U.S. patent application number 13/714062 was filed with the patent office on 2013-06-13 for non-woven, flame retardant, moisture resistant panel and method of construction thereof.
This patent application is currently assigned to Federal-Mogul Powertrain, Inc.. The applicant listed for this patent is Federal-Mogul Powertrain, Inc.. Invention is credited to Ali Khosroshahi, Ritesh Mehbubani, Brian Taylor, Stephen Yanchek.
Application Number | 20130149926 13/714062 |
Document ID | / |
Family ID | 47520266 |
Filed Date | 2013-06-13 |
United States Patent
Application |
20130149926 |
Kind Code |
A1 |
Mehbubani; Ritesh ; et
al. |
June 13, 2013 |
Non-Woven, Flame Retardant, Moisture Resistant Panel and Method of
Construction Thereof
Abstract
A nonwoven, fire retardant, moisture resistant panel and method
of construction thereof is provided. The panel includes a bonded
nonwoven sheet of bast fibers bonded with polymeric binding fibers.
Further, the panel includes a single coating of a dried and cured
solution. The dried and cured coating includes a binder, a Ph
stabilizer and a single flame retardant. The binder is cross-linked
with the bast fibers to form a moisture resistant barrier that
reduces the moisture absorption of the bast fibers
Inventors: |
Mehbubani; Ritesh; (Telford,
PA) ; Taylor; Brian; (Morgantown, PA) ;
Yanchek; Stephen; (Phoenixville, PA) ; Khosroshahi;
Ali; (Exton, PA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Federal-Mogul Powertrain, Inc.; |
Southfield |
MI |
US |
|
|
Assignee: |
Federal-Mogul Powertrain,
Inc.
Southfield
MI
|
Family ID: |
47520266 |
Appl. No.: |
13/714062 |
Filed: |
December 13, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61569975 |
Dec 13, 2011 |
|
|
|
61703613 |
Sep 20, 2012 |
|
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Current U.S.
Class: |
442/1 ; 156/60;
264/324; 442/85 |
Current CPC
Class: |
B27N 1/006 20130101;
E04C 2/16 20130101; Y10T 442/2213 20150401; B27N 9/00 20130101;
Y10T 156/10 20150115; Y10T 442/10 20150401; B27N 3/002 20130101;
D04H 13/00 20130101 |
Class at
Publication: |
442/1 ; 442/85;
264/324; 156/60 |
International
Class: |
E04C 2/16 20060101
E04C002/16; D04H 13/00 20060101 D04H013/00 |
Claims
1. A nonwoven, fire retardant, moisture resistant panel,
comprising: a bonded nonwoven sheet, said bonded nonwoven sheet
including a mixture of bast fibers bonded with polymeric binding
fibers; and a single coating of a dried and cured solution, said
solution including a binder, a Ph stabilizer and a single flame
retardant, said binder being cross-linked with said bast fibers and
forming a moisture resistant barrier that reduces the moisture
absorption of said bast fibers.
2. The nonwoven, fire retardant, moisture resistant panel of claim
1 further including a scrim layer bonded to at least one side of
said panel.
3. The nonwoven, fire retardant, moisture resistant panel of claim
2 wherein said scrim layer is free of formaldehyde.
4. The nonwoven, fire retardant, moisture resistant panel of claim
3 further including said scrim layer being bonded to opposite sides
of said panel.
5. The nonwoven, fire retardant, moisture resistant panel of claim
1 wherein said mixture includes between 50-80 wt % of said bast
fibers fiber and between 15-50 wt % of said polymeric binding
fiber.
6. The nonwoven, fire retardant, moisture resistant panel of claim
1 wherein said bonded nonwoven sheet is between 150 gsm and 1500
gsm.
7. The nonwoven, fire retardant, moisture resistant panel of claim
1 wherein said dried and cured coating has between 30 and 300 gsm
dry pickup weight.
8. The nonwoven, fire retardant, moisture resistant panel of claim
1 wherein the panel contains less than 0.04 ppm formaldehyde.
9. The nonwoven, fire retardant, moisture resistant panel of claim
1 wherein said fire retardant is provided from at least one of the
group consisting of a boron-based, phosphorous-based and
sulfur-based compound.
