U.S. patent application number 12/524502 was filed with the patent office on 2010-04-08 for mineral fibre insulation.
Invention is credited to Tony Aindow, George Baybutt, Roger Jackson.
Application Number | 20100084598 12/524502 |
Document ID | / |
Family ID | 37969919 |
Filed Date | 2010-04-08 |
United States Patent
Application |
20100084598 |
Kind Code |
A1 |
Jackson; Roger ; et
al. |
April 8, 2010 |
MINERAL FIBRE INSULATION
Abstract
A mineral wool insulating product having improved off gassing
characteristics is particularly adapted for high temperature
applications.
Inventors: |
Jackson; Roger; (St. Helens,
GB) ; Aindow; Tony; (St. Helens, GB) ;
Baybutt; George; (St. Helens, GB) |
Correspondence
Address: |
BARNES & THORNBURG LLP
11 SOUTH MERIDIAN
INDIANAPOLIS
IN
46204
US
|
Family ID: |
37969919 |
Appl. No.: |
12/524502 |
Filed: |
January 25, 2007 |
PCT Filed: |
January 25, 2007 |
PCT NO: |
PCT/EP2007/050747 |
371 Date: |
November 12, 2009 |
Current U.S.
Class: |
252/62 |
Current CPC
Class: |
C04B 14/42 20130101;
C04B 30/02 20130101; C04B 26/28 20130101; C03C 13/06 20130101; C04B
2201/30 20130101; D04H 1/42 20130101; F24C 15/34 20130101; C04B
2111/1006 20130101; C04B 26/20 20130101; D04H 1/587 20130101; D04H
1/4209 20130101; D04H 1/4218 20130101; C03C 25/26 20130101; C04B
30/02 20130101; C04B 14/42 20130101; C04B 24/287 20130101 |
Class at
Publication: |
252/62 |
International
Class: |
E04B 1/74 20060101
E04B001/74 |
Claims
1.-19. (canceled)
20. A mineral fiber insulating material comprising mineral fibers
bound by at least about 0.5% by weight of an organic binder,
wherein an initial heating of the mineral fiber insulating material
to a temperature of 2000 degrees C. off-gases a mixture of gases
comprising predominately ketones.
21. The mineral fiber insulating material of claim 20, wherein the
mixture of gases further includes furans.
22. The mineral fiber insulating material of claim 20, wherein the
mineral fiber insulating material has a dust level of less than or
equal to 20 g/m.sup.3.
23. The mineral fiber insulating material of claim 20, wherein the
mixture of gases includes less than about 30 mg/kg of
formaldehyde.
24. The mineral fiber insulating material of claim 20, wherein the
mixture of gases comprises less than about 15 mg/kg of
formaldehyde.
25. The mineral fiber insulating material of claim 20, wherein the
mixture of gases have an odor characteristic of baking.
26. The mineral fiber insulating material of claim 20, wherein the
mineral fiber insulating material has a recovered thickness of at
least about 100% measured in accordance with Annex A of British
standard BS EN 823:1995.
27. The mineral fiber insulating material of claim 20, wherein the
mineral fiber insulating material has an ordinary parting strength
of at least about 100 g/g.
28. The mineral fiber insulating material of claim 20, wherein the
mineral fiber insulating material has a weathered parting strength
of at least about 80 g/g.
29. The mineral fiber insulating material of claim 20, wherein the
mineral fibers are bound by less than about 10% by weight of the
organic binder.
30. The mineral fiber insulating material of claim 20, wherein the
mineral fibers are bound by between about 1.5% and about 8% by
weight of the organic binder.
31. The mineral fiber insulating material of claim 20, wherein the
organic binder is formaldehyde free.
32. The mineral fiber insulating material of claim 31, wherein the
organic binder comprises a product of a reaction including a
reducing sugar.
33. The mineral fiber insulating material of claim 32, wherein the
organic binder comprises at least one Maillard reaction
product.
34. The mineral fiber insulating material of claim 33, wherein the
at least one Maillard reaction product is a reaction product of
reacting at least citric acid, ammonia and dextrose.
35. The mineral fiber insulating material of claim 32, wherein the
mineral fiber insulating material has a density between about 5 and
40 kg/m.sup.3.
