U.S. patent application number 15/538571 was filed with the patent office on 2017-11-16 for polymer foam sheet and barrier layer composite.
The applicant listed for this patent is Palziv Ein Hanaziv Agricultural Cooperative Society Ltd.. Invention is credited to Sam SALADINO, Zeev TZUR, Baruch ZUR.
Application Number | 20170328073 15/538571 |
Document ID | / |
Family ID | 56149373 |
Filed Date | 2017-11-16 |
United States Patent
Application |
20170328073 |
Kind Code |
A1 |
SALADINO; Sam ; et
al. |
November 16, 2017 |
POLYMER FOAM SHEET AND BARRIER LAYER COMPOSITE
Abstract
A moisture barrier layer-foamed polymeric composite sheet
underlayment article comprising a foamed polymeric sheet and a
moisture barrier layer adhered thereto is disclosed. In one aspect,
cork particles are present in the composite.
Inventors: |
SALADINO; Sam; (Toronto,
CA) ; TZUR; Zeev; (Ein Hanatziv, IL) ; ZUR;
Baruch; (Ein Hanatziv, IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Palziv Ein Hanaziv Agricultural Cooperative Society Ltd. |
Ein Hanatziv |
|
IL |
|
|
Family ID: |
56149373 |
Appl. No.: |
15/538571 |
Filed: |
December 21, 2014 |
PCT Filed: |
December 21, 2014 |
PCT NO: |
PCT/IL2014/051114 |
371 Date: |
June 21, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B29K 2311/02 20130101;
B32B 2274/00 20130101; B32B 27/065 20130101; B32B 37/153 20130101;
B32B 2419/04 20130101; B29C 48/0011 20190201; B29C 48/21 20190201;
B32B 27/08 20130101; B32B 27/32 20130101; C08J 2323/04 20130101;
E04F 15/20 20130101; B29C 48/07 20190201; C08J 2205/044 20130101;
B32B 2264/06 20130101; C08J 2201/026 20130101; B32B 2307/7246
20130101; C08J 9/0061 20130101; C08J 9/36 20130101; B32B 13/12
20130101; C08J 2207/00 20130101; C08J 2497/02 20130101; B32B
2266/025 20130101; B29C 48/28 20190201; B29C 48/906 20190201; E04B
1/665 20130101; C08J 2205/052 20130101; B32B 27/304 20130101; B32B
2270/00 20130101; B32B 2307/7265 20130101; C08J 9/06 20130101; C08J
2201/03 20130101; B29C 48/0021 20190201; B32B 5/18 20130101; B32B
2305/022 20130101; B32B 27/306 20130101; C08J 2323/06 20130101;
C08J 2205/048 20130101; B32B 2471/00 20130101; B29K 2105/04
20130101; B32B 2266/08 20130101; E04F 15/18 20130101; B32B 7/12
20130101 |
International
Class: |
E04F 15/18 20060101
E04F015/18; B32B 7/12 20060101 B32B007/12; B32B 13/12 20060101
B32B013/12; B32B 27/06 20060101 B32B027/06; B32B 27/30 20060101
B32B027/30; B32B 27/32 20060101 B32B027/32; B32B 37/15 20060101
B32B037/15; C08J 9/06 20060101 C08J009/06; B32B 5/18 20060101
B32B005/18; E04B 1/66 20060101 E04B001/66; B32B 27/08 20060101
B32B027/08 |
Claims
1. A composite comprising: a foamed polymeric sheet having a first
surface and a second surface; and a moisture barrier layer adjacent
at least one of the first and the second surfaces.
2. The composite of claim 1, wherein the foamed polymeric sheet is
at least partially cross-linked.
3. (canceled)
4. The composite of claim 1, wherein the foamed polymeric sheet
comprises a first average foam cell diameter distribution and a
second average foam cell diameter distribution of foam cells less
than the first average foam cell diameter distribution.
5. The composite of claim 4, wherein a ratio of the first average
foam cell diameter distribution to the second average foam cell
diameter distribution is at least 6:1.
6. (canceled)
7. The composite of claim 4, wherein the first average foam cell
diameter distribution is between 300 micron to 3500 micron and the
second average foam cell diameter distribution is 1 micron to 50
micron.
8. The composite of claim 1, further comprising cork particles,
wherein the cork particles are of an average particle size of 300
micron to 1200 micron and the foamed polymeric sheet comprises an
average foam cell diameter is between 500 micron to 3500 micron,
wherein the foamed polymeric sheet comprises cork particles in an
amount of between 1 PHR to 50 PHR.
9. (canceled)
10. (canceled)
11. The composite of claim 1, wherein the moisture barrier layer
comprises at least one of: a co-extruded
thermoplastic-thermoplastic laminate film, a co-extruded
thermoplastic-polyolefin vinyl acetate film, a co-extruded
polyolefin-polyolefin laminate film, a co-extruded
polyolefin-polyolefin vinyl acetate film, a co-extruded
thermoplastic-cellulose laminate film, and a co-extruded
cellulosic-polyolefin vinyl acetate film.
12. The composite of claim 1, wherein at least a portion of the
moisture barrier layer extends beyond at least one edge of the
foamed polymer sheet.
13. The composite of claim 12, wherein the at least a portion of
moisture barrier layer extending beyond at least one edge of the
foamed polymer sheet comprises an adhesive.
14. A composite comprising: at least partially cross-linked foamed
polymeric sheet; and a moisture barrier layer adhered to at least
one side of the foamed polymeric sheet, wherein the moisture vapor
barrier layer is selected from a thermoplastic film or a
co-extruded thermoplastic-thermoplastic laminate film.
15. The composite of claim 13, wherein the foamed polymeric sheet
is a low density polyethylene.
16. The composite of claim 14, wherein the moisture barrier layer
is at least one of: a co-extruded thermoplastic-polyolefin vinyl
acetate film, a co-extruded polyolefin-polyolefin laminate film, a
co-extruded polyolefin-polyolefin vinyl acetate film, a co-extruded
thermoplastic-cellulose laminate film, or a co-extruded
cellulosic-polyolefin vinyl acetate film.
17. (canceled)
18. The composite of claim 14, wherein the foamed polymeric sheet
comprises a first average foam cell diameter distribution and a
second average foam cell diameter distribution of foam cells less
than the first average foam cell diameter distribution.
19. The composite of claim 18, wherein a ratio of the first average
foam cell diameter distribution to the second average foam cell
diameter distribution is at least 6:1.
20. (canceled)
21. The composite of claim 18, wherein the first average foam cell
diameter distribution is between 300 micron to 3500 micron and the
second average foam cell diameter distribution is 1 micron to 50
micron.
