U.S. patent application number 11/137118 was filed with the patent office on 2005-12-08 for filamentary blanket.
This patent application is currently assigned to Polymer Group, Inc.. Invention is credited to Bridges, Cliff, Carter, Nick, De Leon, Sergio Diaz.
Application Number | 20050272340 11/137118 |
Document ID | / |
Family ID | 35463489 |
Filed Date | 2005-12-08 |
United States Patent
Application |
20050272340 |
Kind Code |
A1 |
Bridges, Cliff ; et
al. |
December 8, 2005 |
Filamentary blanket
Abstract
The present invention is directed to continuous filament
nonwoven fabrics, and more specifically directed to continuous
filament nonwoven fabrics for use as low-cost disposable airline
and rescue operation blankets. Continuous filament fabrics are
formed utilizing the spunbond process. The spunbond process and the
manner of preparing a spunbond web is set forth in U.S. Pat. No.
3,341,394 to Kinney and U.S. Pat. No. 4,043,201 to Brock, et al.,
both of which are herein incorporated by reference. The filamentary
blankets of the present invention may be disposed after a single
use or semi-reusable, wherein the blanket has a limited number of
uses before needing to be replaced. Such blankets are suitable for
a variety of applications, such as insulative blankets, emergency
rescue blankets, institutional blankets, airline blankets, and
other applications where blankets are used only a limited number of
times or in some cases only once before being discarded.
Inventors: |
Bridges, Cliff; (Greensboro,
NC) ; De Leon, Sergio Diaz; (Huntersville, NC)
; Carter, Nick; (Hutchinson, KS) |
Correspondence
Address: |
WOOD, PHILLIPS, KATZ, CLARK & MORTIMER
500 W. MADISON STREET
SUITE 3800
CHICAGO
IL
60661
US
|
Assignee: |
Polymer Group, Inc.
|
Family ID: |
35463489 |
Appl. No.: |
11/137118 |
Filed: |
May 25, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60574668 |
May 26, 2004 |
|
|
|
Current U.S.
Class: |
442/409 ;
442/327 |
Current CPC
Class: |
D04H 3/16 20130101; Y10T
442/60 20150401; D04H 3/11 20130101; Y10T 442/69 20150401 |
Class at
Publication: |
442/409 ;
442/327 |
International
Class: |
D04H 003/00 |
Claims
What is claimed is:
1. A three-dimensionally imaged disposable blanket comprising one
or more layers of thermoplastic continuous filaments and one or
more melt additives, wherein said blanket has a basis weight of
about 60-200 grams per square meter.
2. A three-dimensionally imaged disposable blanket as in claim 1,
wherein said image is imparted by a forming surface selected from
the group of three-dimensional surfaced belts, metal drums, wire
screens, and three-dimensional image transfer devices.
3. A three-dimensionally imaged disposable blanket as in claim 2,
wherein said forming surface is a three-dimensional image transfer
device.
4. A three-dimensionally imaged disposable blanket as in claim 1,
wherein said blanket has a basis weight of about 85-130 grams per
square meter.
5. A three-dimensionally imaged disposable blanket as in claim 1,
wherein said thermoplastic continuous filaments are selected from
the group consisting of polyolefins, polyamides, polyesters, and
the combinations thereof.
6. A three-dimensionally imaged disposable blanket as in claim 5,
wherein said polyolefins are selected from polypropylene,
polyethylene, and the combinations thereof.
Description
TECHNICAL FIELD
[0001] The present invention is generally related to continuous
filament nonwoven fabrics, and more specifically related to
continuous filament nonwoven fabrics for use as low-cost disposable
airline and rescue operation blankets.
BACKGROUND OF THE INVENTION
[0002] Nonwoven fabrics are used in a wide variety of applications
where the engineered qualities of the fabrics can be advantageously
employed. The use of selected thermoplastic polymers in the
construction of the filamentary components, selected treatment of
the components (either while in molten form or in an integrated
structure), and selected use of various mechanisms by which the
filamentary components are integrated into a useful fabric, are
typical variables by which to adjust and alter the performance of
the resultant nonwoven fabric.
[0003] Nonwoven blankets are known in the art. Typically, the
nonwoven blankets comprise one or more lofty fibrous batts of
carded and cross-lapped staple length fiber that is subsequently
bonded by needle-felting or entangling. Preferably, one or more
post treatments are performed on the consolidated batt, such as jet
dyeing and napping in order to lend to the aesthetic appeal of the
blanket or enhance the hand of the blanket.
