US2677496A - Bag, composite material, and method of making - Google Patents

Description

May 4, 1954 H. H. MAYNES 2,677,496

BAG, COMPOSITE MATERIAL AND METHOD OF MAKING Filed Sept. 22, 1950 JNVENTOR.- Harold H. Muynes B ze Y MAW ATTORN EY Patentecl May 4, 1954 BAG, COMPOSITE MATERIAL, AND METHOD OF MAKING Harold H. Maynes, Sparta, N. J., assigner to Arkell Safety Bag Company, New York, N. Y., a corporation of New York Application September 22, 1950, SerialNo. 186,130

3 Claims. 1

The present invention relates to bags made of reinforced laminated or composite crinkled paper, andvfurther relates to such composite material, and method of forming the same.

The obj ect of the invention is to provide a novel and improved bag, composite material and method of this character.

The invention is illustrated, by way of example, in the accompanying drawings, in which:

Figure l is a diagrammatical side View, partly in section, of an apparatus that may be employed in carrying out my improved method;

Fig. 2 is a diagrammatical longitudinal sectional view of the composite material greatly enlarged; and

Fig. 3 is a side view, with one ply partly broken away, of my improved bag.

The composite material from which my improved ba-g is formed may be made of twosheets or webs 2 and Land a sheet or web of non-woven fabric t of ber glass.

The paper sheets or webs 2 and 4 may be made of kraft or other strong crinkled paper. Preferably the crinkles extend generally transversely of the sheets and are of substantially the same stretchability. The degree of stretchability may be varied, but in making bags of the material I have obtained most satisfactory results with crinkled paper having approximately 6% to 8% stretchability. The crinkling is preferably formed by the water-crepe method which consists in passing each web to be orinkled through a water bath to a crinkling cylinder where it is removed by means of a doctor blade. By crinkling the sheets by the water-crepe method, it has been found that they have maximum elasticity.

The non-woven glass fabric 6 is made up of transverse and longitudinally extending yarns or threads 3 and 5, respectively, which are lightly secured together where they cross by asphaltic or other adhesive, the adhesive being applied by first running the longitudinal strands through the adhesive before the longitudinal and transverse strands are brought together one over the other. Any desired mesh may be employed such as 2 x 2 0X2" mesh) and 4 x 4 UA1 mesh), depending on the reinforcement, especially the tensile strength desired. The strands or threads may be relatively fine, corresponding substantially in diameter to ordinary six-cord cotton sewing thread, but the size of the threads may be varied to meet different conditions.

In forming the composite material, the crinkled webs 2 and 4 may be drawn from supply rolls 8, and the glass fabric 6 from a supply roll l0.

The paper Webs with the glass fabric between them pass between two driven nip rolls i2. The upper web 2 passes over idlers M to the tip rolls and the lower web d passes over idlers it and between a coating roll iii and a guide roll 20. The coating roll i8 receives asphaltic adhesive 22 from a metering and doctor roll 2e, thus controlling the amount of adhesive applied to the web 4.

The adhesive in the pan Z5 may be asphalt containing rubber or other elastomer so as to apply a more or less elastic coating to the web d which will remain tacky and elastic when set under Varying atmospheric conditions. The coating applied to the web 6i is preferably thick enough to substantially ll the valleys between the crinkles as well as to cover the ridges of the crinkles As the glass fabric E passes with the paper webs between the nip rolls l2, the strands or threads of the fabric are forced down into the coating o n the lower web 4 so as to be thoroughly embedded and covered thereby. The pressure of the nip rolls is such as to insure iirm adherence of the crests of the crinkles of the web 2 to the web 4 and the threads of the fabric e. Preferably the pressure of the nip rolls should not be suicient to cause the coating to be forced materially into the valleys of the crinlsles of the web 2.

When the two paper webs 2 and 4 and the reinforcing fabrics 6 have been thus brought together and the adhesive coating has become substantially set, the composite material may then be passed through a tubing machine, and the longitudinal edges of the material brought together in overlapping relation and glued to form the longitudinally extending seam 26. The tube as it is formed may be cut into bag lengths. The bag lengths may be closed at one end in any suitable manner as by means of a tape 2B folded over the end and held in place by adhesive or by adhesive and stitching to form the bottom of the bag. The other end of the bag may also be closed if desired and provided with a filling valve, or this end may be closed after lling the bag. The bag may have gusseted sides, or ungusseted sides as desired. Preferably the coated sheet of the bag forms the inner ply of the bag.

With the bag thus formed, the threads of the fabric .are effectively cushioned by the elastic adhesive and the crinkled paper, so that in the use of the bag there is no danger of the threads being sharply bent or fractured. The adhesive surrounding and impregnating the twisted iibers of the threads tends to hold them together and strengthen them, and to keep the threads prop- 9 .2 erly spaced. The dead air spaces provided between the valleys of the outer sheet and the adhesive coating cooperate to form a structure of cloth-like ilexibility and of maximum strength. Thus the threads are not only thoroughly protected and reinforced by the crinkled paper and adhesive, but also during use of the filled bag the fabric, crinkled paper and adhesive are arranged most effectively to cooperate to resist bursting and other strains placed on the bag.

While it is preferred to coat only .one of the webs in order to provide a light weight structure of maximum strength and flexibility, in certain instances the outer sheet may be either lightly coated to add to the moisture-procfness thereof without doing away with the air spaces between the valleys of the crinkles and the adhesive coating on the inner sheet, or a suicient amount of adhesive may be applied to the outer sheet to substantially ll the valleys thereof.

What I claim is;

l. The method of forming composite material which comprises feeding at least two Webs of crinkled paper longitudinally, the crinkles extending transversely of the webs, feeding a web oi unwoven fabric longitudinally between said webs, said fabric web being composed of threads of glass bers extending longitudinally thereof and spaced apartand threads of glass fibers extending transversely thereof and spaced apart, applying a coating of tacky adhesive to the inner side of one of the paper Webs as it is being fed with the adhesive filling the Valleys and extending over the crinkles of said web, positioning the paper and fabric webs together under such pressure as to cause the threads of the fabric to be embedded in the adhesive and to cause the uncoated web to be secured only at the crests of its crinkles to the coated web so as to cause the crinkles of the uncoated web to form air spaces between the webs.

2. Composite material of the class described comprising at least two webs of crinkled paper arranged in superposed relation with the crinkles extending transversely of the webs, a web of unwoven fabric arranged between said paper webs and composed of threads of glass fibers extending longitudinally thereof and spaced apart, and threads of glass fibers extending transversely thereof and .spaced apart, and tacky adhesive securing the webs together, the adhesive nlling the valleys and extending over the crests of the crinkles of one of the paper webs with the threads of the fabric embedded in the adhesive, and the other web being secured by the adhesive only at the crests of the crinkles thereof so as to cause the valleys of the crinkles to form dead air spaces between the webs.

3. A bag made of the composite material of claim 2 with the crinkles thereof extending circumferentially of the bag.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 91,748 Jameson June 22, 1869 1,197,315 Wandler Sept. 5, 1916 1,821,824 Woodward Sept. l, 1931 1,867,071 Collings July 12, 1932 1,870,215 Anderson Aug. 9, i932 1,871,827 Van Hulst Aug. 16, 1932 2,293,245 Fay Aug. 18, 1942 2,314,876 Greene Mar. 30, 1943 2,561,781 Bruce July 24, 1951 2,610,936 Carlson Sept. 16, 1952 FOREIGN PATENTS Number Country Date 817,841 France May 31, 1937

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