U.S. patent application number 15/222122 was filed with the patent office on 2016-11-17 for fiber products having temperature control additives.
The applicant listed for this patent is KNAUF INSULATION, INC., KNAUF INSULATION SPRL. Invention is credited to Charles Fitch APPLEY, Gert MUELLER.
Application Number | 20160333573 15/222122 |
Document ID | / |
Family ID | 44234423 |
Filed Date | 2016-11-17 |
United States Patent
Application |
20160333573 |
Kind Code |
A1 |
MUELLER; Gert ; et
al. |
November 17, 2016 |
FIBER PRODUCTS HAVING TEMPERATURE CONTROL ADDITIVES
Abstract
A fiber product is described which includes fibers, a binder and
a temperature control additive. The fiber product has properties
that make it useful for a variety of applications. The fibers may
be glass fibers and the product may be a fiberglass insulation
product for use in buildings, vehicles, or other structures for
acoustic and/or thermal insulation. The fibers may be cellulosic
fibers and the product may be a wood board product. The temperature
control additive is incorporated into the uncured fiber product to
prevent deleterious self-heating during or after binder curing. The
temperature control additive undergoes an endothermic process that
consumes at least a portion of the energy generated during the
exothermic curing reaction.
Inventors: |
MUELLER; Gert; (New
Palestine, IN) ; APPLEY; Charles Fitch; (Cumberland,
IN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KNAUF INSULATION, INC.
KNAUF INSULATION SPRL |
Shelbyville
Vise |
IN |
US
BE |
|
|
Family ID: |
44234423 |
Appl. No.: |
15/222122 |
Filed: |
July 28, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14810765 |
Jul 28, 2015 |
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15222122 |
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13702144 |
Dec 5, 2012 |
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PCT/EP2011/059317 |
Jun 6, 2011 |
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14810765 |
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61352070 |
Jun 7, 2010 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E04B 1/74 20130101; B05D
3/007 20130101; E04B 1/78 20130101; B29K 2105/12 20130101; D04H
1/587 20130101; E04B 1/88 20130101; E04B 1/84 20130101; B29C 43/22
20130101; B29L 2023/225 20130101; B29K 2003/00 20130101; E04B
2001/7683 20130101; B29K 2309/00 20130101; D04H 1/64 20130101 |
International
Class: |
E04B 1/78 20060101
E04B001/78; D04H 1/64 20060101 D04H001/64; B29C 43/22 20060101
B29C043/22; D04H 1/587 20060101 D04H001/587 |
Claims
1. A mineral fiber insulation product comprising a binder, a
collection of mineral fibers, and a particulate selected from a
group consisting of magnesia, alumina, and calcined gypsum, wherein
the binder is disposed upon the collection of mineral fibers and
the particulate is distributed within the mineral fiber insulation
product, wherein the binder comprises a reaction product of a
carbohydrate and an amine.
2. The fiber product of claim 1, wherein the particulate has a
number weighted average particle size of less than about 200
micrometers.
3. The fiber product of claim 1, wherein the particulate has a
number weighted average particle size of less than about 50
micrometers.
4. The fiber product of claim 1, wherein the particulate has a
number weighted average particle size of less than about 20
micrometers.
5. The fiber product of claim 1, wherein the wherein the fiber
product comprises from about 0.25% to about 15% by weight of the
particulate.
6. The fiber product of claim 1, wherein the wherein the fiber
product comprises from about 3% to about 30% by weight of the
binder.
7. The fiber product of claim 1, wherein the carbohydrate comprises
a monosaccharide and the amine comprises a primary amine.
8. The fiber product of claim 1, wherein the carbohydrate comprises
dextrose, fructose, or mixtures thereof.
9. The fiber product of claim 1, wherein the particulate is
dispersed within the binder.
10. The mineral fiber insulation product of claim 1, wherein the
mineral fiber insulation product comprises about 61% to about 96%
mineral fibers and about 1% to about 15% of the particulate.
11. The mineral fiber insulation product of claim 1, wherein the
particulate has a number weighted average particle size of less
than about 200 micrometers.
12. The mineral fiber insulation product of claim 1, wherein the
particulate has a number weighted average particle size of less
than about 50 micrometers.
13. The mineral fiber insulation product of claim 1, further
comprising an organosilane in contact with the particulate.
14. An uncured mineral fiber insulation product comprising an
uncured binder, a collection of fibers, and a temperature control
additive, wherein the uncured binder is disposed upon the
collection of fibers and the temperature control additive is a
particulate in contact with the collection of fibers, in contact
with the binder, or dispersed throughout the uncured fiber product,
wherein the uncured binder comprises a carbohydrate and an
amine.
15. The uncured fiber product of claim 14, wherein the temperature
control additive is selected from a group consisting of aluminum
hydroxide, magnesium hydroxide, calcium silicate hydrates, and
calcium sulfate dihydrate.
16. The uncured fiber product of claim 14, wherein the carbohydrate
is selected from a group consisting of dextrose, xylose, fructose,
dihydroxyacetone, and mixtures thereof.
17. The uncured fiber product of claim 14, wherein the amine is an
ammonium salt or a primary amine.
18. The uncured fiber product of claim 14 comprising about 61% to
about 96% fibers, about 1% to about 15% of the temperature control
additive, and 3% to about 30% of the uncured binder.
19. The uncured fiber product of claim 14, further comprising a
silicon containing compound, wherein the silicon containing
compound is concentrated at a first interface between the uncured
binder and the fibers and at a second interface between the uncured
binder and the temperature control additive.
20.-26. (canceled)
27. A method of manufacturing an insulation product comprising
contacting a collection of fibers with a binder to form an uncured
insulation product, contacting the collection of fibers with a
temperature control additive, shaping the uncured insulation
product into a configuration adapted for an insulating purpose,
applying an amount of energy to the uncured insulation product
subsequent to contacting the collection of fibers with the
temperature control additive, the amount of energy sufficient to
initiate an exothermic process curing of the binder from an uncured
state to a cured state, and maintaining the temperature of the
binder within a predetermined range.
28. The method of manufacturing an insulation product of claim 27
further comprising forming a dispersion comprising the binder and
the temperature control additive, wherein contacting the collection
of fibers with the binder and contacting the collection of fibers
with the temperature control additive occur concurrently through
contacting the collection of fibers with the dispersion including
the binder and the temperature control additive.
29. The method of manufacturing an insulation product of claim 28,
wherein forming the dispersion includes adding a surfactant.
30. The method of manufacturing an insulation product of claim 27
further comprising forming an aqueous dispersion of the temperature
control additive and a surfactant, wherein contacting the
collection of fibers with the temperature control additive occurs
subsequently to contacting the collection of fibers with the
binder.
31. The method of manufacturing an insulation product of claim 27,
wherein contacting the collection of fibers with the temperature
control additive includes sprinkling the temperature control
additive onto the uncured insulation product, the temperature
control additive being in the form of a dry powder or concentrated
slurry.
32. The method of manufacturing an insulation product of claim 27,
wherein shaping the uncured insulation product includes shaping the
uncured insulation product into a configuration adapted for
insulating walls.
33. The method of manufacturing an insulation product of claim 27,
wherein shaping the uncured insulation product includes shaping the
uncured insulation product into a configuration adapted for
insulating pipes.
34. (canceled)
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser.
No. 14/810,765, filed Jul. 28, 2015, which is a continuation of
U.S. application Ser. No. 13/702,144 (now abandoned), filed Dec. 5,
2012, which is a national stage entry under 35 USC .sctn.371(b) of
International Application No. PCT/EP2011/059317, filed Jun. 6,
2011, which claims the benefit under 35 U.S.C .sctn.119(e) of U.S.
Provisional Application Ser. No. 61/352,070, filed on Jun. 7, 2010,
the disclosures of each of which are incorporated by reference in
their entirety.
TECHNICAL FIELD
[0002] This disclosure relates to a fiber product comprising fibers
and a binder and materials made therewith. In particular, a product
that includes loosely assembled fibers, a binder, and a temperature
control additive is described.
BACKGROUND
[0003] Fiber products may include fibers and a binder material.
