Textile fabric and method of preparation

Method and apparatus for treating a textile fabric with a volatile organic solvent and the resulting treated fabric which comprises, in cooperative sequence, pretreating said fabric in a pretreat stage by sequentially preheating to remove volatile materials and then cooling, followed by applying said solvent to the fabric in an application stage and then drying the fabric by evaporation and condensing and recovering the evaporated solvent in a drying and recovery stage, followed by recycling the recovered solvent back to said application stage. The invention has particular utility by providing a method which enables the recycling of the organic solvent from a fabric treating process and, therefore, provides an improved treated fabric.

This invention relates to a method and apparatus for treating a textile 
fabric and the resulting treated fabric. The invention particularly 
relates to providing a vehicular pneumatic tire cord fabric by treating 
with a volatile organic solvent and recycling said solvent. It further 
relates to such treatment with the solvent as a vehicle for depositing 
fabric reactive materials on the fabric. 
Heretofore, various methods have been utilized for pretreating textile 
fabrics with volatile organic solvents in enclosed systems before further 
treating with other materials such as dyes and coatings. Exemplary of such 
methods is U.S. Pat. No. 2,312,910, teaching the treatment of fabric with 
a volatile organic solvent such as a chlorinated hydrocarbon followed by 
heating the fabric in a chamber to evaporate the solvent and recovering 
evaporated solvent by condensation on a continuous basis. 
It has been particularly desirable to treat vehicular pneumatic tire cord 
fabrics with volatile organic solvents instead of conventional aqueous 
solutions and emulsions. An especial benefit is to provide improved cord 
to rubber adhesion by using the organic solvent as a vehicle for 
depositing reactive materials on the fabric, thus, also providing a 
greater flexibility in choice of coating materials, many of which are 
reactive with water, and further providing greater ability to wet the 
various cord surfaces. 
Heretofore, however, such volatile organic solvent treatments have not been 
entirely commercially successful, especially for tire cord fabric, not 
only because of inherent toxicity and fire hazard but particularly because 
of the high cost of solvent recovery systems which must be very efficient. 
Relatively high purity solvents are typically required. Recovery and 
recycle of the volatile solvent is economically mandatory because of its 
relatively high replacement cost. Yet recycling has typically been 
prohibitive primarily because of formation and build-up of water emulsion 
and other substances in the recovered solvent. The other substances 
apparently tend to promote water emulsions. An excessive treatment time 
for the recovered solvent is necessary to break the water emulsion before 
the solvent can be recycled. The other substances further tend to 
contaminate the treated fabric, particularly when the solvent contains 
reactive materials and because of their often times tacky nature, tend to 
stick to the equipment causing an early shut down. Thus, the recycled 
solvent has been prohibitive for a number of commercial applications from 
both the product quality standpoint and from the process equipment 
standpoint. 
It is, therefore, an object of this invention to provide an improved 
continuous method and apparatus for treating a textile fabric, 
particularly a tire cord fabric, with a volatile organic solvent, removing 
the solvent from the fabric and recycling the solvent. It is a further 
object to provide an improved fabric product. 
It has now been discovered that the contamination of the recycle solvent is 
substantially caused by the volatile portion of the finishing materials, 
including substances such as lubricants and emulsifiers, typically applied 
to the textile fibers during their manufacture as well as residual 
moisture inherently and normally contained in the manufactured cord or 
fabric. Such materials are apparently removed from the fabric by treatment 
with a volatile organic solvent simultaneously upon drying the treated 
fabric and they subsequently contaminate the recovered solvent. This, in 
turn, prohibits economical recycling. 
In accordance with this invention, it has been discovered that a method of 
continuous volatile organic solvent treatment of a textile fabric 
comprises, in cooperative sequence, pretreating said fabric in a pretreat 
stage by sequentially preheating the fabric to a temperature in the range 
of about 70.degree. C. to about 200.degree. C. to remove volatile 
materials therefrom and then cooling said fabric to a temperature at least 
about 5.degree. C. below the boiling point of said volatile organic 
solvent, applying to the pretreated fabric a solution comprising said 
volatile organic solvent in an application stage, drying the fabric by 
evaporation at an elevated temperature and condensing and recovering the 
evaporated solvent in a drying and recovery stage followed by recycling 
the recovered solvent back to said application stage. 
