U.S. patent application number 09/939178 was filed with the patent office on 2003-02-27 for treatment for improving cellulose insulation.
Invention is credited to Rood, Leonard D..
Application Number | 20030039818 09/939178 |
Document ID | / |
Family ID | 25472674 |
Filed Date | 2003-02-27 |
United States Patent
Application |
20030039818 |
Kind Code |
A1 |
Rood, Leonard D. |
February 27, 2003 |
Treatment for improving cellulose insulation
Abstract
A method for manufacturing a fire retardant cellulose insulation
with reduced density and reduced settling. The method consists of
adding a material, the fibers of which have a positive
electrostatic charge, onto a shredded newspaper base either before
or after the addition of a pre-coat, consisting of a mixture of
limestone and an antistat. A fire retardant agent is then added and
the materials are ground in a finish mill. The newspaper fibers
become positioned at an angle to the paper pieces, increasing the
distance between the paper pieces, thereby lowering the density of
the cellulose. Fibers such as ground cardboard, wood mulch,
sawdust, fiberglass fibers and polyester fibers, are examples of
materials with electrostatically positively charged fibers.
Inventors: |
Rood, Leonard D.; (Boynton
Beach, FL) |
Correspondence
Address: |
KREMBLAS, FOSTER, PHILLIPS & POLLICK
7632 SLATE RIDGE BOULEVARD
REYNOLDSBURG
OH
43068
US
|
Family ID: |
25472674 |
Appl. No.: |
09/939178 |
Filed: |
August 24, 2001 |
Current U.S.
Class: |
428/317.9 ;
427/212 |
Current CPC
Class: |
Y10T 428/31982 20150401;
Y10T 428/296 20150115; Y10S 428/921 20130101; Y10S 428/92 20130101;
Y10T 428/2958 20150115; C09K 21/02 20130101; Y10T 428/249986
20150401 |
Class at
Publication: |
428/317.9 ;
427/212 |
International
Class: |
B05D 007/00 |
Claims
1. An improved cellulosic insulation having reduced density and
settling comprising (a) shredded cellulosic fibers and paper pieces
which are precoated with a mixture of limestone and an antistatic
agent either before or after the addition of (b) electrostatically
positively charged fibers and (c) fire retardant chemicals which
are adhered on said shredded cellulosic fibers, electrostatically
positively charged fibers and paper pieces.
2. An insulation in accordance with claim wherein said anti-static
agent is a quaternary ammonium compound.
3. An insulation in accordance with claim 1 wherein said insulation
comprises substantially 0.001% to 0.002% by weight of said
antistatic agent, based on the weight of cellulosic fibers, paper
pieces and positive electrostatic fiber input.
4. An insulation in accordance with claim 1 wherein said mixture of
antistat and limestone comprises substantially 1% to 2% of the
weight of cellulosic fibers, paper pieces and electrostatic
positively charged fibers.
5. An insulation in accordance with claim 1 wherein said insulation
comprises positively charged electrostatic fibers such as wood
fibers, shredded cardboard, wood mulch and sawdust at a level of
substantially 2% to 8% of the weight of cellulosic fibers, paper
pieces and electrostatic positively charged fibers.
6. An insulation in accordance with claim 1 wherein said insulation
comprises positively charged electrostatic fibers such as
fiberglass or polyester fibers at a level of substantially 0.5% to
2% of the weight of cellulosic fibers, paper pieces and
electrostatic positively charged fibers.
7. An insulation in accordance with claim 1 wherein the
electrostatically negative paper fibers are angled predominantly
from about 15% to perpendicular to the surface of the paper
pieces.
8. A method for manufacturing fire retardant cellulosic insulation
of the type comprising shredded cellulosic fibers precoated with a
mixture of limestone and an antistatic agent and having a fire
retardant agent deposited on it wherein the improvement comprises
adding a positively charged electrostatic fiber either before or
after the addition of the mixture of limestone and an antistatic
agent.
9. A method in accordance with claim 8 wherein positively charged
electrostatic fibers such as ground cardboard, wood mulch, and
sawdust are added in the amount of substantially 2% to 8% of the
weight of the cellulosic fibers, paper pieces and electrostatic
positively charged fibers.