22. The composite of claim 21, further comprising cork particles,
wherein the cork particles are of an average particle size of 300
micron to 1200 micron.
23. (canceled)
24. The composite of claim 14, wherein the moisture barrier layer
extends beyond at least one edge of the foamed polymer sheet.
25. The composite of claim 24, wherein the at least a portion of
moisture barrier layer extending beyond at least one edge of the
foamed polymer sheet comprises an adhesive.
Description
TECHNICAL FIELD
[0001] This invention generally relates to a foamed polymeric sheet
and moisture barrier layer composite and methods of continuously
forming and using same as an underlayment for flooring. In one
aspect, the composite comprises cork particles.
BACKGROUND
[0002] In the construction of buildings having subfloors, it is
known to install an underlayment. Underlayments can include one or
more polyethylene films or sheets that may be foamed.
[0003] For producing a foamed sheet, a resin composition in a die
is forced into a narrow passage having a small cross-sectional
area. Strong shearing force acting the resin or stagnation
occurring at the die makes the manufacture of thin foam sheets
difficult, e.g., less than 8 mm.
[0004] Likewise, a partially foamed product extruded from a die may
be bent or bowed, or its surface may be cracked, thus causing a
difficulty in the manufacture of foams, especially thin foam sheets
and especially manufacturing of such forms continuously.
[0005] The prior art does not reasonably disclose a continuous
method for cross-sectionally cutting (profile cut) a compressible
or cellular polyolefin polymer material and laminating with a
moisture barrier layer on at least one of the surfaces resulting
from the cutting. Nor does the prior art disclose a composite
comprising a profile cut thin polyolefin polymer foam with cork
particles process to include a moisture barrier layer.
SUMMARY
[0006] In accordance with a first embodiment of the present
disclosure, a composite is provided. The composite comprising a
foamed polymeric sheet having a first surface and a second surface;
and a moisture barrier layer adjacent at least one of the first and
the second surfaces. In one aspect of the first embodiment, the
foamed polymeric sheet is at least partially cross-linked.
[0007] In one aspect, alone or in combination with any one of the
other aspects of the first embodiment, the foamed polymeric sheet
comprises cork particles. In another aspect, alone or in
combination with any one of the other aspects of the first
embodiment, the foamed polymeric sheet comprises cork particles in
an amount of between 1 PHR to 50 PHR.
[0008] In another aspect, alone or in combination with any one of
the other aspects of the first embodiment, the composite of any one
of the previous claims, wherein the foamed polymeric sheet
comprises a first average foam cell diameter distribution and a
second average foam cell diameter distribution of foam cells less
than the first average foam cell diameter distribution. In another
aspect, alone or in combination with any one of the other aspects
of the first embodiment, the ratio of the first average foam cell
diameter distribution to the second average foam cell diameter
distribution is at least 6:1, or at least 10:1.
[0009] In another aspect, alone or in combination with any one of
the other aspects of the first embodiment, the first average foam
cell diameter distribution is between 300 micron to 3500 micron and
the second average foam cell diameter distribution is 1 micron to
50 micron.
[0010] In another aspect, alone or in combination with any one of
the other aspects of the first embodiment, the cork particles are
of an average particle size of 300 micron to 1200 micron and the
foamed polymeric sheet comprises an average foam cell diameter is
between 500 micron to 3500 micron, or the cork particles are of an
average particle size of 500 micron to 1000 micron and the foamed
polymeric sheet comprises an average foam cell diameter between 600
micron to 1500 micron.
[0011] In one aspect of the second embodiment, the foamed
polyolefin film layer is a low density polyethylene.
[0012] In another aspect, alone or in combination with any one of
the other aspects of the first embodiment, the moisture barrier
layer comprises at least one of: a co-extruded
thermoplastic-thermoplastic laminate film, a co-extruded
thermoplastic-polyolefin vinyl acetate film, a co-extruded
polyolefin-polyolefin laminate film, a co-extruded
polyolefin-polyolefin vinyl acetate film, a co-extruded
thermoplastic-cellulose laminate film, and a co-extruded
cellulosic-polyolefin vinyl acetate film.
[0013] In another aspect, alone or in combination with any one of
the other aspects of the first embodiment, at least a portion of
the moisture barrier layer extends beyond at least one edge of the
foamed polymer sheet. In another aspect, alone or in combination
with any one of the other aspects of the first embodiment, the at
least a portion of moisture barrier layer extending beyond at least
one edge of the foamed polymer sheet comprises an adhesive.
[0014] In accordance with a second embodiment of the present
disclosure, a composite is provided. The composite comprising at
least partially cross-linked foamed polymeric sheet comprising cork
particles in an amount of between 1 PHR to 50 PHR; and a moisture
barrier layer adhered to at least one side of the foamed polymeric
sheet, wherein the moisture vapor barrier layer is selected from a
thermoplastic film or a co-extruded thermoplastic-thermoplastic
laminate film.
[0015] In another aspect, alone or in combination with any one of
the other aspects of the second embodiment, the moisture vapor
barrier layer is a co-extruded layer. In another aspect, alone or
in combination with any one of the other aspects of the second
embodiment, the moisture vapor barrier layer is selected from a
co-extruded thermoplastic-polyolefin vinyl acetate film, a
co-extruded polyolefin-polyolefin laminate film, a co-extruded
polyolefin-polyolefin vinyl acetate film, a co-extruded
thermoplastic-cellulose laminate film, or a co-extruded
cellulosic-polyolefin vinyl acetate film.
[0016] In another aspect, alone or in combination with any one of
the other aspects of the second embodiment, the foamed polymeric
sheet comprises a first average foam cell diameter distribution and
a second average foam cell diameter distribution of foam cells less
than the first average foam cell diameter distribution. In another
aspect, alone or in combination with any one of the other aspects
of the second embodiment, the ratio of the first average foam cell
diameter distribution to the second average foam cell diameter
distribution is at least 6:1, or is at least 10:1.
[0017] In another aspect, alone or in combination with any one of
the other aspects of the second embodiment, the first average foam
cell diameter distribution is between 300 micron to 3500 micron and
the second average foam cell diameter distribution is 1 micron to
50 micron.
[0018] In another aspect, alone or in combination with any one of
the other aspects of the second embodiment, the cork particles are
of an average particle size of 300 micron to 1200 micron and the
foamed polymeric sheet comprises an average foam cell diameter is
between 500 micron to 3500 micron, or the cork particles are of an
average particle size of 500 micron to 1000 micron and the foamed
polymeric sheet comprises an average foam cell diameter between 600
micron to 1500 micron.
[0019] In another aspect, alone or in combination with any one of
the other aspects of the second embodiment, the moisture barrier
layer extends beyond the at least one edge of the foamed polymer
sheet. In another aspect, alone or in combination with any one of
the other aspects of the second embodiment, the at least a portion
of moisture barrier layer extending beyond at least one edge of the
foamed polymer sheet comprises an adhesive.
