US2842473A - Process for coating cloth - Google Patents

Description

y 8, 1958 L. A. CBERLY ETAL 2,842,473

' PROCESS FOR comma CLOTH Filed June 15, 1955 2 Sheets-Sheet 1 0 ammo/m czar/v HAM Zara? 25 29 13 o /2 2/ 23 Jk/PFORZFD F/uw L xx 7/7/7/7/7/ 1NVENTOR5= LOU/.5 A. OBERLY B CARL B. SALZ/NGER Y \/L14 nr ATTO July 8,1958 .1 A. OBERLY ET AL 2,342,473

PROCESS FOR COATING CLOTH Filed June 15, 1955 2 Sheets-Sheet 2 Fly.

INVENTOR5= LOU/5' A. GEE/FLY BYCARL B. .SALZ/NGEI? AT T 01? [Y equivalent woven fabric.

United States Patent I PROCESS FoR COATING CLOTH Louis A. Obeily, Chagrin Falls, and Carl B. Salzinger, Cleveland, Ohio, assignors to Industrial Rayon Corporation, Cleveland, Ohio, a corporation of Delaware Application June 15, 1955, Serial No. 515,668 2 claims; (Cl. 154 120 This invention relates to a cloth coating process and has particular reference to a process for the coating of relatively open construction cloth materials employed as backing supports for subsequently applied film layers of a coating material.

Cloth or fabric, particularly of textile origin, is commonly utilized as a backing support for various coatings. Products suitable for clothing, Leatherette coverings, upholstery and decorating material and the like are advantageously manufactured from coated textile fabrics. Such products beneficially possess composite characteristics of the combined coating material and the backin'g cloth.

it has been found desirable to utilize resin-containing plastic materials as coatings for fabric. The coated fabric product may comprise a film layer of resin-containing plastic material, such as a vinyl polymer resin, applied over one surface of the backing cloth. Coated fabric products of this nature are characterized and known as supported films.

Suitable backing cloth for supported films may be a fabric of various construction. However, it is often advantageous to employ a knit cloth for such purposes. Knit cloth is generally more economicalto construct than In addition, it has the advantage for many purposes of having substantially more uniform strength and extensibility in all directions.

Supported films are frequently utilized for applications where they are required to be sewn or stitched. For this purpose it is advantageous for the backing cloth to be only partially impregnate-d by the film layer of coating material which it supports. When the envelopment of the backing cloth by the film layer is not total or complete, the supported film is enabled to more distinctly retain certain of the desirable characteristics of a textile fabric, particularly with respect to tear resistance and the tear or sew line strength of the material in the vicinity of stitches. In addition, supported films have greater extensibility and resistance to permanent'defor'mation upon elongation when the backing cloth is not completely enveloped.

When only one side of a cloth or fabric is being coated, it is sometimes difiicult to control the extent of the penetration or impregnation of the coating material into the fabric to avoid excessive envelopment of the cloth backing by the supported film layer. This is more pronounced when a relatively open construction or mesh-like backing cloth, such as knit fabric, is employed. Control of penetration is difficult to maintain when relatively thin films, for example, those lighter than about 5 or 6 mils in thickness, are being applied. Such relatively thin coatings, particularly those having a thickness between about 0.5 and 3 mils, are often provided for coated cloth products which are intended to subsequently receive additional film layers of coating material.

When coating techniques are employed which utilize a casting belt of paper, metal or other relatively impervious material which is positioned under the backing cloth 2,842,473 Patented July 8, 1958 as a support during the coating, there is a tendency for the coating material to penetrate or strike through the backing cloth. A greater degree of envelopment than is desirable may result. Should this occur, the supported film'often displays poor resistance to tearing and an insufficient sew line strength for satisfactory application as a coated cloth product. In addition, its extensibility may be materially lessened.

it would be advantageous to manufacture supported films in a manner permitting close control of the degree of envelopment of the backing cloth by the film layer which it supports. It would also be advantageous to eliminate excessive penetration or strike-through of the coating material through the interstices of the backing r cloth, especially when relatively thin film layers are being applied over open construction backing cloth. In this way, the production of supported film products having, among other desiderata, optimum tear resisting charac* teristics for purposes of stitching and sewing and an enhanced extensibility would be achieved.

