US 3026225 A
Description (OCR text may contain errors)
c. A. OSTBY, JR 3,026,225
Mmh 20, 1962 Filed Sept. 9, 1957 [Z /z flf' arc/.4 LA 70/? m M M INVENTOR.
Cliff/JUAN A. 0675) BY \\\;BW;JL
ATTORNEY United States Patent Gflice 3,025,225 Patented Mar. 20, 1962 Jersey Filed Sept. 9, 1957, Ser. No. 682,793 Claims. (Cl. 15450) This invention relates to waterproof garments formed of fabric coated with a thermoplastic material, such as a polyvinyl resin, or coated with any of the synthetic rubbers or combinations thereof. More particularly, the invention relates to the seams of such garments.
Heretofore, such seams have been formed by sewing or by cementing together adjacent pieces of coated fabric, or by a combination of sewing and cementing. In forming such seams, it was necessary to fold the marginal edges to be joined in order to conceal the raw edges of the fabric from the exterior of the garment so as to prevent wicking of water via the fabric into the interior of the garment. In the case of bonding operations, folding of the marginal edges was also necessary to present the coated surfaces in contact with each other. Because of the folding and sewing operations, such seams are of necessity expensive to form, and, because of the presence of the fold or folds, are unduly bulky. In addition to the expensive sewing operation, the stitches of the sewn seam had to be treated with a waterproof material to prevent wicking of water into the interior of the garment through the stitches.
Bonded seams formed by folding the edges of two adjacent panels inwardly and bonding the coated surfaces together in face-to-face relationship, proved to be rather weak, since the stresses set up on the seams during use of the resulting garments caused the coating material on one panel to peel away from the coating material on the adjacent panel, or caused the coating material to peel away from the base fabric with ultimate failure of the seam. Attempts to strengthen such seams by increasing the width of the bonded area merely resulted in a more bulky seam, since little extra strength is derived from a wider seam constructed in this manner, as the stresses tending to destroy the junction are concentrated along the line of first contact of the two panels.
The primary object of the present invention is to provide a seam for a garment formed of fabric coated with a thermoplastic resin or synthetic rubber, with no folding operation, no sewing operation, no additional adhesive, and no additional waterproofing material being required in the formation thereof, and the resulting seam being essentially as strong and as waterproof as the coated fabric and, an important feature, presenting a pleasing outward appearance.
Another object of this invention is to make rainwear of coated textile fabrics with overlapped seams in which the edge of the upper fabric is buried in the underlying coating and in which there is an interlocking of the coated fabrics by the coating material without the use of a stitching thread.
The foregoing as well as other objects will become apparent when the following description is read with the appended drawing in view.
FIG. 1 is a view showing a portion of a rainwear garment embodying the features of this invention;
FIG. 2 is a sectional view of the seam on the line 2-2 in the garment of FIG. 1;
FIG. 3 is a view illustrating the manner in which the sheet material is overlapped prior to the heat sealing operation; and
FIG. 4 is a perspective view showing the material in an apparatus for making the seam.
In accordance with the present invention, the seam for the garment is formed by overlapping the edges of the coated fabric with the face of one layer in contact with the underside of the other layer, and then heating the lapped edges under pressure to cause the coating material to penetrate into and become bonded to the fabric of the top layer and to simultaneously cause the coating material to flow around and seal the raw edge of the fabric on the outward side of the seam to produce a continuous film of coating material on the outside of the garment. In this manner, a waterproof seam having a finished appearance is produced.
Although rainwear garments have a number of seams joining panels or sheets together, all seams in the garment have the same general construction, and, for an understanding of their construction, only one seam need be considered. Accordingly, the garment of the invention is shown in FIG. 1 to comprise two panels 12 and 13 having a seam 14. The particular garment is shown in the form of a coat 11 having a seam 14 extending down the back thereof.
As illustrated in FIGS. 2 and 3, the panels 12 and 13 are formed of a knitted or woven fabric, the fabric of the two panels being separately designated as 15 and 16 and being coated with layers 17 and 18, respectively, of a thermoplastic resin, such as polyvinyl chloride or a synthetic rubber, such as neoprene (polychloroprene). In the case of the synthetic rubber, it is preferable to form the seam while the rubber coating is in the uncured state, with curing of the rubber being carried out subsequent to the seam formation. This subsequent curing step can readily be performed under conditions which will have no adverse effect on the textile fabrics.