Binders are useful in fabricating fiber products because they are
capable of consolidating non- or loosely-assembled matter. For
example, binders enable two or more surfaces to become united. For
example, thermosetting binders may be used to produce fiber
products. Thermosetting binders may be characterized by being
transformed into insoluble and infusible materials by means of
either heat or catalytic action. Examples of a thermosetting binder
include a variety of phenol-aldehyde, urea-aldehyde,
melamine-aldehyde, and other condensation-polymerization materials
like polyfurane and polyurethane resins. Binder compositions
containing phenol-aldehyde, resorcinol-aldehyde,
phenol/aldehyde/urea, phenol/melamine/aldehyde, and the like are
used for the bonding of fibers, textiles, plastics, rubbers, and
many other materials.
[0004] The mineral wool and fiber board industries have
historically used a phenol formaldehyde binder to bind fibers.
Phenol formaldehyde type binders provide suitable properties to the
final products; however, environmental considerations have
motivated the development of alternative binders. One such
alternative binder is a carbohydrate based binder derived from
reacting a carbohydrate and a multiprotic acid, for example, U.S.
Published Application No. 2007/0027283 and Published PCT
Application WO2009/019235. Another alternative binder is the
esterification products of reacting a polycarboxylic acid and a
polyol, for example, U.S. Published Application No. 2005/0202224.
Because these binders do not utilize formaldehyde as a reagent,
they have been collectively referred to as formaldehyde-free
binders.
[0005] One manner in which the alternative binder formulations
differ from the traditionally used phenol formaldehyde type binders
is that the curing reaction conditions vary across the range of
binder compositions. It has been observed that some alternative
binder formulations require higher temperatures to elicit curing.
Still other formulations release more heat during curing (i.e. the
curing reaction is more exothermic). A remaining challenge is the
absence of a single binder composition which can be used across the
entire range of products in the building and automotive sector
(e.g. fiberglass insulation, particle boards, office panels, and
acoustical sound insulation).
SUMMARY
[0006] According to the present disclosure, a fiber product is
described which includes fibers and a binder. The fiber product has
properties that make it useful for a variety of applications. The
fibers may be glass fibers and the product may be a fiberglass
insulation product for use in buildings, vehicles, or other
structures for acoustic and/or thermal insulation. The fibers may
be cellulosic fibers and the product may be a wood board
product.
[0007] In illustrative embodiments, a fiber product comprises a
binder, a collection of fibers, and a particulate additive, wherein
the binder is disposed upon the collection of fibers and the
particulate additive is distributed within the fiber product. In
further illustrative embodiments, a mineral fiber insulation
product comprises a binder, a collection of mineral fibers, and a
particulate selected from the group consisting of magnesia,
alumina, silica, and calcined gypsum. In one embodiment, the fiber
product is a mineral fiber product and the particulate is in
contact with the mineral fiber product.
[0008] In illustrative embodiments, an uncured fiber product
comprises an uncured binder, a collection of fibers, and a
temperature control additive. In one embodiment, the uncured binder
is disposed upon the collection of fibers and the temperature
control additive is a particulate and is in contact with the fiber
product. In another embodiment, the temperature control additive is
selected from a group consisting of aluminum hydroxide, magnesium
hydroxide, silicate hydrates, and calcium sulfate dihydrate.
[0009] In illustrative embodiments, a method of curing a binder
having a temperature control additive comprises heating an uncured
binder to a temperature within a predetermined temperature range,
the temperature range being high enough to cure the binder but low
enough so as to not burn the binder. The uncured binder is
maintained at the temperature within the predetermined temperature
range for a time sufficient to substantially cure the binder. At a
time when the binder is at an elevated temperature, the temperature
control additive undergoes an endothermic process so that the
binder maintains a safe temperature throughout the curing process.
In one embodiment, the predetermined temperature range is from
about 100.degree. C. to about 350.degree. C. In another embodiment,
the predetermined temperature range is from about 170.degree. C. to
about 300.degree. C. In yet another embodiment, the predetermined
temperature range has as its lower boundary a temperature
sufficient to initiate a curing reaction. In another embodiment,
the predetermined temperature range has as its upper boundary a
temperature that the binder undergoes combustion. In one
embodiment, the temperature control additive undergoes an
endothermic process comprising decomposition, dehydration, or a
phase transition. In another embodiment, the temperature control
additive undergoes an endothermic process consuming about 200
calories per gram of the particulate temperature control
additive.
[0010] In illustrative embodiments, a method of manufacturing an
insulation product comprises contacting a collection of fibers with
a binder to form an uncured insulation product, contacting the
collection of fibers with a temperature control additive, shaping
the uncured insulation product into a configuration adapted for an
insulating purpose, and applying an amount of energy to the uncured
insulation product, the amount of energy sufficient to initiate an
exothermic process. In one embodiment, the exothermic process is
the chemical reaction that transitions the binder from an uncured
state to a cured state. The product is maintained at an elevated
temperature for a time sufficient to cure the binder. In one
embodiment, the method further includes forming a dispersion
comprising the binder and the temperature control additive, wherein
contacting the collection of fibers with the binder and contacting
the collection of fibers with the temperature control additive
occur concurrently through contacting the collection of fibers with
the dispersion including the binder and the temperature control
additive. In one embodiment, forming the dispersion includes adding
a surfactant. In another embodiment, the method further comprises
forming an aqueous dispersion of the temperature control additive
and a surfactant, wherein contacting the collection of fibers with
the temperature control additive occurs subsequently to contacting
the collection of fibers with the binder. In yet another
embodiment, contacting the collection of fibers with the
temperature control additive includes sprinkling the temperature
control additive onto the uncured insulation product, the
temperature control additive being in the form of a dry powder or
concentrated slurry.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 shows the temperature profiles inside a curing
fibrous product as a function of time for an illustrative
carbohydrate-based binder product and a comparable phenol
formaldehyde based binder product;
[0012] FIG. 2 shows the temperature profile inside a curing fibrous
product as a function of time for an illustrative
carbohydrate-based binder product in which the fibrous product was
removed from the curing oven when the product reached 220.degree.
C.;
[0013] FIG. 3 shows the temperature profile inside a curing fibrous
product as a function of time for an illustrative
carbohydrate-based binder product in which the fibrous product was
removed from the curing oven when the product reached 260.degree.
C.;
[0014] FIG. 4 shows the temperature profiles inside a curing
fibrous product as a function of time for an illustrative
carbohydrate-based binder product in which the fibrous product was
removed from the curing oven when the product reached 260.degree.
C. and the illustrative carbohydrate-based binder product including
3% of a temperature control additive;
[0015] FIG. 5 shows the temperature profiles inside a curing
fibrous product as a function of time for an illustrative
carbohydrate-based binder product cured in an oven maintained at
220.degree. C. with and without the inclusion of a temperature
control.
DETAILED DESCRIPTION
[0016] While the invention is susceptible to various modifications
and alternative forms, specific embodiments will herein be
described in detail. It should be understood, however, that there
is no intent to limit the invention to the particular forms
described, but on the contrary, the intention is to cover all
modifications, equivalents, and alternatives falling within the
spirit and scope of the invention.
[0017] In the manufacture of fiber products, a binder may be
disposed onto fibers, such as mineral fibers or cellulosic fibers.
The binder adheres to the loosely assembled fibers and causes the
fibers to stick to each other. The collection of the fibers
consolidated with binder forms a fiber product. A binder in its
uncured state is made up of various chemicals capable of reacting
with each other to form a polymer. Even when uncured, this binder
promotes adhesion between the fibers. However, the physical
properties, such as strength, of the binder are enhanced through a
curing step. Curing involves reacting the chemicals together to
form a polymer. The polymer is strong and has many desirable
physical properties. These binder properties provide a fiber
product, such as residential fiberglass insulation, with the
properties to which consumers are accustomed. A fiber product
having a binder in the uncured state may be used in further
manufacturing. For example, the fiber product may be packaged,
sold, and shipped to a customer that uses the product in the
manufacture of another good. For example, the uncured product can
be sold to molders who use cure the fiber product in a mold with a
particular shape for a particular purpose. In another example, the
uncured product may be stored and later cured in a distinct process
by the original manufacturer.
[0018] Uncured binders can be cured. For example, the process of
manufacturing a cured fiber product may include a step in which
heat is applied to the uncured product to cause a chemical
reaction. For example, in the case of making fiberglass insulation
products, after the binder solution has been applied to the fibers
and dehydrated, the uncured insulation product may be transferred
to a curing oven. In the curing oven the uncured insulation product
is heated (e.g., from about 300.degree. F. to about 600.degree. F.
