are suitable as carrier
fibers for the present invention and are within the scope of this
invention.
[0023] Binder fibers have a relatively low predetermined melting
temperature as compared to carrier fibers. As used herein, however,
the term melting as applied to solid polyester binder fibers does
not necessarily refer only to the actual transformation of the
binder fibers into liquid form. Rather, it includes a gradual
transformation of the fibers over a range of temperatures wherein
the fiber becomes sufficiently soft and tacky to cling to other
fibers, including other binder fibers with the same characteristics
and adjacent carrier fibers having a higher melting temperature. In
the case of bicomponent sheath/core fibers, the term melting
includes gradual transformation of the fiber sheaths over a range
of temperatures within which the sheaths become sufficiently soft
and tacky to cling to other fibers, including other bicomponent
sheath/core fibers with the same characteristics and adjacent
carrier fibers having a higher melting temperature. It is an
inherent characteristic of thermoplastic fibers, such as polyester,
that they become sticky and tacky when melted, as that term is used
herein. For purposes of illustrating one embodiment of a nonwoven
fiber batt, and not by way of limitation, the binder fibers may be
KoSa Type 254 Celbond.RTM., which is a bicomponent fiber with a
polyester core and a copolyester sheath having a melting
temperature of approximately 230.degree. F. (110.degree.C.). The
binder fiber, alternatively, may be a polyester copolymer, for
example, rather than a bicomponent fiber.
[0024] While the homogeneous mixture of carrier fibers and binder
fibers can be any of a number of suitable fiber blends, for
purposes of illustrating the process and first blend, the mixture
comprises binder fibers in an amount sufficient for binding the
fibers of the blend together upon application of heat at the
appropriate temperature to melt the binder fibers. In one example,
the binder fibers comprise about 5 percent to about 100 percent by
total volume of the blend. In one embodiment, the binder fibers are
present in the range of about 10 percent to about 15 percent for a
high-loft batt, and in the range of about 15 percent to about 40
percent for a densified batt, as those characteristics are
discussed below. The carrier fibers comprise about 0 percent to
about 95 percent by total volume of the blend. In one embodiment,
the carrier fibers are present in the range of about 85 percent to
about 90 percent for a high-loft batt, and in the range of about 60
percent to about 85 percent for a densified batt, as those
characteristics are discussed below. Blends having other
percentages of binder fibers and carrier fibers are also within the
scope of the invention.
[0025] It will be well recognized that the Method for Relofting a
Nonwoven Fiber Batt is not limited to any specific method of
forming the nonwoven fiber batt. However, for purposes of
illustration, FIG. 2 depicts a schematic top plan view of a general
processing line 110 for forming a nonwoven fiber batt in accordance
with step 72 of FIG. 1, and in accordance with the teachings of the
present invention. The carrier fibers and binder fibers are blended
together in a fiber blender 112 to form a fiber blend. In one
embodiment, the fiber blend comprises carrier fibers, such as
polyester, and binder fibers, such as sheath-core bicomponent
fibers, but the fiber blend may comprise a blend of any binder
fibers and any carrier fibers. The fiber blend is conveyed by
conveyor pipes 114 to a web-forming machine, or, in this example,
three machines 116, 117 and 118. A suitable web-forming machine is
a Garnett machine, for example. An air laying machine, known in the
trade as a Rando webber, or any other suitable apparatus can also
be used to form a web structure.