In the construction of the product of this invention, the resin or rubber coating is applied over one surface of the fabric by any of the coating or laminating methods well known to those skilled in the art. It is preferable to have this waterproof coating material adhere to the surface of the fabric without any substantial penetration into the interstices thereof. The thickness of the coating is generally equal to that of the textile or may possibly be slightly greater. The thickness of the seam is substantially less than twice the thickness of the coated fabric, and can conveniently be less than 1.5 times said fabric thickness. By way of illustration, the textile fabric may Weigh 9 ounces per square yard, have 55 thread ends per inch, a gauge of .0208 inch and a tensile strength of about 150 pounds per square inch. The waterproof coating will have generally the same thickness and a tensile strength of about pounds per square inch. As a result, the composite material of this example has a total tensile strength of about to 200 pounds per square inch and a composite thickness of about .04 inch. In rainwear garments of the heavy duty type, it is desirable that the seams have a tensile strength greater than 100 pounds per square inch, and this result is readily achieved with the process and product of this invention.
In making the seam according to this invention, marginal edge portions of the panels 12 and 13 are disposed in overlapping relationship as shown in FIG. 3, so that the underside of the fabric of one panel lies against the coating on the face of the other panel. The amount of the overlap partially determines the strength of the seam, but from the standpoint of appearance its width is immaterial. For the required tensile strength of greater than 100 pounds, a seam width of one-half inch is satisfactory.
Heat and pressure are next applied to the overlapped area by electrodes or heated bars of suitable width, e.g., one-half inch, and proper length thereby causing the coatings 17 and 18 to soften and flow so as to penetrate the fabrics 15 and 16, with the results that the panels become integrally bonded together and the fabric 16 becomes embedded in united coating layers 17 and 18 as shown in FIG. 2. Simultaneously, a sutficient amount of coating material flows around the raw edge 19 of the fabric 16 to seal this edge against subsequent wicking of water into the interior of the garment. Coating 13 on fabric 15 starts, as shown in FIG; 3, at a higher level than coating 17 on fabric 15, but, as a result of the heat and pressure applied in the seam area, coating 18 is compressed to the level of coating 17 and there is a small taper in the level of coating 13 between the sealed and unsealed portions thereof, as is shown (somewhat exaggerated) at 2-0 in FIG. 2. Actually, the taper made by the fiow of the ma terial is so slight that the step on the coated surface is practically unnoticeable. The step on the fabric side, as at the end 21, is somewhat more pronounced, but, being on the inside of the garment, this does not detract from the pleasing appearance of the seal.
The heat and pressure are conveniently applied to the overlap by means of a press in which the platens are electrodes of a radio frequency oscillator or in which the platens or sealing bars are heated electrically or by any other suitable means. In such apparatus, shown in FIG. 4, the top platen 22 has a width equal to the desired seam width and a length that is practical for operation. It is preferable that the wi th of this platen be greater than the Width of the overlap, as the successful sealing of the raw fabric edge is thereby insured. The lower platen 23 may form part of a table of convenient size to support the panels and acts as a pressure resisting member for the upper platen. The platens are made of a suitably hard, smooth surfaced material such as brass. The overlap is placed on the lower platen 23 with the edge 19 of the top fabric 16. directly under the upper platen 22. On closing of the press and operation of the radio frequency oscillator for brief intervals, the coatings are softened by the generated heat. A pressure of about 30 pounds per square inch and a temperature of about 200 F. are generally suitable in the case of thermoplastic resin coatings. In the radio frequency heat sealing type of apparatus, although the material to be sealed reaches an elevated temperature, the electrodes remain relatively'coo-l. The overlap can be placed into the press with the coated side facing either the upper or lower platen, although the coating-up position is preferred so that the operator can maintain the overlap in proper registration. Apparatus, in which heat is supplied by 2. directly heated upper platen which presses the material against a cold lower platen, can also be utilized in carrying out the invention. in using such apparatus, as well as in the case of the radio frequency type of apparatus, no problem is encountered as regards sticking of the specified coating materials to the platens.
From the above description, it can be seen that the invention comprises a rainwear garment of coated fabric having a seam that is strong, waterproof, and highlypliable, has no raw edge exposed, and is attractive in appearance, and a method for making such seamed garments. This method requires no folding, adhesives, tapes, or stitching in the formation of the seams.