[from about 150.degree. C. to about 320.degree. C]), causing the
binder to cure. As disclosed herein, the cured binder is a
formaldehyde-free, water-resistant binder that binds fibers of the
product together. Note that the drying and thermal curing may occur
either sequentially, simultaneously, contemporaneously, or
concurrently.
[0019] The curing reactions are typically initiated by heating the
insulation product. Once the reaction has started, most curing
reactions release energy in the form of heat. An exothermic process
is one which releases energy, usually in the form of heat, during
the process. An endothermic process is a process which consumes
energy, usually in the form of heat, during the process. As such,
heat is added to the product to initiate curing and then the
exothermic curing reaction provides for the further release of
heat. One aspect of the present disclosure is that a temperature
control additive is used to control the temperature of the fiber
product during an exothermic curing reaction.
[0020] As the exothermic curing reaction releases energy in the
form of heat, the binder and the product incorporating the binder
have a tendency to get hotter. That is, the heat released by the
exothermic process may be retained by the binder or the product.
Retention of heat will generally cause the temperature of the
binder and product to increase. This process may be referred to as
self-heating because it is the binder's release of heat which is
increasing the temperature of the binder. Self-heating may be a
benefit. Since many binder curing reactions are run at elevated
temperatures (compared to ambient), a source of heat is required.
For example, the heat is often provided by an oven or a heated
platen. Self-heating may be beneficial when it facilitates curing
the binder with a lower external heat requirement. For example, it
may be possible to run the platen or curing ovens at lower
temperatures if the binder self-heats. This will result in an
energy cost savings. However, self-heating can also be detrimental
to manufacturing processes. For example, if the temperature of the
insulation product becomes too high, the binder can be damaged or
even catch on fire. Furthermore, self-heating may facilitate
decreased manufacturing cycle times. As a product self-heats,
residency within heat source is no longer needed to maintain
conditions satisfactory to curing (i.e. maintaining a temperature
sufficient for curing). Thus, a product with extensive self-heating
may require a shorter heating cycle. Similarly, the rate of
chemical reaction for a binder is related to the temperature. This
relationship is known to loosely follow the Arrhenius equation. As
such, self-heating increases the temperature of the product beyond
that provided by the oven or platen. The increase in temperature
increases the curing reaction rates as would be expected from the
Arrhenius equation. Thus, curing proceeds more quickly in systems
that exhibit self-heating than it does in systems where
self-heating does not occur.
[0021] If self-heating increases the temperature of a product to
the point where oxidative processes commence, the self-heating may
cause significant damage to the product. For example, flameless
combustion or oxidation may occur when the temperature of the
insulation product exceeds about 425.degree. C. At these
temperatures, the exothermic combustion or oxidation processes
promote further self-heating and the binder may be destroyed.
Furthermore, the temperature may increase to a level in which
fusing or devitrification of the glass fibers is possible. Not only
does this damage the structure and value of the insulation product,
it may also create a fire hazard. The self-heating effect may be
exacerbated by the density, thickness, and binder content of a
particular product. Self-heating may also be more evident in binder
systems exhibiting larger enthalpic changes as a result of the
curing reaction.
[0022] Deleterious self-heating occurs when the heat introduced
into the insulation product, in combination with the heat generated
through the exothermic curing reaction, causes the temperature of
the insulation product to reach a level that has detrimental
effects on one or more of the insulation product components.
Deleterious self-heating may be particularly problematic in
insulation products having high insulating capacity. Insulation
materials having high fiberglass density, high binder density, or a
combination thereof may have an elevated tendency to exhibit
deleterious self-heating. Similarly, insulation products have large
physical dimensions, in particular thickness, may have an elevated
tendency to deleteriously self-heat. One aspect of deleterious
self-heating is that heat generated by the exothermic curing
reactions may be contained within the insulation product due to the
insulation products capacity to retard heat transfer. Accordingly,
one aspect of the present disclosure is that products having high
insulative capacity (i.e. high R-value products) are particularly
susceptible to deleterious self-heating during their manufacture.
Another aspect of deleterious self-heating is that self-heating is
the result of the exothermic chemical reaction associated with the
curing of the binder. Accordingly, insulation products having a
greater concentration of binder per unit volume (denser insulation
products) may exhibit an enhanced tendency to be damaged by
self-heating.
[0023] In one aspect, process conditions can strongly affect
deleterious self-heating. For example, the manner in which heat or
catalytic action is applied to an uncured insulation product to
actuate curing can influence whether a particular composition will
exhibit deleterious self-heating. In one example, relatively thin
fiberglass batts tend not to exhibit deleterious self-heating
because they have relatively low insulating material density,
relatively low binder concentrations, and heat dissipation enables
curing to occur at temperatures that are substantially lower than
those which would cause damage to the binder or the insulating
fibers. However, other insulation products may be more readily
susceptible to deleterious self-heating. For example, fiberglass
pipe insulation is susceptible to deleterious self-heating because
it is highly insulating, confined to a rather small volume having
relatively high density, and has relatively high binder content.
Additionally, fiberglass pipe insulation is manufactured on
equipment which transforms a substantially dehydrated uncured
product into a shaped product and forces air through the material
in order to quickly cure the binder. The speed of the process, the
lack of moisture in the initial uncured binder, the high insulating
capacity, and the high binder content may cause deleterious
self-heating of the finished process to be a substantial concern.
Molded fibrous products, in particular, are made through processes
which are more susceptible to deleterious self-heating.
[0024] One practical manufacturing solution to the deleterious
self-heating problem is readily ascertainable. The manufacturing
process conditions can be modified to avoid the risk of deleterious
self-heating. For example, a lower curing temperature could be used
to cure the binder. Furthermore, external cooling mechanisms could
be installed to force a cool fluid through or around the product.
However, these solutions necessitate additional manufacturing
burdens which may increase residency times in the manufacturing
equipment and reduce the manufacturing rate. In addition these
reasons, one skilled in the art would appreciate that the available
approaches to preventing deleterious self-heating are compromises
which would result in a product and or process with characteristics
that are undesirable.
[0025] One aspect of the present disclosure is that the temperature
control additive increases the homogeneity of curing across the
thickness of a manufactured product. One problem encountered in the
manufacture fiber products from alternative binder systems was that
the homogeneity of the product could exhibit significant variation.
For example, curing of the binder in one location, for example in
the center of the product, may deviate significantly from curing in
another location, for example the edge or face of the product. A
lack of homogeneity would also be evident between different
locations equivalently situated, for example between two distinct
locations on the face of the product. It was speculated that these
deviations in binder curing may, at least partially, be the result
of varying air resistance through the product in different areas.
For example, in a region of increased air resistance, the
exothermic self-heating may not be controlled by the flow of
isothermic air through the product to the same extent as a region
of decreased air resistance. While inhomogeneity in air resistance
across the insulation product can be controlled, to a large extent,
by control of manufacturing processes, a means of preventing
inhomogeneities in curing conditions independent of local
variations in air resistance is desirable.
[0026] One aspect of the present disclosure is that it may be
advantageous to use one binder formulation on a large range of
products within a manufacturing facility. To do so, a binder system
must be operable within a range of different products and
manufacturing processes. As described above, deleterious
self-heating is often related to the product and process
configuration; thus, using a consistent binder formulation across
the range of processes and products may be difficult due to the
propensity of some products and processes to exhibit deleterious
self-heating. Accordingly, it may be advantageous to have a means
of adding a temperature control additive to some products and
processes without changing the binder composition. For example, a
particularly challenging product or process, one that regularly
exhibits deleterious self-heating with a standard binder
formulation, may be made compatible with the standard binder
formulation by incorporation of a temperature control additive.
[0027] One aspect of the present disclosure is that the temperature
control additive functions through a mechanism which does not
interfere with the binder system chemistry. In one embodiment, the
temperature control additive does not chemically react with any of
the binder components. In another embodiment, the temperature
control additive is added to a fiber product at a point in which
binder composition is substantially dry. For example, the
temperature control additive may be added to the binder composition
while substantially dry and the temperature control additive is
added in the form of a powder, the powder will come into contact
with the surface of the binder without being completely embedded
within the binder. Therefore, the temperature control additive's
interaction with the binder, and any chemistry which may occur
within, is limited by the process conditions and structure of the
product.