[0020] In accordance with a third embodiment of the present
disclosure, a barrier layer-foamed polymeric sheet underlayment
composite article is provided. The article comprising a foamed
polymeric sheet; and a moisture barrier layer adhered to the foamed
polymeric sheet, the moisture vapor barrier layer having: a
polyolefin film layer; and at least one co-extruded layer posited
between the polyolefin film layer and the foamed polymeric sheet,
the at least one co-extruded layer configured to adhere to the
foamed polymeric sheet.
[0021] In a first aspect of the third embodiment, the foamed
polyolefin film layer comprises cork particles. In a second aspect,
alone or in combination with any of the previous aspects of the
third embodiment, the at least one co-extruded layer is selected
from a co-extruded thermoplastic-thermoplastic laminate film, a
co-extruded thermoplastic-polyolefin vinyl acetate film, a
co-extruded polyolefin-polyolefin laminate film, a co-extruded
polyolefin-polyolefin vinyl acetate film, a co-extruded
thermoplastic-cellulose laminate film, or a co-extruded
cellulosic-polyolefin vinyl acetate film.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] In order to understand the invention and to see how it may
be carried out in practice, embodiments will now be described, by
way of non-limiting example only, with reference to the
accompanying drawings, in which:
[0023] FIG. 1 is a schematic flow diagram illustrating an exemplary
process in accordance with the broadest aspect of the present
disclosure.
[0024] FIG. 2 is a schematic continuous foam sheet production
process in accordance with an exemplary aspect of the present
disclosure.
[0025] FIG. 3 is a schematic of a cutting and lamination process of
the continuous foam sheet production process in accordance with the
broadest aspect of the present disclosure.
[0026] FIG. 4 is a section view of a composite in accordance with
the broadest aspect of the present disclosure.
[0027] FIG. 5 is a section view of a composite and a flooring in
accordance with the broadest aspect of the present disclosure.
[0028] FIG. 6 is a cross sectional view of a foamed polymeric sheet
with polymer foam cell 605 and cork particle 610.
DETAILED DESCRIPTION
[0029] The present disclosure concerns the development of
polyolefin polymeric foams providing functionality to the
underlayment. Polymeric foams having a moisture barrier on one or
more surfaces provides various advantages, for example, as an
underlayment for flooring, soundproofing, insulation, hard floor
padding, etc. In one aspect, the floor-side (or sub-floor) of the
foamed sheet comprises moisture barrier layer that controls
moisture flow between the sub-floor (or substrate) and the flooring
itself. The present arrangement of an adhered barrier layer
laminate prevents degradation to the flooring/subflooring e.g., by
minimizing moisture damage.
[0030] Thus, the present disclosure provides a polymeric sheet
comprising a first side and a second side opposed to the first
side; and (b) a laminate barrier layer on at least one side. The
sheet can be at least partially cross-linked and/or foamed. The
polymeric sheet can be of thermoplastic, a curable elastomer, or
thermoplastic elastomer. The foamed sheet can be a closed-cell foam
structure. The foamed sheet cork particles. Manufacturing methods
of preparing the laminate barrier layer-foamed polymeric sheet are
provided. In one aspect, the manufacturing is continuous.
[0031] As used in the specification and claims, the forms "a", "an"
and "the" include singular as well as plural references unless the
context clearly dictates otherwise. For example, the term "a
polyolefin" includes one or more polyolefin resins, and the term
"polyolefins" includes one polyolefin resin as well as more than
one type of polyolefin resin. As used herein, the term "or" means
one or a combination of two or more of the listed choices.
[0032] Further, as used herein, the term "comprising" is intended
to mean that the polymeric foam and processes disclosed herein
include the recited elements, but does not exclude others. For
example, when referring to foam comprising a chemically
cross-linked polyolefin, the foam may as well include other
additives, such as a dye and/or cork particles. Similarly,
"consisting essentially of" is used to define foams and processes
that include the recited elements but exclude other elements that
may have an essential significance on the functionality of the
resulting sheet. For example, a foam consisting essentially of
cross-linked polyolefin will not include or will include only
insignificant amounts (amounts that will have an insignificant
effect on physical properties of the foam) of other elements.
"Consisting of" shall mean excluding more than trace amounts of
other elements. Embodiments defined by each of these transition
terms are within the scope disclosed herein.
[0033] Further, all numerical values, e.g., concentration or parts
per hundred parts resin (PHR) or ranges thereof, are approximations
which are varied (+) or (-) by up to 20%, at times by up to 10%,
from the stated values. It is to be understood, even if not always
explicitly stated that all numerical designations are preceded by
the term "about". It also is to be understood, although not always
explicitly stated, that the reagents described herein are merely
exemplary and that equivalents of such are known in the art.
[0034] The term "chemically crosslinked" in the context of the
present disclosure is used to denote that the polymer chains are
inter-connected by a plurality of covalent bonds and that the
covalent bonds are stable mechanically and thermally. Chemically
crosslinked methods encompass peroxide or azo cross-linking, and
silane-cross-linking methods. The term "physical crosslinking" is
used to denote high-energy methods of crosslinking, such as e-beam,
gamma, x-ray and UV methods. The extent of such cross-linking can
be determined with conventional methods, such as solvent swelling.
In one aspect, the extent of crosslinking of the presently
disclosed underlay is about 50 to about 90% as measured by solvent
swelling techniques. In one aspect of the present disclosure,
physical crosslinking is not used.
[0035] The polymeric foam according to the present disclosure
comprises closed-cell polymeric foam. The term "closed cell", in
contrast to "open cell", is known to a skilled person and means
that essentially all cell walls of the foam are undamaged.
Preferably, at least 90% of the cells have undamaged cell walls,
more preferably at least 95%, even more preferably more than
98%.
[0036] In accordance with an embodiment of the invention, the
closed cell's average diameter is between 100 micron and 5000
micron, preferably between 500 micron and 3500 micron, even more
preferably between 600 micron and 1500 micron.
[0037] The term "blowing agent" is known in the art and refers to
any substance which alone or in combination with other substances
is capable of producing a cellular structure in a polymeric or
other material. Blowing agents may include chemical blowing agents
or physical blowing agents. Chemical blowing agents include, for
example, chemical agents that decompose or react under the
influence of heat to form a gas. Chemical blowing agents range from
simple salts such as ammonium or sodium bicarbonate to complex
nitrogen releasing agents. Physical blowing agents include
compressed gases that expand when pressure is released and liquids
that develop cells when they change to gases.