10. A method in accordance with claim 8 wherein positively charged
electrostatic fibers such as fiberglass or polyester are added
substantially in the amount of 0.5% to 2% of the weight of
cellulosic fiber, paper pieces and electrostatic positively charged
fibers.
Description
TECHNICAL FIELD
[0001] This invention relates generally to cellulose insulation of
the type utilizing a shredded newspaper base which is treated with
a fire retardant chemical composition and used for the thermal
insulation of homes and other building structures. More
particularly, the invention relates to the addition of a specific
range of antistat and electrostatically positively charged fibrous
materials to the newspaper base which will lower density and reduce
settling of the insulation.
BACKGROUND ART
[0002] The manufacture of cellulosic insulation, in accordance with
the present state of the art, begins with a grinding operation in
which newspapers are shredded to a level of approximately
1".times.1" pieces and individual fibers. These fibers and paper
pieces, carried in air stream, are then ground in a second
operation in which finely ground fire retardant chemical is added
to the paper and paper pieces.
[0003] The key to the understanding of the underlying basis of
cellulose insulation is to recognize that cellulose insulation is
made up of newspaper pieces and fibers which are affected by static
electricity. Like elements will repel; unlike elements will
attract. A method of determining the electrostatic charge of a
material piece or fiber is to rub the flat side of a nylon
toothbrush about 50 times on a piece of wool. Then attempt to
attract the material in question with the flat side of the
toothbrush. If the material is positively charged, it will attach
to the flat part of the toothbrush. If the material is negatively
charged, it will not be attracted. Based on the above system, the
face of a newsprint paper piece is positively charged and the edge
fibers are negatively charged. The newspaper separate fibers are
also negatively charged.
[0004] U.S. Pat. No. 4,468,336 refers to an insulation "wherein the
loose fill cellulose insulation has a settled density on the order
of about 2.5 pounds per cubic foot before mixing with staple
fibers, and the mixture of cellulosic insulation with from 2% to
25% by weight staple fibers has a settled density in the order from
2.1 pounds per cubic foot to about 1.1 pounds per cubic foot.
Staple fibers were defined as acrylic, polypropylene, acetate etc.
These fibers are electrostatically positively charged.
[0005] Because the paper pieces were positively charged, the
surface of the paper piece attracted negatively charged paper
fibers, essentially parallel to the face of the paper piece. This
attraction caused the paper piece to become neutrally charged and
therefore, no longer statically attractive. Therefore, the
positively charged staple fibers attracted most of the remainder of
negatively charged paper fibers, forming a phase separate from the
paper pieces. This separate phase is not settling stable because
this structure is not supported by the paper pieces and will
condense. It took a large amount of the staple fibers to lower the
cellulose density by producing a separate, lower density, paper
fiber to positively charged fiber structure.
BRIEF DESCRIPTION OF INVENTION
[0006] In an attempt to improve settling and density of cellulose
insulation, I determined that there was an advantage to produce a
specific type of fiber-paper piece structure. In this structure,
use of the limestone-antistat mixture as described in U.S. Pat.
Nos. 5,399,375 and 5,455,065, in a narrow dosage range, reduces the
static charge on the paper pieces and fibers to a level where fire
retardant chemical will adhere to both the paper pieces and fibers.
The preferred structure is where the fibers are attached to the
paper piece at an angle to the face of the paper piece, not
parallel to the face of the paper piece. In this preferred
structure, there is very little separate fiber to fiber
groupings.
[0007] Electrostatically positively charged fibers such as wood,
fiberglass or polyester, added either before or after the addition
of the antistat to the partially ground paper, are attracted to the
negative edges of the electrostatically charged paper piece. The
attached positively charged fibers then attract the negatively
charged paper fibers, producing a reinforced structure which
reduces density and settling.
[0008] These improvements in density and settling result from the
fact that the negative fibers are deposited at an angle to the face
of the paper piece. The amount of electrostatically positively
charged fibers added will vary with the type of fiber used. The key
is that the amount of separate, positively charged fibers to
negatively charged fiber groupings is held to a minimum.