[0028] In another aspect, the temperature control additive
functions through a mechanism which does not negatively interfere
with the physical attributes of binder system. For example, the
binder has been added to the fibers for the purpose of
consolidating the fibers. If the temperature control additive is a
substantial portion of the product, comprises particulates that are
too large, or consumes too much of the binder on its surface, the
binder may not be adequately available for binding the fibers.
While this may be compensated by the addition of more binder, this
may be undesirable in term of cost or other product performance
characteristics. Accordingly, one aspect of the temperature control
additive is that it does not substantially interfere or diminish
the physical properties of the binder on the fibers. This
interference or diminution would be observed through product
characteristics being adversely affected for those products which
contained a temperature control additive in comparison to those
products which do not contain the temperature control additive.
[0029] A solution was discovered addressing the foregoing issues.
Specifically, it was discovered that adding a temperature control
additive to the insulation product prior to curing prevents
deleterious self-heating during or after curing and improves the
homogeneity of the cured binder. While the nature of temperature
control additive is not to be limited by disclosure of a particular
example, it was determined that those additives which undergo
endothermic changes at temperatures in close proximity (within
20.degree. C.) to the cure temperature are particularly useful. For
example, a temperature control additive may release water at a set
temperature (i.e. dehydrate); the release being characterized as
endothermic. Insulation products manufactured with the temperature
control additive did not excessively self-heat and exhibited more
homogeneous cure properties. It was also unexpectedly discovered
that temperature control additives improve the consistency of the
curing across the insulation products.
[0030] The temperature control additive of the present disclosure
is well-suited for the binder compositions and associated reaction
conditions for a number of the newly developed formaldehyde-free
binder formulations. For example, the temperature control additive
is well-suited for the binder formulations described in U.S. Pat.
No. 7,655,711, U.S. Published Patent Application 2007/0123680, and
PCT published application WO 2009/019235, the disclosures of which
are hereby incorporated by reference in their entirety. One aspect
of the present disclosure is that the suitability of combining a
particular binder composition and a temperature control additive
rests, in part, on the extent to which the binder reaction is
exothermic. One aspect of the present disclosure is that many of
the formaldehyde-free binder formulations are either more
exothermic or require higher temperatures for curing than the
traditionally used phenol-formaldehyde chemistries. Since the
reactions are more exothermic, they exhibit greater self-heating.
Reactions requiring higher curing temperatures must be more closely
controlled because even small amounts of self-heating may cause the
temperature to rise so that the binder or fibers become
damaged.
[0031] As used herein, the term binder solution is the solution of
chemicals which can be dried to form the uncured binder. As used
herein, the term uncured binder is the substantially dehydrated
mixture of chemicals which can be cured to form the cured binder.
In practice, the uncured binder may be colorless or white to off
white sticky substance that is typically water soluble. As used
herein, the term cured binder is a polymer which is generally
insoluble. The cured binder may have a characteristic brown to
black color.
[0032] In illustrative embodiments, the binder comprises a reaction
product of a carbohydrate and a source of nitrogen. In one
embodiment, the binders are derived from Maillard reactions. In
another embodiment, the binders comprise melanoidins. In further
embodiments, the binders are based on reducing sugars. In one
embodiment, the binder comprises a reaction product of a
carbohydrate and an amine or polyamine. In further illustrative
embodiments, the binder comprises a reaction product of a
carbohydrate, a source of nitrogen, and an acid precursor. In one
embodiment, the binder comprises a reaction product of a
carbohydrate, ammonia, and an inorganic acid precursor. In another
embodiment, the binder comprises a reaction product of a
carbohydrate, ammonia, and an organic acid precursor. Exemplary
inorganic acid precursors include sulfates, phosphates and
nitrates. Exemplary organic acid precursors include polycarboxylic
acids such as citric acid, maleic acid, tartaric acid, malic acid,
or succinic acid. In one embodiment, the source of nitrogen is an
amine base; for example, the source of nitrogen may be ammonia, an
ammonium salt, or an alkyl diamine.
[0033] In illustrative embodiments, the uncured binder includes the
substantially dehydrated cured binder precursors. For example, the
uncured binder may include the ammonium salts of the organic or
inorganic acids. The uncured binder may also include the dried
carbohydrate compound, for example, dextrose. The dextrose may be
in the form of a hydrate or a salt. In one embodiment, the binder
comprises a dried uncured mixture dextrose and diammonium
phosphate. In another embodiment, the binder comprises a dried
uncured mixture dextrose and diammonium sulfate. In yet another
embodiment, binder comprises a dried uncured mixture dextrose and
triammonium citrate.
[0034] In illustrative embodiments, an uncured fibrous product
comprises an uncured binder, a collection of fibers, and a
temperature control additive. In one embodiment, the uncured binder
is disposed upon the collection of fibers and the temperature
control additive is a particulate and is distributed within the
fibrous product. In one embodiment, the temperature control
additive is aluminum hydroxide, magnesium hydroxide, calcium
silicate hydrates, or calcium sulfate dihydrate. In another
embodiment, the uncured binder comprises a carbohydrate and an
amine base salt of a multiprotic acid. For example, the
carbohydrate may be dextrose, xylose, fructose, dihydroxyacetone,
or mixtures thereof and the amine base salt of the multiprotic acid
may be ammonium citrate, ammonium phosphate, diammonium phosphate
or ammonium sulfate. In one embodiment, a collection of fibers
comprises from about 61% to about 96% by weight of the uncured
fiber product, the temperature control additive comprises from
about 1% to about 15% by weight of the uncured fiber product, and
the binder comprises from about 3% to about 30% by weight of the
uncured of the uncured fiber product. In another embodiment, the
fiber product may also include a silicon containing compound,
wherein the silicon containing compound is concentrated at an
interface between the binder and the fibers and at a second
interface between the binder and the temperature control
additive.
[0035] In illustrative embodiments, the fibers comprise fibers
selected from a group consisting of mineral fibers (slag wool
fibers, rock wool fibers, or glass fibers), aramid fibers, ceramic
fibers, metal fibers, carbon fibers, polyimide fibers, polyester
fibers, rayon fibers, and cellulosic fibers. In one embodiment, the
fibers are glass fibers and the fibrous product is fiberglass
insulation. In another embodiment, the fibers are mineral wool
insulation. In another embodiment, the glass fibers are present in
the range from about 70% to about 99% by weight. In another
embodiment, the collection of matter comprises cellulosic fibers.
For example, the cellulosic fibers may be wood shavings, sawdust,
wood pulp, or ground wood. In yet another embodiment, the
cellulosic fibers may be other natural fibers such as jute, flax,
hemp, and straw. In one embodiment, the cellulosic fibers are
present in the range from about 65% to about 97% by weight.
[0036] As used herein, a temperature control additive is a material
that undergoes an endothermic process at a temperature relevant to
the binder curing reaction. The temperature control additive may
undergo an endothermic process comprising decomposition,
dehydration, or a phase transition. Illustratively, the temperature
control additive may undergo an endothermic process consuming about
200 calories per gram of the temperature control additive
[.about.840 J/g]. In one embodiment, the temperature control
additive is a metal salt hydrate that undergoes an endothermic
dehydration.
[0037] In illustrative embodiments, the temperature control
additive is selected from the group consisting of Al(OH).sub.3,
AlO(OH), Ca(OH).sub.2, Ca.sub.3PO.sub.4.H.sub.2O,
CaSO.sub.4.2H.sub.2O, 5CaO.6SiO.sub.2.5H.sub.2O,
6CaO.6SiO.sub.2.H.sub.2O, MgSO.sub.4.8H.sub.2O,
MgCO.sub.3.3H.sub.2O, 4Mg(CO.sub.3).Mg(OH).sub.2.4H.sub.2O,
Mg(OH).sub.2, MgO.(CO.sub.2).sub.(0.96).(H.sub.2O).sub.(0.30),
Mg.sub.3(PO.sub.4).sub.2.8H.sub.2O, NaAlCO.sub.3(OH).sub.2,
NaBO.sub.3.4H.sub.2O, K.sub.3(citrate).H.sub.2O,
Ba(acetate).sub.2.H.sub.2O, and BaB.sub.2O.sub.4.nH.sub.2O.