36. A heating device adapted for use at an operating temperature of
greater than 100 degrees C. comprising the mineral fiber insulating
material of claim 20.
37. The heating device of claim 36, wherein the heating device is
adapted for use as an oven or range.
38. The heating device of claim 36, wherein the heating device is
adapted for use as a storage heater.
Description
[0001] This invention relates to a mineral fibre insulating
product, particularly having a low formaldehyde or formaldehyde
free binder.
[0002] Industry standard binders used for fibre insulation, for
example glass wool and rock wool insulation are based on phenol
formaldehyde. Whilst such binders can provide suitable properties
to the insulating products there has for some time been a desire to
move away from the use of phenol formaldehyde, particularly due to
environmental considerations.
[0003] Furthermore, where the mineral fibre insulation material is
used in products that operate at high temperatures, for example, as
insulation for ranges, ovens and storage heaters, phenol
formaldehyde binders generally give off an acrid smell when the
products are first heated to their operating temperatures and
sometimes until all or a significant portion of the binder has
decomposed. Such odours are not appreciated by the purchaser of,
for example, a new domestic oven, and can be perceived as a fault
in the product.
[0004] This problem has led to the use of mineral fibre insulation
with acrylic binders with low levels (0.2-0.3% by weight) of
dedusting oil or needled products which do not contain any binder.
Such products are generally expensive and their handling
characteristics can be less than ideal. Alternatively, inorganic
binders can be used avoid the presence of compounds which decompose
or gas off at such temperatures. However, such products have
significant levels of dust which is inconvenient for handling and
assembly. For example, for use in an oven, the mineral insulating
products must be cut to size, have passageways cut away and be
assembled generally under compression into the oven body. These
operations would be simplified if the presence or generation of
dust from the insulation could be reduced or avoided.
[0005] One aim of the invention is to provide an improved
insulation product particularly for such applications.
[0006] According to one aspect, the present invention provides a
mineral fibre insulating material as defined in claim 1. Other
aspects are defined in other independent claims. Preferred and/or
alternative features are defined in the dependent claims.
[0007] The compounds referred to in relation to off gassing are
believed to create pleasant odours the first time the insulating
material is heated to operating temperature. Preferably, the off
gassing consists essentially of the compounds referred to. The
off-gassing may be due to or essentially due to decomposition of
the binder.
[0008] The off-gassing may be analysed by a tube furnace test
and/or by gas chromatography.
[0009] The domination in the off gassing may be in terms of
odour.
[0010] The ketone may comprise or consist essentially of
2-cyclopenten-1-one.
[0011] The furans may comprise or consist essentially of 2,5
dimethyl-furan and/or furan and/or 3-methyl-2,5-furandione.
[0012] The off gassing may comprise at least 50 mg, 100 mg, 500 mg
or 1000 mg or ketones and/or furans per kilogram of binder.
[0013] The dust level is measured according to the Dust Level
Assessment Procedure described below. The dust level is preferably
less than 10 g/m.sup.3, more preferably less than 5 g/m.sup.3 and
most preferably less than 1 g/m.sup.3.
[0014] The mineral fibre insulating product may have the
characteristics defined when first heated to a temperature of
200.degree. C., and preferably when first heated to a temperature
of 250.degree. C. or 300.degree. C., that is to say when newly
provided for use and heated to this temperature.
[0015] Physical characteristics that may be conferred by the binder
on the mineral wool insulation product can be assessed by measuring
Recovered Thickness and/or by measuring Ordinary Parting Strength
and/or Weathered Parting Strength. The procedures for measuring
these characteristics are set out below. The levels defined
facilitate handling of the mineral insulation.
[0016] A binder content of at least 0.5%, preferably at least 1% or
1.5% by weight may provide good resilience and/or recovery and/or
strength to the mineral insulation. A binder content of up to 8% by
weight may provide good physical properties whilst avoiding excess
quantities of binder and/or excessive off gassing when heated to
high temperatures. The binder content may be determined by loss on
ignition.
[0017] As used herein, the term formaldehyde free means that the
composition is substantially free from formaldehyde, does not
liberate substantial formaldehyde as a result of drying or curing
and preferably comprises less than one part per million by weight
of formaldehyde.