In further accordance with this invention, an improved treated fabric 
product is provided, particularly for use as tire cord embedded in rubber 
which exhibits substantially improved peel adhesion, fatigue resistance 
and reduced stiffness. It should be appreciated that, by operation of the 
invention, the actual treated fabric product of the invention evolves 
after a reasonably adequate time for the required sequential 
pretreat/application/drying/recovery and solvent recycle steps to 
substantially equilibrate, such as from about 1 to 2 hours. 
Thus, the invention particularly provides an improved apparatus for 
treating textile fabrics, particularly tire cord fabrics which comprises, 
in cooperative sequence, pretreating means for pretreating the fabric 
comprising its sequential heating step with venting of volatile fabric 
finishing materials and moisture, and cooling step, the application means 
for application of the volatile organic solvent to the fabric, the drying 
and recovery means for evaporation of solvent from the fabric and its 
recovery by condensation, followed by a recycle means for recycling said 
recovered solvent back to said application means. 
It is especially preferred that both the application stage and the drying 
and recovery stage are enclosed and isolated from the atmosphere. It is 
further preferred that the application stage is separated from the drying 
and recovery stage with said drying and recovery stage enclosed as a unit. 
The isolation is typically accomplished by application of vapor locks or 
seals around the entrance or exit openings for the moving textile fabric. 
These openings, in turn, are typically positioned in the upper portions of 
the application stage and the drying and recovery stage to take advantage 
of the solvent vapors being heavier than air. The vapor seals are simply 
accomplished by positioning a cooling means, such as cooling coils, near 
or around the entrances and exits to condense the heavy vapors, thus 
preventing their escape. 
The volatile organic solvent must wet the fabric and can be applied to the 
fabric by various means in the application stage, such as dipping, 
spraying and coating. Application by continuous dipping is preferred with 
the application stage, therefore, referred to as a dip stage. 
The various textile fabrics can be treated by the method and apparatus of 
this invention. Representative of such textile fabrics are woven and 
non-woven textile fabrics prepared from various yarns and continuous 
filaments by processes known to those skilled in the art. Woven tire cord 
fabrics are preferred because of their unique problems and requirements of 
future adherence to rubber under tensioned and flexing conditions. Various 
materials can be used for the fabrics, representative of which are linear 
polyamides, such as the various nylons including nylon 6 and nylon 66, 
aromatic nylons such as p-aminobenzoic acid polymer (p-abap) as described 
in French Pat. No. 1,526,745, linear polyesters such as polyethylene 
terephthalate and cellulose and cellulose derivatives such as cotton and 
rayon. Wire and glass woven fabrics can also be treated. 
In the practice of this invention, the fabric is preferred to be pretreated 
on a continuous basis in the pretreat stage by first heating to a 
temperature of about 70.degree. C. to about 200.degree. C., preferably 
about 90.degree. C. to about 150.degree. C., over a period of about 5 to 
120 seconds, preferably about 10 to about 60 seconds. Various methods can 
be used to heat the fabric such as by radiant, hot air and direct contact 
heating. Thus, a suitable environment for heating the fabric may have a 
temperature range from about 100.degree. C. to 250.degree. C., depending 
upon whether a direct contact, hot gas or radiant means is relied on. For 
example, the heating can easily be facilitated by passing the fabric over 
rotating hot cans which are internally heated with superheated steam. 
Evaporated volatiles, including moisture and finishing materials, can be 
removed from the pretreat stage by venting to the atmosphere or to a 
collecting means such as a condenser. It should be appreciated that 
typically a portion rather than a whole of the finishing materials and 
moisture is evaporatively removed by this invention and this has been 
discovered to be sufficient to effect a comparatively economical 
operation. 
The fabric is further and sequentially pretreated in the pretreat stage by 
continuous cooling to a temperature of about 25.degree. C. to about 
55.degree. C., preferably at least 5.degree. C. and more preferably at 
least about 10.degree. C., below the boiling point of the volatile organic 
solvent to be subsequently used in the application or dip stage, over a 
period of about 5 to about 120 seconds, preferably about 10 to about 60 
seconds. 
Immediately the cooled fabric is fed to the application or dip stage where 
it is continuously contacted with a volatile organic solvent, preferably 
by dipping, for about 0.1 to about 1 second and preferably about 0.1 to 
about 0.4 second at a temperature of about 25.degree. C. to about 
75.degree. C., at least about 5.degree. C. and preferably at least about 
20.degree. C., below the boiling point of the said solvent. 
The dipped fabric is then fed to the upper portion of an enclosed drying 
and recovery stage where it is heated to a temperature of about 80.degree. 
