U.S. patent application number 10/732692 was filed with the patent office on 2005-06-09 for synthetic insulation with microporous membrane.
Invention is credited to Mason, Vanessa, Rumiesz, Joseph.
Application Number | 20050124256 10/732692 |
Document ID | / |
Family ID | 34634488 |
Filed Date | 2005-06-09 |
United States Patent
Application |
20050124256 |
Kind Code |
A1 |
Mason, Vanessa ; et
al. |
June 9, 2005 |
Synthetic insulation with microporous membrane
Abstract
An insulation package and method of formation including a
functional fabric layer, a breathable water repellant insulating
layer, and a highly breathable microporous membrane layer having a
network of pores. The functional fabric, the highly breathable
insulating layer and the microporous membrane layer are laminated
to one another to form a waterproof breathable insultion
package.
Inventors: |
Mason, Vanessa; (Rexford,
NY) ; Rumiesz, Joseph; (Voorheesville, NY) |
Correspondence
Address: |
FROMMER LAWRENCE & HAUG
745 FIFTH AVENUE- 10TH FL.
NEW YORK
NY
10151
US
|
Family ID: |
34634488 |
Appl. No.: |
10/732692 |
Filed: |
December 9, 2003 |
Current U.S.
Class: |
442/394 ;
442/327; 442/340; 442/344 |
Current CPC
Class: |
A41D 31/102 20190201;
Y10T 442/3854 20150401; A43B 1/00 20130101; B32B 27/322 20130101;
Y10T 442/614 20150401; B32B 2307/5825 20130101; B32B 2305/18
20130101; B32B 2307/7265 20130101; Y10T 428/24998 20150401; Y10T
442/60 20150401; Y10T 442/3065 20150401; Y10T 442/674 20150401;
Y10T 442/619 20150401; B32B 2307/304 20130101; Y10T 442/615
20150401; B32B 2307/724 20130101; B32B 27/12 20130101; B32B 2305/02
20130101; Y10T 442/59 20150401 |
Class at
Publication: |
442/394 ;
442/327; 442/340; 442/344 |
International
Class: |
B32B 027/12; D04H
001/00; D04H 003/00; D04H 005/00; D04H 013/00 |
Claims
1. An insulation package comprising: at least one functional fabric
layer; a highly breathable microporous membrane layer having a
network of pores, a breathable water repellant insulating layer;
and wherein the functional fabric, microporous membrane layer and
the insulating layer, are laminated to one another to form a
waterproof breathable insulated fabric.
2. The insulation package of claim 1, wherein at least one of the
at least one functional fabric layers is a water resistant
fabric.
3. The insulation package of claim 2, wherein the functional fabric
layer is coated with a cire coating.
4. The insulating package of claim 1, further comprising a second
functional fabric layer.
5. The insulating package of claim 4, wherein the second functional
fabric is laminated to the insulating layer on the non-membrane
side.
6. The insulation package of claim 1, wherein the size of a pore in
the network of pores is defined by stretching the microporous
membrane.
7. The insulation package of claim 1, wherein the said insulation
package permits vapor transfer and inhibits water transfer.
8. The insulation package of claim 1, wherein the highly breathable
water repellant insulation is nonwoven and comprises fibers
selected from the group consisting of microfibers, macrofiber,
natural fibers, and blends thereof.
9. The insulation package of claim 1, wherein the highly breathable
water repellant insulation is woven and comprises fibers selected
from the group consisting of microfibers, macrofiber, natural
fibers, and blends thereof.
10. The insulation package of claim 1, wherein the highly
breathable water repellant insulating layer has a cohesive fiber
structure comprising an assemblage of: (a) from 70 to 95 weight
percent of spun and drawn, synthetic polymeric microfibers having a
diameter of from 3 to 12 microns; and (b) from 5 to 30 weight
percent of synthetic polymeric macrofibers having a diameter of 12
to 50 microns.
11. The insulation package of claim 1, wherein the breathable water
resistant insulating layer formed as a batt having a smooth surface
compatible for lamination techniques.
12. The insulation package of claim 11, wherein the smooth surface
is formed by at least one process selected from the group
consisting of IR calendaring, hot plate calendaring, using heated
rollers, resin coatings, and hot air oven processing.
13. The insulation package of claim 1, wherein the functional
fabric is selected from the group consisting of fleece, woven, and
nonwoven fabrics.