[0038] Referring now to Table 1, shown is a list of exemplary
temperature control additive and the resulting particulate
generated upon the temperature control additive being exposed to
elevated temperatures. For each example provided, as the
temperature control additive is heated, it undergoes an endothermic
process.
TABLE-US-00001 TABLE 1 Temperature Control Additive Resulting
Particulate Name Formula Formula aluminum hydroxide Al(OH).sub.3
Al.sub.2O.sub.3, AlO(OH) aluminium oxide hydroxide AlO(OH)
Al.sub.2O.sub.3 calcium hydroxide Ca(OH).sub.2 CaO calcium
phosphate monohydrate Ca.sub.3PO.sub.4.cndot.H.sub.2O
Ca.sub.3PO.sub.4 calcium sulfate dihydrate
CaSO.sub.4.cndot.2H.sub.2O CaSO.sub.4.cndot.0.5H.sub.2O tobermorite
5CaO.cndot.6SiO2.cndot.5H2O 5CaO.cndot.6SiO2.cndot.H2O xonotlite
6CaO.cndot.6SiO2.cndot.H2O fractional hydrates magnesium sulfate
octahydrate MgSO.sub.4.cndot.8H.sub.2O MgSO.sub.4.cndot.nH.sub.2O,
where n < 8 magnesium carbonate trihydrate
MgCO.sub.3.cndot.3H.sub.2O MgCO.sub.3 and/or MgO hydromagnesite
4Mg(CO.sub.3).cndot.Mg(OH).sub.2.cndot.4H.sub.2O MgCO.sub.3 and/or
MgO magnesium hydroxide Mg(OH).sub.2 MgO magnesium carbonate
subhydrate
MgO.cndot.(CO.sub.2).sub.(0.96).cndot.(H.sub.2O).sub.(0.30)
MgCO.sub.3 and/or MgO magnesium phosphate octahydrate
Mg.sub.3(PO.sub.4).sub.2.cndot.8H.sub.2O
Mg.sub.3(PO.sub.4).sub.2.cndot.nH.sub.2O, where n < 8 sodium
aluminum carbonate hydroxide NaAlCO.sub.3(OH).sub.2 NaAlO.sub.2
sodium perborate tetrahydrate NaBO.sub.3.cndot.4H.sub.2O
NaBO.sub.3.cndot.H.sub.2O potassium citrate monohydrate
K.sub.3(citrate).cndot.H.sub.2O K.sub.3(citrate) barium acetate
Ba(acetate).sub.2).cndot.H.sub.2O BaCO.sub.3 barium borate hydrate
BaB.sub.2O.sub.4.cndot.nH.sub.2O, where n .ltoreq. 7
BaB.sub.2O.sub.4
[0039] The endothermic process changes at least a portion of the
temperature control additive into what has been described here as a
resulting particulate. The resulting particulates shown in Table 1
are not intended to be a complete listing of the various products
which may form during the endothermic process; rather, it shows the
formula for a primary or significant product. Furthermore, it is
noted that several of the resulting particulates are not stable
under ambient conditions which include 50% relative humidity.
Instead, the resulting particulate may be hygroscopic or otherwise
reactive. In some cases, the resulting particulate will reversibly
convert back to the temperature control additive at some time after
the endothermic process. For example, calcium sulfate dihydrate
will dehydrate to form either an anhydrous or hemihydrous (0.5
moles of water) at high temperatures. It is also known that the
calcium sulfate dihydrate is thermodynamically more stable under
ambient conditions which include room temperature and 50% relative
humidity. Thus, the dihydrate will be present at some time after
curing.
[0040] The present disclosure relates to the use of the temperature
control additive to prevent deleterious self-heating during or
after curing of the binder. Accordingly, the uncured fiber product
will include a temperature control additive and the cured fiber
product will include a resulting particulate. One aspect of the
present disclosure is that the products described herein are not
using the temperature control additive to achieve flame resistance.
Specifically, a goal of the present invention is not to obtain a
flame resistant fibrous product. Rather, one aspect of the present
disclosure is that the cured product will perform in a nearly
identical manner to the same cured product which does not include
the temperature control additive. The distinction between the
product made with the temperature control additive and the product
without the temperature control additive is that the manufacturing
process will be more controllable and the resulting product will
not exhibit the unwanted characteristics of a product that has
undergone deleterious self-heating. This may enable the use of
higher curing temperatures and shorter cycle times with the
temperature control additive because the temperature control
additive prevents deleterious self-heating during the manufacturing
process. While the temperature control additive is incorporated at
a time which primarily advances the purpose of avoiding deleterious
self-heating during curing, the resulting particulate or
re-hydrated resulting particulate (e.g. calcium sulfate dihydrate
described above) may provide a given fibrous product with enhanced
flame resistance. Specifically, the fibrous product may exhibit
improved performance compared to a fibrous product made without the
temperature control additive on flame penetration testing.
[0041] In one embodiment, the temperature control additive is a
metal hydroxide which decomposes at elevated temperature to release
water. For example, the temperature control additive may include
aluminum hydroxide (Al(OH).sub.3) or magnesium hydroxide
(Mg(OH).sub.2). In another embodiment, the temperature control
additive is a compound that undergoes a dehydration and
decomposition. For example, the temperature control additive may
include hydromagnesite (4Mg(CO.sub.3).Mg(OH).sub.2.4H.sub.2O).
Magnesium hydroxide and aluminum hydroxide may be preferred
temperature control additives due to their availability and
relatively low cost.
[0042] Aluminum hydroxide decomposes to form aluminum oxide
(alumina, Al.sub.2O.sub.3) and releases three moles of water while
consuming approximately 280 calories/gram [1172 J/g]. This
decomposition is known to occur at approximately 230.degree. C.
Magnesium hydroxide decomposes to magnesium oxide (magnesia, MgO)
and releases one mole of water while consuming approximately 330
calories/gram [1380 J/g]. The decomposition of magnesium hydroxide
occurs at approximately 330.degree. C. The decomposition and
dehydration of hydromagnesite proceeds with a dehydration to
produce four moles of water at temperatures below 250.degree. C., a
decomposition of Mg(OH.sub.2) to produce MgO with the production of
one mole of water at temperatures between 250.degree. C. and
350.degree. C., and a decarbonation of 4MgCO.sub.3 to produce 4MgO
and four moles of carbon dioxide at temperatures between
350.degree. C. and 550.degree. C.
[0043] In illustrative embodiments embodiment, the temperature
control additive includes a magnesium sulfate hydrate
(MgSO.sub.4.nH.sub.2O), wherein n is an integer less than or equal
to 8. For example, the temperature control additive may be
magnesium sulfate octahydrate or heptahydrate. One of ordinary
skill in the art will appreciate that the various hydrates of the
magnesium sulfate hydrate can be used interchangeably to some
extent and the temperature control additive is likely to include
several forms. Further, one skilled in the art will appreciate that
the enthalpy of dehydration associated with the removal of
additional water may differ. As such, one could tailor the
performance characteristics of the temperature control additive by
varying the ratio of each form of hydrate.
[0044] In further illustrative embodiments, the temperature control
additive includes a calcium sulfate dihydrate (gypsum,
CaSO.sub.4.2H.sub.2O). The dehydration of gypsum is well known in
the art and is known to occur between 100.degree. C. and
150.degree. C. (302.degree. F.). The dehydration is known to
comprise a first partial dehydration in which approximately 75% of
the hydrated water is lost and a final dehydration which results in
anhydrous calcium sulfate. At temperatures over 250.degree. C., the
anhydrous form is prevalent. The partially dehydrated calcium
sulfate is known as the hemihydrate or calcined gypsum and has a
formula of (CaSO.sub.4.mH.sub.2O), wherein m is in the range 0.5 to
0.8. Another aspect of using gypsum as the temperature control
additive is that it can return from either the anhydrous or the
calcined gypsum for to the dehydrate form through exposure to
ambient water vapor levels. Accordingly, an uncured fiber product
would include the dihydrate, a recently cured or curing fiber
product would include primarily the anhydrous or hemihydrate, and
the finished product would include primarily the dihydrate.