10. The nonwoven, fire retardant, moisture resistant panel of claim
9 wherein said fire retardant is provided as disodium octaborate
tetrahydrate.
11. The nonwoven, fire retardant, moisture resistant panel of claim
9 wherein said fire retardant is provided having between about 5-25
wt %.
12. The nonwoven, fire retardant, moisture resistant panel of claim
11 wherein said fire retardant is provided having about 15 wt
%.
13. The nonwoven, fire retardant, moisture resistant panel of claim
1 wherein said panel is an office divider panel.
14. The nonwoven, fire retardant, moisture resistant panel of claim
1 wherein said panel meets the office divider tackable board
requirements of ASTM E-84 Class A.
15. A method of constructing a nonwoven, fire retardant, moisture
resistant panel, comprising: forming a homogenous mixture of bast
fibers and polymeric binding fiber; forming a web of the homogenous
mixture; melting the polymeric binding fiber and bonding the bast
fibers with the material of the polymeric binding fiber to form a
bonded nonwoven sheet; saturating the bonded nonwoven sheet in a
solution including a binder, a Ph stabilizer and a flame retardant;
cross-linking the binder with the bast fibers by drying the
saturated, bonded nonwoven sheet and curing the solution; and
compressing the nonwoven sheet.
16. The method of claim 15 further including compressing the
nonwoven sheet while curing the solution.
17. The method of claim 16 further including cooling the nonwoven
sheet while compressing the nonwoven sheet.
18. The method of claim 15 further including using a modified
polycarboxylic acid with a polyol for the binder.
19. The method of claim 15 further including forming the solution
by diluting the binder with water and compounding a single flame
retardant with the binder and water mixture.
20. The method of claim 15 further including using about 10-20 wt %
of the binder in the solution.
21. The method of claim 15 further including laminating a scrim
layer to at least one side of the panel.
22. The method of claim 21 further including providing the scrim
layer as being free of formaldehyde.
23. The method of claim 15 further including constructing the panel
having less than 0.04 ppm formaldehyde content.
24. The method of claim 15 further including providing the fire
retardant from at least one of the group consisting of a
boron-based, phosphorous-based and sulfur-based compound.
25. The method of claim 24 further including providing the fire
retardant as disodium octaborate tetrahydrate.
26. The method of claim 25 further including providing the fire
retardant having about 15 wt %.
27. The method of claim 24 further including providing the fire
retardant having between about 5-25 wt %.
28. The method of claim 15 further including constructing the
nonwoven, fire retardant, moisture resistant panel so that it meets
the office divider tackable board requirements of ASTM E-84 Class
A.
29. The method of claim 15 further including maintain the nonwoven
sheet as a continuous piece of material until after compressing the
sheet and then cutting the sheet to form the desired length of the
panel.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional
Application Ser. No. 61/569,975, filed Dec. 13, 2011, and the
benefit of U.S. Provisional Application Ser. No. 61/703,613, filed
Sep. 20, 2012, which are both incorporated herein by reference in
their entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Technical Field
[0003] This invention relates generally to nonwoven panels, and
more particularly to flame retardant, moisture resistant nonwoven
structural panels and to their method of construction.
[0004] 2. Related Art
[0005] It is known to construct structural panels, meaning those
capable of functioning as a structural member, such as office
divider panels, for example, from fiberglass composites via bonding
fiberglass with resin. However, the resins used to construct
fiberglass panels include high levels of formaldehyde, which can be
harmful to persons, and due to a new regulation CAL1350, which
calls for the levels of formaldehydes to be below 0.04 ppm, the
fiberglass panels are unacceptable. In addition, the fiberglass
panels are not environmentally friendly given they have a
relatively high carbon footprint in manufacture and are made from
materials that are typically not renewable.
[0006] In addition to fiberglass panels, it is known to construct
panels including natural fibers bonded with resin. However, the
known compositions of these panels are susceptible to water
absorption, which can have a deleterious effect on their structural
capacity. As such, the natural fiber panels typically fail to meet
humidity shock and board stiffness tests required for office
divider tackable board applications. Further, these panels are
typically constructed via processes that are costly, including
requiring multiple coating processes, for example. Accordingly,
their costly construction typically renders them cost ineffective,
and thus, rules them out for use in many applications. Further yet,
natural fiber-based boards typically have a brown color, which is
undesirable for visible office panel applications.