[0004] Such a multi-step fabrication process for blankets can be
rather costly, and it is therefore an objective of the present
invention to manufacture an inexpensive nonwoven blanket for
airlines and rescue operations by utilizing the spunbond process.
The term "spunbonding" refers to a process in which a thermoplastic
polymer is provided in a raw or pellet form and is melted and
extruded or "spun" through a large number of small orifices to
produce a bundle of continuous or essentially endless filaments.
These filaments are cooled and drawn or attenuated and are
deposited as a loose web onto a moving conveyor. The filaments are
then partially bonded, typically by passing the web between a pair
of heated rolls, with at least one of the rolls having a raised
pattern to provide a bonding pattern in the fabric. Of the various
processes employed to produce nonwovens, spunbonding is the most
efficient, since the final fabric is made directly from the raw
material on a single production line.
SUMMARY OF THE INVENTION
[0005] The present invention is directed to continuous filament
nonwoven fabrics, and more specifically directed to continuous
filament nonwoven fabrics for use as low-cost disposable airline
and rescue operation blankets. Continuous filament fabrics are
formed utilizing the spunbond process. The spunbond process and the
manner of preparing a spunbond web is set forth in U.S. Pat. No.
3,341,394 to Kinney and U.S. Pat. No. 4,043,201 to Brock, et al.,
both of which are herein incorporated by reference.
[0006] Nonwoven blankets made in accordance with the present
invention comprise one or more continuous filament webs of
thermoplastic polymers that may be chosen from the group consisting
of polyolefins, polyamides, and polyesters, wherein the polyolefins
are chosen from the group consisting of polypropylene,
polyethylene, and combinations thereof. It is within the purview of
the present invention that the continuous filament web or webs may
comprise either the same or different thermoplastic polymers.
Further, the continuous filaments may comprise homogeneous,
bi-component, and/or multi-component profiles, as well as,
performance modifying additives, and the blends thereof.
[0007] The filamentary blankets of the present invention may be
disposed after a single use or semi-reusable, wherein the blanket
has a limited number of uses before needing to be replaced. Such
blankets are suitable for a variety of applications, such as
insulative blankets, emergency rescue blankets, institutional
blankets, airline blankets, and other applications where blankets
are used only a limited number of times or in some cases only once
before being discarded.
[0008] Other features and advantages of the present invention will
become readily apparent from the following detailed description,
and the appended claims.
DETAILED DESCRIPTION
[0009] While the present invention is susceptible of embodiment in
various forms, there is shown in the drawings and will hereinafter
be described a presently preferred embodiment of the invention,
with the understanding that the present disclosure is to be
considered as an exemplification of the invention, and is not
intended to limit the invention to the specific embodiment
illustrated.
[0010] A spunbond process involves supplying a molten polymer,
which is then extruded under pressure through a large number of
orifices in a plate known as a spinneret or die. The resulting
continuous filaments are quenched and drawn by any of a number of
methods, such as slot draw systems, attenuator guns, or Godet
rolls. The continuous filaments are collected as a loose web upon a
moving foraminous surface, such as a wire mesh conveyor belt. When
more than one spinneret is used in line for the purpose of forming
a multi-layered fabric, the subsequent web is collected upon the
uppermost surface of the previously formed web. The web is then at
least temporarily consolidated, usually by means involving heat and
pressure, such as by thermal point bonding. Using this bonding
means, the web or layers of webs are passed between two hot metal
rolls, one of which has an embossed pattern to impart and achieve
the desired degree of point bonding, usually on the order of 10 to
40 percent of the overall surface area being so bonded.
[0011] The thermoplastic polymers of the continuous filament
spunbond layer or layers are chosen from the group consisting of
polyolefins, polyesters, polyamides, and halopolymers, with
ethylene-fluorocarbon copolymers, particularly
ethylene-chlorotrifluoroethylene (ECTFE), wherein the polyolefins
are chosen from the group consisting of polypropylene,
polyethylene, and combinations thereof. It is within the purview of
the present invention that the continuous filament web or webs may
comprise either the same or different thermoplastic polymers.
Further, the continuous filaments may comprise homogeneous,
bi-component, and/or multi-component profiles, as well as,
performance modifying additives, and the blends thereof.