[0038] The polymeric sheet can be a thermoplastic, thermoplastic
elastomer, or composite or alloys. The polymeric sheet can comprise
at least one polyolefin. As appreciated by those versed in
chemistry, "polyolefins" are a class of organic substances prepared
by the addition polymerization of alkene (hydrocarbons containing
at least one carbon-carbon double bond per molecule), especially
ethylene and propylene. The polymeric sheet of the present
invention can employ one or more polyolefins, and the one or more
polyolefins may be combined with one or more other polymers.
Thermoplastic elastomers and alloys (e.g. thermoplastic
vulcanizates such as SANTOPRENE.TM.) include polyolefin-based
(EPDM), styrene-butadiene-styrene-, styrene-isoprene-styrene-,
styrene-butadiene-, and styrene-isoprene elastomers can also be
used.
[0039] In accordance with one embodiment disclosed herein, the
polymeric sheet is at least partially cross-linked and foamed. The
forming part of the polymeric foam is characterized by a melt index
of the raw material, namely, the polymer in its melt form prior to
being chemically cross-linked with the same or another polymer, of
between 0.3 and 20, preferably between 0.7 and 5. Other melt index
ranges can be used suitable for the polymer chosen.
[0040] In one aspect, the polymeric sheet is a homopolymer or a
copolymer of any C.sub.2 to C.sub.20 olefin. In accordance with one
embodiment, the polyolefin is a copolymer of ethylene and an
alpha-olefin selected from of iso-propene, butene, iso-pentene,
hexane, iso-heptene and octane. An example of such a copolymer
includes, e.g., a metallocene polyolefin, such as ENGAGE.TM. (Dow
Chemical) or EXACT.TM. (ExxonMobil).
[0041] There are a variety of polyolefins which exhibit the above
melt index and thus may be used to form the polymeric foam
disclosed herein. A non-limiting list of possible polyolefins
comprises high density polyethylene (HDPE), Medium density PE
(MDPE), low density PE (LDPE), linear low density PE (LLDPE),
Metallocene-PE, poly-1,2-butadiene, ethylene propylene copolymer,
ethylene butane copolymer, ethylene vinyl acetate (EVA) polymers,
copolymers of ethylene with up to 45% of methyl, ethyl, propyl or
butyl acrylates or methacrylates, and mixtures of two or more of
the above mentioned polymers.
[0042] Polyolefins for chemical cross-linking to form polymeric
foams are readily available in the market. For example, polyolefins
may be purchased from Carmel Olefins, ExxonMobil, Borealis, Dow,
Dupont, Equistar, Mitsui Chemicals, Sabic etc. According to one
preferred embodiment, the at least one polyolefin is LDPE with a
melt index of 0.7-4.
[0043] In one aspect, the foamed polymeric sheet disclosed herein
comprises dispersed or distributed cork particles. In one aspect, a
laminate barrier layer and an at least partially cross-linked
polymeric foam sheet comprising an amount of cork particles is
provided. As appreciated by those versed in the art, cork is a
unique material in that it is made of air-filled, watertight cells
which make the cork an effective, light in weight, insulating
medium. The term "cork particles" denotes naturally occurring as
well as recycled cork. The cork particles may have a common,
regular shape, or irregular shapes. The irregular shape may be
obtained by chopping or dicing larger cork pieces to form cork
chips, pellets, granules etc. In accordance with one embodiment,
the cork particles have an average bulk density of 60-140
kg/m.sup.3, and an average diameter of between about 100 micron and
3000 micron, or an average diameter of between 500 micron and 2000
micron. In one aspect, the cork particles have an average bulk
density of 70-80 kg/m.sup.3, and an average diameter of between
about 100 micron and 3000 micron, or an average diameter of between
500 micron and 2000 micron. Cork material is readily available in
the market and can be purchased, for example from Amorim (de Lamas,
Portugal).
[0044] In accordance with an embodiment, cork particles can be
added to the polymer prior to cross linking, foaming, and
laminating, at an amount of between about 0.1 to about 25 parts per
hundred parts (PHR), or preferably 1-15 PHR or even more preferably
2.5-10 PHR, of the total amount of polyolefin present in the
polymeric foam. Other concentrations may be used provided that the
amount of cork does not materially affect the structure, function,
resiliency, of the foamed polymeric sheet. For example, the amount
and/or particle size of the cork can affect the visual appearance
of the produced sheet, e.g., perforations, cracks, holes, etc, or
it physical properties, e.g. tensile strength, elongation, or
compression set.
[0045] The foamed polymeric sheet disclosed herein has the
advantage that it may be produced as a continuous sheet, without
exhibiting the aforementioned perforations and other defects
typically encountered when attempting to manufacture continuous
sheets of polymeric materials. The polymeric sheet is producible at
a thickness of between 2 mm-20 mm and at any length above 2 m. In
one aspect, the foamed polymeric sheet is at least partially
crosslinked. In yet another aspect, the polymeric sheet is at least
partially cross-linked and then foamed.
[0046] In addition to the above-mentioned characteristics, the
foamed polymeric sheet disclosed herein may be characterized by one
or more of the following properties:
[0047] it has a compression set under constant force in air of
between 5 and 50% measured after 24 hrs;
[0048] it has a tensile strength of between 50 and 80 p.s.i. (345
kPa and 552 kPa);
[0049] it has an elongation at break of between 30 and 500%;
[0050] it has a compressive stress (deflection at 25%) of between 2
and 20 p.s.i. (13.8 kPa and 138 kPa); and/or
[0051] it has a compressive stress (deflection at 50%) of between 5
and 40 p.s.i. (34.5 kPa and 276 kPa)
[0052] The polymeric composition used to form the foamed sheet
disclosed herein may comprise additives typically used in polymer
industry. Such additives may include, with out being limited
thereto, one or more of a dye, such as a color masterbatch; a
stiffener, such as high-density polyethylene HDPE; a softener such
as EVA; an antioxidant such as BHT; an anti-fungal such as nano
silver particles; an anti-static such as GMS; ultra violet
resistant additives; an inorganic filler, such as calcium
carbonate; an organic filler, such as Corn starch or cellulosic
material; a chemical blowing agent (an agent that alone or in
combination with other substances is capable of producing a
cellular structure in a polymer) such as azodicarbonamide; a
co-activator of the chemical blowing agent (catalyst or activator
of the foaming agents to lower temperatures) such as zinc oxide; a
conducting agent, such as Conductive carbon black, a halogenated
flame retardant agent, such as dibromodiphenyl ether or a non
halogenated flame retardant such as magnesium hydroxide, a silanol
condensation catalyst, etc.
