U.S. patent application number 17/517130 was filed with the patent office on 2022-04-07 for method of manufacturing osb with acoustic dampening properties.
The applicant listed for this patent is LOUISIANA-PACIFIC CORPORATION. Invention is credited to ASHWIN HIMATSINGANI, JIANWEN NI.
Application Number | 20220105656 17/517130 |
Document ID | / |
Family ID | 1000006028716 |
Filed Date | 2022-04-07 |
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United States Patent
Application |
20220105656 |
Kind Code |
A1 |
HIMATSINGANI; ASHWIN ; et
al. |
April 7, 2022 |
METHOD OF MANUFACTURING OSB WITH ACOUSTIC DAMPENING PROPERTIES
Abstract
A manufacturing process for manufacturing wood products with
acoustic dampening properties. A noise-dampening polymer is
introduced in-line in the manufacturing process to achieve higher
acoustic performance. The polymer can be a viscoelastic polymer
which is added during blending of the lignocellulosic strands prior
to mat formation, or sprayed or otherwise coated on the
lignocellulosic strands during mat formation, prior to formation of
any boards or panels.
Inventors: |
HIMATSINGANI; ASHWIN;
(BRENTWOOD, TN) ; NI; JIANWEN; (FRANKLIN,
TN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
LOUISIANA-PACIFIC CORPORATION |
NASHVILLE |
TN |
US |
|
|
Family ID: |
1000006028716 |
Appl. No.: |
17/517130 |
Filed: |
November 2, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
15832327 |
Dec 5, 2017 |
11161272 |
|
|
17517130 |
|
|
|
|
62429896 |
Dec 5, 2016 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C08L 97/02 20130101;
B32B 5/26 20130101; B32B 2255/08 20130101; B27N 1/00 20130101; B32B
2307/102 20130101; G10K 11/168 20130101; E04B 1/86 20130101; B27N
3/04 20130101; B32B 2262/067 20130101; B32B 2255/24 20130101; B32B
21/14 20130101; B32B 2607/00 20130101; B27N 7/00 20130101 |
International
Class: |
B27N 3/04 20060101
B27N003/04; C08L 97/02 20060101 C08L097/02; B32B 21/14 20060101
B32B021/14; E04B 1/86 20060101 E04B001/86; B27N 1/00 20060101
B27N001/00; B27N 7/00 20060101 B27N007/00; B32B 5/26 20060101
B32B005/26; G10K 11/168 20060101 G10K011/168 |
Claims
1. A method for producing a noise-dampening manufactured wood
product, comprising the steps of: treating a set of core layer
lignocellulosic material with one or more chemicals or additives;
treating, in a manufacturing production line, the set of core layer
lignocellulosic material with a noise-reducing polymer, wherein the
noise-reducing polymer does not form a homogenous layer; forming a
multi-layer mat of lignocellulosic material, said multi-layer mat
comprising a core layer comprising the treated set of core layer
lignocellulosic material; applying heat and pressure to the
multilayer mat to produce a noise-dampening manufactured wood
product.
2. The method of claim 1, wherein the noise-dampening manufactured
wood product comprises one or more boards or panels.
3. The method of claim 1, wherein the noise-dampening manufactured
wood product comprises a oriented strand board panel.
4. The method of claim 1, wherein the multi-layer mat comprises
three layers.
5. The method of claim 4, wherein the three layers are a top layer,
a bottom layer, and the core layer therebetween.
6. The method of claim 5, further comprising the steps of: treating
a set of top layer lignocellulosic material with one or more
chemicals or additives; and treating a set of bottom layer
lignocellulosic material with one or more chemicals or
additives.
7. The method of claim 6, wherein the step of forming a multi-layer
mat of lignocellulosic material comprises the steps of: forming, in
the production line, the bottom layer from the set of bottom layer
lignocellulosic material; forming, in the production line on the
bottom layer, the core layer from the set of core layer
lignocellulosic material; and forming, in the production line on
the core layer, the top layer from the set of top layer
lignocellulosic material.
8. The method of claim 1, wherein the step of treating the set of
core layer lignocellulosic material with the noise-reducing polymer
comprises blending the polymer with the core lignocellulosic
material prior to formation of the core layer.
9. The method of claim 1, wherein the step of treating the set of
core layer lignocellulosic material with the noise-reducing polymer
comprises spraying, flowing, curtain coating or otherwise coating
the core layer with the polymer.
10. The method of claim 7, further comprising the step of treating
the set of bottom layer lignocellulosic material with the
noise-reducing polymer.
11. The method of claim 7, further comprising the step of treating
the set of top layer lignocellulosic material with the
noise-reducing polymer.
12. The method of claim 1, wherein the noise-reducing polymer is
integrated with the lignocellulosic material forming the core
layer.
13. The method of claim 1, wherein the lignocellulosic material
comprises strands.
Description
[0001] This application is a continuation of U.S. patent
application Ser. No. 15/832,327, filed Dec. 5, 2017, which claims
benefit of and priority to U.S. Provisional Application No.