It is among the objects of the present invention to pro= vide a cloth coating process which permits close control of the envelopment of the backing cloth with the coating material and to also prevent undesirable strike-through'of the coating material on the backing cloth. It is a further object of the present invention to provide a process wherein it is possible to simultaneously and economically produce both a supported and an embossed unsupported or sheet film product in the same operation.

These and other objectives and advantages are accomplished and realized in accordance with the present inven= tion, by partially embedding and temporarily laminating the cloth to be coated with a sheet of a casting filr'n; then applying a film layer of coating material over the unembedded or unlaminated side of the cloth; setting the supported film layer on the temporarily laminated cloth; and subsequently stripping the casting film from the uncoat'ed side of the produced supported film.

Still further features and advantages of the present in vention will be more apparent in the following description and the drawing, in which like reference numerals relate, insofar as possible, to like parts, wherein: V

Figure 1 schematically portrays the coating process of the present invention;

Figure 2 schematically represents an embodiment of the process;

Figure 3 schematically illustrates a variation in the coating technique which maybe employed in accordance with the present invention; and 7 Figures 4 and 5 schematically represent other embodi ments of the process.

With reference to Figure 1, abacking cloth 10 is pressed into and partially embedded in a softened case ing film 11 with which it is temporarily laminated while passing between a pair of pressure laminatingrolls 12 and 14, rotated respectively in the direction of thearrows 13 and 15. The casting film 11 is a sheet or unsup ported film which can be softened to permit the tempor ary lamination of the backing cloth. For example, solvents or plasticiZers may be employed to condition the casting film to a suitable degree of softness. They may be present in the formed film or they may be purposely provided to accommodate the temporary lamination. Advantageously, however, the casting film 11 is a thermo= plastic material, such as a vinyl polymer resin, which can be conditioned and softened by heat for the temporary lamination. In such cases it is advantageous for thepressure laminating r'olls 12 and 14 to be heated to soften the thermoplastic casting film. While the casting film may be of any desired thickness, good results are obtainable with films having a thickness between about 38 and about 32 mils.

The backing cloth may be fabric of any material and construction. It may be a relatively open construction, mesh-like, scroopy or sleazy, material having substantially sized foramina or interstices. For example, loosely knit cloth of continuous filament viscose rayon yarn, having yields varying from about to about 3 square yards per pound may advantageously be employed.

When thermoplastic casting film 11 is employed, theheated rolls 12 and 14 sufficiently soften it to permit thebacking cloth 10 to be embedded in the casting film to a desired degree under the pressure of the rolls. If the casting film is a vinyl polymer resin, it is usually sufficient to heat it to a softening temperature of about 300 F. to 325 F. to partially embed and temporarily laminate the backing cloth. It is ordinarily advantages for the backing cloth to be embedded between about one-third to one-half of its thickness to effect the temporary lamination. The casting film is thus embossed with the structural pattern of the backing cloth. A temporarily laminatedbacking cloth 16 is formed as a first intermediate product in the process.

Roll pressures of about 100 to 1000 pounds and greater per square inch are usually sufficient for this purpose. The proper roll pressure in particular instances may depend on such various factors as the condition of softness of the casting film, the characteristics of the backing cloth, roll hardness and the speed of lamination. For example, good temporary lamination can be achieved within the mentioned pressure range at processing speeds of about 5 to 7 yards per minute when using rubber cover rolls having a durometer reading of about 50.

Other suitable heating means (not shown) may also be employed to soften thermoplastic casting film for temporary lamination with the backing cloth. For example, before the cloth is pressed into the film between therolls 12 and 14 or by other means, the film may be preliminarily brought to a softening temperature by being first passed over heated cans or rollers or over Calrod units. The preheating may also be accomplished through an oven or with infra-red radiation. In such cases the laminatingrolls 12 and 14 may not require internal heating means for softening the casting film. They may then be merely employed as pressure rolls. However, when preheating is employed for softening the film, it may be advantageous to keep the pressure rolls warm to sufficiently maintain the softened condition of the film during the temporary lamination.

