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Патент USA US3020199

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Feb. 6, 1962
3,020,189
‘J, H. WAGGONER
FIBROUS STRUCTURES AND METHODS FOR MANUFACTURING SAME
Original Filed Sept. 12, 1950
3 Sheets-Sheet 1
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Feb- 6, 1962
J. H. WAGGONER
3,020,189
FIBROUS STRUCTURES AND METHODS FOR MANUFACTURING SAME
Original Filed Sept. 12, 1950
3 Sheets-Sheet 2
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Feb. 6, 1962
J, H. WAGGONER
3,020,189
FIBROUS STRUCTURES AND METHODS FOR MANUFACTURING SAME
Original Filed Sept. 12, 1950
3 Sheets-Sheet 3
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Patented Feb. 6, 1§62
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of glass ?bers could be subjected to temperatures in ex
3,020,189
cess of 1000“ F. without harm to the ?bers or the struc
FEBROUS STRUCTURES AND METHODS FOR
ture. More important by way of further illustration, high
concentrations of resinous material, such as phenolfor
MANUFAtITURlNG SAME
Jack H. Waggoner, Newark, Ohio, assiguor to Owens
Corning Fiberglass Corporation, a corporation of Dela
maldehyde, so sti?'ens ‘and embrittles the glass ?ber mass
that it detracts from its acceptability as an insulation or
ware
textile product. It reduces its recovery and also greatly
reduces its tear and strength properties.
Continuation of application Ser. No. 184,355, Sept. 12,
1950, now Patent No. 2,772,603, dated Dec. 4, 1956.
This application Oct. 19, 1956, Scr. No. 617,091
4 Claims. (Cl. 156—34)
Attempts have been made to make use of inorganic
10 binder compositions, such as bentonite and other clays, for
the purpose of maintaining the inorganic character of the
This application is a continuation of my copending ap
?nal product while gaining the bene?t of the mass
plication Ser. No. 184,355, ?led September 12, 1950, en
integrity imparted by the use of such binder compositions.
titled “Fibrous Structures and Methods for Manufactur
While binding materials such as these are resistant to high
ing Same,” now Patent No. 2,772,603.
This invention relates to glass ?ber products and par 15 temperatures, they exhibit high attraction for moisture
and are hygroscopic, and since it is the usual practice to
ticularly to the manufacture of thermal insulation, sound
apply such compositions in aqueous medium, removal of
insulation, structural board, and ?brous sheets which may
be used as such or'in the manufacture of laminates, mats
and batts and the like, and in which glass ?bers constitute
the diluent and the moisture combined in the binder ma
the use of other ?bers which have some of the character
Weight bentonite or the like. Such amounts cause gella
tion in the ?brous structure upon formation with aqueous
terial requires considerable heat treantment. In the clay
the major constituent. This invention also contemplates 20 systems, it is necessary to use as much as 15 percent by
istics of glass ?bers, such, for example, as ?bers drawn
from synthetic resins.
medium and it is practically impossible to achieve proper
ventilation for the removal of Water at a rapid rate during
The use of attenuated ?ber of glass or synthetic resin
in the manufacture of ?brous structures is faced by the 25 the ?nal steps in manufacture. Reliance must be had upon
difficulty of integrating or otherwise forming the glass
surface evaporation, which is slow and expensive. Fur
thermore, the presence of such large amounts of clay re
sults in a product which is dusty, brittle and friable and
?bers and the like exist in the form of rod-like ?laments
therefore limited in application as Well vas ?exural strength
of substantial length having little, if any, cn'mp or curl
and having perfectly smooth rounded surfaces. There is 30 and tear strength.
It is ‘an object of this invention to produce a ?brous
nothing on the glass ?ber surfaces which might cause
structure of attenuated glass or synthetic resinous ?bers.
the ?bers to cling together upon contact with one \an
and the like having high mass integrity with little, if any,
other, and, therefore, it is di?icult to felt the ?bers into a
adhesive, and it is a related object to provide methods for
self-sufficient mass. Because of the smooth, nonporous
nature of the glass ?ber surfaces coupled with their hydro 35 producing same.
Another object is to produce glass ?ber structures of
phobic characteristics, it is di?jcult to bond resinous ma
glass ?ber modi?ed in its surface characteristics to cause
terials or other adhesive to the glass ?ber surfaces for the
the ?ber to cling together in the formation of a felted mass
purpose of integrating the ?bers one with another. Al—
having high integrity and which may be markedly in
though these properties may be used to advantage in some
?bers into a self-suf?cient mass. This is because the glass
applications, they detract from or impair the assembly of 40 creased in strength thereafter by the incorporation of a
minimum amount of resinous binder, and it is 1a related
the ?bers into ?brous structures having a high degree of
object to provide a method for producing same.
mass integrity.
A further object is to produce glass ?ber products in
By way of comparison, other common natural ?bers,
which the ?bers may be formed into a self~su?icient mass‘
such as Wool, cotton and the cellulose ?bers, have their
of high strength by the use of a bonding agent that does
surfaces covered with a large number of tiny ?ngers or
not detract from the use of the ?nished article for purposes
hairy projections which apparently cause the ?bers to cling
of the type described.
to one another upon contact. This agglomerating or com
A still further object is to produce a ?brous product
bining characteristic permits felting together in a dry
of the type described employing a small amount of a bind
state or from liquid suspension to form ?brous structures
of considerable strength.
In ?brous structures of this 50 ing agent which is ?brous in character, and it is a related
object to produce a ?brous structure of the type described
type, it is often unnecessary to make use of additional
in which the binding agent operates ?exibly to space the
binder in the form of resinous materials or the like to
glass ?bers one from another to increase flexibility and
achieve strength sufficient for the purpose for which the
reduce the possibility of self-destruction by mutual abra
structure is intended.
On the other hand, the inability of glass ?bers and the 55
. like to interfelt into a mass
suf?cient strength and in
tegrity to resist forces to which it might be exposed as an
incidence to normal handling, makes it necessary to in
SlOIl.
A basic object is to combine attenuated glass ?ber with
felt bonding ?bers which become associated or orientated
with the glass ?bers to enable the arrangement thereof
'into a structure having high mass integrity and which
corporate binders or cements to gain a limited degree of
bond between the ?bers, Whether in the form of a mass, 60 protects the glass ?ber surfaces against abrasion of the
type which has heretofore limited the use of glass ?ber
Web, yarn, strand or other preformed body.
in textiles, mats, or batts.
Aside from the usual high cost of the adhesive or binder
A still further object is to produce a glass ?ber product
and its application, it has often been found necessary to
of the type described in which the binding agent consists
employ such large amounts of binder in order to elfect
a desired degree of mass integrity that other desirable 65 chie?y of a ?brous material which is present in such small
quantities as to permit the product to retain practically
properties of the structure are handicapped. For example,
all of the original characteristics of the glass ?bers, such
most organic materials which might be used as binder
as ?ame-proofness, heat resistance, and resistance to eX
compositions begin to decompose by thermal reaction,
posure. at high temperature.
upon exposure to temperatures of 400° to 500° F. so that
A still further object is to produce glass ?ber products
products in which they are embodied are limited to low 70
of the type described which may be varied in density
temperature applications. This is important because, in
from below three pounds per cubic foot to thirty pounds
the absence of such organic binder, heat insulation formed .
3,020,189
".7
4
per cubic foot (or more) and which may be further
treated or impregnated with the usual resinous materials‘
to produce a product having new and improved charac
teristics.
A still further object is to produce a glass ?ber product
of the tlpe described which employs a new and improved
ing purposes in accordance‘ with" the concepts of this in»
:3
vention, there are situations wherein such substitution“
cannot be made because the process is applicable only to’
asbestos type ?bers or the like or to cellulose pulp ?bers,
or the like, as will hereinafter be developed.
The term “glass ?bers,” as used herein,‘ is meant to in-~
clude glass ?bers of the staple of wool type,‘ such as are:
attenuated from molten streams of glass by reaction with:
binding agent to produce a product having high strength
and mass integrity without the necessity of employing or
ganic or inorganic adhesives of the usual type.
high pressure air or steam. Included also, are continuous ~
A still further object is to produce ?brous insulation ll) ?bers mechanically drawn ‘at high speed‘fr'oim streams of‘
and structural boards ‘and other preformed shapes char
molten glass and which may be cut to desired lengths for‘
acterized by high temperature resistance, incombustibility,
manufacture of ?brous structures embodying’the'concepts
high tensile strength, high ?exure and impact strength,
of this invention. ‘It has been found that structures em‘
and nail holding ability while having su?cient porosity
to serve as sound and thermal insulation, and it is a re
bodying features of this invention may be prepared of‘
15 glass ?bers of considerable length ‘or of relatively short.
lated object to provide new and improved processes for
manufacturing same.