[0026] Garnett machines 116, 117, and 118 card the blended fibers
into a web and deliver the web to cross-lappers 116', 117', and
118' to cross-lap the web onto a slat conveyor 120, which is moving
in the machine direction. Cross-lappers 116', 117', and 118'
reciprocate back and forth in the cross direction from one side of
conveyor 120 to the other side to form a web 100 having multiple
thicknesses in a progressive overlapping relationship. The number
of layers that make up the web 100 is determined by the speed of
the conveyor 120 in relation to the speed at which successive
layers of the web 100 are layered on top of each other and the
number of cross-lappers 116', 117', and 118'. Thus, the number of
single layers that make up the web 100 can be increased by slowing
the relative speed of the conveyor 120 in relation to the speed at
which cross layers are layered, by increasing the number of
cross-lappers 116', 117', and 118', or both. Conversely, a fewer
number of single layers can be achieved by increasing the relative
speed of conveyor 120 to the speed of laying the cross layers, by
decreasing the number of cross-lappers 116', 117', and 118', or
both. In the present invention, the number of single layers making
up the web 100 of fibers will vary depending upon the desired
characteristics of the nonwoven fiber batt. As a result, the
relative speed of the conveyor 120 to the speed at which cross
layers are layered, and the number of cross-lappers 116', 117', and
118' for forming the web 100 may vary accordingly.
[0027] The conveyor 120 then transports the web 100 to housing 130
for mechanical and/or vacuum compression and heating. While there
are a variety of thermal bonding methods suitable for the purposes
contemplated herein, one such method is the application of vacuum
pressure through perforations (not shown) in first and second
counter rotating drums 140, 142 positioned in a central portion of
the housing 130. The first and second counter rotating drums 140,
142 heat the web 100 to the extent necessary to melt the binder
fibers in the web 100. For example, heating the web 100 to a
temperature of approximately 225-275.degree. F. for a period of
three to five minutes is suitable for the purposes contemplated
herein. Alternatively, the web 100 may instead move through an oven
by substantially parallel perforated or mesh wire aprons that
mechanically compress the batt and simultaneously melt the binder
fibers, as will be discussed in more detail herein.
[0028] As the web 100 exits the housing 130, the web 100 is
compressed and cooled using a pair of substantially parallel wire
mesh aprons 170, only one of which is visible in FIG. 2. The aprons
170 are mounted for parallel movement relative to each other to
facilitate adjustment for a wide range of web thicknesses. The web
100 can be cooled slowly via exposure to ambient temperature air
or, in the alternative, ambient temperature air can be forced
through the perforations of one apron 170, through the web 100 and
through the perforations of another apron 172 (shown in FIG. 3A) to
cool the web 100 and set it in a compressed state. The web 100 is
maintained in compressed form upon cooling because the binder
fibers solidify to bond the fiber blend together in that state.
[0029] While there are a variety of thermal bonding methods that
are suitable for the present invention, one such method,
illustrated in FIG. 2 and FIG. 3A, comprises holding the web 100 by
vacuum pressure applied through perforations of first and second
counter-rotating drums 140, 142 and heating the web 100 so that
binder fibers in the batt melt to the extent necessary to fuse
together the fiber blend in the web 100.
[0030] As depicted in FIG. 3A, the vacuum pressure method may be
implemented using counter-rotating drums 140, 142 having
perforations 141, 143 therein, respectively, which are positioned
in a central portion of the housing 130. The housing 130 also
comprises an air circulation chamber 132 and a furnace 134 in an
upper portion and a lower portion, respectively. One drum 140 is
positioned adjacent an inlet 144 though which the web 100 is fed.
The web 100 is delivered from the blending and web-forming
processes described with respect of FIG. 1 by means of an infeed
apron 146. A suction fan 150 is positioned in communication with
the interior of the drum 140. The lower portion of the
circumference of the drum 140 is shielded by a baffle 151
positioned inside the drum 140 such that the suction-creating air
flow is forced to enter the drum 140 through the perforations 141,
which are proximate the upper portion of the drum 140, as the drum
140 rotates.
[0031] Another drum 142 is positioned downstream from the first
drum 140 in the housing 130. The drums 140, 142 can also be mounted
for lateral sliding movement relative to one another to facilitate
adjustment for a wide range of batt thicknesses (not shown). The
second drum 142 includes a suction fan 152 that is positioned in
communication with the interior of the drum 142. The upper portion
of the circumference of the drum 142 is shielded by a baffle 153
positioned inside the drum 142 so that the suction-creating air
flow is forced to enter the drum 142 through the perforations 143,
which are proximate the lower portion of drum 142, as the drum 142
rotates.
