US 2739919 A
Description (OCR text may contain errors)
March 27, 1956 w. w. ARTZT 2, 3 I
PROCESS FOR COATING FABRICS Filed Aug. 14, 1955 BY 139'. #2 divans]: 7
PROCESS FOR COATING FABRICS Walter Artzt, New York, N. Y., assignor to Dualoy, Inc, New York, N. Y., a corporation of New York Application August 14, 1953, Serial No. 374,317 8 Claims. Cl. 154-95 The present invention relates generally to a process for coating fabrics, and is particularly directed to the coating of fabrics or materials having relatively large openings or crevices in the surface thereof, such as, for example, loosely knitted fabrics, mesh or net materials and laces.
Heretofore, it has been the general practice to apply waterproofing orother coatings directly to the fabric using knife coating, roller coating or brush or spray equipment for the purpose of applying the coating in a liquid condition. This practice is successful, particularly if a relatively thin and smooth coating is desired, only when the fabric being coated is tightly woven or knitted and has a relatively smooth surface. Since the coating applied in a liquid condition directly to the fabric tends to seep into the openings or crevices in the surface of the fabric and to follow the irregularities of that surface, the use of such a coating procedure in connection with looselywoven or knitted fabrics, such as, net, mesh and lace, results in a coating having a rough surface and non-uniform thickness penetrating, at points, completely through the fabric. If further coatings are applied on top of the initial coating in an attempt to smooth out the surface of the coating, the resultant coating becomes objectionably thick and coarse. Further, where the coating is applied directly to a fabric having large openings therein, there is a likelihood that the coating will fail to close all of such openings and the coated fabric will not be fully waterproofed.
The usual practice of applying the coating in liquid condition directly to the fabric requires that the latter be longitudinally-tensioned or stretched during the coating operation to obtain some degree of uniformity in the thickness of the coating applied thereto. However, such longitudinal tensionirig of the fabric during coating tends to reduce or completely eliminate the longitudinal elasticity of the fabric following the application of the coating and also reduces the transverse dimension of the fabric.
Accordingly, it is an object of the present invention to provide a process for coating fabrics, which may be loosely woven or knitted, while avoiding the above mentioned objectionable characteristics and disadvantages of the usual coating procedures.
More specifically, it is an object of the present invention to provide a process for applying a coating to a fabric, which may be loosely woven or knitted, wherein the resulting lamination may be completely impervious to water, presents a smooth coated surface, is resilient and can have a small thickness with any desirable hand, that is, texture or feel.
In accordance with the present invention, the foregoing, and other objects, features and advantages appearing in the following detailed description, are achieved by first casting a thin film of any suitable coating material, preferably a plastic of the thermo-setting type, in a liquid or semi-liquid condition on a smooth carrier surface, for example, the surface of a carrier sheet, and then solidifying the cast film. An adhesive or binder is nextapplied 2,739,919 Patented Mar. 27, 1956 to the cast filmon the carrier sheet and the fabric or material to be coated is then rolled onto the adhesive bearing surface of the cast filni aiid adhered to the latter with a minimum of longitudinal tension being applied to the fabric or material. I Finally, the carrier sheet is stripped from the coating film to lea've a lamination including the coating film and the material or fabric to which it is adhered.
In order that the present invention may be fully understood, an illustrative embodiment thereof is hereinafter described in detail, merely by wayof'ekample, with reference being bad to the accompanying drawing forming a part hereof and wherein;
Fig. 1 is a diagrammatic side elevational view of apparatus in which an initial step or operation of a process embodying the present invention may be-perfor med;
Fig.2 is aflfr'agmentar'y and, diagrammatic top plan view of a portion of the apparatus shown inFig. 1; and
' Fig. 3 is a diagrammatic side elevational view of apstance thereon to provide; a smooth surface which will-- not adhere to the coatingmaterial when the latter is cast onto the carrier strip, is drawn from a roll 14 and passes horizontally under the hopper 10 over asuitable support, such as, for example, a series of idler rollslfi, so that the coating material pours from the-hopper and is deposited npon the upper surface of the carrier strip. Suitable guides 18 extend from the'vici'nity of the hopper along the opposite longitudinal edge portions of thelrori- Zontally moving carrier strip to limit the lateral extent of the layer or film of coating material cast on the carrier strip, and such guides are preferably adjustable laterally for varying the lateral dimensions of the cast film of coating material. i
A doctoring knife 20 extends laterally between the discharge ends'o'f the guides 18 and is vertically adjustable,
for example, by agear and rack arrangement 22, to
spread the coating material deposited on the moving carrier strip to thedesired thickness, for example, a thickness of approximately three-thousandths of an inch. After passing under the doctoring knife 20, the carrier'strip 12, having a thin film 24 of coating material thereon, moves through an oven 26 and is. there subjected to suflicient heat for solidifying or coagulating the film 24. The temperature in the .oven 26 maybe within the range from 500 to 600 Fahrenheit for coating with a vinyl resin, but it is apparent thatthis temperature may vary from the stated range in dependence upon the length of the oven, the speed of travel ofthe carrier strip through-the oven and the material making up the cast film 24. Upon removal from the oven 26, the carrier strip having a cast film of coating material thereon is either wound into a roll 28 orfed directlytoapparatus (Fig. 3) inwhich further steps or operations are performed inaccordance with the present invention;
While a particular method and apparatus has been described for obtaining the coagulated film of coating material upon thecarrier strip, it is to be understood that the invention is not "limited thereto since the film of coating material may be deposited by any other conventional and suitable equipment, such as, for example, by spraying,
brushing or rolling a film of coating material on the carrier strip, and the cast film of coating material may be coagulated or solidified on the carrier strip .by known chemical means in place of the heating provided by passage through the oven. t
After the film 24 of coating material has been cast on the carrier strip 12, a film of suitable adhesive having a strong afiinity for the coating material and for the material or fabric to be coated, such as,'t or example, adhesives of the solvent evaporation, thermal fusion, thermosetting 'or pressure-sensitive types, is deposited upon the cast film of coating material and the material or fabric to be coated is then rolled onto the adhesive film under pressure, or under combined pressure and heat depending upon the adhesive employed. After the material or fabric to be coated has been afiixed to the'filmof coating material, the carrier strip is separated fromthe latter for reuse leaving a lamination of the material or fabric witha coating thereon.