[0018] The binder may: [0019] be based on a reducing sugar; and/or
[0020] be based on reductosis; and/or [0021] be based on an
aldehyde containing sugars/and/or [0022] include at least one
reaction product of a carbohydrate reactant and an amine reactant;
and/or [0023] include at least one reaction product of a reducing
sugar and an amine reactant; and/or [0024] include at least one
reaction product of a carbohydrate reactant and a polycarboxylic
acid ammonium salt reactant; and/or [0025] include at least one
reaction product from a Maillard reaction.
[0026] The binder may be based on a combination of a polycarboxylic
acid, for example citric acid, a sugar, for example dextrose, and a
source of ammonia, for example ammonia solution. It may be based on
a combination of ammonium citrate and dextrose. Where the binder is
based on sugars and/or citric acid and or comprises significant
--OH groups, it is particularly surprising that such levels of
Weathered Parting Strength can be achieved. It would have been
thought that the --OH groups for example in the sugars and/or
citric acid would be readily subject to hydrolysis and that the
binder would consequently loose significant strength in humid
and/or weathering conditions.
[0027] The binder may comprise a silicon containing compound,
particularly a silane; this may be an amino-substituted compound;
it may be a silyl ether; it may facilitate adherence of the binder
to the mineral fibres.
[0028] The binder may comprise melanoidins; it may be a thermoset
binder; it may be thermally curable.
[0029] The binder may be one of those disclosed in International
patent application n.degree. PCT/US2006/028929, the contents of
which is hereby incorporated by reference.
[0030] The insulating material may be provided as a package. The
package may comprise one or more mineral wool insulating products
arranged and/or bound together, for example to facilitate
transport; it may comprise an enveloping film, for example of a
plastics material. The package may consist of a roll of insulating
material or an assembly of individual slabs of insulating material.
The insulating material may be provided in a compressed state.
[0031] The insulating material may have [0032] a nominal thickness
in the range 1.5 to 20 cm, or in the range 2 to 12 cm; and/or
[0033] a thermal resistance R of R.gtoreq.to 3 m.sup.2K/W,
preferably R.gtoreq.to 4 m.sup.2K/W at a thickness or 200 mm;
and/or [0034] a thermal resistance R of R.gtoreq.to 1.5 m.sup.2K/W,
preferably R.gtoreq.to 2 m.sup.2K/W at a thickness or 100 mm;
and/or
[0035] a density in the range 5-40 kg/m.sup.3.
[0036] The mineral fibres may be glass wool or rock wool; the
fibres may have an average diameter between 2 and 9 microns; they
may have an average length between 8 and 80 mm.
[0037] The mineral fibre insulating material may be advantageously
used in heating devices adapted to operate at temperatures greater
than 100.degree. C. or greater than 200.degree. C.; it may be
particularly adapted for use in heating devices adapted to operate
at temperatures greater than 400.degree. C. or greater than
500.degree. C., for example, self cleaning ovens and/or
precipitators.
[0038] A non-limiting example of the invention is described below
with reference to FIG. 1 which shows the form of samples used for
testing parting strength.
[0039] An aqueous binder can be prepared by mixing together:
TABLE-US-00001 Approximate % by weight Powdered dextrose
monohydrate 11% Powdered anhydrous citric acid 2% Soft water 84%
19% aqueous ammonia 3% SILQUEST A-1101 silane 0.05%
[0040] This binder can be used in the manufacture of a fibre glass
insulating product on a standard manufacturing line, the binder
being sprayed onto glass fibres just after fiberising using
internal spinners and the coated fibres being collected, assembled
in to a mat and cured in the usual way.