[0032] Thus, the nonwoven web 100 is held in vacuum pressure as it
moves from the upper portion of the rotating drum 140 to the lower
portion of the counter rotating drum 142. The furnace 134 heats the
air in the housing 130 as it flows from the perforations 141, 143
to the interior of the drums 140, 142, respectively, to melt the
binder fibers in the web to the extent necessary to bind the fiber
blend in the web together.
[0033] Referring now to FIG. 3B, in an alternative thermal bonding
process, the web 100 enters a housing 130' by a pair of
substantially parallel perforated or mesh wire aprons 160, 162. The
housing 130' comprises an oven 134' that heats the web 100 to melt
the binder fibers to the extent necessary to bind the fiber blend
in the web 100 together.
[0034] Collectively referring again to FIGS. 2, 3A and 3B, the web
100 is compressed and cooled as it exits the housing 130 or housing
130' by a pair of substantially parallel first and second
perforated or wire mesh aprons 170, 172 of FIG. 3A or 160, 162 of
FIG. 3B. The aprons 170, 172 or 160, 162 are mounted for parallel
movement relative to each other to facilitate adjustment for a wide
range of web thicknesses (not shown). The web 100 can be cooled
slowly through exposure to ambient temperature air or,
alternatively, ambient temperature air can be forced through the
perforations of one apron, through the web 100 and through the
perforations of the other apron to cool the web 100 and set it in a
compressed state. The web 100 is maintained in a compressed form
upon cooling since the binder fibers are solidified during cooling
to bond the fiber blend of the web 100 together in its compressed
state. After bonding, compression and cooling, the cooled web is
referred to as a batt 122. Referring to FIG. 2, the fiber batt 122
then moves into a cutting zone 180 where the lateral edges of the
batt 122 are trimmed. The fiber batt 122 is also cut transversely
to a desired length.
[0035] In alternative embodiments of the method, it is contemplated
that other bonding methods, such as mechanical bonding and resin
bonding, may be used to bond the fiber batt 122 together in lieu of
the thermal bonding methods described herein. Mechanical bonding is
the process of bonding the nonwoven batt 122 together without the
use of resins, binder fibers, adhesives, or heat. Examples of
mechanical bonding methods include needle punching and hydro
entanglement. Needle punching is the process of entangling the
fibers in the web together using barbed needles. Hydro entanglement
uses streams of high pressure water to entangle the fibers of the
nonwoven web. Resin bonding is a process by which the carrier
fibers are coated in adhesive resin. Once it is cured in an oven,
the adhesive resin bonds the carrier fibers together, thereby
accomplishing the same task as the binder fibers. For resin bonded
batts, resin is generally used in lieu of the binder fibers in the
nonwoven batt. It will be readily apparent to one of ordinary skill
in the art that the Method for Relofting a Nonwoven Fiber Batt
includes nonwoven production methods other than those described
herein, and should not be limited thereto.
[0036] In one embodiment of the nonwoven fiber batt 122, the
weight, density, and thickness of the nonwoven fiber batt 122 are
determined by, among other factors, the process of compressing the
batt 122 during cooling, as discussed in more detail below. The
ratio of batt density to batt thickness generally dictates whether
the nonwoven fiber batt is a high-loft batt or a densified batt.
For purposes of description herein, a densified batt has a weight
(in ounces per square foot) greater than its thickness (in inches).
Thus, a densified fiber batt generally has a density greater than
about 0.75 pounds per cubic foot (pcf). Conversely, a high-loft
fiber batt has a weight (in ounces per square foot) less than its
thickness (in inches) and/or a density less than about 0.75 pcf.
High-loft batts also generally have at least about 90 percent air
by volume and a thickness of at least about 3 millimeters.
[0037] After the fiber batt 122 is formed per step 72, the fiber
batt 122 is compressed per step 74 of method 70 depicted in FIG. 1.