SUMMARY OF THE INVENTION
[0007] In accordance with one aspect of the invention, a nonwoven,
fire retardant, moisture resistant panel is provided. The panel
includes a bonded nonwoven sheet of bast fibers bonded with
polymeric binding fibers. Further, the panel includes a single
coating of a dried and cured solution. The dried and cured coating
includes a binder, a Ph stabilizer and a single flame retardant.
The binder is cross-linked with the bast fibers to form a moisture
resistant barrier that reduces the moisture absorption of the bast
fibers.
[0008] In accordance with another aspect of the invention, the
panel meets the requirements of regulation CAL1350 calling for
levels of formaldehydes to be below 0.04 ppm.
[0009] In accordance with another aspect of the invention, the
panel is formed as an office divider panel that passes an ASTM E-84
flame test.
[0010] In accordance with another aspect of the invention, the
mixture includes between 50-80 wt % of bast fibers fiber and
between 15-50 wt % of polymeric binding fiber.
[0011] In accordance with another aspect of the invention, the
bonded nonwoven web is between 150 gsm and 1500 gsm.
[0012] In accordance with another aspect of the invention, the
dried and cured coating has between 30 gsm and 300 gsm dry pickup
weight.
[0013] In accordance with another aspect of the invention, a
formaldehyde free scrim layer is bonded to at least one side of the
panel.
[0014] In accordance with another aspect of the invention, a method
of constructing a nonwoven, fire retardant, moisture resistant
panel is provided. The method includes forming a homogenous mixture
of bast fibers and polymeric binding fiber; forming a web of the
homogenous mixture; melting the polymeric binding fiber and bonding
the bast fibers with the material of the polymeric binding fiber to
form a bonded nonwoven sheet; saturating the bonded nonwoven sheet
in a solution including a binder, a Ph stabilizer and a flame
retardant; cross-linking the binder with the bast fibers by drying
the saturated, bonded nonwoven sheet and curing the solution; and
compressing the nonwoven sheet.
[0015] In accordance with another aspect of the invention, the
method includes maintaining the levels of formaldehydes in the
panel below 0.04 ppm.
[0016] In accordance with another aspect of the invention, the
method includes compressing the nonwoven sheet while curing the
solution.
[0017] In accordance with another aspect of the invention, the
method includes cooling the nonwoven sheet while being
compressed.
[0018] In accordance with another aspect of the invention, the
method includes using a modified polycarboxylic acid with a polyol
for the binder.
[0019] In accordance with another aspect of the invention, the
method includes providing the fire retardant as a single fire
retardant.
[0020] In accordance with another aspect of the invention, the
method includes bonding a formaldehyde free scrim layer to at least
one side of the panel.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] These and other aspects, features and advantages of the
present invention will become more readily appreciated when
considered in connection with the following detailed description of
presently preferred embodiments and best mode, appended claims and
accompanying drawings, in which:
[0022] FIG. 1 is a process flow diagram showing the steps of
constructing a panel in accordance with one aspect of the
invention.
DETAILED DESCRIPTION OF PRESENTLY PREFERRED EMBODIMENTS
[0023] Referring in more detail to the drawings, FIG. 1 illustrates
a nonwoven, fire retardant, moisture resistant panel, referred to
hereafter as panel 10, 10', 10'', constructed in accordance with
the invention, as well as a method of construction of the panel 10,
10', 10'' in accordance with another aspect of the invention. The
panel 10, 10', 10'', includes a bonded nonwoven sheet 12 and a
dried and cured coating 14 formed from a single solution 16 (FIG.