14. A method of forming a waterproof insulation package comprising
the steps of: providing a first layer of functional fabric;
providing a second layer of microporous membrane; providing a third
layer of breathable water repellant insulation; bonding the first
layer to said second layer; and bonding the second layer to the
third layer.
15. The method of claim 14, further comprising the step of forming
the third layer as a batt.
16. The method of claim 15, further comprising the step of forming
a smooth surface on said batt.
17. The method of claim 14, wherein the bonding of the first and
second layers is a lamination process.
18. The method of claim 14, wherein the bonding of the second and
third layers is a lamination process.
19. The method of claim 14, further comprising the step of
providing a second functional fabric layer.
20. The method of claim 17, wherein the second functional fabric
layer is laminated to the insulating layer.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Filed of the Invention
[0002] The present invention is directed to waterproof breathable
insulation material and in particular such material for use in
outdoor clothing and boots.
[0003] 2. Description of the Related Art
[0004] Outdoor enthusiasts have continually demanded technically
advanced gear to protect themselves from the elements. This demand
resulted in the development of several waterproof, breathable
fabric constructions where the fabric is typically laminated to
thin films or membranes. Waterproof breathable fabrics have been
used in performance garments for many decades and have proven to be
a preferred performance component. Both the prevention of water
reaching the body from outside the clothing, and the removal of
vapor produced by the body are of great importance to the wearer in
terms of comfort. However, the disadvantage to such fabrics has
always been that although they are classified as being breathable,
they do not offer significant moisture vapor transport. Further,
most breathable fabrics tend to have very limited insulating
properties. Still further, fabrics laminated to certain types of
membrane types tend not be very flexible and generate noise when in
use. Accordingly, despite their claims most waterproof breathable
fabrics tend to be less breathable than desired, offer limited
insulating properties so that they must be used in conjunction with
some form of insulating material, and require the user to endure
their stiff and noisy nature.
[0005] Insulating materials are often used in conjunction with or
incorporated into performance garments to provide for thermal
protection. However, most insulating materials do not provide for
water repellency or alternatively provide water repellency at the
cost of a corresponding diminution in thermal protection.
PrimaLoft.RTM. insulation, as described in U.S. Pat. Nos. 4,992,327
and 4,588,635 and incorporated herein by reference, is unique to
the synthetic insulation world in that it offers superior water
repellency in addition to the thermal performance indicative of the
micro and fine fiber construction.
[0006] However, PrimaLoft.RTM. insulation has been primarily used
as a replacement for natural down with the added benefit that it is
waterproof. Alternatively, PrimaLoft.RTM. batt has been
incorporated into clothing manufacture where it is a separate
insulating layer. Often it is mechanically secured to other layers
of woven or non-woven material for example through quilting.
However, the PrimaLoft.RTM. insulation by itself does not have
sufficient structural integrity, or aesthetic appearance to suffice
as both an insulating material and an outer garment layer.
[0007] Another element of many waterproof breathable fabrics are
monolithic membrane films, which are used to impart a breathable
barrier to the fabric. Monolithic membranes promote the permeation
of water vapor through the use of a hydrophilic polymer layer which
absorbs the water next to skin and transmits it to the external
environment.
[0008] Unfortunately, monolithic films typically experience
significant swelling of the hydrophilic layer which significantly
alters the vapor removal characteristics of the film and the
comfort for the user. Further, although this type of membrane also
has a very high tear strength, which is generally favorable in
performance fabrics, this also results in extraordinary stiffness
in a garment that is usually not viewed as a positive
attribute.
[0009] Accordingly, there is a need for an waterproof, breathable,
insulation material which provides superior water repellency or
waterproofing characteristics coupled with superior vapor removal
characteristics which will not swell and has sufficient tear
strength, but which is not unduly stiff or noisy for the
wearer.
SUMMARY OF THE INVENTION
[0010] One embodiment of the present invention is directed to an
insulation package having a functional fabric layer, a highly
breathable microporous membrane layer having a network of pores,
and a breathable water repellant insulating layer, the layers being
laminated to one another to form a waterproof breathable insulated
fabric.
[0011] In another embodiment of the present invention the
insulating layer is a breathable water repellant insulating layer
in the form of a cohesive fiber structure, which structure
comprises an assemblage of:
[0012] (a) from 70 to 95 weight percent of synthetic polymeric
microfibers having a diameter of from 3 to 12 microns; and
[0013] (b) from 5 to 30 weight percent of synthetic polymeric
macrofibers having a diameter of from 12 to 50 microns.