[0012] Additionally the continuous filamentary web may comprise one
or more discontinuous filament webs through application of the
meltblown process. The melt-blown process is a related means to the
spunbond process for forming a layer of a nonwoven fabric, wherein,
a molten polymer is extruded under pressure through orifices in a
spinneret or die. High velocity air impinges upon and entrains the
filaments as they exit the die. The energy of this step is such
that the formed filaments are greatly reduced in diameter and are
fractured so that microfibers of finite length are produced. This
differs from the spunbond process whereby the continuity of the
filaments is preserved. The process to form either a single layer
or a multiple-layer fabric is continuous, that is, the process
steps are uninterrupted from extrusion of the filaments to form the
first and subsequent layers through consolidation of the layers to
form a composite fabric. It is also within the purview of the
present invention to further include, juxtaposed to the melt-blown
barrier layer, additional layers selected from the group consisting
of nonwoven, fabrics, woven fabrics, films and combinations
thereof.
[0013] Nano-denier filaments may be incorporated as well. Suitable
nano-denier continuous filament layers can be formed by either
direct spinning of nano-denier filaments or by formation of a
multi-component filament that is divided into nano-denier filaments
prior to deposition on a substrate layer. U.S. Pat. Nos. 5,678,379
and 6,114,017, both incorporated herein by reference, exemplify
direct spinning processes practicable in support of the present
invention. U.S. Pat. Nos. 5,678,379 and 6,114,017, both
incorporated herein by reference, exemplify direct spinning
processes practicable in support of the present invention.
[0014] Prior to extrusion, the molten polymer can be compounded
with various performance enhancing melt-additives, such as thermal
stabilizers, softening agents, antimicrobial agents, fire-retarding
agents, cross-linking agents, slip additives, and wetting agents,
UV, anti-stats, colorants, and nucleating agents. A nucleating
agent may be specifically compounded to produce a more stable
spinning process, and, at equal process conditions, can produce a
further increase in strength. The fabric may be exposed to further
performance enhancing additives after fabric formation.
[0015] Depending on the blanket end-use application, it may be
desirable to have a blanket that exhibits a high degree of
strength. It has been contemplated that utilizing polymeric resins
with low melt indexes, such as between about 5-20 MI, may enhance
the strength of the blanket; however, it is also suitable to
utilize polymeric resins with higher melt indexes, about 20-35 MI,
depending on the application.
[0016] According to the present invention, filaments with varying
geometric cross-sections may be utilized, as disclosed in U.S. Pat.
No. 5,057,368 to Largman, et al.; U.S. Pat. No. 5,322,736 Boyle, et
al.; and U.S. Pat. No. 5,834,119 to Roop. Multi-component filaments
may also be utilized as well, such as side-by-side filaments,
sheath-core filaments, and islands in the sea filaments. Splittable
fibers are also suitable for use in the present invention, wherein
upon impact the components of such fibers separate. The
aforementioned filaments may be used in whole or in part within one
or more layers of the continuous filament blanket.
[0017] In one embodiment, the nonwoven blanket of the present
invention is comprised of extruded and thermally bonded continuous
polyethylene filaments. The resultant blanket has excellent
drapeability and hand with a preferred basis weight of about 50-200
grams per square meter and a most preferred basis weight of about
85-130 grams per square meter. Prior to extrusion of the filaments,
a pigment was added to the polymeric melt to impart a color into
the blanket. Further, subsequent to thermal bonding, the blanket
fabric was subjected to a napping post treatment so as to produce a
low cost blanket that has the desired insulative, tactile, and
visual properties often sought in a blanket.
[0018] Optionally, the continuous filament blanket may be
hydroentangled on an imaged forming surface, wherein such surfaces
include three-dimensionally surfaced belt, metal drums, wire
screens, and three-dimensional image transfer devices. Such surface
treatments enhance the aesthetic appearance of the blanket, as well
as improve the overall bulk and hand of the blanket. Additional
surface treatments that may be utilized include mechanical
compaction as practiced in micrexing or sanforizing ("Sanforized"
is a registered trademark of Cluett, Peabody & Co., Inc).
[0019] The filamentary blankets of the present invention are
low-cost and suitable for disposed after a single use. Alternately,
the blankets may be considered semi-reusable, wherein the blanket
may be used a limited number of times before needing to be
replaced. Such blankets may be used as insulative blankets,
emergency rescue blankets, institutional blankets, airline
blankets, as well as in other applications where blankets of
limited use are required or in cases where blankets are used once
before being discarded.
[0020] From the foregoing, it will be observed that numerous
modifications and variations can be affected without departing from
the true spirit and scope of the novel concept of the present
invention. It is to be understood that no limitation with respect
to the specific embodiments illustrated herein is intended or
should be inferred. The disclosure is intended to cover, by the
appended claims, all such modifications as fall within the scope of
the claims.
* * * * *