2) that is dried and cured in a single process, thereby minimizing
the space requirements and process steps in manufacture. The sheet
12 is formed from a mixture of bast fibers 18 and polymeric binding
fiber 20 bonded with one another via a process that melts, at least
partially, the polymeric binding fiber 20. The solution 16 includes
a solution-based binder, a Ph stabilizer and a single flame
retardant. The binder from the solution 16 is cross-linked with the
bast fibers 18 to form an impervious or substantially impervious
moisture resistant barrier that greatly reduces the tendency of the
bast fibers 18 to absorb moisture. Accordingly, the structural
integrity of the bast fibers 18 and the panel 10, 10', 10'',
constructed in part therefrom, is maintained in use, even in the
presence of moisture, which allows the panel 10, 10', 10'' to meet
stringent requirements required for office divider tackable board
under ASTM E-84 Class A, and further, to pass humidity shock and
board stiffness tests. Thus, the panel 10, 10', 10'' has a high
strength and high stiffness, and as such, is suitable for use as a
structural member, such as an office divider panel, for example.
Further, the panel 10, 10', 10'' is environmentally friendly, in
that the materials used to construct the panel 10, 10', 10'' can be
reclaimed, are renewable, are mostly natural and biodegradable, and
further, contain less than 0.04 ppm levels of formaldehydes,
referred to hereafter as "very low levels of formaldehyde", and
thus, the panel 10, 10', 10'' is suitable for use in applications
needing to pass regulation CAL 1350, which requires formaldehyde
contents in office divider boards to contain less than 0.04 ppm
formaldehyde.
[0024] The bast fibers 18 can be provided from a variety of natural
fibers, such as jute, kenaf, hemp, flax or mixture thereof, by way
of example and without limitation. The bast fibers 18 are generally
provided having a content between about 50-85 wt %, and in one
example was provided as 80 wt % kenaf.
[0025] The polymeric binding fiber 20 can be provided from a
variety of thermally bonding materials, including polypropylene,
polyethylene, copolyesters, nylons, polyactic acid (PLA), and
bicomponent fibers (sheath/core fibers, wherein the sheath is
typically a low melt polymeric material and the core is a higher
temperature polymeric material), by way of example and without
limitation. The polymeric binding fiber 20 is generally provided
having content between 15-50 wt %, and in the example, was provided
as 20 wt % bicomponent, including a polyester core and a modified
polyester sheath.
[0026] In the example, the solution-based binder was provided as a
modified polycarboxylic acid with a polyol diluted with water. The
polyol is used primarily as a crosslinking agent while the modified
polycarboxylic acid is compatible with the natural fibers of the
bast fibers 18 and forms a good crosslink between the natural
fibers and the melted resin of the polymeric binding fiber 20,
thereby facilitating formation of an impervious or substantially
impervious barrier that greatly reduces the tendency of the bast
fibers 18 to absorb moisture. It is important for the binder to be
solution-based, as regular dispersion based latex binders have been
found to burn under the ASTM E-84 test method, and thus, do not
meet the requirements for a Class A rating. The binder content can
range from between 10-20 wt %, and in the example, 14 wt % binder
content was used.
[0027] The flame retardant is provided as a single flame retardant
and applied in a single process, thereby minimizing the complexity
and cost of the manufacture process. The flame retardant can be
provided as boron-based, phosphorous-based, or sulfur-based
constituent, by way of example. With the polycarboxylic acid having
a low Ph, a Ph stabilizer is used to blend the fire retardant in
the binder. The fire retardant used in the example was disodium
octaborate tetrahydrate, by way of example and without limitation.
The amount of fire retardant content can be provided between about
5-25 wt %, and in the example, 15 wt % content was used based on a
30 wt % dry pick-up from the chemical solids.
[0028] The process of constructing the panel 10 includes the
following steps: forming a homogenous mixture of bast fibers 18 and
polymeric binding fiber 20, shown generally at 22; forming a web 24
of the homogenous mixture 22; heating the web 24 and melting the
polymeric binding fiber 20 at least partially and bonding the bast
fibers 18 with the melted material of the polymeric binding fiber
20 to form a bonded nonwoven sheet 12; providing a solution 16
including a binder, a Ph stabilizer and a flame retardant;
saturating the bonded nonwoven sheet 12 with the solution 16;
cross-linking the binder in the solution 16 with the bast fibers 18
by drying the saturated, bonded nonwoven sheet 12; curing the
solution and compressing the nonwoven sheet 12, and optionally, if
desired to provide enhanced stiffness and change of color from that
of the natural fibers, the method further includes bonding a
formaldehyde free scrim layer 25 to at least one side (panel 10')
or both sides (panel 10'') of the sheet 12.