[0014] The present invention is also directed to a method of
forming a waterproof insulation package. The steps include
providing a first layer of functional fabric, a second layer of
microporous membrane, and a third layer of breathable water
repellant insulation. Further the first layer is bonded to the
second layer, and the second layer to the third.
[0015] The various features of novelty which characterize the
invention are pointed out in particularity in the claims annexed to
and forming a part of this disclosure. For a better understanding
of the invention, its operating advantages and specific objects
attained by its uses, reference is made to the accompanying
descriptive matter in which preferred embodiments of the invention
are illustrated.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] For a more complete understanding of the invention,
reference is made to the following description and accompanying
drawings, in which:
[0017] FIG. 1 is a cross-sectional view of a waterproof insulation
package according the present invention; and
[0018] FIG. 2 is a cross-sectional view of another waterproof
breathable insulation package according the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0019] Turning now to the drawings, the present invention is
directed towards an insulation package 10 shown generally in FIG. 1
that is both waterproof and breathable. As shown in FIG. 1 an
insulating package 10 is comprised of an insulating material 12, a
microporous membrane 14, and a functional fabric 16. The insulating
material 12, the microporous membrane 14 and the functional fabric
16 are bonded to one another, preferably through known lamination
techniques. In a preferred embodiment, the laminated package 10
consists of PrimaLoft.RTM. insulation as the insulating material 12
and any woven, non-woven, fleece, or other fabric structure as the
functional fabric 16 adhered or laminated to the surface of the
microporous membrane 14, which is itself laminated to the
PrimaLoft.RTM. insulation. In certain situations it may be
desirable to add an additional layer of functional fabric or a
liner 18 to the non-membrane side of the insulation material 12, as
shown in FIG. 2.
[0020] A microporous membrane 14 is preferred because it is has a
highly breathable interconnected network of micropores that can be
manipulated. The breathability and air permeability properties of
the microporous membrane 14 are selectively defined through
stretching and manipulation of the membrane. This stretching alters
the original membrane pore size. Further, the microporous membrane
lends itself to applications using lamination techniques.
[0021] In application a pore network of the microporous membrane is
constructed so that the work path and size of the pores permit the
optimal transfer of moisture vapor while still inhibiting the
transfer of water, yet not at the level acceptable for
consideration as a waterproof, breathable membrane.
[0022] One of the advantages of the microporous membrane 14 is that
it does not absorb water or exhibit swelling. Monolithic membranes
of the prior art are typically polyurethane based, and function
through the solubility of water molecules in the membrane layer. As
a result, despite their general resistance to tearing, they are
less desirable as they are prone to swelling. Such swelling is
known to alter the hydrophilic properties of the monolithic
membranes.
[0023] In contrast, microporous membranes function through the
diffusion of moisture vapor across the pores. Typical pore size is,
for example, between 1 and 8 .mu.m. Because of this pore size
range, the microporous membrane of the present invention is not
itself considered waterproof or hydrophobic. Further, microporous
membranes are typically formed of polytetraflourethylene or other
polymeric material with a low crystalinity (generally less than
30%). In addition the polymeric material may be blended with an
inorganic filler with a particle size of 0.5-5 .mu.m. A microporous
membrane may generally have a thickness of approximately between 30
and 50 .mu.m. Importantly, such microporous membranes do not
experience the swelling common of monolithic membranes.
[0024] Further, by laminating the insulating layer 12 to a
microporous membrane 14 the resistance to tearing of the
microporous membrane, which is generally less than that of
monolithic membranes, is greatly increased. In addition, the
stiffness of the combination is significantly less than that
created by the bonding of an insulating material to a monolithic
membrane.
[0025] To further enhance the waterproof nature of the insulation
package the functional layer 16 may be coated with a durable water
repellant treatment or cire coating.