Referring in' detail to Fig. 3 of the drawing, suitable I apparatus is there shown for applying adhesive to the film of coating material, for rolling the'material or fabric to be coated onto the adhesive, for setting the adhesive, and'then for separating the carrier strip from the lamination of fabric and coating. In such apparatus, the carrier strip 12 with the film 24 of coating material thereon is drawneither from the roll 28 or directly from the discharge end of the apparatus of Figs. 1 and'2 and moves horizontally over suitable sup'portingmeans,forexample, idler rollers 16a, under the discharge spout of a hopper 10a in which a suitable adhesive, for example, a vinyl resin adhesive, is stored. The adhesive pours onto the film 24 of coating material and is laterally limited by guides 18a extending along the opposite longitudinal edge portions of the moving strip, while a laterally extending doctoring knife 20a at the discharge ends of the guides serves to determine the thickness of the film of adhesive deposited on the film bf coating material. The knife '20a'is preferably vertically adjustable to control the thickness of the adhesive film which is approximately three-thousandths of an inch.
The fabric or material to be coated, which may be loosely woven or knitted, for example, mesh, net or lace fabric, or paper, leatherand the like, isdrawn from a roll 30 under a guide roller 32 in front of the doctoring knife 2%, and the fabric or material to be coated 34 is pressed against the adhesive on the upper surface of the coating film 24 by a set of pressure rollers 36 between which the fabric or material 34 and the carrier strip. 12
In order to solidify the adhesive bond between the fabric or material 34 and the coating film 24, the lamination thereof passes from the pressure rollers 36 through a suitable oven 33 heated to a temperature of approXi mately 550 Fahrenheit which is sufficient to fuse the adhesive to the fabric or material beingfcoated.
After emergence from the oven 38, the fabric or material 34 with the coating 24 thereon is taken up on a roll 40, while the carrier strip 12 is wound onto a separate take-up roll 42 thereby separating the carrier strip from the coating on the fabric or material 34 and salvaging the relatively expensive'release paper of the carrier strip for reuse in the process.
it is to be understood that suitable fillers, chemicals and the like can beadded tothe coating material and to the dhesive, or to either alone, for varying the charac- 'teristics, such as elasticity and porosity, of the completed lamination. Further, when the material vor fabric 34 to be coated is formed of a substance, such as 'hylon, which contracts when subjected to heat and moisture or either alone, such fabric'is initially heated before being affixed to the adhesive carrying coating, for example, by heating the guide roller 32, so" that the fabric 34 will be contracted by the preheating'and no distortion of the lamination will occur during heating thereof in the oven 33. lreferably, the pre-heat setting of the fabric or material to be coated is carried out at a temperature greater than a 4 that employed within the oven 38 to ensure the dimensional stability of the lamination.
While the adhesive is applied to the cast film 24 of the coating material in the above described embodiment of the invention, it may be desirable in certain circumstances to apply the adhesive to the under surface of the fabric 34, as by spraying, as it is drawn from the roll 30. Further, at times it may be possible to dispense with the adhesive, and to secure the fabric 34 directly to the cast film 24 by rolling the fabric into the 'latterafter the coating material, or at least the upper surface thereof has been suitably softened. The elimination of. the adhesive permits production of a thinner lamination, but; it also detracts from the water proofing characteristics thereof.
If the fabric or material 34 is longitudinally elastic, it retains that elasticity even after application to the cast film of coating material as there is no need to apply'any substantial tension to the fabric during passage through the set of pressure rollers 36. However, if it is desirable to obtain a lamination of restricted elasticity in the longitudinal direction, this characteristic can be obtained merely by longitudinally tensioning the fabric 34 as it is being adhesively aflixed to the film of coating material.