FIG. 4A depicts one embodiment of an apparatus 220 used to compress
the fiber batt 122. The fiber batt 122 shown in FIG. 4A may be a
single fiber batt 122 or a plurality of fiber batts 122 laminated
atop of one another. As shown in phantom in FIG. 4A, absent a
compressive force, the fiber batt 122 has a first thickness,
T.sub.1. However, when the fiber batt 122 is placed between a lower
plate 224 and an upper plate 226 and a compressive force is applied
that causes a plunger 228 to move the upper plate 226 towards the
lower plate 224, the apparatus 220 compresses the fiber batt 122 to
a second thickness T.sub.2 that is less than the first thickness
T.sub.1. The apparatus 220 may be adapted to compress the fiber
batt 122 only in the thickness direction (z-direction), without
substantially expanding or compressing the fiber batt 122 in the
cross-direction (x-direction) or the machine direction
(y-direction). The apparatus 220 compresses the fiber batt 122 so
as to substantially reduce the spaces in the fiber batt 122;
however, the apparatus 220 does not compress the fiber batt 122 so
much that the resilient memory inherent in the fiber batt 122 is
substantially altered or destroyed. In other words, the apparatus
220 only compresses the fiber batt 122 such that the fiber batt 122
will expand if the compressive force is released, but not to the
point where the fiber batt 122 is permanently positioned in its
compressed state. In one embodiment, the apparatus 220 does not
utilize heat to compress the fiber batt 122. However, in other
embodiments, heat may be used to assist in compressing the fiber
batt 122 so long as the heat does not substantially alter or
destroy the resilient memory inherent in the fiber batt 122.
[0038] In an alternative embodiment, of the apparatus 220 of FIG.
4A, a vacuum source (not shown) may be connected to a plurality of
apertures (not shown) in the lower plate 224 such that air is
passed through the upper and side surfaces of the fiber batt 122
and into the apertures, thereby compressing the fiber batt 122.
This vacuum embodiment may be used in lieu of the upper plate 226
of FIG. 4A to compress the fiber batt 122. This vacuum embodiment
may also be used in conjunction with the apparatus 220 shown in
FIG. 4A to compress the fiber batt 122.
[0039] FIG. 4B illustrates an alternative method for compressing
the fiber batt per step 74 of method 70. FIG. 4B depicts an
embodiment of an apparatus 220' that compresses the fiber batt 122
between an upper roller 226' and a lower roller 224', then rolls
the compressed fiber batt 122 onto the upper roller 226'. The fiber
batt 122 shown in FIG. 4B may be a single fiber batt 122 or a
plurality of fiber batts 122 laminated atop of one another. When
the fiber batt 122 passes between the upper roller 226' and the
lower roller 224', a force is applied that causes the plungers 228'
to press the upper roller 226' against the lower roller 224',
thereby compressing the fiber batt 122 from the first thickness,
T.sub.1 to the second thickness, T.sub.2. As the fiber batt 122 is
compressed, it is wound onto the upper roller 226', which rotates
at the same rate as the fiber batt 122 is fed into the apparatus
220'. In addition, the compressive force applied to the plungers
228' is controlled such that, as the diameter of the roll of
compressed fiber batt 122 increases, the upper roller 226' is
raised, thereby keeping a consistent amount of compression on the
thickness of the entire length of the fiber batt 122. Using this
compressive procedure, the apparatus 220' only compresses the fiber
batt 122 in the thickness direction (z-direction) and does not
substantially expand or compress the fiber batt 122 in the
cross-direction (x-direction) or the machine direction
(y-direction).
[0040] The apparatus 220' compresses the fiber batt 122 so as to
substantially eliminate most of the air spaces in the fiber batt
122; however, the apparatus 220' does not compress the fiber batt
122 so much that the resilient memory inherent in the fiber batt
122 is substantially altered or destroyed. In other words, the
apparatus 220' only compresses the fiber batt 122 such that the
fiber batt 122 will expand if the compressive force is released,
but not to the point where the fiber batt 122 is permanently
positioned in its compressed state. In one embodiment, the
apparatus 220' does not utilize heat to compress the fiber batt
122. However, in other embodiments, heat may be used to assist in
compressing the fiber batt 122 so long as the heat does not
substantially alter or destroy the resilient memory inherent in the
fiber batt 122.