An object of this invention is to provide an improved
binder system for glass ?ber products and to provide new
length, and that very often most satisfactory results‘ are-1
secured by the use of glass ?ber having considerable varia~ ~
tion in length between long to very short ?bers’ of a few?
microns in length. Glass fibers of the type described may/
processes making use of same in the manufacture of 20 be used in the condition in which they are delivered from‘;
?brous structures.
the ?ber forming unite-that is, with or without lubricant
A still further object is to produce and to provide a
or size thereon, but it is preferred to remove the size or.‘
method for producing a bonded ?brous structure having
coating prior to use in the formation ‘of ?brous structures;
microscopic bubbles or voids arranged in substantially
in accordance with this invention. Porous and. bond'edl
uniform distribution adjacent the glass ?ber surfaces to
mats or batts of glass ?bers may also be used to form:
achieve the properties of a highly bulked-up‘ glass ?ber
structures having new and improved characteristics enn
structure with minimum concentration of binding agent.
A still further object is to produce a porous glass ?ber
bodying features of this invention, as will hereinafter be»:
structure embodying expanded or pu?ed mineral as a bulk
.1} basic concept of this invention resides ‘in the orienta—:
ing agent to increase porosity without detracting from the
other properties of the ?brous structure.
A still further object is to produce and to provide a
tio‘n’of binder ?bers in small proportion'with' the glass;
described.
_
p
_
surfaces‘whereby the ?bers together are able to formi
into; a‘f'elted‘ mass" and interlock in’a vr'n'anner to provide;
sufficient strength: to resist; forces incident to‘- normal ham-‘>
method for producing a ?brous structure loaded with
microscopic bubbles and to employ ultrasonic and super
dling'and‘hse: The desirable properties“ of-the glass still‘
35 remain: inf‘that" the' structure issubstantially incapable of 5
sonic vibration in the manufacture of same.
These and other objects and advantages ofthis inven
combustion, it'pis able toresist temperatures in excess of.’
1000° F.,‘it_has high strength, is‘rot-proof, vermin-proof;
tion will hereinafter appear and for purposes of illustra
tion, but not of limitation, embodiments of this invention
are shown in the accompanying drawings, in which—
FIGURE 1 is a schematic view of one system for manu
and substantially inert‘, and is admirably‘ adapted for use:
40
facturing ?brous structures embodying features of this
invention;
as sound insulation‘,: heat insulation; resinous reinforce-~
ment, coated fabrics," textile fabrics, and the like. The:
desirable properties of the-small amount}, of binder ?bers
are clearly evident in that the ?bers'in-th‘est'ructure cling:
,
FIGURE 2 is a schematic view of another process for
to each other strongly.
_
The reasons why such small amount of binder ?bers‘~
FIGURE 3 is a schematic view of another set-up for 45 are able to impart the desired results‘ have not yet been.
carrying out this invention;
7
nique which may be used in the practice of this invention;
fully developed. It appears, however, upon- examina-‘
tion, that the glass ?ber surfaces become" covered subr
stantially throughout with the felt binding ?bers and be
FIGURE 5 is a schematic view of apparatus for manu
come so well integrated with the glass ?ber surfaces‘ as to=
carrying out this invention;
FIGURE 4 is a schematic View of a still further tech
facturing bubble ?lled ?brous products embodying fea
tures of this invention;
.
FEGURE 6 is a schematic View of a technique for man
ufacturing tubing embodying concepts of this invention;
FIGURE 7 is a further view showing a step in the man
manufacture of tubing, and
appear as a part thereof and impart felt bonding charace
teristics thereto.
The forces by which the binder pulp ?bers integrate with‘
the glass ?ber surfaces appear to be greater than that.
which results from merely felting out the pulp ?bers onto
the glass ?ber surfaces. In addition, the coverage of the’:
FIGURE 8 is a schematic sectional view of apparatus
glass ?ber surfaces with what appears almost as a mono-
for the manufacture of gaseous?lled ?brous products
embodying features of this invention.
molecular layer of the pulp ?bers substantiates the concept:
that the pulp ?bers, such as kraft ?bers, carry a negative
As used herein, the term “binder ?bers” relates to
charge (anionic), while portions of the glass ?ber sur-'
?bers having large numbers of fuzzy ends, hairs or ?exible
?ngers extending from the sides which cause the ?bers
vfaces remain positively charged (cationic), whereby a type
to cling to each other and interlock upon contact, es
pecially after being felted from a highly dispersed condi
tion and then dried.
Characteristics such as these are
exhibited by natural ?bers such as cellulosic ?bers derived
from wood, paper pulp, cotton, corn stalks, sisal, hemp
and the like, and from inorganic ?bers such as asbestos
?bers of the type amosite, chrysotile and materials of
the type Paligorskite, commonly known as “mountain
leather.”
Use as a binder ?ber may also be made of
of ionic bond forms between the kraft and glass ?bers—-~
the like charges in the kraft pulp ?bers causing the ?bersv
to repel each other in aqueous ‘dispersion and to be
strongly attracted to the glass ?ber surfaces until the
charges thereon are substantially completely satis?ed upon
deposition of a layer of binder ?bers thereon. Thus phys
ical-chemical forces are involved in the original orienta—
tion of the colloidal pulp ?bers with the glass ?ber surfaces to the end that the glass ?bers are substantially com
pletely covered with a small amount, compared to the
synthetic ?brous minerals such as rock wool, synthetic
weight of the glass ?bers, of binder pulp ?bers. The glass
asbestos fibers and the like, and even glass under certain '
circumstances which will hereinafter be described. Al
though for many purposes such ?bers may be usable in
terchangeably or in combination with each other for bind 75
?ber so modi?ed is capable of felting in the manner of
the pulp ?bers disposed thereon. This is evidenced by
the fact that a small percentage of colored pulp ?bers,
less than 5 percent by weight of the glass ?bers, are
3,020,189
able to cover the glass ?bers so completely throughout
when deposited from dilute aqueous solution and dried
that the glass ?ber appears to be of the same color
throughout and becomes invisible per se by the naked eye.
For example, when 10 parts of a yellow pulp ?ber was
mixed with 1000 parts of Water and 90 parts by weight of
glass ?ber was mixed with 20,000 parts by weight water
and the two dispersions combined, the ?ne pulp ?bers
E6
asbestos type.
When cellulose type ?bers are used in
amounts set forth, the resulting ?brous structure retains
the high temperature resistance and the ?ame-proo?ng
characteristics of glass ?bers. When asbestos constitutes
the binding medium, the resulting structure is not only
?ame-proof but it is unaifected when exposed to tem
peratures as high as 1200° ‘F., or more. Very desirable
structures can be manufactured with pulp binder ?bers '
present in amounts ranging as high as 30 percent by
begin to bond and felt all over the glass ?ber surfaces to
impart to them the same color and the characteristics of 10 weight, but further amounts of pulp ?ber seemingly have
a deleterious effect upon the strength, heat resistance, and
the felt binder ?bers. These pulp ?bers arrange them
electrical insulation characteristics of the resulting ?brous
selves all around the glass ?bers and thereby enable the
structure.
glass ?bers so coated to felt together into a ?brous struc
For example, 5 percent of highly pulped kraft ?ber
ture of high mass integrity.
For best operation, it is desirable to so thinly disperse 15 (about 1-10 microns) is just as effective as a binder in
the manufacture of a ?brous structure as 8 percent of
the pulp binder ?bers in the aqueous medium that they
are able freely to move about and ?oat away from each
such ?bers which have not been pulped to as great an
other. The separation of the pulp ?bers is encouraged by
extent (about %4 inch). The dif?culty encountered with
the ionic forces which cause them to repel each other while
the use of highly pulped ?bers resides in the “freeness”
of the form ?ber structure. This relates to the ability
binding with the glass ?ber surfaces is encouraged through
out by the attraction‘that exists between unlike charges.
It appears that upon drying, some shrinkage occurs
as the pulp ?bers form into a porous interfelted network
rapidly to remove the aqueous medium from the mass
formed upon separation of the ?bers from suspension.
When the binder ?bers are used in the amounts de
scribed, freeness or elimination of the water from the
about the glass ?bers, whereby the pulp ?bers retreat in
part to the glass ?ber intersections. Thus the dried pulp 25 deposited ?brous structures does not present a problem
because it is possible to suck hot air through the deposited
?bers concentrate at the glass ?ber intersections where
they are more ably adapted to achieve their interbonding
function. It appears further that the highly dispersed net
work of pulp ?bers lose their colloidal properties and
?brous structure so that drying can be effected in rela
tively short time. In this manner moisture can be elimi
nated and the product dried in a matter of 5~15 minutes.
Particular importance is attributed to the fact that the
shrink to an open but tangled mass completely interlocked 30
longer and comparatively coarser glass ?bers maintain
with the glass ?bers. At the same time, the network of
sul?cient spacing in the ?brous mass to permit the major
glass ?bers keep the ?brous structure from shrinking to
portion of the free water to drain while leaving an open
a higher bulk density in the absence of compression. The
structure through which air can be drawn to accelerate
pulp ?bers integrated all around the glass ?ber surfaces
and especially at the glass ?ber intersections operate not 35 evaporation of the remaining water. The air can be
heated further to reduce the drying time. By way of
only to tie the glass ?bers together but also maintain a
comparison, when clay binder systems are used, the
desired spaced relation between them. In this way the
highly gelatinous character of the clays causes the ?brous
abrasive effect, such a mutual abrasion, is greatly reduced
to make the felted fabric particularly useful in the textile
art.
structure to become completely plugged so that internal
40 ventilation is substantially impossible.