The unembedded side of the intermediate temporarily laminatedbacking cloth 16 is covered with a film layer of a desired coating material, such as a vinyl polymer resin. Any desired method of coating may be employed, including any of the various well-known techniques of spread or dispersion coating or coating by calendering techniques which are practiced in the art. In each instance the particular method utilized may vary with the specific coating materials being applied and the characteristics desired in the supported film product.

For purposes of convenient illustration, knife coating is depicted in Figure l. The temporarily laminated backingcloth 16 is passed over a support roll 17, rotated in the direction of thearrow 18. A quantity of coating composition is supplied behind a knife ordoctor blade 20 to maintain apool 21 of the coating composition which is spread as a thin supportedfilm layer 23 upon and over the upper unembedded surface of the backing cloth. A film of any desired thickness may be applied, depending upon the particular use anticipated for the coated cloth product. Strike through of the coating material is physically prevented by the casting film which is temporarily laminated'to the backing cloth. The coating material is thus able to penetrate or impregnate the backing cloth only to a controlled depth equivalent to its unembedded portion in the casting film, regardless of the intersticial area of the cloth.

After application to the temporarily laminated backingcloth 16, thefilm layer 23 of coating material is set or cured according to suitable conventional techniques for the particular coating material employed. This is accomplished in a curing, setting or dryingzone 25 which is operated according to the requirements of the particular situation. For example, in order to cure or set many coating materials, heating or drying by means of heated air or other fluid, infra-red radiation or by other heat-exchanging contact or conducting means may be required. Most vinyl polymer resin compositions including emulsions, plastisols and organisols require sufficient heat to remove volatile constituents and to fuse or fiux the resin to its finished form. If hot melt coating is being practiced, the curing or setting of the supported film layer may require that cooling means be employed.

The usedcasting film 10, having the pattern of the backing cloth embossed on its surface, is stripped from the uncoated side of thebacking cloth 16 at aseparation point 27. The supportedfilm product 29, after being freed from the temporarily laminated casting film, is taken up for collection in any suitable fashion. For example, a wind up reel may be employed. The stripped casting film 11 may also be collected in any desired manner.

The process of this invention may be carried out with apparatus patterned after that schematically illustrated in Figure 2. A four-rollinverted L calender 30 may be employed to produce the casting film 11 for temporary lamination to thebacking cloth 10. Thecalender 30 comprises a stack ofrolls 32, 34, 37 and 40 revolving in close proximity to one another in the direction of thearrows 33, 35, 38 and 41 respectively. A suitable film forming material, advantageously a thermoplastic material such as a vinyl chloride resin composition, is supplied to the nip between therolls 32, 34 to maintain a rolling bank 31 of resin therein. When thermoplastic materials are employed therolls 32, 34, 37 and 40 in the calender stack are conveniently heated. The resin composition, according to conventional practice, is supplied from a mixer, such as a Banbury mixer or the like afer being suitably compounded with plasticizers, fillers, stabilizers, etc. in blending apparatus. The film pro duced in the nip of therolls 32, 34 follows around theroll 34 at 36 to the nip of theroll 37 with theroll 34. The film is reduced in the nip betweenrolls 34, 37 and follows around theroll 37 at 39 to the nip of theroll 37 with the roll 40. The film is further reduced in the nip betweenrolls 37, 40 and follows around the roll 40 at 42 from which the finished sheet of unsupported casting film 11 is delivered to the laminating rolls 12, 14.

As mentioned, the casting film may, if desired, be softened in any suitable manner prior to entering between the laminating rolls. Advantageously, a thermoplastic casting film is softened by preheating and the laminating rolls 12, 14 are heated. The backingcloth 10 is payed out from asupply reel 45 around a roll 46. It is pressed into the softened casting film under the pressure of the laminating rolls 12, 14.

The intermediate temporarily laminated backingcloth 16, comprised of thebacking cloth 10 embedded in and temporarily laminated with the casting film 11, is passed from the laminating rolls 12, 14 around and under aroll 48, rotating in the direction ofarrow 49, then around and over aroll 50, rotating in the direction of thearrow 51. The coating is applied to the temporarily laminated backingcloth 16 from thesupply pool 21. It is spread over the open, unembedded surface of the backing cloth by theknife 20 on the upper side ofroll 50. The sup portedfilm layer 23 of coating material on the temporarily laminated backingcloth 16 is passed over a consecutive pair of support rolls 52, rotating in the direction of the arrows 53, through a curing or dryingzone 55. This sets the applied film layer on the supporting backing cloth.