[0041] In an alternative embodiment, of the apparatus of 220' of
FIG. 4B, a vacuum source (not shown) may be connected to a
plurality of apertures (not shown) in the upper roller 226' such
that air is passed through the outside and ends of the rolled fiber
batt 122 and into the apertures, thereby compressing the fiber batt
122 on the upper roller 226'. This vacuum embodiment may be used in
lieu of the lower roller 224' of FIG. 4B to compress the fiber batt
122. This vacuum embodiment may also be used in conjunction with
the apparatus 220' shown in FIG. 4B to compress the fiber batt 122.
It will be readily apparent to one of ordinary skill in the art
that the Method for Relofting a Nonwoven Fiber Batt also includes
compression methods other than those described herein and should
not be limited thereto.
[0042] Returning again to FIG. 4A, after it is compressed, the
fiber batt 122 is secured in its compressed state with a restraint
per step 76 of method 70 shown in FIG. 1. The upper plate 226 and
the lower plate 224 illustrated in FIG. 4A contain a plurality of
notches 230 that allow a user to wrap a restraint 232, such as a
band or strap, around the fiber batt 122 while the fiber batt 122
is in its compressed state. Specifically, the user may position the
restraint 232 around the compressed fiber batt 122 and fasten the
restraint 232 to itself or to the fiber batt 122 using any means
generally known within the art, such as adhesives, staples, brads,
rivets, or the like. Alternatively, a thin polymeric film shrink
wrap (not shown) may be wrapped around the compressed fiber batt
122 to secure the fiber batt 122 in its compressed state.
[0043] FIG. 4B illustrates an alternative method for securing the
fiber batt 122 in its compressed state with a restraint per step 76
of method 70 shown in FIG. 1. The lower roller 224' illustrated in
FIG. 4B contains a plurality of notches 230' that allow a user to
wrap a restraint 232, such as a band or strap, around the fiber
batt 122 while the fiber batt 122 is in its compressed state.
Specifically, the user may position the restraint 232 around the
compressed fiber batt 122 and fasten the restraint 232 to itself or
to the fiber batt 122 using any means generally known within the
art, such as adhesive, staples, brads, rivets, or the like.
Alternatively, a thin polymeric film shrink wrap (not shown) may be
wrapped around the compressed fiber batt 122 to secure the fiber
batt 122 in its compressed state. It will be readily apparent to
one of ordinary skill in the art that the Method for Relofting a
Nonwoven Fiber Batt includes securing methods other than those
described herein and should not be limited thereto.
[0044] After the fiber batt 122 has been secured per step 76 of
method 70 shown in FIG. 1, the fiber batt is transported from a
first location to a second location per step 78 of method 70. In
one embodiment, the first location is the manufacturing facility
that forms the fiber batt 122 and the second location is a separate
relofting facility located apart from the manufacturing facility.
In one embodiment, the method of transporting the compressed fiber
batt 122 from the first location to the second location comprises
loading the compressed fiber batt 122 into the trailer of a
commercial freight carrier, such as a ship, a train, an aircraft,
or an 18-wheeler truck, for example. Commercial freight carriers
typically charge by the trailer load, subject to certain weight
restrictions. Because the weight restriction is large compared to
the volume capacity of a trailer, fiber batt manufacturers are
essentially charged by the trailer load. Reducing the volume of
each individual nonwoven fiber batt allows for a greater quantity
of fiber batts 122 to be loaded into the trailer, thus reducing the
individual transportation (shipping) cost associated with each
individual fiber batt 122. Consequently, the process described in
method 70 is particularly advantageous in that it allows fiber batt
manufacturers to compress the fiber batts 122 so as to reduce their
per batt transportation costs, while still retaining the resilient
memory of the fiber batt 122.