[0053] The foamed polymeric sheet disclosed herein may have various
applications as discussed above. In accordance with one embodiment,
the embossed polymeric sheet disclosed herein is used as
underlayment with soft and hard flooring surfaces, e.g. wood floors
(residential or commercial) or other floor covering, e.g., tile
laminate flooring, wood flooring, floating floors, peel-and-stick
flooring, etc. In addition, the sheet disclosed herein can also be
used with stone flooring surfaces such as ceramic, cement, etc. In
one embodiment, the foamed polymeric sheet is laminated to provide
a moisture barrier.
[0054] A moisture vapor barrier layer is next applied to an upper
surface of the foamed polymeric sheet. "Moisture vapor barrier"
means that the layer is substantially moisture vapor impervious.
Some trace amount of moisture may penetrate through the layer after
it is adhered to the foamed polymeric sheet layer, but the layer
prevents moisture vapor from penetrating through the layer and into
the foamed polymeric sheet layer.
[0055] The moisture vapor barrier layer may be a casted or blown
film, or a laminate film having a thickness between about 10 micron
to about 500 micron. The film must have sufficient bond strength,
elongation and tensile strength to conform to and remain on the
upper surface of the foamed polymeric sheet when rolled or
otherwise installed. Suitable moisture vapor impervious layers
include polyethylene-ethylene vinyl acetate laminate films,
polyolefin-polyvinyl acetate (PVA) films, polyolefin-polyvinyl
chloride (PVC) films, and polypropylene-polyvinyl acetate,
cellulose, cellulose acetate, polyester, polyamide, polybutadiene,
polycarbonate, and copolymers thereof.
[0056] Preferably, the moisture vapor barrier layer is applied with
a hot roll laminator, known to those of skill in the art. The
moisture vapor barrier layer may also be adhered to the upper
surface of the base layer with a flame. Once the barrier layer has
been adhered to the base layer, the underlayment structure provides
a low moisture vapor flow through the product.
[0057] As disclosed herein, in a first embodiment, the method for
manufacturing a continuous sheet comprising an exemplary moisture
barrier layer and an at least partially cross-linked, foamed
polymeric sheet, as described. A continuous process, where each
step is continuously operated, thereby allowing the formation of a
continuous, composite sheet can be employed. In one aspect, the
entire process is continuous, including the adhering of the
moisture barrier laminate. In another aspect, the adhering of the
moisture barrier laminate can be performed as a separate
process.
[0058] Thus, (raw) materials comprising at least one polyolefin
resin, optionally, at least one cross-linking agent, and
optionally, at least one blowing agent, are continuously fed into a
mixing arrangement set at a temperature of between 60.degree. C.
and 200.degree. C. to form a homogeneous molten blend (at times
referred to by the term "homogenous melt").
[0059] The homogenous melt is fed into an extrusion line,
constructed to form from the homogenous melt, a continuous
polymeric sheet. The continuous polymeric sheet is optionally
transferred into a heating module for heating the continuous sheet
to a first temperature at which at least partial cross-linking of
the polymeric resin can be performed, albeit being lower than the
temperature required for activating the blowing agent. In at least
one aspect, a cross-linking agent is used, and as a result, a
cross-linked polyolefin sheet is obtained.
[0060] Optionally, the present method comprises elevating the
temperature within the heating module or in a separate oven,
thereby further heating the polymer sheet (or cross-linked sheet)
to a second temperature at which the optional blowing agent present
in the melt can be activated. In at least one aspect, a blowing
agent is used and as a result, a continuous, foamed polymeric sheet
is obtained. In yet another aspect, a cross-linking agent is used
and a blowing agent is used, and as a result, a continuous, at
least partially cross-linked, foamed polymeric sheet is
obtained.
[0061] In accordance with a first embodiment, raw material
comprises also one or more additives selected from a dye, a
stiffener, a softener, a plasticizer, an antioxidant, an
anti-fungal, an anti-static, an ultra violet resistant additive, an
inorganic filler, an organic filler, a chemical blowing agent
kicker, a conducting agent, and a flame retardant agent, as will be
further discussed below.
[0062] Raw materials are mixed at a temperature of between about
60.degree. C. and about 200.degree. C. and more specifically, from
about 80.degree. C. to about 150.degree. C., so as to allow the
formation of a molten blend in which the various constituents are
homogenously dispersed in the blend.
[0063] The homogenous melt may be obtained by using a variety of
mixers known in the polymer industry. Some exemplary, non-limiting
mixers include a Banbury mixer, a dispersion mixer, a batch mixer,
an internal Mixer, a kneader and others. As appreciated by those
versed in the art, mixing in the mixer may take from about several
seconds to about several minutes until the homogenous molten blend
is obtained. Once ready, the homogenous melt is transferred, via,
e.g. a feed hopper, into an extrusion line.
[0064] A typical extrusion line may consist of the raw material
feed hopper, a single extruder or a combination of extruders
connected in a series, an extrusion die, a calibration unit, and
haul-off. The extruders typically comprise a heated barrel
containing therein a single or plurality of rotating screws. The
extrusion line may include a single extruder or combinations of
extruders which may be any one of the extruders known in the
polymer industry, including, without being limited thereto, single
screw extruder, tapered twin extruder, tapered twin single
extruder, twin screw extruder, multi-screw extruder. The extrusion
line may also comprise a sheet pre-forming machine. The melt moves
from the back of the screw to the head of extrusion die channel in
which the melt is simultaneously heated, mixed and pressurized to
take up an approximate shape of a sheet.
[0065] In one aspect, when the crosslinking agent is employed, the
continuous sheet is transferred to a heating arrangement comprising
a cross-linking module in which the chemical cross-linking is
initiated. When a blowing agent is used in combination with the
cross-linking agent, the at least partially cross-linked sheet is
continuously introduced into a blowing module in which the blowing
agent is activated resulting in the at least partially chemically
cross-linked foamed polymeric sheet. The sheet may be cooled or
heated between the cross-linking module and the blowing module,
e.g., chill/hot rolls, serpentine rollers, etc. Heating in either
module can be via conduction, convection, or infra-red means
conventionally employed in the art.
[0066] The cross-linking module comprises a conveyer oven adapted
to heat the continuous sheet to a first temperature which permits
being lower than that required for activating the blowing agent, if
included a priori in the raw blend.
[0067] According to one embodiment, the conveyer oven is a
horizontal oven typically of a length of 10-50 meters, however,
other lengths can be used. The oven is equipped with a moving belt
(e.g. stainless steel belt) which slowly transports the sheet at a
temperature range which induces either cross-linking or blowing or
both (in two distinct sections). According to one embodiment, the
temperature range (the said first temperature) is between about
70.degree. C. and about 160.degree. C. so as to activate and induce
cross-linking. It is noted that the oven can have a fixed
temperature or a temperature gradient. The belt transports the
sheet at a speed that is variable and is determined upon by the
density and thickness of the foam to be produced. Other ovens,
e.g., a salt bath or Teflon roll oven and the like and/or heating
configurations can be used to heat the extruded sheet to provide
for crosslinking and foaming.