This is true with
Microscopic examination reveals the presence of pulp
clay contents even as low as 8 to 10 percent by weight.
?ber nests at the points of intersection between glass ?bers
in the end product. These concentrations at glass‘ ?ber
intersections may result, in part, from the reactions de
As will hereinafter be described, clay may be incorporated
as an ingredient in ?brous structures embodying features
of this invention, primarily for the purpose of improving
scribed above, but the amount indicates a further settling 45 flame-proofness, but in that event, the predominance of
as by felting, ?ltration or merely settling out at points
I of glass ?ber contact Where the presence of such high con
the glass and pulp ?bers still provides for an open
structure.
centrations greatly bene?t the characteristics of the ?nal
Excellent results are secured by the use of pulped
product. They not only provide greater bond Where it
Will be most effective, but they function as spacers more
newsprint as the binding medium because the lignin,
the natural binder in the cellulose product, remains and
fully to separate the ?bers in the fabric and protect the
is able to function as a binding agent, especially after
heating. ‘When kraft pulp ?bers are used from which
lignin has been removed, improved results are secured if
the lignin is later replaced by incorporating with the na
ture.
tural cellulose binder in the aqueous slurry or by in
Though mass integrity flows from the practice of the in
corporating the lignin in the formed ?brous structure. It
vention as described, it has also been found that a small
appears that the lignin incorporated in this manner con
amount of resin may be used in addition greatly to increase
centrates at the ?ber intersections where it is better able
the strength far beyond that which results from the use of
to function for the purposes for which it is intended. It
an equivalent amount of resin in ordinary glass ?ber or
will be understood that when other pulp ?bers of the type
felted ?brous structures.
60
described are embodied as the binding material, lignin as
The length of the glass ?ber is not controlling except
well as other resinous material may be used to improve
for the understanding that strength generally is in propor
the strength properties of the ?ber structure, as herein
tion to length and, as previously pointed out, highest
after will be described.
strength results from the use of glass ?bers which vary
The following examples are illustrative of typical
in length from very short to fairly long. it is best if 65
formulations embodying concepts of the invention so far
the pulp binder ?bers are reduced to the smallest length
described:
possible. Lengths less than big inch may be used but the
amount that is necessary is directly proportional to length.
Example 1
Similarly, equivalent strength results from the use of
less pulp ?ber which has been more ?nely pulped.
70 0.12 pound kraft pulp (6% ?ber in aqueous medium)
It has been found sufficient if the amount of pulp or
4 pounds White wool glass ?ber
binder ?bers present in the ?brous structure constitutes
132 pounds water
as little as 3 percent by weight, but best results are
secured when used in amounts ranging from 5-15 percent
This formulation results in the manufacture of a ?brous
structure having about 3.3 percent pulp ?ber and 96.7
pulp ?bers of the cellulose type or 15-25 percent of the
?bers from destruction by mutual abrasion. This, in part,
is responsible for the greater flexibility of the ?brous struc
3,020,189
‘F
5;’;
percent glass ?ber. The ?brous structure has excellent
may be dried in about one hour.
strength, especially in the lengthwise direction, and is able
air is drawn through the board, drying may be completed
to serve as a structural board when compressed sufficiently,
as will be described.
in as little as ten minutes.
Example 7
01
Example 2
However, if the hot
In another method, shown in FIGURE 2, a formula
tion such as that given in Example 4, may be used. In
this process, glass ?bers 3% are fed directly from a ?ber
forming unit into a mixing tank 31 having an inlet 32
through which the slurry of pulp ?bers is admitted. The
materials are kept under constant agitation by a suitable
mixer and the over?ow 33 spills onto a foraminous mem
Parts by Percent by
Weight Weight of
Solids
ber, such as an endless screen or belt 34 which separates
out the ?bers on the surface thereof to form their de
sired felted sheet 35 while permitting the water 36 to
drain therethrough. The drainage of the water may be
assisted by a suction box 37 located below the binder,
whereby a greater proportion of the water is withdrawn
from the felted mass. Without suction, water in equal
proportion to ?ber may remain, but with suction, the
Example 3
10 parts by weight asbestos pulp waste
50 parts by Weight glass ?ber
Water in amount to make up 2% concentration of ?ber
in the dispersion
moisture content may be reduced to 50—75 percent of the
Example 4
?ber.
10 parts by weight Paligorskite
40 parts by weight glass wool ?bers
ing members, as previously describedin connection with
Water to make up about 0.3% dispersion
25 the foregoing example, or it may be fed directly into the
drying oven maintained at a temperature in the range of
Example 5
300-1000" F., since organic constituents are absent.
Partsby Percent by
Weight
Weight or
Solids
Kraft pulp __________________________________ __
L~ nin ______________________________ __
‘
The formed ?ber structure may be densi?ed by co-act
l0
6. 2
___
4
2.4
-
150
91.4
W titer _______________________________________ . _
50, 000
__________ __
The product secured by the practice of this phase of
strength even when the
the invention has ‘relatively high
30 interlocking ?brous material is
small as 15 percent by weight.
support combustion and it is not
present in amounts as
The structure does not
changed by exposure to
temperatures as high as 1250” F.
Example 8
In a still further modi?cation illustrated in FlGURE 3,
?nely powdered binder ?bers of the asbestos or cellulose
The systems which will now be described illustrate
type may be fed in desired concentration through conduit
various inventive concepts which may be used to manu
4i} and blown by propeller ill into the path of staple
facture ?brous structures with formulations of the type 40 glass ?bers 42 which are rained down from above. The
described.
glass ?bers may be fed directly from the glass forming
Example 6
unit 43 and may be joined by the pulp ?bers 44 in a
conventional forming hood. It is desirable thoroughly to
As shown in FIGURE 1, kraft ?bers or newsprint of
wet the ?bers in association in order to enable the afore
the type employed in Examples 1 and 2, may be reduced
mentioned ionic forces to have e?ect for full orientation.
to small dimension in the shredder it}: The shredded
Such moisture may be incorporated vinto the forming
?bers are fed into adigester 11 in advance of their being
100.0
35
hood as a spray from nozzle 47, or else the deposited dry
?brous structure may be flow coated or fully submerged
in a water bath. The mixture of ?bers is deposited in
fed into a pulper 12 by which the ?bers are further re
duced in dimension and are formed into a slurry with
water admitted through inlet 13. The slurry is advanced
felting arrangement on a conveyor belt such as a member
by pump 14 to a mixing tank 15 into which the glass
45, through which the water drains. In the event that
greater densi?cation is desired, the layer may be fed
?bers are fed in the desired proportion along with addi
tional water and steam for the purpose of creating suf
through compacting rollers or the'like while drying.
?cient agitation for mixing purposes. From the mixing
tanks 15, the suspension of pulp ?bers and glass ?bers
In a system of the type described, binder resins or ad
hesives may be sprayed into the forming hood for ad
may be fed into a head box 16 in advance of an Oliver
type rotary ?lter 17 which separates ?bers on a peripheral
surface to form a felted sheet 18 which may be contin
mixture With the ?brous materials in the event that greater
strength is desired in the ?brous structure. Such ‘binder
materials may be activated under heat and pressure after
formation of the ?brous structure, that is, during drying
or in a separate molding step. Instead of incorporating
hinder or adhesives at this stage of the forming process,
uously stripped therefrom as the water is drained through
the wall and into a suction boX.
The formed sheet 18 may be passed directly through
a drying area for the purpose of eliminating the remain
ing moisture, but when it is desired to form board or
they may be subsequently applied, as, for example, by
spraying onto the collecting ?bers while or after they are
separated on the screening wall.
Still greater ?ber orientation and other improvements
sheet stock of relatively high density, it is best to pass
the formed ?brous layer between cooperating endless
belts l9 and 2% which, in cooperation with rollers 21
and 22, compress the layers therebetween before or dur
are secured when the binder ?bers are injected as a
slurry sprayed onto the ?bers in the forming hood. in
the event that such technique is employed, binders, if
ing the drying process. Upon leaving the compression
area, the board 23 is advanced along rollers 24 or other
any, may likewise be incorporated in solvent or aqueous
conveying means through a drying oven 25 for the pur
70 medium in the forming hood or onto the collecting layer
pose of driving off more of the remaining moisture.
Drying may be carried out quite rapidly at tempera
tures between 25910 and 450° F., depending upon the
type of circulation therein and the thickness and density
of the ?ber structure. When the air is merely circulated
about a board one~half to three-quarters inch thick, it
of ?bers.