[0026] According to one aspect of the present invention, the
insulating layer 12 is a synthetic fiber thermal insulator material
in the form of a cohesive fiber structure, which structure
comprises an assemblage of:
[0027] (a) from 70 to 95 weight percent of synthetic polymeric
microfibers having a diameter of from 3 to 12 microns; and
[0028] (b) from 5 to 30 weight percent of synthetic polymeric
macrofibers having a diameter of from 12 to 50 microns,
[0029] wherein at least some of the fibers are bonded at their
contact points, the bonding being such that the density of the
resultant structure is within the range 3 to 16 kg/M.sup.3 (0.2 to
1.0 lb/ft.sup.3), the bonding being effected without significant
loss of thermal insulating properties of the structure compared
with the unbonded assemblage.
[0030] Microfibers and macrofibers for use in the present invention
may be manufactured from polyester, nylon, rayon, acetate, acrylic,
modacrylic, polyolefins, spandex, polyaramids, polyimides,
fluorocarbons, polybenzimidazols, polyvinylalcohols,
polydiacetylenes, polyetherketones, polyimidazols, and phenylene
sulphide polymers such as those commercially available under the
trade name RYTON or any other material suitable for the
purpose.
[0031] The bonding may be effected between at least some of the
macrofibers to form a supporting structure for the microfibers, or
may be between both macrofibers and microfibers at various contact
points. The macrofibers may be selected from the same material or
from a variety of materials and may be either the same material as
the microfibers or different.
[0032] In one advantageous embodiment of the invention microfibers
are formed from polyethylene terephthalate and the macrofibers are
selected from polyethylene terephthalate or a polyaramid, such, for
example, as that commercially available under the trademark
"Kevlar".
[0033] The macrofibers can be monofibers, i.e., fibers having a
substantially uniform structure or they may be multi-component
fibers having a moiety to facilitate fiber to fiber bonding. The
fiber may be a fiber mixture in which at least 10% by weight
comprises macrofibers of a lower melting point thermoplastic
material to assist the fiber to fiber bonding. In a further
embodiment of the invention the macrofibers may be a fiber mixture
comprising multi-component macrofibers and a monocomponent
macrofiber capable of bonding one with the other and/or with the
microfibers.
[0034] In another embodiment of the present invention the macro
component fiber may be a mix or blend of macrofibers having
different properties, for example, a macrofiber mix may comprise
two or more different fibers such as a polyester fiber to give the
desired bonding and a "Kevlar" fiber to give stiffness. The
proportion of stiffening fiber to bonding fiber may be varied to
provide different properties subject to the requirement that the
proportion of bondable fibers is sufficient for the macrofiber
structure to provide an open support for the microfibers as
hereinafter described.
[0035] Some materials, such as, for example, polyphenylene sulphide
fibers, aromatic polyamides of the type commercially available
under the trade name "APYIEL", and polyimide fibers such as those
manufactured by Lenzing AG of Austria, exhibit flame retardant
properties or are nonflammable. Such materials can, therefore,
confer improved flame or fire resistant properties on manufactured
products containing the materials in accordance with the present
invention.
[0036] The bonding of the fibers of the insulting layer 12, in
accordance with one aspect of the invention, is preferably,
principally between the fibers of the macrofiber component at their
contact points. The purpose of the macrofiber to macrofiber bonding
is to form a supporting structure for the micro-fiber component,
said supporting structure contributing significantly to the
mechanical properties of the insulating material. By bonding the
macrofibers, the macrofibers maintain an open bonded fiber
structure within which the microfibers can be accommodated.
Alternatively, the macrofibers and/or the microfibers may be bonded
at their contact points.
[0037] Any means of bonding between the macrofibers may be employed
such, for example, as by the addition of solid, gaseous or liquid
bonding agents or preferably through the application of heat to
cause the lower temperature fiber component to melt and fuse at
contact points.
[0038] The method of bonding the components of the insulating layer
12 is not critical, subject only to the requirement that the
bonding should be carried out under conditions such that neither
fiber component loses its structural integrity. It will be
appreciated by one skilled in the art that any appreciable change
in the macro--or microfibers during bonding will affect the thermal
properties adversely; the bonding step needs, therefore, to be
conducted to maintain the physical properties and dimensions of the
fiber components and the assemblage as much as possible.
[0039] The thermal insulating properties of the bonded insulating
layer 12 are preferably substantially the same as, or not
significantly less than, thermal insulating properties of a similar
unbonded assemblage.
[0040] In a particular embodiment of the present invention bonding
within the insulating layer 12 may be affected by heating the
fibers for a time and at a temperature sufficient to cause the
fibers to bond. Such heating period may be at a temperature of from
about 125.degree. C. (257.degree. F.) to 225.degree. C.