C. to about 150.degree. C., preferably at or up to about 10.degree. C., 
above the boiling point of said volatile organic solvent, over a period of 
about 6 to about 120 seconds, preferably about 10 to about 60 seconds, and 
sufficient to evaporate at least about 95 percent, preferably at least 
about 97 percent and more preferably at least about 99.8 percent by weight 
of said solvent from the fabric. The fabric can be heated by various 
methods such as by direct contact, hot gas or vapor and by radiant heat. 
In this stage the solvent is recovered by condensation, such as by 
exposure to cooling coils, and then recycled back to the dip stage. 
Additional treating materials, such as polyisocyanates, can be added to 
the recycled solvent and, if desired, the recycled solvent can be further 
treated before adding to the dip stage to remove small amounts of residual 
fines and moisture. 
During the pretreatment, solvent application and drying steps, sufficient 
tension is typically placed on the fabric to prevent shrinkage. Such 
tension can range from about 0.2 to about 7 pounds per cord. A typical 
range may be from about 1 to about 2.5 pounds per cord. 
It should be appreciated during the various operations of this invention 
that the actual temperature of the fabric is typically continually 
increasing or decreasing within a particular heating or cooling step and 
that the indicated required temperature is measured at the appropriate 
entrance or exit of a particular stage and is typically a respective 
maximum or minimum for that stage. For the purposes of this invention, the 
fabric temperature can conveniently be measured by direct fabric surface 
contact with a copper disc of about 20 gauge thickness having embedded 
therein an iron-constant thermocouple (J-type). The temperature is read 
directly in degrees Fahrenheit from a potentiometer pyrometer connected to 
the thermocouple, obtainable as Model 80200 from the Thermo Electric 
Company, Inc of Saddle Brook, N.J. 
Various organic solvents can be used for the application or dip stage, 
representative of which are chlorosubstituted hyrocarbons selected from 
unsaturated hyrdocarbons such as dichloroethylene, trichloroethylene, 
1,1,2,2-tetrachloroethylene; and from chloro-substituted saturated 
hydrocarbons such as dichloromethane, 1,2-dichloroethane, trichloroethane, 
including 1,1,1-trichloroethane or methyl chloroform, and 
1,1,2,2-tetrachloroethane, with methyl chloroform being perferred; from 
liquid ketones containing from 3 to 7 carbon atoms such as acetone, methyl 
ethyl ketone, methyl isobutyl ketone, methyl isoamyl ketone and diacetone 
alcohol, with acetone and methyl ethyl ketone being preferred; and from 
liquid aromatic hydrocarbons such as benzene, toluene and xylene, with 
benzene and toluene being preferred. 
It is preferred that the organic solvent vapor has a specific gravity 
greater than air and is a chlorosubstituted hydrocarbon. It is further 
preferred that the solvent be characterized by being typically inert to 
isocyanates. 
If desired, various materials can be mixed with the volatile organic 
solvents to form a solution for the purpose of depositing on or reacting 
with the textile fabric. It is generally preferred that they be reactive 
with the fabric and that they be characterized by having a boiling point 
at least about 5.degree. C., and preferably at least about 20.degree. C., 
above the boiling point of said solvent. Representative examples of such 
materials are polyisocyanates having an isocyanato functionality of 2 to 3 
such as: 
Polymethylene polyphenylisocyanate (PAPI) 
Triphenyl methane-triisocyanate (TMTI) 
2,4-tolylene-diisocyanate (2,4-TDI) 
2,6-tolylene-diisocyanate (2,6-TDI) 
Bitolylene diisocyanate (TODI) 
Dianisidine diisocyanate (DADI) 
Hexamethylene diisocyanate (HDI) 
m-Phenylene diisocyanate (PDI) 
1-alkyl-benzene-2,4-diisocyanate (AB-2,4-DI) 
1-alkyl-benzene-2,5-diisocyanate (AB-2,5-DI) 
2,6-dialkyl-benzene-1,4-diisocyanate (DBDI) 
1-chlorobenzene-2,4-diisocyanate (CDI) 
Dicyclohexylmethane-diisocyanate (CXDI) 