[0041] The cured glass fibre insulating product can have: [0042] a
binder content of about 5% by weight as determined by loss on
ignition [0043] a thickness of about 100 mm [0044] a density of
about 12 kg/m.sup.3
[0045] Desired characteristics and results achieved are set out in
Table 1:
TABLE-US-00002 TABLE 1 Acceptance More Most Result Units limit
Preferred Preferred preferred achieved Dust level g/m.sup.3
.ltoreq.20 .ltoreq.10 .ltoreq.5 .ltoreq.1 .ltoreq.1 Recovered % of
.gtoreq.95 .gtoreq.100 .gtoreq.110 .gtoreq.120 103 Thickness
nominal Ordinary g/g .gtoreq.95 .gtoreq.100 .gtoreq.150 .gtoreq.200
122 Parting Strength Weathered g/g .gtoreq.75 .gtoreq.80
.gtoreq.100 .gtoreq.150 112 Parting strength
[0046] When heated to about 200.degree. C., the insulating material
gave off a slight odour which was a pleasant baking smell.
[0047] Dust Level Assessment Procedure
[0048] Three specimens are cut from the test material using a 150
mm diameter cutter; the specimens should have clean edges and be
free from dirt and foreign matter.
[0049] The first specimen is placed in the sieve of a Pascall Sieve
Shaker; it should not be compressed by the lid but should fit
snugly. If necessary, layers are built up to achieve this. The lid
and receiver of the sieve are fitted and the complete unit is
secured on to the Pascall Sieve Shaker and set to shake for 10
minutes.
[0050] When the shaker has stopped, the lid of the sieve is
removed, the specimen is taken out and its weight recorded.
[0051] The procedure is repeated with the second and third
specimens.
[0052] Once the three specimens have been shaken, the dust is
collected from the receiver with the aid of a soft brush. The whole
inner surface of the receiver should be gently brushed and the dust
collected together prior to being transferred to a weighing dish
and weighed to the nearest 0.0001 g.
[0053] The dust level in g/m.sup.3 is calculated weight of dust
collected from the three specimens and the total volume of the
three specimens.
[0054] By way of precaution, all apparatus should be thoroughly
clean and dry and free from grease before use. It may be washed in
hot soapy water and dried completely before use.
[0055] Testing of Recovered Thickness:
[0056] Recovered Thickness is tested and measured in accordance
with Annex A of British standard BS EN 823: 1995 (incorporated
herein by reference) and expressed as a % of the nominal or
announced thickness for the product measured.
[0057] Testing of Ordinary Parting Strength and Weathered Parting
Strength:
[0058] Parting strength is a measure of the tensile strength of
mineral fibre mats determined by placing an O shaped sample over
cylindrical jaws, separating the jaws and measuring the load to
break the fibres. Although it can be measured in Newtons per gram,
the parting strength is expressed in grams/gram being the total
breaking load of six test specimens divided by their total
weight.
[0059] The test is carried out on mineral fibre mats as received
for testing (Ordinary Parting Strength) and after an accelerated
weathering test as explained below (Weathered Parting
Strength).
[0060] A first set of six samples of the form and dimensions shown
in FIG. 2 are cut from the mineral fibre mat to be tested; the long
axis of the samples should be parallel to the conveyor direction
and the samples should be taken across the full width of the
mineral mat. A second set of six samples is then taken in the same
way. The dimensions in FIG. 1 are in mm.
[0061] The total weight of the first group of six samples W1 in
grams is recorded.
[0062] The total weight of the second group of six samples W2 in
grams is recorded; these samples are then placed in a preheated
autoclave and conditioned on a wire mesh shelf away from the bottom
of the chamber under wet steam at 35 kN/m.sup.2 for one hour. They
are then removed, dried in an oven at 100.degree. C. for five
minutes and tested immediately for parting strength.
[0063] To test the parting strength, each sample is mounted in turn
on the jaws of the tensile strength machine and the maximum
breaking load in grams or Newtons is recorded. If the breaking load
is measured in Newtons it is converted to grams by multiplying it
by 101.9. Six results in grams are obtained for each set of
samples: G1 G2 G3 G4 G5 and G6 for the first set of samples and G7
G8 G9 G10 G11 and G12 for the second set of samples.
[0064] The Ordinary Parting Strength is calculated from the first
set of samples using the formula Ordinary Parting
Strength=(G1+G2+G3+G4+G5+G6)/W1.
[0065] The Weathered Parting Strength is calculated from the second
set of samples using the formula Weathered Parting
Strength=(G7+G8+G9+G10+G11+G12)/W2.
* * * * *