[0045] In illustrative embodiments, the temperature control
additive is a calcium silicate hydrate. As used herein, a calcium
silicate hydrate includes those hydrates produced through silicic
acid-calcium reaction between a siliceous raw material and a
calcareous raw material in the slurry thereof under high
temperature and high pressure condition, wherein the siliceous raw
material means a material mainly consisting of SiO.sub.2 such as
silica sand, silica powder, diatomaceous earth, silica fume,
feldspar, clay mineral or fly-ash; and the calcareous raw material
means a material mainly consisting of CaO such as quick lime or
slaked lime. When a slurry made of the siliceous raw material and
the calcareous raw material dispersed into water is heated with
agitation under pressure, a calcium silicate hydrate such as a
tobermorite and/or xonotlite can be formed through silicic
acid-calcium reaction in the slurry.
[0046] In illustrative embodiments, the temperature control
additive is selected from the group consisting of potassium citrate
monohydrate (K.sub.3(citrate).H.sub.2O), tricalcium phosphate
monohydrate (Ca.sub.3PO.sub.4.H.sub.2O), sodium perborate
tetrahydrate (NaBO.sub.3.4H.sub.2O), barium acetate monohydrate
(Ba(acetate).sub.2).H.sub.2O) and barium borate dihydrate
(BaB.sub.2O.sub.4.2H.sub.2O), barium borate heptahydrate
(BaB.sub.2O.sub.4.6H.sub.2O). One skilled in the art appreciates
that the use of some of these compounds presents some handling and
safety concerns which may require an additional treatment step or a
final use within a limited and/or specific application. As such,
while not optimal in every application, these temperature control
additives possess unique chemical properties such that the additive
itself or the resulting particulate may provide for specific
disadvantages and/or advantages according to some fibrous product
applications.
[0047] It was also discovered that various compounds could be used
together as an effective temperature control additive. For example,
in some applications a combination of aluminum hydroxide and
calcium sulfate dihydrate are particularly effective at preventing
deleterious self-heating during curing. Similarly, a combination of
aluminum hydroxide and magnesium hydroxide may be particularly
effective in certain applications.
[0048] While aluminum hydroxide, magnesium hydroxide, and
hydromagnesite have been used previously as a flame retardant and
incorporated into plastics as such, the present application can be
distinguished from these uses. In particular, the temperature
control additive is being incorporated into uncured binder
compositions to aid in the curing process. The curing process does
not involve the use of direct flames; rather, heat energy is
typically applied without flames. As such, the temperature control
additive is not used for flame retardancy. During the curing of the
product, the temperature control additive is converted to its
dehydrated or decomposed state. For example, during curing,
aluminum hydroxide is converted into aluminum oxide. Thus, the
manufactured fibrous product may not include any temperature
control additive because it was entirely consumed during the
manufacturing process.
[0049] As described herein, one characteristic of a temperature
control additive is that it undergoes an endothermic process upon
heating. Differential scanning calorimetry (DSC) and
thermo-gravimetric analysis (TGA) have been widely applied to study
the thermal dehydration and decomposition of various compounds that
can be used as temperature control additives. The analytical
results established that various grades of particulates may perform
with differing efficacy according to the average particle size.
Furthermore, the apparent dehydration and decomposition behavior
may also be influenced by the analytical procedure used. It was
determined that sample size, heating rate, inert gas flow rate and
degree to which the pan was sealed could influence the observed
results. It was determined that the efficacy of the temperature
control additive in the manufacturing process is a function of the
particle size and means of incorporating the temperature control
additive into the manufacturing process.
[0050] In illustrative embodiments, the temperature control
additive is a particulate. In one embodiment, the particulate is a
fine particulate. For example, the particulate may have a number
weighted average particle size of less than about 200 micrometers,
50 micrometers, or 20 micrometers. In another embodiment, the
particulate has a number weighted average particle size of between
about 5 micrometers and about 200 micrometers. In one embodiment,
the uncured fibrous product comprises from about 0.5% to 20% of a
temperature control additive. In another embodiment, the uncured
fibrous product comprises from about 1% to about 10% of a
temperature control additive by weight. One skilled in the art will
appreciate that temperature control additives that function through
dehydration and/or decomposition may lose significant mass as a
result of the dehydration and/or decomposition. Accordingly, the
weight of a temperature control additive may be significantly
reduced through the curing process such that the cured product may
include a much smaller percentage of the resulting particulate. For
example, the resulting particulate may comprise from about 0.2 to
about 20% of the cured product. As described above, since the
temperature control additive may rehydrate in ambient conditions
after the curing process is complete, the upper bound of the
temperature control additive and the resulting particulate may be
the same.
[0051] Binder compositions described herein can be used to
fabricate a number of different materials. In particular, these
binders can be used to produce or promote cohesion in non- or
loosely-assembled matter by placing the binder in contact with the
matter to be bound. Any number of well known techniques can be
employed to place the aqueous binder in contact with the material
to be bound. For example, the aqueous binder can be sprayed on (for
example during the binding glass fibers) or applied via a roll-coat
apparatus.
[0052] It was found that the temperature control additive can be
added to the binder formulation that is sprayed onto the fibrous
products to provide an essentially homogeneous distribution, or it
can be applied to the finished, uncured fibrous product, i.e. by
applying the additive as a powder or as a dispersion onto the
surface of the uncured fibrous product.
[0053] The temperature control additives described herein are
generally considered insoluble or only slightly soluble in water,
thus form dispersions in aqueous solutions. One skilled in the art
appreciates that a dispersion is a liquid phase in which a solid
phase has been distributed. In one embodiment, the temperature
control additive is a monodispersed dispersion. As used herein, a
monodispersed dispersion is one in which at least 75% of the weight
of the particulate in solution is in the form of single particles
in contrast to a solution containing aggregated or coagulated
particles. One skilled in the art will appreciate the numerous
analytical techniques available to establish the extent to which a
dispersion is monodispersed. In one embodiment the dispersion
containing the temperature control additive includes a surfactant
suitable for dispersing the temperature control additive. One
skilled in the art will appreciate that the use of a surfactant may
enhance the monodispersity of a dispersion. In one embodiment, the
dispersion is prepared through the use of mechanical and/or sonic
mixing techniques. For example, one skilled in the art will
appreciate that a dispersion of particles within a solution may
require the imposition of shear forces on the solution through
stirring and/or sonication. The methods described herein include
those techniques undertaken to form an appropriate dispersion.
[0054] In illustrative embodiments, the temperature control
additive is useful for controlling the temperature during a curing
step. In one embodiment, a method includes curing the binder by
passing the fibrous product through at least one zone of a curing
oven or mold press at a temperature within the range 170.degree.
C.-300.degree. C. for a time with an oven residence time in the
range 30 seconds to 30 minutes.
[0055] In illustrative embodiments, a method of curing a binder
comprises heating an uncured binder and maintaining the binder
temperature within a predetermined temperature range. In one
embodiment, the heating includes initiating an exothermic curing
reaction. In another embodiment, the maintaining is for a time
sufficient and at a temperature sufficient for the uncured binder
to substantially cure. In another embodiment, the maintaining
includes causing a particulate temperature control additive to
undergo an endothermic process, the endothermic process consuming
at least a portion of heat generated by the exothermic curing
reaction. In one embodiment, heating the uncured binder includes
initiating an exothermic curing reaction between a carbohydrate and
an amine base salt of a multiprotic acid. In another embodiment,
heating the uncured binder includes initiating an exothermic curing
reaction between dextrose, xylose, fructose, dihydroxyacetone, or
mixtures thereof and ammonium citrate, ammonium phosphate,
diammonium phosphate or ammonium sulfate. In another embodiment,
the method of curing a binder includes decomposing a hydroxide
salt, liberating water. In yet another embodiment, the
predetermined temperature range is from about 100.degree. C. to
about 350.degree. C. In another embodiment, the predetermined range
of about 170.degree. C. to about 300.degree. C. In one embodiment,
the method of curing a binder includes causing the particulate
temperature control additive to undergo an endothermic process
consuming about 200 calories per gram of the particulate
temperature control additive [837 J/g].