3,3-dimethoxy diphenyl methane-4,4'-diisocyanate (DDMDI) 
1-nitrobenzene-2,4-diisocyanate (NDI) 
1-alkoxy-benzene-2,4-diisocyanate (ABDI) 
1-alkylbenzene-2,6-diisocyanate (ADI) 
m-Xylylene-diisocyanate (XDI) 
1,3-dimethyl-4,6-bis(.beta.-isocyanatoethyl)-benzene-diisocyanate (DBIBDI) 
Hexahydrobenzidine-4,4'-diisocyanate (HBDI) 
Ethylene-diisocyanate (EDI) 
Propylene-1,3-diisocyanate (PDI) 
Cyclohexylene-1,2-diisocyanate (CDI) 
3,3'-dichloro-4,4'-biphenylene diisocyanate (DBDI) 
2,3-dimethyl-tetramethylene diisocyanate (DTDI) 
p,p'-Diphenylene diisocyanate (DPDI) 
2-chlorotrimethylene diisocyanate (CTDI) 
Butane-1,2,2-triisocyanate (BTI) 
Trimethylene diisocyanate (TMDI) 
Tetramethylene diisocyanate (TDI) 
Propylene-1,2-diisocyanate (PDI) 
Butylene-1,2-diisocyanate (BDI) 
Ethylidene diisocyanate (EDI) 
Metaphenylene diisocyanate (MPDI) 
Diphenylmethane 4,4'-diisocyanate (DP-4,4-DI) 
Diphenyl 4,4'-diisocyanate (DPDI) 
1,5-diisocyanate naphthalene (1,5-DIN) 
2,4-diisocyanate chlorbenzene (2,4-DICB) 
4,4',4"-triisocyanate triphenyl methane (4,4',4"-TITM) 
Polymethylene diisocyanate (PMDI) 
It is typically required that the solvent solution contain about 0.1 to 
about 1 weight percent of the polyisocyanate, and/or other fabric reactive 
materials, and preferably about 0.2 to about 0.5 percent based on the 
solvent. The polymethylene polyphenylisocyanate, having an average 
isocyanato content of about 2.3 to about 3, is a preferred polyisocyanate. 
Further objects and advantages of this invention can be more readily 
observed by reference to the drawing showing a diagramatic view of a 
fabric treating apparatus comprising, in sequence, a pretreat stage and 
substantially enclosed dip and drying and recovery stages.

The pretreated fabric is fed to an upper portion of a dip stage 6, through 
a vapor seal down through a liquid chloro-substituted hydrocarbon solution 
dip 7, such as methyl chloroform, which may contain about 0.5 weight 
percent of a fabric treating compound such as a polyisocyanate having an 
isocyanato functionality of about 2.5 to about 3. 
The dipped fabric is then fed to a drying stage 8 around heating cans 9 
where it is heated to a temperature of about 80.degree. C. to about 
150.degree. C. to substantially remove at least about 99 weight percent of 
the chloro-substituted hydrocarbon solvent from the fabric. The evaporated 
chloro-substituted hydrocarbon solvent is condensed in the recovery stage 
by cooling coils 10 into a container 11 and recycled back to the dip stage 
by the recycle means as a pump 12. The cooling coils 10 also operate to 
effect a vapor seal for the entrance and exit of the fabric from the 
drying and recovery stage. 
The practice of this invention is further illustrated by reference to the 
following examples which are intended to be representative rather than 
restrictive of the scope of the invention. Unless otherwise indicated, all 
parts and percentages are by weight. 
EXAMPLE I 
A polyester textile fabric of 1000 denier with 2 yarns and 12 turns per 
inch, (1000/2; 12/12), containing 30 cord ends per lateral inch (epi) and 
with a weight of 8.18 ounces per linear yard was continuously fed from a 
roll at a rate of 20 linear yards per minute under a tension of 0.4 pounds 
per cord to a pretreat stage. 
In the pretreat stage, the fabric was sequentially fed around two 23-inch 
diameter tubular rotating hot cans, each with about 300.degree. of 
contact, in a manner illustrated in the accompanying drawing. The hot cans 
were internally heated with 20 pounds per square inch gauge (psig) 
superheated steam. The fabric had a residence time of 10 seconds in this 
porton of the pretreat stage and was heated to approximately 80.degree. C. 
Volatile finishing materials and moisture evaporated from the fabric were 
vented to the atmosphere. In the second portion of the pretreat stage, the 
fabric was cooled for about 10 seconds to about 55.degree. C. by passing 
around two 23-inch diameter rotating cold cans, each with about 
300.degree. of contact, which were cooled with water at a temperature of 
20.degree. C. 