[0068] A variety of cross-linking agents may be included in the
melt, so as to allow cross-linking of the at least one polyolefin
in the melt. Typically used to this end are peroxides (compounds
containing an oxygen-oxygen single bond). A non-limiting list of
peroxide-based cross-linking agents comprises dicumyl peroxide,
di-t-butyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane,
2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3,1,3-bis(t-butylperoxyisopropyl-
)benzene, 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane,
n-butyl-4,4-bis(t-butylperoxy)valerate, benzoyl peroxide,
p-chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, t-butyl
peroxybenzoate, t-butyl perbenzoate, t-butyl peroxyisopropyl
carbonate, diacetyl peroxide, lauroyl peroxide and t-butyl cumyl
peroxide.
[0069] In one aspect, a peroxide based cross-linking agent in
accordance with the present disclosure is dicumyl peroxide. The
cross-linking agent may alternatively be an organosilane linker and
a silanol condensation catalyst. For example, the one step
"Monosil" process can be used, or alternatively, the two step
"Sioplas" technology can be employed. For those knowledgeable in
the art, either method can be utilized to produce
silane-crosslinked polyolefinic foams.
[0070] The blowing module, e.g., for creating the voids in the
polymer, may constitute a second conveyer oven or a second portion
of the conveyer in which cross-linking has occurred. The blowing
module is adapted to continuously receive and to heat the sheet
(cross-linked or non-cross-linked) to a second temperature capable
of activating the blowing agent. The second temperature is
typically higher than that required for cross-linking so as to
avoid foaming during the cross-linking process. Typically, the
second temperature, according to one embodiment, is between about
150.degree. C. and 250.degree. C.
[0071] The blowing agent in one aspect is a chemical blowing agent.
A non-limiting list of chemical blowing agents comprise
azodicarbonamide, barium azodicarboxylate, azobisisobutyronitrile,
and azodicarboxylic amide, nitroso compounds, such as
N,N'-dinitrosopentamethylenetetramine,
N,N'-dimethyl-N,N'-dinitrosoterephthalamide, and
trinitrotrimethyltriamine, hydrazide compounds, such as
4,4'-oxybis(benzenesulfonylhydrazide),
paratoluenesulfonylhydrazide,
diphenylsulfone-3,3'-disulfonylhydrazide, and
allylbis(sulfonylhydrazide), semicarbazide compounds, such as
p-toluilenesulfonylsemicarbazide, and
4,4'-oxybis(benzenesulfonylsemicarbazide), alkane fluorides, such
as trichloromonofluoromethane, and dichloromonofluoromethane, and
triazole compounds, such as 5-morpholyl-1,2,3,4-thiatriazole. In
one aspect, the blowing agent in accordance with the present
disclosure is azodicarbonamide.
[0072] It is to be appreciated by those versed in the art that the
cross-linking and blowing may take place in two different conveyer
ovens, or in a single conveyer oven having a first section being
heated to the first temperature where cross-linking takes place,
either as a fixed temperature or as a gradient and a second section
receiving the cross-linked polymer, and having a second
temperature, either as a fixed temperature or as a gradient, where
the blowing agent is activated and foaming of the cross-linked
sheet takes place.
[0073] The temperatures in the two different ovens or in the two
sections of a single oven and the transport velocity of the
transporting belts are adjusted, so that the cross-liking process
is brought to a predetermined level (e.g., completely or at least
partially) before the blowing process takes place.
[0074] According to one embodiment, the cross-linking temperatures
are in the range of 120.degree. C. to 150.degree. C. During the
cross-linking stage, the polymer sheet is softened, crosslinking
takes place, and the melt strength goes up enough so that when,
towards the end of the oven (or the first section of the oven), the
temperatures can be raised up to a predetermined temperature
capable of activating the blowing agent or providing a material
that can be foamed. The predetermined temperature of the second
oven or second section are typically greater than that of the first
oven or first section. In one aspect, the predetermined temperature
of the second oven or second section is over 200.degree. C.
(typically in the range of 220.degree. C.-250.degree. C.). At this
temperature the foaming occurs and the sheet material comes out of
the oven as a foam sheet.
[0075] The continuous rolled sheet may be aged for a sufficient
period of time for optimal annealing and relaxation before
performing further processing such as welding, laminating of
materials etc. as further described below with reference to the
different applications of the continuous rolled sheet. It is noted
that instead of rolling, the continuous polymeric foamed sheet
exiting the conveying oven may be cooled and sliced into blocks or
sheets (or rolls) of fixed length for storage.
[0076] A variety of combinations of raw materials may be used to
form the continuous sheet in accordance with the present
disclosure. In an exemplary embodiment, a continuous sheet of at
least partially cross-linked foamed polymer is prepared using
materials comprising a mixture of at least one polyolefin resin,
0.2-25 PHR (preferably 2-20, more preferable, 5-15) of chemical
blowing agent blowing agent, 0.1-2 PHR (preferably 0.4-1.2) of a
cross-linking agent, and 0-3 PHR (preferably 0.1-1) of a dye (color
Masterbatch can be used). In one aspect, 0.1-25 parts by weight per
hundred parts (PHR) (preferably 1-50 PHR, more preferably 2.5-25
PHR) of cork particles can be added. If cork particles are used, in
one aspect, the raw material comprises 2.5-10 PHR cork
particles.
[0077] In accordance with the same or other embodiments, the raw
materials may comprise 5-15 PHR of chemical blowing agent. Alone or
in combination with the chemical blowing agent, the raw materials
may comprise 0.4-1.2 PHR of a cross-linking agent.
[0078] Specifically, FIG. 1 illustrates a process 300 where firstly
the mixture of raw materials comprising at minimum at least one
material, e.g., polyolefin resin, a cross-linking agent and a
blowing agent that is fed, e.g., into a mixer (Step 310). The mixer
may be any commercial mixer available in the industry, some
examples of same provided hereinabove. The mixer (310) includes, in
addition to the at least one polyolefin, the blowing agent and a
radical generator such as a peroxide, and may include cork
particles and/or colorant, and or filler. In one aspect, the
mixture comprises an amount of cork particles.
[0079] The mixer is also configured to convey heat at a temperature
of between about 80.degree. C. to about 150.degree. C. Thus, while
being continuously mixed, the raw materials melt while they are
homogenized into a melt (320). Once an essentially homogeneous melt
is obtained and the temperature of the melt and the mixer inner
chamber are essentially the same (although these criteria may vary,
depending on the raw materials used), the melt is transferred (fed)
into an extrusion line set to exert heat onto the melt received and
contained therein at a temperature of between about 80.degree. C.
to about 200.degree. C. The molten blend is then extruded via a
flat die (Step 336) in the form of a continuous sheet.