When organisol or plastisol paste compositions of vinyl polymer resins are employed for coating, they may be dried and fused on the backing cloth with air at a temperature of between about 175 F. and 450 F., or by direct infra-red radiation from electrically heated elements at a source temperature of about 1000? to 2000" F.

The supported film, still temporarily laminated to the casting film, is passed around cooling rolls 58, rotating in the direction of thearrows 59. The embossed casting filmis stripped from the supported film orcoated cloth product 29 at theseparation point 27 by the strippingrolls 611, 62 and 63. Ordinarily a pulling force of between about pound and 2% pounds per linear inch is suificient to separate the casting film from the supported film product. The supportedfilm 29 is passed around therdlls 65, 66 to be wound in a take-up reel 68. The stripped casting film is wound in a take-up reel 70.

In Figure 3 a reverse roll coater is employed to illustrate a calender coating or so-called bank-skimming technique to apply the supported film layer. The casting film H, which for purposes of illustration is thermoplastic, may be conveniently supplied from asupply reel 42 of already formed unsupported film. It is temporarily laminated tothe backing cloth iii between the heated laminating rolls l2, M. The casting "film may be formed in any desired manner including calendcring or extrusion. Also, as illustrated, it may be produced in advance of requirements for its temporary lamination with the backing cloth The temporarily laminated backingcloth 16 is passed under and around the roll 43, rotating in the direction of thearrow 49, then over the roll St rotating in the direction of the arrowSl. Coating material is applied from the roll '76 after being formed as a film between the roll: 74, F6. A rollingbank 72 of the coat ing material is r 'u'ntained in the nip of therolls 7d, 76, rotated respectively in the directions of the arrows 75', '77. The film to be applied follows around the roll 77 at 78. "It is literally wiped onto the unembedded surfaces of the temporarily laminated backing cloth 1%, moving in a direction oppos' to theroll 76. Thefilm layer 23 is then set as a sorted film product on the backing cloth. The embossed casting film i1 is su critly stripped away and separated from the supported film product.

Embossed. film may, if desired, be reclaimed for reuse in the production of fresh casting film. be accomplished b remelting or recomp-ouuding the use casting film F mation of fresh film through calendering or other film forming techniques. in addition, it is possible to smooth the embossed surface of used casting film by means of ed pressure resurfacing rolls in order to make it more so able for additional temporary lamination whenever an absolutely smooth surfaced casting film is necessary or desirable. this way, greater service may be obtains. from a given quantity or casting film before reclamation or other disposal is necessary.

Advantageously, however, the used casting film may be employed as an embossed unsupported film product hay ing the structural pattern or design of the impressed backing cloth on its surface. An economic benefit may thus be realized in the process since both a coated cloth or supported film product and embossed sheet or unsup ported film product simultaneously manufactured. if desired, the embossed, unsupported film product may be pressed onto a backing cloth to for an embossed, supported film. both surfaces of the casting film may be employed fo tire temporary lamination to the backing cloth before i s either reclaimed or disposed of as an embossed film.

The casting m, especially if it is of thermopiastic nature, may also be ernpl yed as a continuous belt. This eliminates the necessity to take up used casting film after it is separated from the supported film. As shown in Figure 4, the casting film ii is passed as continuous belt This may around the plurality of rollers 7d, rotating in the direction of thearrows 71. The backing cloth 10' from thesupply reel 45 is embedded in the belt of casting film between the heated laminating rolls 12, 14. The unembedded side of the temporarily laminated backing cloth to is coated with material from thesupply pool 21 spread by theknife 20 on the upper side ofroll 50, rotating in the direction of thearrow 51. The supportedfilm layer 23 on the temporarily laminated backingcloth 16 is passed under a drier 55 to set the applied film on the cloth. The intermediate temporarily laminated supported fihn product is then cooled between the cooling rolls 59, rotating in the direction of the arrows 5%, or by other suitable cooling means. The supportedfilm product 29 is separated from the continuous belt casting film 11 with the separatingroll 62. it collected on the take-up reel 68.