(437.degree. F.) for a period of the order of 1 minute to 10
minutes and preferably at a temperature of from about 140.degree.
C. (284.degree. F.) to 200.degree. C. (392.degree. F.) for a period
of about 3 to 7 minutes; these periods are, of course, dependent
upon the materials of the fiber component mix.
[0041] PrimaLoft.RTM. as described above is suitable for lamination
applications with a microporous membrane as described herein.
Lamination techniques require a substantially smooth surface on the
insulation for application and sustainability of adhesion to a
fabric.
[0042] This smooth surface can be created through processes known
in the art such as IR calendaring, hot plate calendaring, heated
rollers, resin coatings, and/or unique hot air oven processing
(unique being defined as temperature and air flow manipulation). In
addition to surface treatments, the internal structure of the
batting needs to be well bonded in order to maintain the integrity
of the structure through repeated use and laundering of a laminated
article without delamination.
[0043] Although in the preferred embodiment a Primaloft.RTM.
insulation, and in particular a batt material formed of
Primaloft.RTM. is used, it should be understood that other
insulating materials can be used without departing from the scope
of the present invention including woven and non-woven insulating
materials formed from natural and synthetic fibers or blends
thereof.
[0044] Experimental Data
[0045] This insulation package 10 provides water protection above
2.0 psi hydrostatic pressure according to AATCC Test Method 127
titled, "Water Resistance: Hydrostatic Pressure Test." It is
typically accepted in the outdoor garment industry that any fabric
with a hydrostatic pressure capability above 2.0 psi be considered
waterproof by definition. AATCC is the abbreviation for the
American Association of Textile Chemists and Colorists. AATCC 127
is a test method that measures the resistance of a fabric to the
penetration of water under hydrostatic pressure and is applicable
to all types of fabrics. One surface of the test specimen is
subjected to pressurized water where the pressure is increasing at
a constant rate until three points of leakage are observed on the
other side of the specimen. In one experiment, the insulation
package 10 utilizing a Primaloft.RTM. batt as the insulating layer
12 was found to have a resistance to hydrostatic pressure that
exceeded 185 cm-H.sub.2O or 2.63 psi. Accordingly, the insulation
package 10 was found to exhibit water resistance characteristics
that far exceeded that necessary to be considered waterproof.
[0046] Another test performed on the insulation package was a
determination of the Water Vapor Transmission Rate (WVTR). This was
done in accordance with ASTME 96-00 Procedure E. The WVTR is a test
to determine the amount of water vapor that can pass through the
fabric over a given period.
[0047] For example, one known microporous membrane often cited in
the prior art as a basis for comparison and control in experiments
is CELGARD.RTM. 2500 which is known to have a WVTR of 5000
g/m.sup.2/24 hrs.
[0048] Breathable outerwear garments of the prior art such as that
described in Example 1 of U.S. Pat. No. 6,100,208 having a first
layer of multicomponent fibers, a second layer of multicomponent
fibers and a water impermeable barrier in between formed of low
density polyethylene have been shown to have a WVTR of 3465
g/m.sup.2/24 hrs. However, the garment described in the '208 patent
does not provide an insulating layer as that of the present
invention. It would be expected that the addition of an insulating
layer would decrease the WVTR of the outdoor fabric.
[0049] The test of the insulating package of the present invention
was performed at 37.8.degree. C. and at 90% relative humidity. In
this test a sample of laminated SUPPLEX fabric, microporous
membrane material, and Primaloft.RTM. insulation, as described in
the present invention achieved at WVTR of 3521 g/m.sup.2/24 hrs.
This is significant because the test sample provides an insulating
layer not present in the two examples described above, yet has
greater WVTR than the un-insulated laminate outdoor fabric and
nearly as great an WVTR as the microporous membrane by itself. As
such the insulating package of the present invention demonstrates
that a wearer of clothing constructed using the insulation package
should expect to remain in reasonable comfort despite significant
athletic activity.
[0050] It has thus be shown that the objects set forth above, among
those made apparent from the preceding description, are efficiently
attained and, because certain changes may be made in carrying out
the above method and in the construction(s) set forth without
departing from the spirit and scope of the invention, it is
intended that all matter contained in the above description and
shown in the accompanying drawings shall be interpreted as
illustrative and not in a limiting sense.
* * * * *