[0009] The following convention will be used. Newspaper pieces,
wood fibers, cardboard fibers, fiberglass fibers and polyester
fibers are positively charged. Newspaper fibers and cardboard
pieces are negatively charged. The relationship of the positively
charged fibers to the negatively charged paper fibers can only be
understood by using a high powered microscope.
DETAILED DESCRIPTION
[0010] The amount of wood fiber necessary to reinforce the paper
piece/paper fiber structure is in the range of 2% to 8% of the
weight of the paper and positive electrostatic fiber input. The
amount of fiberglass fiber and polyester fiber to reinforce the
settling stable structure is in the range of 0.5% to 2% of the
paper and positive electrostatic fiber input. The preferred amount
of electrostatic positively charged reinforcing fibers is
determined by the structure achieved, as seen using a high powered
microscope.
[0011] The anti-static constituent of the precoat mixture of
antistat and finely ground limestone is preferably on the order of
0.001% to 0.002% by weight of the paper and positive electrostatic
fiber input. The limestone component range is 1% to 2% of the
weight of paper and positive electrostatic fiber input. Other fine
ground additives may be used in place of the limestone, but fire
retardancy will be decreased. This range of antistat reduces the
static charges of the paper pieces, paper fibers and
electrostatically positively charged fibers so that positively
charged fine ground fire retardant chemicals will adhere to the
paper pieces, paper fibers and electrostatically positively charged
fibers.
[0012] In this range, the fibers will attach, essentially at an
angle to the paper pieces, causing a greater distance between paper
pieces and a lower density. Antistat levels above this range will
reduce the static charges so that the attachment of fibers to the
paper pieces will be diminished and paper fiber to
electrostatically positive fiber groupings will occur, reducing the
settling stability effect. Antistat levels below this range will
tend to inhibit the attachment of fire retardant chemical to the
paper pieces, reducing fire retardancy.
EXAMPLE 1.
[0013] A trial was made using 95% newspaper and 5% sawdust. The
newspaper was ground in a shredder to a size of about 1".times.1".
A precoat mixture was then added to the shredded newspaper, the
precoat containing dimethyl distearyl ammonium chloride in the
amount of 0.0015%, combined with limestone in the amount of 1.5% of
the weight of paper and positive electrostatic fiber input. Sawdust
in the amount of 5% of the weight of paper and positive
electrostatic fiber input was then added. These materials were fed
in an air stream into a finish mill along with 10% of a finely
ground fire retardant chemical, based on the total weight of the
system.
[0014] The initial material had a density of 0.70 lbs./cu.ft. This
material was placed in a 12".times.12".times.6" high cardboard box
in an atmosphere of 50% relative humidity and 70 degrees F. for a
period of one month. Settling was 8% after one month.
[0015] Commercial cellulose, not containing the sawdust or
antistat, under the same conditions as above, had an initial
density of 1.3 lbs./cu.ft and settled 16% over the same period.
EXAMPLE 2
[0016] A trial was made similar to Example 1 but the sawdust was
first combined with the newspaper base before the addition of the
limestone antistat mixture. Under conditions similar to Example 1,
settling after 30 days was 12% after one month and initial density
was 0.80 lbs./cu.ft.
EXAMPLE 3
[0017] A trial was made similar to Example 1 but 2% fiberglass was
substituted for the sawdust used in Example 1. Under conditions
similar to Example1, settling after 30 days was 7% and density was
0.75 lbs./cu.ft.
EXAMPLE 4
[0018] A trial was made similar to Example 2 but 2% fiberglass was
substituted for the sawdust used in Example 2. Under conditions
similar to example 2, settling was 9% and density was 0.81
lbs./cu.ft.
EXAMPLE 5
[0019] A trial was made similar to Example 1 but 1% polyester
fibers were substituted for the sawdust used in Example 1. Under
conditions similar to Example 1, settling after 30 days was 8% and
density was 0.78 lbs./cu.ft.
EXAMPLE 6
[0020] A trial was made similar to Example 2 but 1% polyester
fibers were substituted for the sawdust used in Example 2. Under
conditions similar to Example 2, settling after 30 days was 12% and
density was 0.87 lbs./cu.ft.
* * * * *