When utilizing casting film as a continuous belt, it may be advantageous to employ belt tensioning means to countereffect any slack that may develop. Additional heated pressure rolls may also be advantageously employed to smooth the embossed surface of the casting film after its temporary lamination. In addition, supplemental coating means may also be employed to maintain a predetermined casting belt thickness in order to overcome any attenuation that may develop as a result of belt passage around and between the various rollers.

As is illustrated in Figure 5, these features, when desired, may be added to the basic continuous belt arrangement of Figure 4. The continuous belt of casting film 11, after being stripped from the supportedfilm product 29, is passed around a floating roll belt tensioning means 86 positioned between therolls 85, 87. The tensioning means 86, as shown, consists of a counterweighted vertically movable roll around which the belt passes. Of course, other suitable belt tensioning means may also be employed. If attenuation and belt elongation becomes greater than can be compensated for by a belt tension device, it may become necessary on occasion to cut and splice the casting film belt.

A pair of heated pressure rolls 86 and 82, rotating in V the direction of thearrows 81, 83, may be utilized to smooth the surface of the thermoplastic casting belt from impressions of the backing cloth which are embedded therein during the temporary lamination. The supplemental coating means for the be t of casting film may be a reverse roll center, as depicted, comprising the rolls Q2, 94 rotating in the direction of thearrows 93, 95. A desired additional thickness of coating material is applied from the rollingbank 96 of film forming material in the nip of therolls 92, 94 to the surface of the casting film 11 while it is passing over theroll 90, rotating in the direction of thearrow 91. Other supplemental coating means may also be employed for maintaining the thickness of the castin g belt.

.The surface of the casting film may, if desired, be treated or prepared with various agents to facilitate stripping and separation from the supported film product. Treatment with such agents may, as desired, be effected before or after the casting film is conditioned or softened for temporary lamination with the cloth, although it is frequently more convenient to do so before softening the film. Finishes which contain commonly known partitioning agents may advantageously be applied for this purpose before the casting film is temporarily laminated with the backing cloth. For example, certain hydrophobic and hydrophilic colloids including those selected from the group consisting of silicones, stearates and some of the alkali metal salts of higher melting point fatty acids may beso employed. Also where the required time and temperature conditions for curing the applied finish would not be deleterious to the castingfilm, certain urea formaldehyde, phenol formaldehyde and like compounds and derivatives may be employed.

The casting film may be of any film forming material, preferably thermoplastic, capable of being formed or worked into unsupported sheets and conditioned for temporary lamination to the backing cloth. Advantageously, as mentioned, the casting film comprises a composition which essentially contains a vinyl polymer resin, such as a vinyl chloride resin or copolymers of vinyl chloride and other ethylenically unsaturated compounds, well-known to the art.

Likewise, the coating may be of any suitable material. While vinyl polymer resins are most advantageously employed, the coating material may also comprise polymeric substances of a varying nature including polyamide and polyester type materials well-known in the art. Suitable coating materials of any origin, capable of being spread or calendered over backing cloth and for t ed into a supported film product, may be employed in the process the present invention.

The coated cloth or supported film product may receive subsequent coatings, if desired. Supported films of any desired thickness may be produced in accordance with the present invention.

The applied coating may also serve as an adhesive layer or anchor coating for subsequent application through calendaring or lamination of an additional, alreadyformed sheet or unsupported film of desired material, such as an unsupported sheet of a vinyl polymer resin. In such cases, as mentioned, it is advantageous for the coated cloth product to have a film thickness between about 0.5 and 3 mils.

The invention may be better understood by reference to the following examples and description in which all parts, unless otherwise indicated, are by weight.

Example I A casting film composition was compounded containing about 100 parts of a substantially pure polyvinyl chloride resin; about 20 parts of dioctyl phthalate as a primary plasticizer for the film; about 12 parts of dioctyl sebacate as a low temperature plasticizer; about 10 parts of tri cresyl phosphate as a flame proofing lasticizer; about 4.5 parts of a stabilizer comprising a mixture of a barium cadmium soap, an epoxy compound and a chelating (scquestering) agent; about 15 parts or" calcium carbonate filler; and about 0.25 part of triple pressed stearic acid as a lubricant. The ingredients, after being blended, were mixed in a Banbury mixer and dumped at a temperature of about 310 F. Casting film having a thickness of about 20 mils was produced on a four-roll inverted L calender operated at a temperature of about 320 F.