[0045] In an alternative embodiment, the fiber batt 122 is
transported from a first location to a second location, wherein the
first location is the manufacturing facility that forms the fiber
batt 122 and the second location is a storage facility, either
within the manufacturing facility or separate from the
manufacturing facility. Manufacturing facilities often include
storage facilities so that inventory may be stored for customers.
Manufacturing facilities generally own their storage facilities or
lease their storage facilities from a third party. In either case,
the storage volume is finite and the manufacturing facility incurs
additional costs associated with such storage space. By utilizing
the aforementioned steps 72, 74, and 76 of method 70, the
manufacturing facility may store more fiber batts 122 in the
storage facility than was previously possible. In some cases, where
the manufacturing facility leases or rents the storage facility,
the manufacturing facility may reduce its overall storage costs by
utilizing all or part of method 70. It will be readily apparent to
one of ordinary skill in the art that the Method for Relofting a
Nonwoven Fiber Batt includes transportation methods other than
those described herein and should not be limited thereto.
[0046] After the fiber batt 122 has been transported, the
restraints 232 may be removed from the compressed fiber batt 122
per step 80 of method 70 depicted in FIG. 1. FIGS. 5A and 5B show
the restraints 232 being removed from the compressed fiber batt 122
by a knife 240. In FIG. 5A, the fiber batt 122 is shown expanding
from its compressed thickness, T.sub.2 (shown partially in phantom
in FIG. 5A), to an expanded thickness, T.sub.3, which is greater
than T.sub.2. In FIG. 5B, the rolled fiber batt 122 is shown
expanding and/or unraveling when the restraints 232 are removed.
The original size of the rolled fiber batt 122 is shown in phantom
in FIG. 5B. In either case, the fiber batt 122 expands to the
expanded thickness T.sub.3 because the fiber batt 122 still retains
some or all of its resilient memory. If the fiber batt 122 retains
substantially all of its resilient memory, the expanded thickness
T.sub.3 will be substantially the same as the original fiber batt
thickness T.sub.1. If the fiber batt 122 retains only a portion of
its resilient memory, the expanded thickness T.sub.3 will be less
than the original fiber batt thickness T.sub.1. Regardless of the
extent of expansion of the fiber batt 122, it is contemplated that
the batt 122 will expand enough to be suitable for use in
applications requiring a high-loft fiber batt 122. It will be
readily apparent to one of ordinary skill in the art that the
Method for Relofting a Nonwoven Fiber Batt includes restraint
removal methods other than those described herein and should not be
limited thereto.
[0047] After the restraints 232 are removed, the fiber batt 122 may
optionally be relofted per step 82 of method 70 depicted in FIG. 1.
Relofting is a process wherein the thickness of the fiber batt 122
is increased by heating the fiber batt 122 in a relofting
apparatus, one embodiment of which is shown in FIG. 6. As shown in
FIG. 6, the fiber batt 122 enters a relofting apparatus 250 where
the fiber batt 122 is supported by a moving conveyor 254. A heating
source (not shown), such as an oven, burner, or infrared lamp, in
the relofting apparatus 250 produces heat 252 that passes through
holes (not shown) in the conveyor 254 to increase the temperature
of the fiber batt 122. As the temperature increases, the binder
fibers within the fiber batt 122 begin to soften, and some of the
binder fibers and/or carrier fibers begin to realign with, and/or
detach from, the softened binder fibers. The realigning and/or
detaching binder and/or carrier fibers cause the fiber batt 122 to
increase in thickness, thereby decreasing the density of the fiber
batt 122.