It has been found that the releasepaper einployedfor the carrier strip 12 can normally bereused only eight times. Since this paper is relatively expensive, its reuse can be extended up to ten times its normal life by spraying nylon thereon so as to encase the paper carrier and then baking the nylon coated paper in an oven at a tempera Further, if desired, an inked 'or painted impression can be applied to the carrier strip 12 prior to thecasting of the film 24 thereon so that, when thecarrier strip is finally separated from the lamination, such inked. or painted impression is transferred to the exposed surface of the film of coating material. Other decorative effects can be obtained either by embossing the completed lami nation of fabric and coating material'or byvinitially embossing the carrier strip so that the film of coating material 'cast on the embossed carrier strip will conform to the pattern of the latter. 1
When the coating material; is applied to a fabric in accordance with the process embodying this invention, that is, by initially casting a filmof the coating material on a carrier strip or surface, eXcess penetration of the coating material into the fabric is avoided as the latter rests upon the cast film rather thanserving as a support for the coating material as thelatter is being applied.
Further, the film of coating materiaLis always smooth even when aflixed to a coarse textured fabric or to a fabric having large openings therein since thecast film follows the relatively smooth surface of the carrier strip rather.
than the irregular surface of, the base fabric being coated. While specific embodiments of the invention have been described in detail merely byway of example, it is to be understood that the inventionis not limitedto these preto the latter, and separating said carrier sheet from the V lamination formed by said film of coating material and the sheet material bonded thereto. I
2. A process for coating sheet materials comprising the steps of applying a low viscosity film'of coating material to the upper surface of a carrier strip, solidifying said filmuof coating material on the carrier strip,'applying. I
adhesive to the solidified film of coating material on the carrier strip and then immediately rolling a sheet material onto the adhesive carryi 11g film of coating material and setting said adhesive to bond said sheet material to said film of coating material, and separating said carrier strip from the lamination formed by said film of coating material and the sheet material bonded thereto.
3. A process for coating fabric comprising the steps of applying a film of thermo-set'ting plastic in liquid condition to the upper surface of a carrier strip, heating said film to effect the solidification thereof, applying an adhesive to the solidified film on the carrier strip and then immediately rolling a fabric onto the adhesive carrying surface of the plastic film, setting the adhesive to bond said fabric to the plastic film, and separating said carrier strip from the lamination formed by said plastic film and the fabric bonded thereto.
4. A process for coating fabric comprising the steps of applying a film of vinyl resin in liquid condition to the upper surface of a carrier strip, heating said film to effect the solidification thereof, applying a vinyl resin adhesive in liquid condition to said solidified film on the carrier strip, pressing a fabric onto the adhesive carrying surface of said film prior to setting of the adhesive, heating said fabric, adhesive and film on the carrier strip to set the adhesive and bond said fabric to the film, and separating said carrier ship from the lamination formed by said film and said fabric bonded thereto.
5. A process for coating a nylon fabric comprising the steps of applying a low viscosity film of thermo-setting coating material to a carrier strip, heating said film on the carrier strip to effect the solidification thereof, applying a flowing film of thermo-setting adhesive to said solidified coating, heating the nylon fabric to be coated to a temperature substantially greater than that required for setting of said adhesive and pressing said heated fabric against the adhesive carrying surface of said film while the adhesive is in flowing condition, heating said fabric, adhesive and film to effect setting of said adhesive so that said fabric is bonded to said film, and separating said carrier strips from the lamination formed by said film and said fabric bonded thereto.
6. A process for coating fabric comprising the steps of passing a carrier strip formed of release paper horizontally below a hopper discharging a thermo-setting coating material in at least semi-liquid condition, spreading the discharged coating material to provide a relatively thin film thereof on the top surface of the carrier strip, heating said film to effect solidification thereof, applying a flowing film of thermo-setting adhesive on top of the solidified film of coating material, bringing a fabric into contact with the adhesive carrying surface of said film of coating material while the adhesive is still in a flowing condition and passing said fabric, coating material and carrier strip through pressure rollers and then through a heated zone to set the adhesive and provide a firm bond between said fabric and said film of coating material, and separating said carrier strip from the lamination for-med by said film of coating material and the fabric bonded thereto.
7. A process for coating sheet materials comprising the steps of applying a pigmented impression to a carrier strip having little affinity for the impression, applying a film of coating material onto said strip over the pigmented impression, adhering a sheet material to said film of coating material on the carrier strip, and separating said carrier strip from the lamination formed by said film of coating material and the sheet material adhering to the latter so that the pigmented impression is transferred to the exposed surface of said film of coating material.
'8. A process for coating sheet materials comprising the steps of embossing a carrier strip to provide a design in relief on the latter, applying a film of coating material on said carrier strip, adhering a sheet material to said film of coating material on the embossed carrier strip, and separating said carrier strip from the lamination formed by said film of coating material and the sheet material adhering to the latter so that the exposed surface of the coating material carries a design in relief corresponding to that initially embossed in said carrier strip.
References Cited in the file of this patent UNITED STATES PATENTS 2,404,073 Karfiol et a1 July 16, 1946 2,631,958 Francis Mar. 17, 1953