62/429,896, filed Dec. 5, 2016, and is entitled to those filing
dates for priority. The specifications, figures, and complete
disclosures of U.S. Provisional Application No. 62/429,896 and U.S.
patent application Ser. No. 15/832,327 are incorporated herein in
their entireties by specific reference for all purposes.
FIELD OF INVENTION
[0002] This invention relates to a method and system for
manufacturing wood products (such as OSB, oriented strand board)
with acoustic dampening properties.
BACKGROUND OF THE INVENTION
[0003] Acoustic comfort is important in building design. Noise is
the often the primary complaint by home-owners in residential
single-family homes, and noise reduction also is an important
performance criterion in multi-family and commercial construction
(particularly in the healthcare and education segments). Airborne
noise/STC (Sound Transmission Class) rating and impact noise
(Impact Insulation Class, IIC) rating in wall and floor or ceiling
assemblies often is specified in codes and standards by ANSI, IgCC
and LEED.
[0004] Airborne noise from outside or inside the living space has
been addressed with various field-applied and pre-fabricated noise
dampening constructions products, such as resilient channels,
clips, staggered studs, multiple layers of drywall, wall cavity
insulation, and laminated acoustic drywall. Acoustic materials have
been used to laminate two panels of various building materials
through a secondary process to improve acoustic performance.
However, there are no building materials, such as OSB-based siding,
sheathing, roofing or flooring, that incorporate a sound dampening
material in the primary manufacturing process of panels with
improved acoustic performance.
SUMMARY OF THE INVENTION
[0005] In various exemplary embodiments, the present invention
comprises a method or process for manufacturing wood products with
acoustic dampening properties. The manufactured wood product
include, but are not limited to, oriented strand board (OSB), LSL,
MDF, particleboard, or various wood composites. The system
introduces a noise-dampening polymer in-line in the manufacturing
process to achieve higher acoustic performance (e.g., STC and IIC
rating) in siding, sheathing, roofing, flooring, and similar
applications using the manufactured wood product. The polymer can
be a viscoelastic polymer which is added during blending or
formation of the wood product. In one exemplary embodiment, as
described in greater detail below, viscoelastic polymer is added to
the center strand layer during the OSB manufacturing process.
[0006] General elements of the OSB manufacturing process include
the drying and storing of wood strands, the treatment or blending
of designated strands (e.g., bottom, core, top) with applicable
chemicals or additives (e.g., wax, resin binders, and the like) the
forming of the appropriate layers in order (first bottom surface,
then core, then top surface) using designated strands, the
application of heat and pressure to the mats to form boards, and
subsequent processing (e.g., panels cut to size, edges sealed, and
packaging) to produce the finished product.
[0007] In a first embodiment of the manufacturing process, the core
strands are coated with the noise-dampening polymer in a strand
blender or blender. The polymer can be blended with the core
strands separately, or along with other additives typically added
during the OSB process, such as waxes or resin binders. These
treated core strands are used to form the central layer, sandwiched
between the bottom surface and top surface. The finished product is
an OSB panel with a central layer with core strands blended with
the noise-dampening acoustic material or materials. This coating by
blending can also take place for strands in other layers.
[0008] In another exemplary embodiment, the noise-dampening
acoustic material or materials are applied through a spraying,
flow, curtain, or other coating process in the forming line before,
during or after the center strand layer is laid on the forming
line. This coating can also take place for strands in other
layers.
[0009] The finished product is an OSB or manufactured wood panel
with a central layer with core strands (and possibly other layers)
integrally coated, permeated or infused with the noise-dampening
acoustic material or materials.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 shows a view of a system in accordance with an
embodiment of the present invention.
[0011] FIG. 2 shows another system in accordance with another
embodiment of the present invention.
[0012] FIG. 3 shows another system in accordance with another
embodiment of the present invention.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0013] In various exemplary embodiments, the present invention
comprises a method or process for manufacturing wood products with
acoustic dampening properties. The manufactured wood product
include, but are not limited to, oriented strand board (OSB), LSL,
MDF, particleboard, or various wood composites.
[0014] In several embodiments, the present invention comprises a
system for introducing a noise-dampening polymer in-line in the
manufacturing process to achieve higher acoustic performance (e.g.,
STC and/or IIC rating) in siding, sheathing, roofing, flooring, and
similar applications using the manufactured wood product. The
polymer can be a viscoelastic polymer which is added during
blending or formation of the wood product. In one exemplary
embodiment, as described in greater detail below, viscoelastic
polymer is added to the center strand layer during the OSB
manufacturing process.
[0015] General elements of the OSB manufacturing process in
accordance with the present invention, as seen in FIGS. 1 and 2,
include the drying and storing of wood strands 10, the treatment or
blending of designated strands (e.g., bottom, core, top) with
applicable chemicals and/or additives (e.g., wax, resin, and the
like) 30, the forming of the appropriate layers in order (first
bottom surface, then core, then top surface) using designated
strands, 30, 40, 50, the application of heat and pressure to the
mats using a primary press to form boards 60, and subsequent
trimming 70 and processing (e.g., panels cut to size, edges
primed/sealed, and packaging) 80 to produce the finished product
100. Strands for a particular layer typically are blended with
applicable chemicals and/or additives in a bin, separate from
strands for other layers, although this is not always the case.