'
Example 9
A still further method which may be used in the prac
75
tice of this invention is schematically illustrated in
8,020,189
9
10
at temperatures as high as 1400” F. Color of a prominent
character may be embodied in the formed ?brous struc
FIGURE 4 of the drawing. In this system, the desired
amount of glass wool With or without binder or size is
fed continuously as a felted web ‘50 along a conveyor 51
into a tank 52 containing a slurry 53 of the pulp ?bers
in the ratio described. The slurry is kept under constant
agitation in the tank so as to keep the pulp?bers in uni~
ture by judicial selection of metal oxides; such color sys
tems are especially desirable because of their permanent
character and the ability to gain uniform distribution of
the coloring particles throughout the ?brous mass so that
depth of color and color intensity can be achieved.
One of the di?iculties encountered in the manufacture
of ?brous structures of the type described resides in the
inability always to maintain a uniform dispersion of the
pulp and glass ?bers. Settling out or nonuniform dis
form distribution by recirculating the slurry from the
underside of the tank through conduits 54 and 56 to re
admit the slurry with any makeup admitted from reser
voir 55 through the inlet 56 in the upper region of the
tank. Such circulation generated by pump ‘57 also causes
tribution tends to take place, especially when cellulosic
the slurry to pass through the layer of wool ?bers as they
and glass ?ber mixtures are used. It has been found that
are submerged by rollers 58 and carried lengthwise
the stability of the dispersion may be greatly increased
through the tank along an endless conveyor 59. Such
forced circulation of the slurry through the web of glass 15 by the addition of ?nely-divided loading agents, espe
cially the clay or earth minerals. These tend to aid the
?bers insures the in?ltration of the pulp into the innermost
dispersion and cause better distribution of the materials in
regions of the ?brous layer so as to enable the pulp ?bers
the separated ?brous layer. When the pulp ?bers are to
to become fully oriented and cover the glass ?ber sur
be added into already formed glass ?ber layers or ?brous
faces and concentrate at the intersections for better bind
structures of the type described, the presence of such in
ing purposes. In the treatment of white wool ?bers, such
as this, it is best to make use of dispersing agents such
as will hereinafter be described to enhance penetration
and minimize ?ltering out the pulp ?ber on the wool
mass. It is still better to make use of materials which
20
organic dispersion agents permits fuller penetration with
minimum separation on the surface of the felted struc~
ture. For this purpose, from 1 to 5 percent dispersing
agent is satisfactory, but more may be used since the en
tire quantity may also serve as a bulking or loading agent
increase the penetrating characteristics of the slurry, such, 25
as described. As a loading or bulking agent, up to 30
for example, as the ?oc'culating agents or like substances
or 40 percent ?nds bene?cial use, especially with organic
which seem to eliminate, temporarily, the ?brous nature
of the pulp ?bers united de?occulated, as will also ‘be de
scribed hereinafter.
Excess slurry and water is expressed between squeeze
rolls 60 and 61 as the ?brous mass is carried out of
binder ?bers to reduce their combustibility and to increase
density.
it has also been found that organic-inorganic com
pounds which may be formed of these inorganic loading
materials function in a manner to improve the dispersion
and distribution of particles while in the wet stage and
formed may be advanced to compressing means for densi
are thereafter able to function as a binding agent for
?cation or else may be advanced directly to a drying
the
glass ?bers after the felted mass has been formed.
oven or other processing elements.
35 An example of this concept is in the use of amino ben
vIt has been found that intaglio and raised designs may
the tank by the conveyor 59. The ?brous layer 62 thus
be permanently formed in the ?ber structure by ‘deposit
ing the ?bers or by compressing the ?brous layer during
tonites. In its natural form, the amine bentonite, prefer
ably in amounts up to 10 percent by weight, functions
drying on a correspondingly contoured surface. Instead,
the ?brous structure may be formed ‘between plates to
upon drying. Materials of this type might also function
have such raised ‘or grooveddesigns so long as about
1-3 percent free moisture remains in the ?nal product.
Other shapes may also be ‘formed as an incidence to the
manufacture of the ?brous structure or afterwards so
long as the desired amount of moisture is present. For
example, compressed boards may be formed with grooves
as a dispersing agent in aqueous system and as a binder
as a binding agent when the organic group is driven off,
leaving nascent bentonite particles integrated with the
glass ?ber composition. Such systems are used to ad
vantage with either asbestos or cellulosic pulp ?bers.
Although stresses suf?cient to maintain considerable
weight are secured in ?brous structures of the type de
scribed, it is often desirable to achieve still greater mass
integrity and strength, especially in the direction which
in one end and tongues in the other which inter?t to
establish a desired relation.
is crosswise of the direction in which most of the ?bers
It has also been found that the density of the formed
?brous structure can be increased when desired or the 50 are oriented upon separation from aqueous suspension
upon a moving belt. For this purpose, additions are
incom‘bustibility and heat resistance of the ?bers structure
made of suitable resinous binder incorporated with the
may be improved, or both characteristics may be achieved
?bers in the slurry or after the ?bers have been de
at the same time by the introduction of colloidal or ?nely
posited. If the resinous materials are incapable of ad
divided inorganic substances into the bonded ?brous struc
ture. Such inorganic loading agents may be formulated 55 hesion in the manner incorporated, such as when they
are applied as solid particles in the dispersing phase,
as a constituent of the ?brous suspension for use in the
‘bonding
characteristics may be developed by subsequent
formation of the ?brous layer, or they may be sepa
heat treatments, such as in the drying operation or by a
rately introduced later. v1For such purposes, use may be
‘special treatment between heated members.
made of inorganic loading agents such as phosphate clays,
china clay, bentonite, colloidal metallic oxides, expanded 60 The binder particles preferentially become lodged with-7
in the nests formed of the pulp ?bers at the glass ?ber
perlite, exfoliated vermiculite, diatomaceous earth, ?nely
intersections and over the surface of the ?bers. Such
divided glass ?bers, dicalite, silica and the like. Densities
concentrations in this area‘ and the novel arrangement
in the range of 10 to 30 pounds per cubic foot may be ’
of ?bers already bonded, permits the use of considerably
achieved in the ?brous structure, depending upon the
concentration of the loading agent and the amount of 65 less hinder or enables more effective use of the binder
that is used without detracting from the structure. The
compression of the ?brous layer during drying. Without
pulp ?bers located over the surface of the glass ?bers
a loading agent it is difficult to achieve speci?c gravities
enables substantial coating of the ?bers throughout their
higher than 30 pounds per cubic foot. With the use of
length. Organic binder materials may be used such as
expanded minerals of the type described, reduced com
tures having as much as 10 percent organic pulp binder
thermoplastic'resins of the type polystyrene, polymethyl
methacrylate, and other polycrylates, polyethylene, poly
butylene, rubber hydrochloride, polyvinylchloride, poly
?bers and loaded with inorganic particles of the type de
vinyl-acetate, polyvinylidene chloride and the like; or
scribed are able to withstand extended exposure at ele
thermosetting-resinous materials in an intermediate stage,
bustibility is achieved coupled with reduction in density of
the type desired in insulation materials. Fibrous struc
vated temperatures, with asbestos pulp, exposure may be 75 of polymeric growth such as phenol formaldehyde, urea
11
3,020,189
vl2
formaldehyde, melamine formaldehyde, polyesters, fur
Example 16
furyl alcohol resin and the like; or other binder compo
sitions such as asphalt, tar, pitch, glue, shellac or the al
cohol insoluble residue of the extract of pine wood pitch
(Vinsol), or water-soluble resins such as the A-stage
resins of phenol formaldehyde, urea formaldehyde, mel
amine formaldehyde, or cellulose others and esters such
70 pounds glass ?bers
20 pounds phenol formaldehyde resins
5 pounds Vinsol
5 pounds newspaper pulp
as methylcellulose, carboxymethylcellulose, hydroxyeth
ylcellulose, polyvinyl alcohol, glues and the like.
The product deposited together from aqueous disper
Fibrous structures prepared of glass ?bers in combi
salts, sodium lauryl (sulphates, and other aromatic sul‘
sion has a speci?c gravity of 91/2pounds per cubic foot.
Bene?cial results are derived by the additional use of
.As little as 1 percent by weight resinous binder may 10
dispersing or surface-active agents ‘in the slurry in order
be bene?cially used. It is not desirable to exceed 40 or
to maintain the ?bers in the desired uniform distribution
50 percent by weight under most circumstances, and best
for ?ber formation. Such dispersing agents may be in
use is made when l0—20percent by weight of the resin
the £01m of Wetting agents such as quaternary ammonium
ous material is present in the ?brous structure.
phonates, organic sulphonated others such as dioctyl ester
nation with pulp ?bers of asbestos or ‘cellulose ?nd ere
cellent use as a polishing cloth. :‘When inorganic load
of sodium sulpho succinate, sodium alkyl naphthaline
ing agents are combined, an excellent scouring cloth is
sulphonates, and the like.
produced. If the ?brous structure with or without a load
ally considered dispersing ‘agents- but which in these par
Materials which are not usu
ing agent is further impregnated with wax or the like, its
ticular formulations ?nd exceptional use as dispersing or
use as a polishing or scouring cloth is more markedly
penetrating agents include tannic acids, iron citrates, gum
The following are further examples of compositions
‘of ?brous structures embodying features of this inven
aluminum trichloride, stannic chlorides, and the like.
improved.
tragacanth, pectin or the like, or metal chlorides such as
'tion.v
The latter materials, such ‘as the tannic acids, citrates and
25 metal chlorides, ?nd most bene?cial use in combinations
with asbestos pulp as the binding ?ber. Instead of such
Wetting or in combination therewith, foaming agents may
also be used in the separation of the beaten ?bers. These
Example 10
465 parts by Weight glass wool ?bers (0.1-0.5 inch)
3.0 parts by weight phenol formaldehyde resins
5 parts by weight paper pulp
include such materials as asphalt emulsions and Vinsol,
pine oil, cresols, and the like. In ‘any event, amounts in
the range of 0.1-5.0 percent by Weight of wetting agent
The product deposited from an aqueous dispersion has
a speci?c grvaity of about 20 pounds per cubic foot.
may be used.