The fabric was immediately passed through a cold vapor seal to a dip stage 
which was isolated from the atmosphere under a tension of about 0.4 pounds 
per cord. Therein, it was dipped for about 0.1 seconds in a dip solution 
at a temperature of about 28.degree. C. The dip solution was a 0.4 weight 
percent solution of polymethylene polyphenyl isocyanate having an 
isocyanato content of about 2.5 to about 2.8 in methyl chloroform. The 
polyisocyanate was of the type prepared by phosgenating an aldehydeamine 
product and obtainable under the trademark "PAPI" from the Upjohn Company. 
The dipped and wetted fabric was fed directly, without atmospheric contact, 
through a cold vapor seal into the upper portion of an enclosed drying 
stage isolated from the atmosphere. In the drying stage, the fabric was 
passed around two 23-inch diameter rotating hot cans, each with about 
300.degree. of contact, under a tension of about 0.4 pounds per cord for 
12 seconds. The hot cans were internally heated with 100 psig steam to 
heat the fabric to about 95.degree. C. The fabric was then passed out the 
top portion of the drying stage through a cold vapor seal for further 
treatment such as coating with various materials. 
Cooling coils, water cooled to about 16.degree. C., were positioned inside 
the drying stage both to prevent heavy methyl chloroform vapors from 
escaping through the vapor seals and to condense the methyl chloroform. 
The condensed methyl chloroform was collected at the bottom of the drying 
stage and passed through a heat exchanger, where it was cooled to about 
32.degree. C., to a tank where most of any water contained therein 
separated to form a top layer. The liquid methyl chloroform was filtered 
through a diatomaceous earth filter, obtainable as Model 33 with a 33-inch 
diameter cartridge from the Sparkle Company, to remove any residual fines 
or solids which may be present. The solvent was subsequently passed 
through an ion exhange dehydrating bed to remove any residual moisture 
onto a bulk storage tank and then recycled to the dip stage. Additional 
polyisocyanate was added to the dip stage as needed. 
It is important to note that although the pretreat stage of this invention 
does not remove all moisture or harmful finishing materials from the 
textile fabric, it does remove most of such materials and without such a 
pretreatment, the drying and filtering treatment of the condensed methyl 
chloroform from the drying stage would be insufficient to effect an 
economical process. 
EXAMPLE II 
Two textile fabrics of the type used in Example I were treated according to 
the method of Example I and herein identified as fabrics A and B, except 
that fabric B was not pretreated in the pretreat stage. 
After the drying step of Example I, each fabric was fed to a second dip 
stage where it was coated with a blocked isocyanate adhesive, identified 
herein as an R/F/L/BNCO adhesive, and then dried. The R/F/L/BNCO adhesive 
dip was an aqueous solution of an isocyanate blocked 
resorcinol/formaldehyde/latex composition. About 6 weight percent of the 
adhesive composition was deposited on the fabric and the coated fabric 
dried at about 230.degree. C. for about 2 to 3 minutes. 
The adhesive coated fabrics were then embedded in a rubber stock compounded 
according to Table 1. 
Table 1 
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Ingredients Parts 
______________________________________ 
Natural rubber 100 
Zinc oxide 3.00 
Carbon black 29.80 
Stearic acid 2.00 
Pine tar 7.00 
Mercaptobenzothiazole 1.25 
Sulfur 3.00 
Diphenylguanidine 0.15 
Phenyl beta naphthylamine 
1.00 
______________________________________ 
The resulting rubber embedded fabric was tested for peel adhesion, 
stiffness and fatigue with fabric B being a control and assigned arbitrary 
values of 100. The comparative values are shown in Table 2. 
Table 2 
______________________________________ 
Test Fabric A Fabric B 
______________________________________ 
Peel adhesion 117 100 
Stiffness 68 100 
Fatigue 162 100 
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Peel adhesion is determined in the following manner. Onto the surface of a 
12 mil thick sheet (12 inch .times. 12 inch) of rubber (MRS) is laid the 
treated cords which are then covered with a second sheet (12 inch .times. 
12 inch) of 12 mil gauge rubber (MRS). This "sandwich" arrangement of 
rubber cord and rubber is then doubled onto itself with a piece of Holland 
cloth extending one inch into the doubled assembly from the open end from 
which assembly is clicked 1 inch .times. 3 inch samples, which samples are 
then cured in a mold at 290.degree. F. for 20 minutes. The cured sample is 
then placed in an Instron machine, heated at 250.degree. F. and the two 
strips of rubber separated by the Holland cloth are then moved in opposite 
directions at the rate of 2 inch per minute to determine the average 
force. 
The fatigue test is made by forming a tube of the cord embedded rubber and 
tested in accordance with the "Mallory" tube fatigue test described in 
ASTM D-885-59T, Section 42, and also as described in U.S. Pat. No. 