A backing cloth of about 3 ounces per square yard circular knit viscose rayon cloth was pressed into the casting film at a rate of about five yards per minute between a pair of heated laminating rolls. The film was warmed to a softening temperature of about 320 F. which facilita'ted partially embedding the cloth to about half its 3 The efate as a primary plasticizer; about 3 parts of a heat. and

light stabilizer containing a suitable metallic soap, an epoxy compound and a chelating agent; about 4 parts of a suitable viscosity depressant; and about 20 parts of a calcium carbonate filler. The applied coating composition forming the supported film layer had an average approximate thickness of about 7 mils. The plastisol was set in a drying oven at a temperature of about 300 P. which fused the film on the backing cloth.

After the cured supported film coating was cooled, the

temporarily laminated backing film was stripped from;

the coated cloth product. The surface of the used casting film was embossed with the design of the knit backing cloth. It made a suitable embossed unsupported vinyl film product which could be further pressed to backing cloth to produce an embossed supported film.

The adhesion strength of the supported film on the backing cloth was at least about four pounds per inch wide strip. The coated cloth product had a desirable minimum tear strength of about five pounds. Its stitch tear strength (as measured by the pulling force required to separate two pieces sewn together with about 12 stitches per inch) was about eighty pounds in the lengthwise direction and about fifty pounds in the cross direction. It had good extensibility, retaining not more than about 1 /3% permanent stretch in any direction after being pulled with about a ten pound force for about ten minutes.

Example 11 A casting film was compounded and formed as descibed in Example I excepting that octyl decyl phthalate was employed as the primary plasticizer and the film was calendered to a thickness of about 30 mils. A backing cloth of about 5.3 ounces per square yard circular knit viscose rayon cloth was temporarily laminated with the casting film according to the procedure set form in Example I. The temporarily laminated backing cloth was reverse roll coated with the plastisol composition as described in Example I with the exception that about 20 parts of a color pigment was incorporated in the plastisol formulation. The applied coating had a thickness of about 15 mils. The coated cloth product, after being stripped from the casting film, displayed excellent properties. The adhesion strengthbetween the supported film and the backing cloth was about four and one-half pounds. Its tear strength was at least about five pounds. Its stitch tear strength was about ninety pounds longitudinally and about sixty pounds crossways.

The extensibility of the coated cloth was equivalent to that described in Example I.

The used casting film was reclaimed by being remelted, mixed in a Banbury and then recalendered into fresh film. Coated cloth produced on reclaimed casting film had characteristics and properties equivalent with that described above.

Example 111 The coating procedure of Example I is followed excepting that the backing cloth employed for supporting the coating is a 3 ounce per square yard woven x thread count viscose rayon fabric. The properties of the coated cloth product are about equivalent to those described in Example I excepting that the extensibility of the material, due to the nature of the backing cloth, is not uniformly as good in all directions.

Example IV The coating procedure of Example I is repeated on a 2 ounce circular knit viscose rayon cloth excepting that the applied supported films layer has a thickness of only about 2 mils. After the supported film product is separa- I ted from the casting film, it is pressed to an unsupported vinyl film which is laminated to the plastisol coating on the backing cloth. The final supported film product weighs about 24 ounces per square yard. The adhesion strength of the film layer to the backing cloth is about four and one-quarter pounds. Its strip tear strength is at least about five pounds and its stitch tear strength about eighty pounds lengthwise and about fifty pounds across. The extensibility of the supported film product is good. The material does not retain more than about l permanent stretch in any direction after it is pulled with about a ten pound force for about ten minutes.

