Process for the manufacture of coated fabric

May 21, 1963 a. e. jannarelli 3,090,102

PROCESS FOR THE MANUFACTURE OF COATED FABRIC

Filed Dec. 29, 1960

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INVENTOR.

ALBERT E. JANNARELLI

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ATTORNEYS . - „ — z-k/Y? 3,090,102

United States Patent Uince Patented May 21, 1963

3,090,102

PROCESS FOR THE MANUFACTURE OF COATED FABRIC

Albert E. Jannarelli, Cumberland, R.I., assignor to OwensComing Fibergias Corporation, a corporation of Dela- । war©

Filed Dec. 29, 1960, Ser. No. 79,757

Claim. (Cl. 28—75)

The present invention relates to improved insect screen- ·, ing and to methods for the preparation thereof, and particularly to the realization of such improvements in conjunction with insect screening formed from fibrous glass.

In recent years, a new material comprising an open mesh fabric woven from coated fibrous glass strands or yarns, has gained significance in the realm of insect screening. Such screening is disclosed by U.S. 2,867,891 wherein fibrous glass strands or yams are provided with a coating of thermoplastic material, woven into an open mesh fabric and set in the woven form or arrangement by means of the fusion of the thermoplastic coating.

The popularity of this type of screening has derived from the fact that such fabrics resist deformation, abrasion, rot and weather, and are highly resilient, strong and flameproof.

However, the coated, fibrous glass fabrics and the processing thereof are plagued by drawbacks in the form of coating defects which serve to detract from both the appearance of the screening and from its weathering qualities. These defects take the form of bare or uncoated areas occasioned by various processing difficulties including restrictions in the orifices of the dies which are employed to coat the basic strand, and from broken filaments or “fuzz” which project through the coating. In addition to yielding an unsightly appearance, these defects also reduce the weathering power of the screening since the exposed glass fibers are subject to attack by moisture. Accordingly, a product of less than satisfactory qualities is obtained.

It is an object of the present invention to provide an improved method for the preparation of insect screening.

A further object is the provision of insect screening exhibiting unusual weathering and aesthetic qualities.

Additional objects, advantages and features of the invention will be understood from the detailed description which is provided hereafter and from the accompanying drawings in which:

FIGURE 1 is a simplified view in elevation of a production line designed to conduct the process of the invention.

FIGURE 2 is a fragmentary sectional view at the point of intersection of a warp and woof yarn.

The aforegoing objects are achieved by means of the application of a second coating or top coating which is applied to the insect screening. This is accomplished by subjecting the screening woven from coated fibrous glass strands and bonded through the medium of the coating material at the points of intersection of the strands, to a second coating which serves to cover and conceal the defects in the first or base coating and to mask projecting glass filaments.

The method is best described in conjunction with FIGURE 1 which depicts a production line by means of which the process of the invention may be conducted. As shown, coated yarns 1, are woven upon a conventional loom 2 to provide a fabric 3 comprising coated fibrous glass strands. The fabric 3 is then passed through an oven 4 maintained at a temperature above the fusion point of the coating material but below the fusion point of the glass fibers, wherein the coated strands are set or bonded in the woven arrangement by virtue of the fusion and interbonding of the coating material at the points of intersection of the warp and woof strands.

The coated and heat set fabric 5 is then subjected to a second coating or impregnation step by means of passage through a receptacle 6 which contains a quantity of coating material 7, such as a vinyl plastisol. Excess impregnant may then be expressed from the coated fabric by means of squeeze rolls 8 and quantities of the resin which have blocked the fabric interstices or foramina may be removed by means of a rotary brush 9 whose bristles project through the foramina. The fabric may then be passed through a second oven 10 which serves to cure or set the second or superimposed coating.

In employing the method of the invention, a number of changes in the apparatus depicted in FIGURE 1 may be resorted to. For example, the screening need not be woven but may comprise a series of strands in a perpendicular relationship as in the case of non-woven fabrics wherein all of the transverse strands are in the same plane and all of the longitudinal strands are in the next adjacent plane and the two series are adhered at the points of intersection of the longitudinal and transverse strands. In such case, the loom 2 could be replaced by apparatus which merely serves to superimpose a series of parallel strands upon, and at right angles to the warp strands 1 until such time as the superimposed strands are bonded to the warp strands at their points of intersection. Secondly, the ovens 4 and 10, depicted in FIGURE 1 may be supplanted by less cumbersome heating elements such as heating rods backed by a reflective surface, dielectric heating apparatus, etc. In fact, the heating means may be completely supplanted if bonding is achieved by means other than the thermoplastic nature of the coating material. For example, a solvent may be employed to ί soften the coating and the solvent dispelled after the coating material has flowed together or fused at points. of intersection. Alternatively, a coating material possessing some degree of pressure sensitivity may be employed, and mechanical pressure in the form of squeeze rolls or the like may be utilized to force together and cohere the coating material at the points of intersection. Further, coating methods and applicator apparatus other than the bath 6, illustrated in FIGURE 1 may be employed. Conventional spray and transfer techniques, as well as other immersion methods may be used and a conventional textile padder will suffice. Excess resin may also be removed by apparatus other than the depicted rotary brush 9. For example, a fluid blast or jet may be directed at the fabric to remove the excess resin which tends to cover the fabric interstices.