2,412,524. 
The R/F/L/BNCO adhesive solution is prepared by mixing and aging an RFL 
composition and an isocyanate blocked resin (BNCO). 
The isocyanate blocked resin is prepared by first forming an R/F identified 
herein as Resin A and then blocking with a polyisocyanate of the type 
hereinbefore described for the first fabric dip. 
The Resin A is formed by mixing 110 parts of resorcinol, 25 parts by volume 
of fomalin (37% formaldehyde in methanol and water), and 20 parts by 
volume of water. The mixture is reacted in a vessel equipped with both 
heating and cooling coils, a reflux condenser and a suitable agitator. The 
mixture is heated to reflux temperatue (100.degree. C.) and allowed to 
remain at this temperature for 15 minutes, after which an additional 30 
parts by volume of formalin was added over a period of 10 minutes. After 
being refluxed for an additonal 30 minutes, the resin formed in the 
reaction vessel was allowed to cool to room temperature. A thick, syrupy 
resin (for convenience referred to as Resin A) containing 60 percent 
solids, a viscosity of 750 cps. and pH of 7 was obtained. 
Twenty parts of the Resin A is then reacted with 6 parts of polymethylene 
polyphenylisocyanate (PAPI) for 48 hours at about 22.degree. C. At the end 
of this time, the resulting reaction mixture is treated with 0.1 parts of 
sodium hydroxide and 100 parts of water. The resulting neutralized 
resin-blocked polyisocyanate (BNCO) may be used as such or may be allowed 
to age for 8 hours before being used. 
The R/F/L portion of the adhesive is made in accordance with the following 
formula: 
______________________________________ 
R/F/L Adhesive 
Ingredients Parts 
______________________________________ 
Resorcinol 98 
Formaldehyde (37%) 53 
Terpolymer rubber latex of styrene/butadiene- 
1,3/vinylpyridine 15/70/15 (41%) 
1152 
Water 543 
______________________________________ 
This R/F/L adhesive is prepared by adding 98 parts of the resorcinol to 196 
parts of water, followed by the addition of 53 parts of formaldehyde. The 
resulting mixture is aged for one hour and then 1152 parts of terpolymer 
rubber latex is added. The resulting mixture is aged for a period of 24 
hours. After aging, the balance of the water is added. 
The R/F/L/BNCO dip is then prepared by mixing 65 parts of the R/F/L 
composition with 35 parts of the resin blocked isocyanate BNCO and allowed 
to age at about 22.degree. C. for about 4 hours. 
EXAMPLE III 
A polyester fabric was treated according to the method of Example II, and 
identified herein as fabric C, except that in the pretreat stage the 
fabric was heated with forced hot air at a temperature of about 
390.degree. F. for about 90 seconds instead of with the internal heating 
of the hot cans with heated steam. The fabric was then cooled in the 
pretreat stage to about 28.degree. C. before passing to the dip stage. 
The resultant treated fabric after coating with the R/F/F/BNCO adhesive and 
encased in the rubber deomonstrated substantially improved peel adhesion, 
fatigue and reduction in stiffness compared to control fabric B as more 
clearly illustrated in the following Table 3. 
Table 3 
______________________________________ 
Rating 
Pretreated Un-Pretreated 
Test Fabric C Fabric B 
______________________________________ 
Peel Adhesion 112 100 
Stiffness 90 100 
Fatigue 160 100 
______________________________________ 
EXAMPLE IV 
The recovered solvents from Example II with and without the pretreat step 
are herein identified as recovered solvents A and B, respectively. As a 
dramatic measure of the effectiveness of the pretreat step upon the 
substantially improved quality of the recovered methyl chloroform solvents 
from the drying and recovery stage, their appearances were noted and water 
content determined and compared in Table 4. As shown in Table 4, the water 
content in parts per million was substantially reduced. 
Table 4 
______________________________________ 
Recovered Water 
Solvent Appearance Content 
______________________________________ 
A (pretreated 
fabric) Clear 807 
B unpretreated 
fabric) Cloudy 1462 
______________________________________ 
The water content was determined by Karl Fischer reagent titration. For 
convenience in the laboratory, the technique of titrating has been 
standarized as F. D. test No. 12-2 and identified as Aquatest II. 
While certain representative embodiments and details have been shown for 
the purpose of illustrating the invention, it will be apparent to those 
skilled in this art that various changes and modifications may be made 
therein without departing from the spirit or scope of the invention.