Example V The coating procedures of Examples I, II and III are repeated using the unembossed side of a previously used casting film for temporary lamination with the backing cloth. The coated products obtained have properties which are commensurate with those described in the first three examples. I

Example VI The coating procedures of Examples I, II and III are repeated excepting that the casting film is formed and employed for substantial periods as a continuous belt. The backing film is temporarily laminated with the moving continuous belt on which its unembedded side is coated. After the supported film product is stripped from the belt, the embossed surface produced from the temporary lamination of the backing cloth is smoothed between heated pressure rollers before the film is returned to be further temporarily laminated with uncoated backing cloth. The coated products obtained have properties corresponding to those described in the first three examples.

Since certain changes and modifications may readily be entered into in the practice of the present invention without substantially departing from its intended spirit or scope, it is to be understood that all of the foregoing be interpreted and construed as being merely illustrative and in no sense or manner limiting of the invention, as particularly pointed out and defined in the appended claims.

What is claimed is:

1. Process for coating cloth on a moving belt of thermoplastic casting film which comprises passing said belt of casting film through heat softening means; partially embedding cloth under pressure in the'softened portion of said moving belt of casting film to temporarily laminate said cloth with said belt; applying a film layer of coating material over the unembedded side of the cloth while it is temporarily laminated withvsaid moving belt of casting film; curing the applied film layer of coating material on the cloth while it is temporarily laminated with said moving belt of casting film; separating the coated cloth from the moving belt of casting film; maintaining 10 said moving belt of casting film under a substantially constant tension; and smoothing the surface of said moving vbelt of casting film to remove cloth impressions after the belt is separated from said coated cloth before returning through the said heat softening means.

2. Process for coating cloth on moving belt of thermoplastic casting film which comprises passing said belt of casting film through heat softening means; partially em bedding cloth under pressure in the softened portion of said moving belt of casting film to temporarily laminate said cloth with said belt; applying a film layer of coating material over the unembedded side of the cloth while it is temporarily laminated with said moving belt of casting film; curing the applied film layer of coating material on the cloth while it is temporarily laminated with said moving belt of casting film; separating the coated cloth from the moving belt of casting film; maintaining said moving belt of casting film under a substantially constant tension; smoothing the surface of said moving belt of casting film to remove cloth impressions after the belt is separated from said coated cloth and before returning through said heat softening means; and applying additional quantities of casting film forming material directly on said belt to maintain it at a predetermined thickness.

References Cited in the file of this patent UNITED STATES PATENTS 1,634,710 Crowell July 5, 1927 2,193,496 Schwartz et a1 Mar. 12, 1940 2,442,443 Swallow June 1, 1948 2,444,094 Duggan June 29, 1948 2,595,127 Coffey Apr. 29, 1952, 2,618,580 Lancaster Nov. 18, 1952 2,700,630 Bukey et a1 Jan. 25, 1955 2,706,699 Plansoen et al Apr. 19, 1955 2,723,962 Hedges et a1. Nov. 15, 1955

Claims (1)

1. PROCESS FOR COATING CLOTH ON A MOVING BELT OF THERMOPLASTIC CASTING FILM WHICH COMPRISES PASSING SAID BELT OF CASTING FILM THROUGH HEAT SOFTENING MEANS, PARTIALLY EMBEDDING CLOTH UNDER PRESSURE IN THE SOFTENED PORTION OF SAID MOVING BELT OF CASTING FILM TO TEMPORARILY LAMINATE SAID CLOTH WITH SAID BELT, APPLYING A FILM LAYER OF COATING MATERIAL OVER THE UNEMBEDDED SIDE OF THE CLOTH WHILE IT IS TEMPORARILY LAMINATED WITH SAID MOVING BELT OF CASTING FILM, CURING THE APPLIED FILM LAYER OF COATING MATERIAL ON THE CLOTH WHILE IT IS TEMPORARILY LAMINATED WITH SAID MOVING BELT OF CASTING FILM, SEPARATING THE COATED CLOTH FROM THE MOVING BELT OF CASTING FILM; MAINTAINING SAID MOVING BELT OF CASTING FILM UNDER A SUBSTANTIALLY CONSTANT TENSION, AND SMOOTHING THE SURFACE OF SAID MOVING BELT OF CASTING FILM TO REMOVE CLOTH IMPRESSIONS AFTER THE BELT IS SEPARATED FROM SAID COATED CLOTH BEFORE RETURNING THROUGH THE SAID HEAT SOFTENING MEANS.

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