[0080] The uniformly produced continuous sheet exiting optional
calendaring (Step 338) is transferred to a conveyer oven which is
set at a temperature sufficient for commencing crosslinking (Step
342) of the polymers in the continuous sheet, and following in
line, a second section, which is set at a temperature sufficient
for activating the blowing agent and blowing the received,
chemically cross-linked polymeric sheet, to obtain the respective
foamed sheet (Step 344). The sheet can then be split into 2 sheets
of essentially equal (Step 348) thickness or of different
thickness. The sheet can then be laminated (Step 350) followed by
cooling on chiller rolls and the cooled continuous sheet is then
wound on a core.
[0081] Reference is now made to FIG. 2 which shows an exemplary
process 500 (mixing raw materials and extrusion) and process 501
(crosslinking/foaming). Thus, raw material is added to mixer 541 to
provide blended or mixed material to extruder 561. Extruder 561 is
shown with sheet die 571 for directly extruding the continuous
sheet 503. Other dies can be used, e.g., for extruding a continuous
sleeve having a uniform annular wall thickness. If a sleeve die is
used, the continuous sheet may be formed by cutting through the
sleeve wall immediately following the extrusion of the sleeve. Such
an extruded form can optionally be sent through calender rolls 591
to adjust the thickness and/or width of sheet 503. As shown,
exemplary extruded sheet 503 is a generally planar, continuous
sheet, but other extruded shapes may be formed using the method of
the present disclosure. The continuous sheet will typically have an
uncured, unfoamed thickness that may range from about 39 mil (1
millimeter) to about 236 mil (6 millimeter) or thicker.
[0082] Sheet 503 is passed to a first oven or first section 502 for
activation of the cross-linking agent, if one is used. Sheet 503
then exits first oven 502 and, if a blowing agent is employed,
enters second oven or second section 542 having a higher
temperature than first oven 502. Foaming of the sheet occurs and
foamed sheet 581 of greater thickness than sheet 503 exits second
oven 542. Drive rolls 518 take up and can optionally cool/heat
foamed sheet 581.
[0083] Alternatively, an e-beam or other high energy source can be
used in place of the oven and peroxide. Alternatively, a
silane-grafted polyolefin can be used, and the oven can be
configured to provide moisture, e.g., via steam, to promote silane
cross-linking.
[0084] With reference to FIG. 3, cutting and laminating operations
504, 506 are depicted and discussed below. In cutting operation
504, foamed polymer sheet 581 may be cut using conventional cutting
material such as a blade or a hot wire cutter. A slab of such
material is cut by moving the slab relative to the blade or one or
more hot wires, for example. The blade may be stationary or
rotatable about a fixed plane relative to the extruded sheet.
[0085] At least one compression rollers 556 is positioned close to
the outer surface of a drive roller 518 to define a predetermined
gap. The roller 556 position is adjustable, such that the outer
surface of the roller may be closer or farther from the outer
surface of the drive roller 518 to change the gap. Foamed polymer
sheet 581 is fed into the gap set to a distance that causes the
compressible material to be at least slightly compressed between
the outer surface of the compression roller 556 and drive roller
518.
[0086] A knife blade 576 is held just downstream from the gap such
that as the foamed polymer sheet 581 passes through the gap, the
sheet is cut by the blade 576. The cut slabs emerges with a
profile-cut through the thickness thereof, and at least one of the
two cut sheets are taken up by for laminating or roll up/storage.
The composite can be sold as a roll or cut in various tile-like
sizes, for example 3 ft.times.3 ft or 2 ft.times.4 ft.
[0087] Lamination can be performed using conventional techniques,
including, but not limited to, heated rolls, pinch rolls, and the
like. The lamination can utilize existing rolls of the continuous
process or be carried out on a dedicated processing line. In one
aspect, moisture barrier layer is the surface facing the flooring
e.g., the bottom, the barrier layer serving as a vapor barrier.
Having the composite installed with the barrier layer facing up,
e.g., against the flooring system, the back-side (or underside) of
the flooring is best protected from having air moisture and floor
wetness settle between the connections (e.g., tongue and grove) of
floors planks. In addition, this configuration provides a smoother
surface and most importantly, a surface that will not easily
puncture from protruding subfloor materials--such as nails,
concrete stones, etc. By reducing and or restriction air moisture
and floor wetness from entering between the floor boards `floor
cupping` is reduced (where the edges of a board are higher than its
center).
[0088] In one aspect, the barrier layer laminate does not extend
beyond any edge of the foam sheet. In another aspect, the barrier
layer laminate extends beyond one or both of the longitudinal edges
of the foamed polymer sheet for coupling sheets together during a
flooring process.
[0089] The at least partially cross-linked and foamed sheet can be
laminated with a film or layer comprising one or more moisture
barrier layers (e.g. the barrier layer can be a laminate) to
provide a composite. The moisture barrier layer can be any one or
more of thermoplastic films, a thermoplastic elastomer films, or
adhesive layers such as a pressure sensitive or peel-and-stick
adhesives. In one aspect, the moisture barrier layer is a
multi-film laminate that is configured to assist in the lamination
of the thermoplastic foamed sheet with the moisture barrier layer.
Thus, in one aspect, the moisture barrier layer laminate comprises
a first surface comprising a moisture vapor barrier material, and a
second surface configured for facilitating adhesion to the foamed
polymeric sheet.
[0090] Reference is now made to FIG. 3, which depicts a down-stream
operation that may be continuous from that of the process shown in
FIG. 2 or carried out separately, where the down stream operation
includes the additional steps of a cutting process 504 of foamed
polymer sheet 581 and/or a lamination process 506. Thus, moisture
barrier layer 515 is pulled from roll 513 to mate with surface 581'
of sheet 581 via nip roll 511. Laminate moisture barrier layer 515
can be heated via heater 520 prior to mating with sheet 581. Nip
roll 511 can be heated to a predetermined temperature suitable for
melt bonding of laminate moisture barrier layer 515 to sheet 581,
or for activating an adhesive applied to the surface of moisture
barrier layer 515. Alternatively or in addition, a flame heater 520
can be configured to activate surface 515' of moisture barrier
layer 515 prior to mating with surface 581' of sheet 582. Composite
sheet 582, e.g., with laminate moisture barrier layer 515 on at
least one side of sheet, can then be taken up for storage.