‘Concepts of this invention may ‘also be practiced with
glass ?bers which have ‘already been bonded into a ?brous
35 structure with other medium. In that event, the pulp
binder ?bers function as an additional binding agent and
further improve the strength ‘and ?exibility character
13 parts kraft pulp (7% solids)
istics of the product. The d-i?iculty with the after 'in
corporation of the pulp ?bers in bonded glass ?ber struc
The resulting product deposited from a dispersion in
880 gallons of Water has an ignition loss of 19.1 percent 40 tures resides in the uniform distribution of the pulp ?bers
into the interior of the ?brous structure. The pulp ?bers
and a density of 13 pounds per cubic foot.
Example 11
38 parts asphalt
100 parts starch
100 parts glass wool
Example 12
77 pounds glass wool ?ber
20 pounds asbestos
3 pounds paper pulp
45
2 ounces wetting agent
Gen
erally, the viscosity of the slurry may be varied by giv
per cubic foot.
200 pounds glass wool
21 pounds kraft pulp (6%)
unbonded glass ?ber structure, materials having the ability
of reducing the viscosity of the slurry ‘are used.
The structure has a speci?c gravity of about 13 pounds
Example 13
have a tendency to ?lter out onto the surface of the Web
or mass. In order to minimize separation of the pulp
?bers on the outer walls of the glass ?ber structure and
in order to assist penetration thereof into the bonded or
ing consideration to the ionic or acidic nature of the
v50
slurry. For example, if the slurry is applied to the glass
?ber structure within a pH range just below 7, the viscos
tiy is lowered ‘to enhance penetration. It has been found
that such ?bers may be coagulated after penetration has
been achieved by changing the pH to about 7-8.5, such
The ignition loss of the product, deposited from a dis
persion diluted to 750 gallons with water, is 7.1 percent
and the density 20 pounds per cubic foot.
as by the addition or after treatment with solutions of
ethylamine or other amines, sodium phosphate or other
Example 15
the ?ber structure.
It has been found further that in the use of an asbestos
alkaline substances of like nature. Throwing the slurry
further onto the ‘acid side by the addition of stronger
Example 14
acids, such as hydrochloric ‘acid, sulfuric acid, or the
like, will also thicken the slurry and ?occulate the ?ber
70 pounds glass Wool ?ber '
60 in position of use.
15 pounds asbestos
When such ?bers, particularly asbestos ?bers, are in
15 pounds bentonite
corporated in glass ?ber mats bonded with organic res
The product deposited from an aqueous dispersion has
ins, it is possible to expose the structure to elevated tem
a speci?c gravity of about 20 pounds per cubic foot.
peratures to‘ burn out the resinous material and still main
tain a satisfactory bond because of the binder ?bers in
80 pounds glass ?ber
22.5 pounds asbestos
7.5 pounds dry pulp ?ber
Water was added to make up 700 gallons. The ignition
loss of the product deposited from a dispersion of 700
gallons in water was 6.0 percent and the density about
11 pounds-per cubic foot.
slurry, bentonites and other corresponding clay mate
70 rials are able to ‘assist the penetration of the asbestos
into the glass ?ber structure. Upon heating, orientation
between the asbestos and bentonite seems ‘further to im
prove the bonded nature of the inorganic product. By
the use of this technique, bentonite may be incorporated
in amounts ranging ‘from 5-50 percent in the product
3,020,189
13
and the product can be exposed to temperatures as high
as 1200“ F. without change.
Another important concept of this invention resides
14
foraminous member to separate out the ?bers in a felted
layer on the surface while the greater portion of the free
Water passes therethrough. Thereafter, the layer is soaked
for one hour with the ammonia-copper sulphate solution
scribed having particular relation to the use of cellulosic C1 and then the solutions drained off by washing with about
?ve gallons water. The solvation mixture of ammonia
materials as the pulp binder ?ber. Considerable im
in the manufacture of a ?brous structure of the type de
provement in the bonding property of the cellulose ?bers
is derived by the react-ion of the pulp ?bers before or
after they are associated with the glass ?bers in the ?brous
structure in a manner to convert ‘at least a part of such
and copper sulphate is inactivated by application of the
solution formed of concentrated sulphuric acid, sodium
sulphate and zinc sulphate.
The mass may again be
washed with a large amount of water and then dried.
?bers to have resinous quality. For such purpose, the
Example 18
cellulosic pulp ?bers are gelatinized in whole or in part
Materials:
by conversion partially to a composition of the type
(a) 85 grams of bone dry glass wool ?ber are dispersed
which is used in the spinning of rayon and viscose ?ber.
In one system, a felt bonded glass ?ber structure is 15 in four gallons of water.
(b) 15 grams of kraft paper is pulped in 500 grams
formed as previously described and then the wet matted
Water.
?bers are exposed to chemical reagents by which cellu
(c) 2,1000 grams zinc chloride are dissolved in sul?
lose is dissolved or gelatin-ized for rayon manufacture.
cient water to make about one gallon.
1
For example, wetting the ?brous structure with a solu
Procedure: (12) is dispersed in (a). After about 21/2
tion of zinc chloride has the desired effect of gelatiniza 20
gallonsof water have been removed from the mixture of
tion and partial solution of the ‘cellulose ?ber. Copper
(a) and (b), (c) is added and the mixture is allowed
sulphate [and ammonium hydroxide or any ammonium
to stand for about one hour or until the desired degree
ion may also be used as the medium to provide reactions
of gelation of the kraft ?bers has been achieved. At
of the type desired. Carbon disulphide and sodium sul
this point, the water removed in the previous step or an
phate, such as employed in the viscose process, is also
equivalent amount is added and the mixture poured onto
suitable for the partial gelatinization of the cellulosic
a forming screen for separation of the ?brous materials
pulp ?bers. Before all of the cellulose ?bers have gelled
as a layer thereon while the water drains through. The
and after the gelled portions of the ?bers have combined
formed layer is then washed with ?ve or more gallons of
with one another so as to bind the glass ?bers therebe
water followed by draining and drying.
tween, further gelatinization or solution is stopped by re
moval of the chemical reagents, such as by washing out
Example 19
the solvation chemicals or by introducing a coagulated
Materials:
solution, such as dilute sulfuric acid, sodium sulphate so
(a) 2,000 grams of zinc chloride are dissolved in 2
lution, zinc sulphate solution, or the like.
In another system embodying the concepts described,
gallons of water.
(b) Beat 75 grams of cellulose pulp into a uniform dis
the gelatinization or solvation chemicals, such as cupri
persion.
ethylene diamine, or the copper ammonium complex or
(0) Glass ?bers ‘arranged in a porous batt.
zinc chloride solution, is introduced into the cellulose
Procedure: The well ?uffed, bone dry glass wool batt
pulp slurry before introduction of the glass ?bers or be
fore the pulp ?bers are incorporated with the glass ?bers 40 ‘is placed between rigid screen members arranged in a
otherwise deposited. When gelatinization of the pulp
?bers has progressed to the desired degree, deposition of
holder capable of movement in such fashion as to create
a di?erential pressure between the faces. This may be
the ?brous mixture on a foraminous separating wall is
accomplished by a piston type set-up or by change of air
or hydraulic presure on the ?uid head from either side.
carried out as before and the partially gelled cellulosic
(a) and (b) are mixed and allowed to stand from one
materials, which are still ?brous in nature, but resinous 45
to three hours. The mixture is applied onto one side
in their outer surface, deposit with the glass ?bers and
function more effectively to bind the ?bers into an inte
grated mass. The solvation chemicals, if any remain
upon drying, enhance the ?ame-proofness of the ?brous
structure.
By the practice of this system in the manufacture of
bonded ?brous structures, still less pulp ?bers may be
used to achieve equivalent strengths in the end product.
Asbestos pulp ?bers may be employed in admixture with
the glass or cellulose ?bers in the manufacture of the
?brous structure but the asbestos ?bers, like the glass
?bers, are unaffected by the solvation chemicals. By
the practice described, it is possible to retain the ?brous
character of the binding pulp since it is suf?cient if only
of the batt- arranged within the holder. The composition
is worked back and forth through the batt until the par
tially gelatinized cellulose has found its way through the
?brous layer. Thereafter the batt is soaked freely in
water for the purpose of removing by dilution the zinc
salt. A ?brous structure having a high degree of mass in
tegrity and considerable strength is produced upon drying.