Examples of primary processes are described in U.S. Pat. Nos.
6,461,743; 5,718,786; 5,525,394; 5,470,631; and 5,425,976; all of
which are incorporated herein in their entireties by specific
reference for all purposes.
[0016] FIG. 2 shows an embodiment of the manufacturing process
where the core strands are coated with the noise-dampening polymer
in a strand blender or blenders 120. The top and bottom surface
strands are blended separately 20a, although in some embodiments,
one or both sets of strands also may be blended with a
noise-dampening polymer. The polymer can be blended with the core
strands separately, or along with other additives typically added
during the OSB process, such as waxes or resin binders. The treated
core strands are used to form the central core layer 140,
sandwiched between the bottom surface and top surface. The finished
product is an OSB panel (or other manufactured wood product) with a
core layer with core strands blended with the noise-dampening
acoustic material or materials. The heat and pressure applied
during the primary pressing process promotes the noise-dampening
acoustic material to integrally coat, permeate or infuse the core
layer, and in several embodiments, portions of the bottom and/or
top surface layers.
[0017] FIG. 3 shows another second embodiment of the manufacturing
process where, after blending of the strands 20a, b, the
noise-dampening acoustic material or materials are applied through
a spraying, flow, curtain or other coating process 240 in the
forming line before, during, or after the center core strand layer
is laid on the forming line. The finished product is an OSB panel
(or other manufactured wood product) with a central layer with core
strands coated with the noise-dampening acoustic material or
materials. As described above, the heat and pressure applied during
the primary pressing process promotes the noise-dampening acoustic
material to integrally coat, permeate or infuse the core layer, and
in several embodiments, portions of the bottom and/or top surface
layers.
[0018] The components and parameters of the above processes can
vary. In one exemplary embodiment, the wood strands can be derived
from hard (e.g., aspen) or soft (e.g., southern yellow pine) woods,
and can be homogenous (i.e., single wood type) or mixed, and green
(moisture content from about 30% to about 200%) or dried (e.g.,
moisture content up to about 12%) (where moisture content %=(weight
of water in wood/oven-dry weight of wood).times.100). Binders
include, but are not limited to, isocyanate resin,
urea-formaldehyde, phenol formaldehyde, melamine formaldehyde,
bio-adhesives, or combinations thereof. In one embodiment,
polymeric isocyanate resin (pMDI, or polymeric diphenylmethane
diisocyanate) is used at about 1.2 to about 20 weight %. Waxes
include, but are not limited to, a molten wax or emulsion was (in
one embodiment, up to about 2.5 weight %). Other chemicals or
additives may be used, including, for example, fire retardants,
weather-resistant chemicals, or the like. Viscoelastic polymer is
added as described above to the center layer or any other layer in
the mat. Press time is from 1 to 20 minutes at a temperature from
about 100.degree. C. to about 240.degree. C. The resulting panel
can range in thickness from about 3/4'' to about 7'', and in
density from about 25 pcf to about 60 pcf (pounds per cubic
foot).
[0019] In any of the above embodiments, the thickness and/or
density of the top or bottom strand layer, or both, can be modified
as well to achieve an improved acoustic performance/STC rating. The
present invention thus provides an OSB or manufactured wood panel
with a noise-dampening polymer introduced in-line, with a resulting
increase (1) in acoustic performance as compared to a standard OSB
panel, and (2) in efficiency and reduction in cost compared to
secondary manufacturing processes. The noise-dampening polymer
becomes integrated with, and infuses or permeates the layer or
layers of the panel.
[0020] In several embodiments, the noise-dampening of the present
invention applies to both airborne sound transmission loss and
impact sound insulation. In some embodiments, panels produced in
accordance with the present invention smooth airborne sound
transmission loss curves in the ASTM E90 test method, particularly
increasing loss (dB) in frequency ranges where sound is transmitted
more effectively due to physical characteristics (i.e., of a
similar panel but without the sound-dampening agent). In one
embodiment, the present invention increases airborne transmission
loss in the sound frequency ranges of from about 1.5K to about 4K
Hz (more particularly, from about 2K to about 3.2K Hz, or even more
particularly, from about 2.5K to about 3.15K Hz).
[0021] In additional embodiments, panels produced in accordance
with the present invention demonstrate increased impact sound
insulation and decreased sound pressure levels. In one embodiment,
such panels have a tested apparent impact insulation class (AIIC)
rating in the range from about 26 to about 34, as determined by
ASTM Standard E-1007 (2016). In contrast, a control panel without
noise-dampening polymer had an AIIC rating of 19.
[0022] Thus, it should be understood that the embodiments and
examples described herein have been chosen and described in order
to best illustrate the principles of the invention and its
practical applications to thereby enable one of ordinary skill in
the art to best utilize the invention in various embodiments and
with various modifications as are suited for particular uses
contemplated. Even though specific embodiments of this invention
have been described, they are not to be taken as exhaustive. There
are several variations that will be apparent to those skilled in
the art.
* * * * *