[0091] Composite sheet 582 provides a moisture/liquid/vapor
permeation barrier for the underlayer sheet, e.g., to protect the
flooring/sub-flooring. Composite sheet 582 can be provide
separately with, or comprise, an adhesive (e.g., pressure sensitive
adhesive, peel-off tape) or melt adhesive, or a water-based acrylic
adhesive, to bond an adjacent composite sheets 582 together during
flooring installation. Composite sheet 582 can comprise an
adhesive, e.g., a pressures sensitive adhesive or peel-and-stick
adhesive, on the foam side and/or on the moisture barrier layer
side of the composite to assist in the flooring installation.
Alternatively, the moisture layer extending beyond the edge of the
foamed polymeric sheet can be used for overlapping of the adjacent
sections of underlayment and such extensions can include adhesive,
e.g., a peel-and-stick type adhesive configuration. Composite sheet
582 can include flame retardant material, anti-microbial material,
and/or fungicide and/or anti-slip agents.
[0092] In one aspect, the cut foamed polymer sheet 581 having a
cut-side 581' is laminated on at least one side with a moisture
barrier layer 513 having a co-extruded laminate film on at least
one side 515 to join with cut-side 581' for providing laminate
sheet 582. An exemplary laminate barrier layer 513 is selected from
low density polyethylene-ethylene vinyl acetate coextruded films,
or cellulose-LDPE films, or PET-polyolefin films, or
polyvinyl-polyolefin films and the like. In one aspect, the barrier
layer is of a thickness of about 3 mil (76 micron) to about 10 mil
(254 micron), in other aspects, a thickness of about 4 mil (102
micron) to about 8 mil (203 micron) can be used, and in yet other
aspects, a thickness of about 5 mil (127 micron) to about 6 mil
(152 micron) can be used, where the ratio of the thickness of the
co-extruded films of the co-extruded barrier layer laminate is
about 6:1, 5:1, 4:1, 3:1, or 2:1. In one aspect, the ratio of the
thickness of the co-extruded films of the co-extruded barrier layer
laminate is 4:1. Thus, for example, a co-extruded barrier layer can
be employed consisting of a coextruded sheet composed of a
polyolefin layer, e.g., such as a low density polyethylene of 4.2
mil (120 micron) thickness and 1.2 mil (30 micron) of co-extruded
layer, e.g., for improving the adhesion of the barrier laminate
film to the foamed polymer sheet, consisting of a polyolefin-vinyl
acetate material, for example.
[0093] In one aspect, the composition can be installed in a free
floating manner on a concrete or wood subflooring, with the barrier
layer of the foam sheet contacting the surface of the subflooring.
The laminate composition can be provided in long strips, so when it
is installed one edge of one strip abuts an adjacent strip. With
reference to FIG. 4, the application of the composite 203 is shown
with barrier layer 202, co-extruded layer 204 and at least
partially crosslinked, foamed polymeric sheet 206.
[0094] With reference to FIG. 5, in one aspect, in particular, for
a concrete- or ceramic-subfloor 212, the adjacent strips of
laminated foamed polymeric sheet 200 are sealed with tape or other
adhesive (not shown) where adjacent strips are abutted together to
provide a continuous non-interrupting barrier layer between the
subfloor and the flooring material 214, shown as wood flooring. In
another example, in particular, for a non-concrete or not ceramic
subfloor, the adjacent strips are left abutted together without the
use of sealant or tape to provide at least some level of
"breathing" between the subfloor and the flooring.
[0095] The present disclosure of product and method is generally
applicable for use in any floor system such as an apartment, house,
or commercial building. A floor system contains a subflooring and a
finished flooring. A wood floor system has wood or steel joists
supporting both the subflooring and the finish flooring. The
subflooring can be for example half-inch (12.7 mm) to one-inch
(25.4 mm) thick softwood or hardwood boards or plywood panels and
is typically used in residential homes or apartments. The finish
flooring is typically thinner and often is hardwood boards. The
floor system in steel-framed buildings is typically supported by
open-web steel bar joists or steel beams. The floor deck or
subflooring on the bar joists or beams can be, for example, a steel
deck, a precast concrete slab or panels, or a precast hollow-core
concrete slab or panels. The floor system can be a
reinforced-concrete floor system typically used in multi-floor
buildings. The floor system in a reinforced structure is commonly
constructed in a monolithic manner with the structural framing
system. The reinforced-concrete subflooring can be flat-slab
construction, flat-plate construction, or slab-band
construction.
Example
[0096] A 3.6 mm cork-containing composite sample product was
prepared using the above method, comprising a linear low density
polyethylene (LLDPE) foamed polymer sheet and a co-extruded
laminate barrier layer of LLDPE and ethylene vinyl acetate. The
sample provide an average Water Vapor Transmission Rate of 0.493
(2.8% CV) and a permeance of 8.62 (2.8% CV) ng/Pa/s/m.sup.2 when
tested under NALFA UL 01-2008 Sec. 3.5. Similar thickness (3.6 mm)
samples tested under ASTM E96/E96M-10 Proc. B yielded an average
Water Vapor Transmission Rate of 0.302 (1.7% CV) and a permeance of
2.49 (1.7% CV) ng/Pa/s/m.sup.2. Thus, the presently disclosed
product is useful as a vapor barrier underlayment for flooring and
would be classified as a Class 1 Vapor Retarder. FIG. 6 is a cross
sectional view of the foamed polymeric sheet with polymer foam cell
605 and cork particle 610.
[0097] A conventional underlayment typically consists of an
impermeable film that is installed on a below grade concrete
subfloor with a permeable to semi-impermeable vapor barrier grading
(without or without a vapor sheet) installed on top of the
impermeable film, the two films being maintained loosely together.
This arrangement provides for moisture between the two films, and
as a result, moisture will eventually penetrate the permeable to
semi-impermeable barrier over time. Indeed, most conventional
underlayments are Class 2 or Class 3 Vapor Retarders. In contrast,
the present composite with an attached moisture vapor barrier to
the foam, qualifies as a Class 1 Vapor Retarder and eliminates or
reduces the risk of moisture build-up compared to conventional
underlayment techniques by eliminating any gap between the layers
of the underlayment.
[0098] Although the present disclosure has been described in
conjunction with specific embodiments thereof, it is evident that
many alternatives, modifications and variations will be apparent to
those skilled in the art. The present disclosure will now be
described with reference to the following non-limiting example.
[0099] Furthermore, while certain embodiments of the present
disclosure have been illustrated with reference to specific
combinations of elements, various other combinations may also be
provided without departing from the teachings of the present
disclosure. Thus, the present disclosure should not be construed as
being limited to the particular exemplary embodiments described
herein and illustrated in the Figures, but may also encompass
combinations of elements of the various illustrated embodiments and
aspects thereof.
* * * * *