‘Increased density may be derived by application of pres
sure for compacting the mass especially during the last
stages of the drying process.
The inventive concept-which will hereinafter be de—
scribed is applicable to ?brous structures wherein asbestos
type ?bers comprise the principal binding medium. It has
the surfaces of the ?bers are gelled before or after the 60 been found that if the aqueous medium in which the
cellulose ?bers are incorporated into the fibrous structure.
asbestos ?bers are dispersed is adjusted by certain acidic
compounds, taken alone or in combination, the ?bers have
Example 1 7
a tendency temporarily to deflocculate so that their ?brous
character is minimized and the dispersion becomes more
100 grams of bone dry glass Wool ?ber (77.2 percent)
is gently stirred into four gallons of water. Beat 22 grams 65 ?uid. When this character has been imparted to the
asbestos pulp ?bers, the dispersion is capable of penetrat
of kraft pulp (17 percent) and 7.5 grams of ?ne glass
ing substantially completely into a ?brous mass without
?ber (5.8 percent) into 100'grarns of water. Combine
?ltration of the asbestos felt ?bers onto the surfaces there’
" 300 grams of ammonia solution (28% NH3) with 100
of. The acidic nature of the dispersion functions at the
grams copper sulphate (CuSO4 5H2O) into 3,000 grams
water. In a fourth mixture, combine 400 grams of con 70 same time to impart another bene?cial effect in that it
makes the glass ?ber surfaces more receptive for the bond
centrated sulphuric acid, 240 grams of sodium sul
ing agent and the acid reacts with the materials on the
' phate (Na2SO4), and 32 grams of Zinc sulphate (ZnSO4)
glass ?ber surface to make available greater surface
in 4,000 grams of water.
area to which the pulp ?bers might integrate; When the
Procedure: Mix the beaten pulp with the dispersion of
glass wool ?bers and pass the dispersion through a 75 slurry is adjusted to a pH which is variedslightly below
3,020,189
16
Example 24
neutral, the ?brous character of asbestos is falsi?ed and
the slurry becomes very ?uid. The pulp ?bers may be
de?occulated or caused to reappear in their natural form
upon increase or decrease of pH by the use of acid or
basic substances or use may be made of other known de
Asbestos (lmicron to 1/32”) ________________ __'__
5
10
Hydrochloric acid solution ___________________ __
1
Water __________ -a ________________________ -_
500
?occulating agents.
Example 25
Compounds capable of de?occulation of the type de
scribed with asbestos pulp ?bers may be selected of or
ganic and inorganic compounds and mixtures thereof, such
as tanning acids and their salts represented by tannic
acid and its salts, citric acid and its salts and the like; metal
Asbestos (chrysotile)____a ___________________ __
10
chlorides, metal sulphates and metal salts represented by
aluminum chloride, magnesium chloride, zinc chloride,
ferrous sulphate, chromium nitrate, chromium chloride,
chromium sulphate, stannic chloride, ‘ferric chloride and
the like; and combinations of such organic acids and their
salts with the inorganic metal salts of the type described.
Further improvement is achieved by the use of alkylol
Ferric chloride ________ ___'_’ __________________ _._
10
l
Chromium nitrate ___________________________ __
0.5
Water _____________________________________ _.
500
The ‘above examples, and particularly Example 20,
may be formulated by beating the materials together for
about ?ve minutes to form an excellent dispersion in
which little, if any, settling takes place. When mixed
with glass ?bers in the desired proportion and dried in a
felted layer, the asbestos pulp ?bers deposit over the glass
amines with one or more of the described organic or in
?ber surfaces and form nests at the ?ber intersections
organic acidic substances. Representative of suitable
alkylolamines are ethanolamine, di-ethanolamine, tri-eth
upon drying to provide an excellent bonding agent.
Applicant has found a number of novel systems which
anolamine and the like.
may be employed in the fabrication of bonded ?ber struc
The concepts described above are particularly well
tures based upon the principles hereinabove described.
adapted for the incorporation of asbestos ?bers into
In a preferred system, the deflocculated pulp ?bers in
bonded glass ?ber products since better penetration to 25 admixture with the desired quantity of glass ?bers are
secure uniform distribution of the asbestos ?bers amongst
coagulated or precipitated by coagulating agents just in
the glass ?bers may be achieved. Separation of the
advance of the separation of the ?bers in a separating
asbestos onto the glass ?ber surfaces may be effected by
wall. In this manner excellent distribution of the pulp
the techniques previously described or by providing the
and glass ?bers is secured throughout to provide a uni
bonded glass ?ber surfaces with a dry coagulating agent
forrnly bonded ?brous structure. Very little, if any,
or by de?occulating the asbestos slurry after full pene
?ber passes through and that which does may be returned
tration has been achieved. If desired, such further addi
to the process by reuse of the water or by recirculation.
tions of pulp ?bers may be achieved in ?brous structures
When so deposited very little, if any, ?ber is thereafter re
which have already been formed in accordance with the
moved by subsequent applications of Wash Water.
concepts of this invention earlier described. In this man
IIn a desirable system, glass ?bers may be ?rst deposited
. net the amount of pulp ?bers might be increased for the
in a layer with a coagulating chemical dried on the sur
purpose of improving the bonding relation.
By way of further modi?cation, resins such as poly
?bers has passed through the glass ?ber layer and the
faces thereof. When the dispersion of reacted asbestos
vinylidene chloride, phenol formaldehyde, polyvinyl chlo
asbestos contacts the wetted glass ?ber surfaces, the as
ride and the like resins which are unaffected by the acids 40 bestos ?bers are coagulated immediately and attach them
selves ?rmly to the glass ?ber surfaces.
may be incorporated with the slurryof reduced viscosity.
Fibrous structures of the type produced by the con
When resinous materials of the type described are in
corporated, they may be activated at elevated tempera
cepts just described, composed almost entirely of in
organic materials, are capable of withstanding tempera
tures, such as by ironing the ?brousrstructure between
heated rolls or upon drying and-baking at temperatures 45 tures as high'as 1200“ ‘F. and remain unchanged under
in the range‘of 300°—500° F.
direct ?ame.
It is well known that maximum separation between
Speci?c examples of various formulations embodying
‘glass ?bers is desired to achieve greatest utility of the
this phase of the invention are as follows:
Example 20
glass ?ber structure.
- Calcium aluminate __________________________ __
?ber separation of the type described by the use of large
5
.
Asbestos (chrysotile) ________________________ __
10
'
Tannic acid ________________________________ __
0.2
'
Water ____________________________________ __
500
amounts of resinous material or by the use .of large
amounts of loading agents, alone or in combination with
55 the resinous materials.
The use of high concentrations and proportions of
resinous materials is undesirable because of the high cost
of such materials and because of the stiffness and in
Example 21
Asbestos (amosite) _________________________ __
Aluminum sulphate _________________________ __
Magnesium chloride ________________________ __
Tannic acid ________________________________ __
Water
____________________________________ __
5
1
0.2
Asbestos (chrysotile) ________________________ -s
’
?exibility which such resinous materials naturally impart
60 to the ?brous structure.
0.0
10
_______ __c ___________________ __
0.4
Tannic acid _______ -a _________ _.;_ ___________ __
0.2.
'Water ________ _;___a ______________________ __
500
Loading agents, on the other
hand, detract from many .of the other properties of the
glass ?ber structure when present in high concentration.
500
Example 22
Ethanolamine
This permits high ?exure of the
50 ?ber structure without fearof destruction of the ?bers
by mutual abrasion. It has been the practice to secure
Grams
Applicant has found an entirely new system to achieve
separation between ?bers in the manner accomplished
6,. by the use of large amounts of resin without being handi
capped by high cost or loss of desirable properties of the
?brous structure. The desired separation may be achieved
more satisfactorily by means which cause the develop-v
ment of a large number of bubbles of microscopic size,
,
especially in the regions adjacent the glass ?ber surfaces
or in the bonding agent.
Example 23
Aluminum chloride _________________________ __
1
It is an object here to improve the quality of glass
?ber structures by providing a large number of micro
scopic bubbles in the ?brous structure to reduce the
Water.____._ .......... _..... _______________ __
500
75 speci?c gravity and increase the bulk of the product while
Asbestos (amphobile) _______________________ __
5
3,020,189
18
17
reducing the possibility of abrasion between ?bers by in—
creasing the distance between them. The presence of
such microscopic bubbles between the ?bers increases
the radius of curvature through which the ?ber may bend
under conditions of use, and protects the ?bers so that
force applied at any one point is cushioned and distributed
Example 27
,
Percent
Carbon dioxide equivalent ___________________ __
. Carbowax ' ______________________________ _a_____
40
Gelatin _______________________________ __‘____'_ 35
Colloidal kaolin ___________________________ -_l__ 21
throughout the length of the ?ber and to adjacent ?bers.