[0029] In further detail, the process includes blending the bast
fibers 18 and polymeric binding fiber 20 in a mixer and then fine
openers until the mixture 22 is homogenous. The homogeneity
provides the uniform distribution of the polymeric binding fiber 20
needed to obtain maximum and uniform stiffness throughout the
entirety of the finished panel 10.
[0030] Then, upon forming the homogenous mixture 22 of the bast
fibers 18 and polymeric binding fiber 20, the mixture 22 is
processed in a web forming machine to create the nonwoven web 24.
The weight of the web 24 can be varied from about 150 gsm (grams
per square meter) up to about 1500 gsm, wherein the weight of the
sample was formed around 700 gsm.
[0031] Then, upon forming the web 24, the web 24 is heated, such as
in an oven identified generally at 26, to a temperature suitable to
at least partially melt the polymeric binding fiber 20, thereby
bonding the bast fibers 18 and polymeric binding fiber 20 together
to form the bonded nonwoven sheet 12.
[0032] Then, the bonded nonwoven sheet 12 is saturated with the
solution 16, such as by being passed through a bath of the solution
16 identified generally at 28, that includes the solution-based
binder, which has a low Ph; a Ph stabilizer to offset the low Ph of
the binder, and a flame retardant, as described above, and further
being diluted with water, if not used as the Ph stabilizer. The
amount of saturation is performed to provide about a 10-40%
dry-pick-up of the solution 16, wherein the total binder pick-up in
the example was about 30% dry pick-up; the total disodium
octaborate tetrahydrate pick-up is between about 5-25 wt % based on
a 30% dry pick-up from the chemical solids.
[0033] Then, the saturated, bonded nonwoven sheet 12 is heated
sufficiently to dry the sheet 12 and cure the solution 16, such as
in a continuous compression belt oven 30, by way of example and
without limitation. During the drying and curing heating process,
the water from the solution 16 is first substantially evaporated to
leave about 8-10% moisture content in the bonded nonwoven sheet 12.
Then, upon achieving the desired moisture content, the temperature
is increased to about 180-200 degrees Celsius, at which temperature
the binder of the solution 16 is cured and cross-linked with the
bast fibers 18. While the binder is curing, the bonded sheet 12 is
compressed under a force F to a predetermined finished thickness,
such as between a pair of high compression belts 32, by way of
example and without limitation. Further, while still being
compressed between the belts 32 and upon being fully cured, the
resulting panel 10 is cooled, wherein the heating, compression and
cooling can all be performed within the continuous compression belt
oven 30.
[0034] The cooled and compressed panel 10, if necessary to meet
requirements of the intended application, can then be further
processed by laminating at least one formaldehyde free scrim layer
25, such as fiberglass or polypropylene, by way of example and
without limitation, to one side or both sides of the respective
panel 10', 10'' via a scrim laminator 34. The resulting finished
panel 10, 10', 10'' meets the Class A rating for flame as per ASTM
E-84, while the panel 10', 10'' also attains enhanced board
stiffness, even in the presence of moisture, due to the synergies
provided by the solution-based binder, binding fibers 20, and scrim
layer(s) 25, and also has a very low formaldehyde content. Of
course, if deemed unnecessary for the intended application, the
panel 10 can remain free of the scrim layer 25, though this will
result in the panel 10 having a diminished strength relative to the
panels 10', 10''. Throughout the process, the sheet 12 remains a
continuous piece of material from the beginning of the process
until after compressing, curing and cooling, or if a lamination
scrim layer(s) 25, until after lamination. The desired length of
panel 10, 10', 10'' can be cut via a cutting operation 36, shown as
being after compression and after lamination, if performed.
[0035] Many modifications and variations of the present invention
are possible in light of the teachings above. It is, therefore, to
be understood that the invention may be practiced otherwise than as
specifically described, and that the scope of the invention is
defined by any ultimately allowed claims.
* * * * *