While the use of certain specific fabrics, coatings, temperatures, etc. have been described in connection with the invention, it is to be understood that this is for the purpose of illustration and that changes and modifications may be made therein without departing from the spirit and scope of the invention which is intended to be covered by the appended claims.
Having thus described my invention, what I claim and desire to protect by Letters Patent is:
l. A waterproof garment comprising at least two adjoining panels of single ply textile fabric, each of said panels having an adhering, substantially non-penetrating coating of a material selected from the group consisting of thermoplastic resins and synthetic rubbers on the exterior surface of said fabric, the adjacent marginal edge portions of said adjoining panels being overlapped with their coated surfaces facing in the same direction and joined together by penetration of said coating material into the interstices of the fabric in the overlapped marginal edge portions through the application of heat and pressure to said overlapped portions, the coatings of the overlapped portions being united together by said penetration so as to interlock the adjoining panels, and the total thickness of said overlapped marginal edge portions being substantially less than twice the thickness of the coated fabric panels.
2. A waterproof garment comprising at least two adjoining panels of single ply textile fabric selected from the group consisting of knitted fabric and woven fabric, each of said panels having arr adhering, substantially nonpenetrating coating of a material selected from the group consisting of thermoplastic resins and synthetic rubbers on the exterior surface of said fabric, the adjacent marginal edge portions of said adjoining panels being overlapped with their coated surfaces facing in the same direction and joined together by penetration of said coating material into the interstices of the fabric in the overlapped marginal edge portions through the application of heat and pressure to said overlapped portions, the coatings of the overlapped portions being united together by said penetration so as to interlock the adjoining panels, the overlapped edge of the fabric of the outer one panel being embedded in the coating of the other panel and the coating of said outer one panel tapering into and uniting with the coating of said other panel at said overlapped edge so as to form a continuous film of coating material on the exterior surface of said garment and to seal said overlapped edge, and the total thickness of said overlapped marginal edge portions being substantially less than twice the thickness of the coated fabric panels.
3. A waterproof garment as defined in claim 2 wherein the coating material is a polyvinyl chloride resin.
4. A method of joining at least two panels of single ply textile fabric, each of said panels having an adhering, substantially nonpenetrating coating of a material selected from the group consisting of thermoplastic resins and uncured synthetic rubbers on one side of said fabric, comprising overlapping adjacent marginal edge portions of said panels with the uncoated surface of one panel in contact with the coated surface of the other panel, applying heat and pressure to said overlapped marginal portions to soften and force said coating material into the interstices of the fabric in the overlapped marginal portions so as to unite the coatings of said overlapped marginal portions thereby interlocking the adjoining panels, and to compress the total thickness of said overlapped marginal portions to substantially less than twice the thickness of the coated fabric panels, and, in the case of the synthetic rubber coatings, subsequently curing said synthetic rubber coating;
5. A method of making a waterproof garment from at least two adjoining panels of single ply textile fabric, each of said panels having an adhering, substantially nonpenetrating coating of a material selected from the class consisting of thermoplastic resins and uncured synthetic rubbers on the exterior surface of said fabric, comprising overlapping adjacent marginal edge portions of said panels with the uncoated surface of the upper one panel incontact with the coated surface of the other panel,
applying heat and pressure to said overlapped marginal fabric panels, and to embed the overlapped edge of the outer one panel in the coating of the other panel and to simultaneously taper and unite the coating of the upper one panel with the coating of the other panel at said overlapped edge thereby forming a continuous film of coating material on the exterior surface of said garment and sealing said overlapped edge of the outer one panel, and, in the case of the synthetic rubber coatings, subsequently curing said synthetic rubber coating.
References Cited in the file of this patent UNITED STATES PATENTS 6 Steinberger Apr. 4, 1939 Wagner Oct. 17, 1939 Reiss et al. Oct. 7, 1941 Shmikler Feb. 12, 1946 Rodman July 8, 1947 Callahan et al June 8, 1948 Platt a Jan. 31, 1950 Kennedy Dec. 18, 1951 Kaplan Sept. 9, 1952 Cunningham Oct. 28, 1952 Messing Dec. 9, 1952 Arnold July 20, 1954 FOREIGN PATENTS Great Britain of 1897