A dispersion of the above is incorporated with a slurry
There are a number of techniques which have been de
of newsprint and precipitated with glass ?bers mixed
veloped for accomplishing the desired relation in the
10 therein upon a foraminous belt. The wet ?brous struc
?brous structure.
ture is exposed to vapors of hydrochloric acid which cause
(1) The development of microscopic bubbles in the
the release of carbon dioxide gas in the product. The
binder composition can be accomplished by subjecting
the binder itself to high temperature, electrical or chemi
cal treatment in such manner as to cause the release of
gases from elements therein, or a binder having micro
scopic bubbles already provided therein may be used
for securing the ?bers one to another in the mass.
(2) Microscopic bubbles may be released from chemi
?bers so treated may be dyed or a pigment may be em-‘
ployed as an ingredient with the binder. ‘Instead of kaolin,
15 other additives may be used such as talc, silica, bentonite,
zinc oxide, titanium oxide, decalite, powder glass and the
like.
.
(3) Gases'absorbed or otherwise present in the diluent,
such as dissolved gases in the slurry may be freed to form
cal compounds such as from particles of calcium car
bonate or other gas-forming chemical compound which 20 microscopic bubbles in the formed ?brous structureby
may be incorporated as part of the hinder or as a load
ing agent with the ?bers during formation of the ?brous
structure.
The liberation of gas bubbles may be accom
plished just before ?nal formation of the ?brous structure,
during formation or subsequent to its formation. Libera
tion of the microscopic gas bubbles in position of use
may be accomplished upon exposure of the chemical com~
pound to acidic medium, by heating to relatively high
temperature in the range of 5GO°-1200° F. for a short
time, or‘by ultrasonic or'supersonic vibration.
For example, when the chemical compound is in posi~
tion of use, the structure may be exposed to acid-forming
gases such as vapors of hydrochloric acid or the like.
heat treatment or by ultrasonic vibration. For’this purf
pose it is possible to dissolve gases in the slurry which are
highly soluble therein under normal conditions or under
positive pressure. Representative are ammonia, carbon
25 dioxide, sulphur dioxide and the like. 'Usually tempera
' tures in excess of 400° F. are best for releasing the gases
in situ on the glass ?ber surfaces where they may be en
trapped with the binder composition. Release of gases
in position of use may be further aided by subjecting the
30 ?brous structure to reduced atmosphere. I
(4) Gases may be caused to be adsorbed in large quan
tity on the surface of certain substances incorporated or
forming a part of the bonding agent and these may be
released in position of use by thermal treatment or by
Instead, it may be ‘incorporated with acid-forming com;
,
pounds such as the metalchlorides of the type aluminum 35. supersonic or ultrasonic vibration.
chloride, iron chloride, tinv chloride and the like, the
acid being formed upon ionization in vapor or water to
cause the release of gases in position of use. The use of
water vapor is best because the gases then do not have a
chance of being washed from the ?brous structure or to
dissolve in the aqueous medium. The use of such acidic
Ingredients capable of having gases dissolved thereon
for release in the ?brous structure and which may them
selves ?nd desirable use in the structure include the
loading agents in colloidal form represented by talc,
silica, kaolin, bentonite, titanium oxide, diatomaceous
earth, wood ?our, powdered glass ?ber and they like.
These may be dispersed in the slurry of pulp ?bers as
earlier described. The liberated gases cause foaming of
the resinous materials if employed, or else remain en'
sistant to the acidic media or exposed thereto for only
trapped with the pulp ?bers which serve as a bonding
45
short duration.
.
substances here and in other systems described should be
restricted to treatments wherein the glass ?bers are re
In carbonate systems and the like employing acidic
medium for the liberation of gases, additional resinous
and many substances may be used as part of the binding
agent, such as carbowax, polyethylene, polystyrene, poly
agent ‘and cause the desired separation and spacing be
tween the glass ?bers at their intersections.
'
'(5) The binding agent may be formulated with a plas
ticizer or diluent which is not removed under normal
vinylidene chloride, gelatin and the like. Materials such 50 treatment for drying the formed ?brous mass. However,
as these are una?ected by acids but will allow the acids‘
to soak through and react with the carbonates to liberate
carbon dioxide within the binder system. The calcium
oxide or other by-product which remains will serve merely
as additional bulking agent.
I
'
upon subsequent treatment under more rigid conditions
the lower boiling diluent or plasticizer may be released as
vapor which forms as small bubbles which may be en
trapped in the ?brous structure to cause the desired sepa
55 ration of ?bers. Treatment to release the vapor may be
When acid-forming salts are used in the binder agent . in the form of high temperature insu?icient to decompose
the binder but su?icient to volatilize the lower boiling plas
or mixed salts which form acid upon ionization, it is
ticizer or solvent. Ultrasonic or supersonic vibration may
possible merely to soak the ?brous structure in aqueous
also be used.
'
medium and allow the moisture to permeate into the
(6) Highly porous additives may be incorporated with
fabric and cause the release of gases by reaction of the 60
the ?brous materials in forming the ?brous structure.
chemical compound.
.
Such additives include expanded perlite and exfoliated
vermiculite. These mineral substances bene?cially aifect
the ?brous structure but their incorporation in uniform
About 3 parts by weight calcium carbonate is milled 65 distribution has been di?icult to achieve because of their
low speci?c gravity, as will hereinafter be pointed out.
into a binderlformed of 10 parts by weight gelatin and
When temperature is employed for the purpose of lib
20 parts by weight Carbowax. The binder is formed into
erating the gaseous medium to form bubbles, it is possible
a dispersion which may be incorporated into a slurry of
in structures of the type described to employ tempera
pulp binder ?bers or used alone to form the binding agent
in the formation of a glass ?ber structure. After the 70 tures in excess of 1000” F. whereby gaseous liberation can
be achieved at a desirable rapid rate. Temperatures
?brous structure has ‘dried, the ?brous structure maybe
Example '26
treated with an acid solution which permeates into the
binder and evolves carbon dioxide as small microscopic
bubbles that remain entrapped within the binder or ?brous
structure.
'
such as these cannot be used in the organic systems here'-'
tofore employed.
_
'
‘
In a new and novel system microscopic air bubbles may
75 be incorporated directly into the ?brous structure in form~
3,020,189
19
,
ing. As illustrated in FIGURE 5, water 75} is recirculated
through tank '71 from an inlet pipe 72 at the front end to
an outlet 73 at the opposite end. Glass wool ?bers ‘74
and the binder pulp 75 are fed into the tank at the front
. 20.
to rise to the surface as rapidly as the expanded perlite"
or vermiculite. The ?brous materials may become uni
formly mixed with such expanded materials at the surface’
so that they may be led off together as a continuous ?
end. 'The ?bers naturally fall en masse towards the
brous layer from the surface of the tank for subsequent
bottom of the tank. Just before the ?bers reach the
bottom, very ?ne air bubbles '76 are introduced from the
layer.
underside by injection of air under high pressure through
treatment as by compression or drying to form a ?brous
'
‘ Applicant has foundthat the concepts of ultrasonic or
amicroporous screen 77 located in the bottom wall 78
supersonic vibration may be advantageously employed in
of the tank.
10 the various concepts of this invention. For example, the
As the bubbles 76 rise up into the ?brous mixture, such
possible variations of vibrations from a high rate to a
agitation is maintained by mixers 28 and the rising bubbles
relatively low rate in' the supersonic or ultrasonic range
as will cause the bubbles to become entrapped in the
may have the effect in one instance of de?occulating the
pulp ?bers in the manner achieved by the use of metal
?brous mass. The buoyancy added by the bubbles will
cause the ?rous mass to rise to the surface where it can 15 chlorides and tannic acids with asbestos or by the use
be picked up by a conveyor belt '79 which lifts the
of metal chlorides and pulp ?bers.
?bers as a felted layer Sit out of the tank and over a
the ?bers are about to settle upon the separating screen,
the supersonic effect may be changed to cause de?occula
tion of the ?brous materials so that they settle out to
suction box or drying equipment or both, as previously
At the point where
described.
Instead of introducing the microscopic air bubbles 20 gether in the desired arrangement with the glass ?bers in
through a screen, it may be more practical to embody
a ?otation system wherein microscopic air bubbles are
introduced into the lower portion of the tank 31 inter
the formation of desired ?brous structures.
‘
The supersonic or ultrasonic vibration principles may
also be employed in the techniques for liberating gas bub
bles during fabric formation so that the bubbles will re
mediate its ends by formation and actuation of a paddle
Wheel located along side the tank, see FIGURE 8. Air 25 main and separate the ?bers one from another. Bubble
separation may be achieved by supersonic vibration of
is pumped through an annular opening 82 about the driv
the aqueous medium in which gases have been absorbed
ing shaft 83 and broken down into a froth or bubbles by
in high concentration or from the surfaces of the particles
reaction with the turning blades 84 of the wheel. The
in which such gases have been absorbed. Supersonic
shaft is driven by a pulley 85 connected to a driving
vibration may also be employed in the carbonate system
motor 86 by a belt 87. The froth or microscopic bubbles
either to impart acidic environment to the ?ber-forming
seem to attach themselves onto the ?bers 88 introduced
into the tank as described in connection with FIGURE 5
whereby the pulp and glass ?bers rise as a formed ?brous
structure with the ?bers in the desired arrangement where
they are continuously removed as a formed web‘ for fur 35
ther processing.