[0056] In illustrative embodiments, a method of manufacturing an
insulation product comprises contacting a collection of fibers with
a binder to form an uncured insulation product, contacting the
collection of fibers with a temperature control additive, shaping
the uncured insulation product into a configuration adapted for an
insulating purpose, applying an amount of energy to the uncured
insulation product subsequent to contacting the collection of
fibers with a temperature control additive, the amount of energy
sufficient to initiate an exothermic process transitioning the
binder from an uncured state to a cured state, and maintaining the
temperature of the binder within a predetermined range. In one
embodiment, the method of manufacturing an insulation product
further comprises forming a dispersion comprising the binder and
the temperature control additive, wherein contacting the collection
of fibers with the binder and contacting the collection of fibers
with the temperature control additive occur concurrently through
contacting the collection of fibers with the dispersion including
the binder and the temperature control additive. In another
embodiment, forming the dispersion includes adding a surfactant. In
yet another embodiment, the method of manufacturing an insulation
product of further comprises forming an aqueous dispersion of the
temperature control additive and a surfactant, wherein contacting
the collection of fibers with the temperature control additive
occurs subsequently to contacting the collection of fibers with the
binder. In one embodiment, contacting the collection of fibers with
the temperature control additive includes distributing the
temperature control additive, the temperature control additive
being in the form of a powder, onto the uncured insulation product.
In another embodiment, shaping the uncured insulation product
includes shaping the uncured insulation product into a
configuration adapted for insulating walls. In yet another
embodiment, shaping the uncured insulation product includes shaping
the uncured insulation product into a configuration adapted for
insulating pipes. In another embodiment, shaping the uncured
insulation product includes shaping the uncured insulation into a
shape adapted to a pipe insulation product.
[0057] The additive can be applied in form of an aqueous dispersion
sprayed on the fibrous product or by applying the additive as a
powder on top of at least one surface of the product. In case the
additive is applied in form of an aqueous dispersion, it could be
added to the binder formulation that is sprayed on the fibrous
product. This can be achieved by either homogeneously mixing the
additive in the binder formulation batch, or by inline-injection of
an aqueous dispersion of the additive to the binder formulation
just prior to the application point of the binder formulation to
the fibrous product. Dispersions of the water release additive can
be achieved as known in the art, i.e. by use of suitable mixing
devices, dispersing agents, and if needed by using coated water
release additives.
[0058] The combination of binder and temperature control additive
of the present disclosure is distinguishable from those binder
formulations previously developed utilizing phenol-formaldehyde
(PF) binder chemistries. In particular, those binders described in
U.S. Pat. Nos. 3,907,724, 3,919,134, 3,956,204, and 5,043,214 each
disclose modifying the binder reactants so that the binder resists
self-heating during curing. This approach is disfavored because it
involves the modification of the binder chemistry. Modification of
the binder chemistry for the purpose of avoiding self-heating is
undesirable because modifications necessarily entail a compromise
with some other characteristic (i.e. strength, weatherability,
cost). As described above, it is also undesirable to have multiple
binder formulations within a manufacturing facility because certain
products or processes tend to exhibit deleterious self-heating. The
temperature control additives described herein do not require
modification of the binder chemistry; thus, they can be used
without compromising the binder properties or changing binder
compositions between the various products and processes.
[0059] Additional features of the present disclosure will become
apparent to those skilled in the art upon consideration of
illustrative embodiments exemplifying the best mode of carrying out
the disclosure as presently perceived.
[0060] Embodiments of the invention are further described by the
following enumerated clauses:
[0061] 1. A fiber product comprising a binder, a collection of
fibers, and a particulate selected from a group consisting of
magnesia, alumina, and calcined gypsum, wherein the binder is
disposed upon the collection of fibers and the particulate is
distributed within the fiber product.
[0062] 2. The fiber product of clause 1, wherein the particulate
has a number weighted average particle size of less than about 200
micrometers.
[0063] 3. The fiber product of clause 1, wherein the particulate
has a number weighted average particle size of less than about 50
micrometers.
[0064] 4. The fiber product of clause 1, wherein the particulate
has a number weighted average particle size of less than about 20
micrometers.
[0065] 5. The fiber product of any one of clauses 1-4, wherein the
wherein the fiber product comprises from about 0.25% to about 15%
by weight of the particulate.
[0066] 6. The fiber product of any one of clauses 1-5, wherein the
wherein the fiber product comprises from about 3% to about 30% by
weight of the binder.
[0067] 7. The fiber product of any one of clauses 1-6, wherein the
wherein the binder comprises a reaction product of a carbohydrate
and an amine.
[0068] 8. The fiber product of clause 7, wherein the carbohydrate
comprises a monosaccharide and the amine comprises a primary
amine.
[0069] 9. The fiber product of clause 7, wherein the carbohydrate
comprises dextrose, fructose, or mixtures thereof.
[0070] 10. The fiber product of any one of clauses 1-9, wherein the
particulate is dispersed within the binder.
[0071] 11. A mineral fiber insulation product comprising a binder,
a collection of mineral fibers, and a particulate selected from a
group consisting of magnesia, alumina, and calcined gypsum wherein
the binder is disposed upon the collection of mineral fibers and
the particulate is distributed within the mineral fiber insulation
product.
[0072] 12. The mineral fiber insulation product of clause 11,
wherein the mineral fiber insulation product comprises about 61% to
about 96% mineral fibers and about 1% to about 15% of the
particulate.
[0073] 13. The mineral fiber insulation product of clause 11 or 12,
wherein the particulate has a number weighted average particle size
of less than about 200 micrometers.
[0074] 14. The mineral fiber insulation product of clause 11 or 12,
wherein the particulate has a number weighted average particle size
of less than about 50 micrometers.
[0075] 15. The mineral fiber insulation product of any one of
clauses 11-14, wherein the binder is a product of reacting a
carbohydrate and an amine.
[0076] 16. The mineral fiber insulation product of any one of
clauses 11-15, further comprising an organosilane in contact with
the particulate.
[0077] 17. An uncured fiber product comprising an uncured binder, a
collection of fibers, and a temperature control additive, wherein
the uncured binder is disposed upon the collection of fibers and
the temperature control additive is a particulate in contact with
the collection of fibers, in contact with the binder, or dispersed
throughout the uncured fiber product.
[0078] 18. The uncured fiber product of clause 17, wherein the
temperature control additive is selected from a group consisting of
aluminum hydroxide, magnesium hydroxide, calcium silicate hydrates,
and calcium sulfate dihydrate.
[0079] 19. The uncured fiber product of clause 17 or 18, wherein
the uncured binder comprises a carbohydrate and an amine.
[0080] 20. The uncured fiber product of clause 19, wherein the
carbohydrate is selected from a group consisting of dextrose,
xylose, fructose, dihydroxyacetone, and mixtures thereof.
[0081] 21. The uncured fiber product of any one of clauses 17-20,
wherein the amine is an ammonium salt or a primary amine.
[0082] 22. The uncured fiber product of any one of clauses 17-21
comprising about 61% to about 96% fibers, about 1% to about 15% of
the temperature control additive, and 3% to about 30% of the
uncured binder.
[0083] 23. The uncured fiber product of any one of clauses 17-22,
further comprising a silicon containing compound, wherein the
silicon containing compound is concentrated at a first interface
between the uncured binder and the fibers and at a second interface
between the uncured binder and the temperature control
additive.
[0084] 24. A method of curing a binder having a temperature control
additive, comprising heating an uncured binder to a temperature
within a predetermined temperature range, the temperature range
being high enough to cure the binder but low enough so as to not
burn the binder and maintaining the temperature within the
predetermined temperature range for a time sufficient to
substantially cure the binder, wherein maintaining the temperature
includes the temperature control additive undergoing an endothermic
process.
[0085] 25. The method of clause 24, wherein the predetermined
temperature range is from about 100.degree. C. to about 350.degree.
C.
[0086] 26. The method of clause 24, wherein the predetermined
temperature range is from about 170.degree. C. to about 300.degree.
C.
[0087] 27. The method of any one of clauses 24-26, wherein the
predetermined temperature range has as its lower boundary a
temperature sufficient to initiate a curing reaction.
[0088] 28. The method of any one of clauses 24-27, wherein the
predetermined temperature range has as its upper boundary a
temperature at which the binder ignites.
[0089] 29. The method of any one of clauses 24-28, the temperature
control additive undergoing an endothermic process comprising a
decomposition, a phase transition, or a dehydration.