The preferred coating material for both the base or first coating and the second or masking coating, comprises a vinyl plastisol. Such materials are desirable not only for reasons of economy but also because of their excellent thermoplastic qualities in respect to the embodiment of the invention which employs a thermal setting of the fabric. Such plastisols comprise dispersions of a resin such as polyvinyl chloride and may be prepared by methods conventional in the plastisol art.

While a variety of vinyl plastisols will satisfy the requirements of the methods of the invention, a preferred formulation comprises:

Polyvinyl chloride resin-----------Dioctyl phthalate (plasticizer) ----Trioctyl phosphate (plasticizer)----Dioctyl sebacate (plasticizer)------Anitmony trioxide (flame retardant) Mineral spirits (diluent)----------Barium-cadmium salts (stabilizer) _

When employing the above plastisol, which has a fusParts . 100 . 30 . 20 _ 10 _ 5 _ 3 _ 3.5

3,090,102 ing temperature of approximately 350° F., the conditions necessary to interbond the plastisol coated strands is determined by the temperature and time of exposure. It has been found that passing the fabric through an oven 32 feet long and maintained at 425° F., at a rate of 450 5 feet per minute will suffice to fuse and interbond the vinyl coating material. A similar treatment will also serve to set or fuse the second coating in the second oven 10.

When colored fabrics are desired, pigments or dyes may be incorporated in the plastisol. ₁₀

The invention, however, is not limited to the use of vinyl resms. . Other thermoplastic materials such as asphalt, polyamides, polyethylene, cellulose compounds, styrene, etc. may also be utilized and if bonding is achieved -by other than thermal means, coating materials possessing 15 the requisite degree of solubility, pressure sensitivity etc may -be substituted.

In addition, the first or base coating and the second or masking coating may comprise dissimilar materials so long as an adequate degree of adherence is available. For 20 example, the coating material superimposed upon the -base coating may be provided with a greater degree of masking, occluding or coloring power through the addition of a higher proportion of pigment, filler or the like. Alternatively, pigment may be employed only in the second or 25 exterior coating since the base or first coating is not visible in products prepared according to the invention.

The product and advantages yielded by the invention are best described in relation to FIGURE 2 of the accompanying drawings, which depicts a fragmentary sectional ³⁰view at the. point of intersection of a warp and a woof yarn, in which the warp yarn is seen in longitudinal section while a radial section of the woof yarn is shown.

As may be -observed, the warp yarn 11 and woof yarn 12 comprise a plurality of substantially parallel glass ³⁵fibers, and each of the yarns 11, 12 are provided with base coatings 13 which are fused together at the point of intersection 14 of the yarns. The second coating 15 which is superimposed upon the base coating 13, serves to fill in and conceal defects 16 such as pits, uncoated areas, cracks and the like, which occur in the base coating 13, as well .as “plastering down” and concealing broken fibers 17 which project through the base coating 13.

The coated, continuous, fibrous glass strands employed 45 in the preparation of the fabrics treated according to the invention may be produced according to the methods of

U.S. 2,867,891 wherein the strands are passed through a resin plastisol supply and subjected to the tandem action of a wiper and a die. The strands utilized preferably have a diameter in the area of 10-15 mils.

. While, the. quantity of either the base or exterior coating applied is not critical, it has been found that a -base coating comprising between 35 and 55% by weight of the strand-resin composite is adequate to provide the requisite covering and bonding power while between 2 and 15% by weight of the exterior coating is sufficient to conceal the defects present in the base coating.

It is apparent that the present invention provides new and unusual methods for the preparation of coated fibrous glass screening as well as providing coated fibrous glass screening which exhibits unusual aesthetic and weathering characteristics.

It is further obvious that various changes, alterations and substitutions may be made in the methods and products.of the invention without departing from the spirit of the invenion as defined by the following claim