[0048] As depicted in FIG. 6, the fiber batt 122 enters the
relofting apparatus 250 at the unrestrained, expanded thickness
T.sub.3. However, as the relofting apparatus 250 heats the fiber
batt 122, its thickness increases to a relofted thickness T.sub.4,
which is greater than T.sub.3. The final relofted thickness T.sub.4
is dependent upon the temperature within the relofting apparatus
250 and the residence time, which is the overall time that the
fiber batt 122 is exposed to the increased temperature within the
relofting apparatus 250. In one embodiment, a temperature of
approximately 180.degree. F. is sufficient to reloft the binder
fibers as described herein. In another embodiment, the temperature
and the residence time may be similar to the temperature and
residence time in the housing 130 shown in FIG. 2: i.e.
approximately 225-275.degree. F. for three to five minutes. Higher
or lower temperatures and/or residence time may be selected
depending upon the desired relofted thickness T.sub.4 of the fiber
batt 122. Further, depending on the selected temperature and the
residence time, the relofted thickness T.sub.4 may be greater than
or less than the original fiber batt thickness T.sub.1. Generally,
a greater residence time and/or a higher temperature within the
relofting apparatus 250 will tend to create a fiber batt 122 having
a relofted thickness T.sub.4 greater than the original fiber batt
thickness T.sub.1. Alternatively, a lesser residence time and/or a
lower temperature within the relofting apparatus 250 will tend to
create a fiber batt 122 having a relofted thickness T.sub.4 greater
than the expanding thickness T.sub.3, but less than the original
fiber batt thickness T.sub.1. As will be readily apparent to one of
ordinary skill in the art, the Method for Relofting a Nonwoven
Fiber Batt includes relofting methods other than those described
herein and should not be limited thereto.
[0049] an alternative embodiment, the relofting step 82 of method
70 may be combined with a quilting process. In particular, the
fiber batt 122 may be laminated onto a quilt backing after the
restraints 232 are removed from the compressed fiber batt 122, as
described above. The lamination is then fed into a
quilting/relofting apparatus that relofts the fiber batt 122 per
step 82 and also quilts the fiber batt 122 to the quilt backing.
One of ordinary skill in the art will appreciate that the
quilting/relofting apparatus may be a single machine or may be a
plurality of separate machines. In addition, a person of ordinary
skill in the art will appreciate that the quilting/relofting
apparatus may contemporaneously or consecutively reloft and quilt
the lamination. If the quilting/relofting apparatus quilts and
relofts the lamination consecutively, the quilting and relofting
processes may be performed in either order. It will also be well
appreciated by a person of ordinary skill in the art that the fiber
batt 122 may be laminated onto a quilt backing prior to
compression. In such an embodiment, other layers of material, such
as polymeric foam or other densified or high-loft nonwoven or woven
fiber batts, for example, may be laminated onto the fiber batt 122
and the quilt backing prior to compressing the lamination. If
additional layers are laminated onto the fiber batt 122, the
lamination may be compressed, restrained, and transported as
described above. The restraints may then be removed from the
lamination, and the lamination relofted and quilted as described
above.
[0050] The nonwoven fiber batt 122 manufactured according to the
Method for Relofting a Nonwoven Fiber Batt described herein is
suitable for a variety of applications. The fiber batt 122 may be
used, for example, to manufacture articles of furniture, including
chairs, sofas, loveseats, ottomans, beds, and so forth. Moreover,
the fiber batt 122 may be used for automobile, airplane, or other
vehicle upholstery. The fiber batt may also be used in mattresses,
quilts, pillows, comforters, bedding, and other household articles.
The Method for Relofting a Nonwoven Fiber Batt also includes other
applications not specifically listed, and the scope of the
invention should not be restricted to the aforementioned
applications.
[0051] While a number of preferred embodiments of the invention
have been shown and described herein, modifications thereof may be
made by one skilled in the art without departing from the spirit
and the teachings of the invention. The embodiments described
herein are exemplery only and are not intended to be limiting. Many
variations, combinations, and modifications of the invention
disclosed herein are possible and are within the scope of the
invention. Accordingly, the scope of protection is not limited by
the description set out above, but is defined by the claims which
follow, that scope including all equivalents of the subject matter
of the claims.
* * * * *