[0090] 30. The method of curing a binder of clause 29, wherein the
temperature control additive undergoing an endothermic process
consumes at least about 200 calories per gram of the particulate
temperature control additive.
[0091] 31. A method of manufacturing an insulation product
comprising contacting a collection of fibers with a binder to form
an uncured insulation product, contacting the collection of fibers
with a temperature control additive, shaping the uncured insulation
product into a configuration adapted for an insulating purpose,
applying an amount of energy to the uncured insulation product
subsequent to contacting the collection of fibers with the
temperature control additive, the amount of energy sufficient to
initiate an exothermic process curing of the binder from an uncured
state to a cured state, and maintaining the temperature of the
binder within a predetermined range.
[0092] 32. The method of manufacturing an insulation product of
clause 31 further comprising forming a dispersion comprising the
binder and the temperature control additive, wherein contacting the
collection of fibers with the binder and contacting the collection
of fibers with the temperature control additive occur concurrently
through contacting the collection of fibers with the dispersion
including the binder and the temperature control additive.
[0093] 33. The method of manufacturing an insulation product of
clause 32, wherein forming the dispersion includes adding a
surfactant.
[0094] 34. The method of manufacturing an insulation product of any
one of clauses 31-33 further comprising forming an aqueous
dispersion of the temperature control additive and a surfactant,
wherein contacting the collection of fibers with the temperature
control additive occurs subsequently to contacting the collection
of fibers with the binder.
[0095] 35. The method of manufacturing an insulation product of
clause 31, wherein contacting the collection of fibers with the
temperature control additive includes sprinkling the temperature
control additive onto the uncured insulation product, the
temperature control additive being in the form of a dry powder or
concentrated slurry.
[0096] 36. The method of manufacturing an insulation product of any
one of clauses 31-35, wherein shaping the uncured insulation
product includes shaping the uncured insulation product into a
configuration adapted for insulating walls.
[0097] 37. The method of manufacturing an insulation product of any
one of clauses 31-35, wherein shaping the uncured insulation
product includes shaping the uncured insulation product into a
configuration adapted for insulating pipes.
[0098] 38. Use of a particulate selected from the group consisting
of aluminum hydroxide, magnesium hydroxide, calcium silicate
hydrates, and calcium sulfate dihydrate as a temperature control
additive in the manufacture of fibrous products.
[0099] 39. The use of clause 38, wherein the fibrous product is
mineral wool insulation or fiberglass insulation.
EXAMPLES
[0100] Referring now to FIG. 1, shown is the temperature profile
inside a curing fibrous product as a function of time for an
illustrative carbohydrate-based binder and a comparable phenol
formaldehyde based binder. The graph shows the temperature versus
the time for three separate temperature probes. The solid black
line shows the temperature of the curing oven used in this
particular experiment measured with a probe inside the curing oven,
but not in contact or direct proximity to either of the fibrous
products. This temperature profile shows that the temperature
inside the oven returns to the set temperature of 220.degree. C.
shortly after the fibrous products are inserted into the oven and
the door is closed. The temperature of the oven was maintained at
220.degree. C. by the temperature control electronics of the oven,
thus it does not increase or decrease in response to the exothermic
reactions occurring therein. The trace comprising the circular data
markers shows the temperature inside of a sample of a fibrous
product having a phenol formaldehyde (PF) based binder system. The
trace comprising the (+) data markers shows the temperature inside
of a sample of a fibrous product having a carbohydrate based binder
system.
[0101] The temperature probes were placed in the center of a
6''.times.6''.times.6'' cube of fiberglass insulation product
initially comprising uncured binders. At time 0, the cubes were
placed inside the curing oven. The PF binder was made according to
the methods and formulations well-known in the art, such as U.S.
Pat. No. 6,638,882 to Helbing et al. The comparative examples are
binders made according to Published PCT Application WO 2009/019235.
Specifically, Binder 1 includes dextrose, diammonium phosphate, and
a silane. The traces show the temperature at the center of the cube
over the course of 160 minutes.
[0102] Initially, the temperature inside the PF sample and the
Binder 1 sample exhibit a similar behavior. Specifically, each of
the probes shows a gradual increase in temperature. However,
between 40 and 60 minutes the temperature inside the Binder 1
sample crosses over the trace of the PF sample and the curing oven
temperature. Accordingly, the temperature inside the Binder 1
sample exceeds the temperature of the oven. This leads to the
conclusion that the curing of Binder 1 is self-heating the product.
It should be noted that the temperature inside the PF sample never
significantly exceeds the oven temperature, thus the PF sample is
not exhibiting significant self-heating. The temperature of the
Binder 1 sample eventually reaches a maximum temperature of about
425.degree. C. before the temperature begins to decrease. The
decrease in temperature can be attributed to a lack of self-heating
and a dissipation of heat which can be attributed to the completion
of the curing reaction. The temperature reached by the Binder 1
sample was high enough so that the binder's properties were
compromised by the elevated temperature. The temperature was
sufficiently high to damage the product, thus the self-heating can
be described as deleterious self-heating. However, it is noted that
the product did not ignite and no flames were observed. Examination
of the cured product did show that it was charred and discolored
near its center.
[0103] Accordingly, FIG. 1 captures one aspect of the challenges
presented by the new class of environmentally friendly binder
compositions. The exothermic reaction which occurs during curing
can result to deleterious self-heating.
[0104] As discussed herein, one approach to dealing with the
exothermic nature of the curing reaction would be to change the
process parameters to manage the temperature that the sample
reaches. Referring now to FIG. 2, an exemplary fibrous product was
made with the same composition and method as described with the
Binder 1 sample as described above. Furthermore, the experiment was
performed in an identical method as described above except that
when the temperature inside the product reached the set point of
the oven, the sample was removed from the curing oven. Because the
sample was not in the oven, heat could dissipate from the product
more readily and the temperature of the sample remained low. The
self-heating did not become deleterious as the dissipation of heat
prevented the temperature of the product from reaching temperatures
which damaged the product. It should be noted that the product made
in FIG. 2 may not have been cured sufficiently for adequate binder
performance. Specifically, the temperature was maintained above
200.degree. C. for only about 18 minutes. The residency time
requirements are product specific. While this approach is useful,
the inherent difficulty is shown in FIG. 3. FIG. 3 shows an
identical experiment to that shown with respect to FIG. 2, except
the curing oven is set to maintain 260.degree. C. When the sample
temperature reached the oven temperature, the sample was removed
from the oven. However, the temperature of the sample continued to
increase to approximately 620.degree. C. At this temperature,
deleterious self-heating is observed and much of the binder is
severely burned.
[0105] Referring now to FIG. 4, the experiment shown in FIG. 3 was
repeated except with the inclusion of a temperature control
additive. Specifically, a temperature control additive (designated
as TCA in FIG. 3) was added at a level of 3% by weight, based on
the total dried product. The temperature control additive was
aluminum hydroxide, as described herein. The trace of the sample
shows that the temperature control additive prevents the
deleterious self heating and keeps the internal temperature of the
sample to less than or equal to about 320.degree. C. As such, the
temperature control additive has prevented deleterious self-heating
with a binder and process conditions that would typically exhibit
deleterious self-heating (e.g. the example of shown in FIG. 3).
[0106] Referring now to FIG. 5, shown is a comparison between a
sample containing a temperature control additive added at a level
of 1.4% by weight, based on the total dried product and a
comparable sample without the temperature control additive. The
samples were kept in the oven through the curing reaction. The
sample containing the temperature control additive reached a
maximum temperature of about 290.degree. C. in the oven set at
220.degree. C. The sample without the temperature control additive
reached a maximum temperature of about 420.degree. C. Thus, it is
apparent that even relatively small amounts of a temperature
control additive are sufficient to prevent deleterious
self-heating.
[0107] Furthermore, it was found that the effectiveness of the
temperature control additive was not limited to one particular
method of applying it to the product. Illustratively, the same
effectiveness was achieved by either applying the additive on the
product in the form of an aqueous dispersion or by applying the
additive in form of a powder on one product surface. It was also
found that the temperature control additive can be added to the
binder formulation that is sprayed onto the product prior to drying
the binder solution to form an uncured product.
* * * * *