The concepts of mineral ?otation are particularly well
adapted in the practice of this phase of the invention, espee
ciaHy when it is desired to manufacture a ?brous struc
ture of low density. Depending upon the particular com
position of the dispersed ?bers, frothers, promoters, de
pressants, activators, sulphidizers and regulators may be
employed as in ?otation systems. The sulphidizer, such
composition whereby carbon dioxide is liberated from the
corresponding carbonate or else supersonic vibration may
be employed to provide high temperature which causes
carbon} dioxide and like gases to- be released from
chemical compositions in which they form a part. The
possibility of causing heat to be generated by supersonic
vibration might also be adapted for the formation of
vapors by vaporization of solvent or aqueous medium
associated with the mat of the glass ?ber structure.
I have found that the concepts of this invention may
be employed in a new and novel method for manufactur
ing pipe covering or like insulation products. As ‘shown
in FIGURES 6 and 7, pipe covering may be prepared by
as phosphorus pentasulphide, sodium sul?de and the Xan
thates, function to provide a sulphide coating on the oxide 45 lowering a foraminous mandrel 90 into a tank 91 com
taining a dispersion 92 of glass ?bers and pulp ?bers
surfaces of the glass ?bers to render them more recep
of the type described. The mandrel is supported from
tive to attachment of bubbles. The collectors and pro
cover 93. One end is ?tted with a block connected for
moters, such as alkaline metal salts, function to collect
imparting rotational movement while the other end has
intov aggregates the ?bers and attach the ?bers to the
bubble. The frothing agent, such as pine oil, higher alco
hols, coal tar creosotes and the like,- lowers the surface
tension of the liquid and supplies the bubble essential
for attachment and rise of the ?bers. The regulator, which
is an alkaline substance such as lime, or an acid such as
‘sulphuric acid, operates to adjust the hydrogen ion con
centration to that which is most suitable for the process.
Without squeezing, ?brous products having densities
. a coupling 94 connected through an adapter 95 to suction
'means so ‘as to enable the suction throughout the length
of the mandrel while being rotated. A felted layer of
glass and pulp ?bers form on the outer wall of the man
drel while the water is sucked there through to provide
a well integrated ?brous structure capable of sufficient
mass integrity and strength independent of any additions
of binder which might be made.
When the desired build up of felted ?bers hasbeen
lower than ?ve pounds per cubic foot may be produced.
achieved on the outer wall of the mandrel, it may be
It appears that the pulp ?bers of asbestos or cellulose,
when used, orient themselves about the surfaces of the 60 removed with its cover from the ?ber dispersion and the
?brous structure 96 stripped from the mandrel. Re
bubbles-with the result that a structure having greatly
moval may be e?ected before drying but it is best to
improved characteristics is secured.
accomplish this after drying since the dried product main
More important is a system which makes possible the
tains substantially permanent shape, and hot air can be
incorporation'of expanded inorganic minerals of the type
drawn through the structure while it is on the mandrel to
perlite and vermiculite as loading agents in ?brous struc
accelerate drying as‘ has been previously pointed out.
tures of the type described. Although it is possible to
When dried, sufficient shrinkage takes place to enable the
mix expanded perlite in glass ?ber mixtures having little
formed ?brous tube to be stripped endwise from the
Water, the uniform incorporation of such expanded min
mandrel. It is preferred, however, to wrap the'for‘med
erals with glass ?bers has been di?icult to achieve in a
?brous layer with a piece of cloth and then cut through
highly diluted water system because such minerals natu
the layer lengthwise to enable the ?brous structure to ‘be
rally flow to the surface whereas the ?brous materials gen
opened and stripped from the mandrel or the formed
erally separate and flow towards the bottom of the aqueous
?brous tube may be cut into semi-circular sections, as
system. By the use of the foaming agents such as the
shown in FIGURE 7, to enable removal.
injection of air in the manner ‘described through the
It has been found that under certain circumstances,
bottom- wall of the tank, the ?brous mass may be caused
glass ?bers may be made to function in a manner some
3,020,189
21
22
>
what similar to the asbestos or cellulose pulp ?bers for
bonding other longer glass ?bers into a ?brous structure. ’
to enhance ionic attraction between the pulp ?bers and
Glass ?bers ground so ?ne as to appear as a powder
2. The method of manufacturing a ?brous structure,
comprising raining glass ?bers down from above onto a
collecting wall, spraying a binder in the form of dry pulp
binder ?bers into the path of the glass ?bers uniformly to
distribute the pulp ?bers therewith before the ?bers de
to the naked eye have been found to still be ?brous in
nature under the electron microscope and when in such
?nely divided form, they have some of the clinging effect
characteristic of the pulp ?bers heretofore described.
Such ?ne glass ?bers appear to have a dimension of about
1 to 10 ten-thousandths of an inch or less. Thus glass
the glass ?ber surfaces.
posit on the collecting wall, spraying dry resinous binder
onto the ?bers before they gather on to the collecting wall,
?bers pulped and ground to ?nely divided form may be 10 and exposing the collected layer of ?bers to resinous acti-' '
vation temperatures whereby the resinous material is
used in the techniques described to bond glass ?bers _of
carried through an adhesive stage.
longer length into ?brous structures. This is considered
3. The method of manufacturing a ?brous structure as
to be an important advance in the technology of glass
claimed in claim 2, which includes the additional step of
?bers and ?brous structures. It makes available for
the ?rst time a complete felted glass ?ber fabric which 15 compressing the ?brous mass while being subjected to the
elevated temperatures for resinous activation.
does not require other substances to impart strength and
4. The method of manufacturing a ?brous structure,
comprising the steps of raining glass ?bers down from
It will be manifest from the description that I have
above onto a collecting wall, spraying a binder in the
provided a number of concepts which may be used in the
manufacture of new and improved ?brous structure, 20 form of a slurry of pulp binder ?bers having an excess
amount of free water into the path of the glass ?bers be
capable of many new’ uses and adapted to function bet
integrity thereto.
ter in many applications already developed for glass ?ber
products. The product of this invention is not subject
to the limitations imposed by the presence of large quan
tities of organic material but may be used successfully in 25
applications wherein the product will be subjected to
temperatures in excess of 500° F. or even where it might
be exposed to direct ?ame. From a practical stand
point, importance resides also in the economy of manu
facture of the types described because ?ber which does 30
not separate to form the structure is not lost but may
be returned with the water to form ?brous suspensions.
The product of this invention is a highly porous prod
uct which has exceptional flexural strength and ?exibility
and may be varied from a board of high density and
strength to a porous insulation product.
It will be understood that numerous changes may
be made in materials, composition and apparatus with
out departing from the spirit of the invention, especially
fore they deposit on the collecting wall, draining the water
from the deposited layer to leave the glass ?bers bonded
in the ?brous structure by the pulp ?bers,’and then drying
the felted layer that is formed. }
References Cited in the ?le of this patent
UNITED STATES PATENTS
2,008,141
McClellan ____________ __ July 16, 1935
2,083,132
Williams et al ________ _r____lune 8, 1937
2,152,901
Manning ________ __. ____ __ Apr. 4, 1939
2,156,308
Schuh _________________ __ May 2, 1939
2,184,316
Plummer __- __________ __ Dec. 26, 1939
2,189,840
Simison et a1 __________ __ Feb. 13, 1940
2,286,968
Landt' ________ -2 ____ __ June 16, 1942
2,300,137
2,312,776
Salisbury __________ __1__ Oct. 27, 1942
Rankin ____________ __'__ Mar. 2, 1943
2,316,998
2,466,906
Smith ________ __' ______ __ Apr. 20, 1943
Miller ____ __- ________ __ Apr. 12, 1949
as de?ned in the following claims.
40
I claim:
1. The method of manufacturing a ?brous structure,
2,581,069
Bertolet _______________ __ Jan. 1, 1952
comprising the steps of raining glass ?bers down from
above onto a collecting wall, spraying dry pulp binder
?bers into the path of the glass ?bers in advance of their 45
deposition upon the collecting wall whereby the ?bers
2,596,364
2,695,855
2,711,381
Brennan _____________ .. May 13, 1952
Stephens -.._> __________ __ Nov. 30, 1954
Novotny et al _________ __ June 21, 1955
2,747,994
Hoopes ____________ __ May 29, 1956
become uniformly mixed and interfelted to form a ?brous
structure in which the pulp ?bers comprise a bonding
agent, and wetting the ?bers with water in liquid form
2,772,157
Cilley et al. ___________'__ Nov, 27 ,1956
2,772,603
2,825,389
Waggoner ____________ __ Dec. 4, 1956
Stephens __-_ _____ __'_____ Mar. 4, 1958
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