US2046146A - Bag - Google Patents

Description

.June 30, 1936. Q v. BRADY 2,046,146

BAG

Filed April 22, 1955 Patented June 30, 1936 UNITED STATES PATENT OFFICE BAG ration of Missouri Application April 22, 1935, Serial No. 17,585

6 Claims.

This invention relates to bags, and with regard to certain more specific features, to bags particularly adapted for the packaging of powdered material.

Among the several objects of the invention may be noted the provision of a bag adapted to package powdered material, such as sodium aluminate, flour, powdered asphalt, insecticides, and the like, which, upon filling the bag, carry entrapped air, said bag being provided with a structure whereby the entrapped airis immediately released, whereby a tightly filled bag is at once obtained; and the provision of a bag of the class described which is simple in construction and economical to manufacture. Other objects Will be in part obvious and in part pointed out hereinafter.

The invention accordingly comprises the elements and combinations of elements, features of construction, and arrangements of parts which will be exemplified in the structures hereinafter described, and the scope of the application of which will be indicated in the following claims.

In the accompanying drawing, in which are illustratedseveral of various possible embodiments of the invention,

Fig. 1 is a perspective View of a bag embodying the present invention, certain seams being opened or unfolded in order to show the construction of the bag.

Fig. 2 is a cross section taken substantially along line 2-2 of Fig. 1;

Fig. 3 is a greatly enlarged, diagrammatic cross section illustrating one form of the invention; and,

Figures 4 and 5 are sections similar to Fig. 3, illustrating further forms of the invention.

Similar reference characters indicate corresponding parts throughout the several views of the drawing.

It is a well known fact that certain finely powdered materials, such as those above set forth, exhibit a tendency upon their being discharged into a bag, in the course of their packaging, to entrap quantities of air which are not readily released from the mass of powdered material in the bag, unless the bag is porous and hence not waterproof. There are numerous instances when it iS necessary that such materials (which will be referred to hereinafter as being puiy) be packaged in waterproof bags. In such instances, with prior types of bags, one of two procedures needed to be followed: (l) either the lled bag had to be allowed to stand for some time until the entrapped air all came to the top, and thereafter seamed shut, or (2) a bag of excessively great capacity for the amount of material to be packaged needed to be employed. In the rst instance, storage space was required during the settling of the material. In addition, the time element necessary for settling was objectionable. In the .second in- 5 stance, the larger bags for a given quantity of material were necessarily more expensive, and in addition, when the air entrapped in the material finally did separate, the result was a abby, loosely packed bag.

The present invention provides a successful solution of the problem of providing waterproof bags for such puffy, powdered materials.

Referring now more particularly to Fig. 1, there is illustrated a bag made in accordance with the 15 present invention. The bag comprises an outer envelope I, together with an inner envelope or tube 2. The outer envelope I is formed of a laminated material (see Fig. 2), made up of a fabric (usually burlap) layer 3 on the outside, to which 20 is adhered, by a cementitious layer 4, an inner paper layer 5. The cement 4 frequently comprises asphalt or latex, either of which is eminently suitable. 'I'he paper layer 5 frequently comprises creped paper, as is customary in this art. This 25 laminated material is so formed that it is siftproof, waterproof, and otherwise impervious.

In forming the bag or envelope I from the laminated material thus constituted, a sce-m 6 (see also Fig. 2) is made along the joined longitudinal 3U edges of the laminated fabric web. This seam 6 is so constructed, that there is a region I provided in which the fabric layers overlap each other, as well as a region 8, in which the paper layers overlap each other. Adhesive material, such as latex, 35 is desirably positioned in each of these overlapping positions, as indicated at numeral 9; but it is desirable that the adhesive 9 in the region 8 be prevented from extending entirely to the end of said region, leaving a region Ill in which there '-0 is a loose overlap of paper. The construction of the seam E is not a part of the present invention, and hence is not described in great detail herein.

The envelope I thus comprises a tube open at both ends. In order to form this tube into a 4 bag, one end thereof is closed by a folded cover strip II (see Figures l and 3) held in position by adhesive such as latex. This construction is also claimed elsewhere. and per se forms no part of the present invention. 5

The envelope I, it will readily be seen, is a complete bag in itself. However, it is so impervious or non-porous, that if it be attempted to ll it with a powdered puffy material such as those hereinbefore indicated, it does not provide for release of the entrapped air and all the diiculties noted above are thus encountered. It is through the use ofthe additional, inner envelope or tube 2 that these diiiculties are eliminated. The tube 2 preferably comprises a porous paper. Such a paper, for example, comprises an uncalendered, unsized or substantially unsized manila or like paper. It is .formed to tubular contour by overlapping its edges and cementing or gluing them together in a simple lap seam I3 (see Fig. 2). The tube 2 is desirably made just enoughsmaller in diameter than the tube I, so that it will t easily but snugly there- 1n.

In the finished bag, no separate closure is ordinarily provided for the-bottom end of the tube 2. A portion of the cement which holds the cover strip II to the bag may penetrate into the interiorof the bag and lightly tack or secure the lower end of the envelope 2 to the lower endl of the envelope I. Thus, the envelope 2 may be held to the bag as a composite unit.

The bag, as thus provided with the loose fitting paper liner 2, is extraordinarily effective for the packaging of powdered material such as those described. The reason for this effectiveness is brought out diagrammatically in Fig. 3, which is an enlarged cross section of an edge region on a filled bag. The paper layer 2, it will be recalled. is porous. This means that it will permit the passage therethrough of entrapped air from the materials being packaged, indicated by numeral I5. At the same time, it' is not so porous that it would readily permit the sifting therethrough of the material I5. It will be seen that the air initially entrapped with the inflowing material finds its way to the porous envelope 2 because the shortest exit distances through the mass of material are lateral.

The creped paper layer 5 has, it will be understood, an irregular surface I6. This surface I6 provides a large number of irregular channels or passages I'I, all of which lead, through more or less devious paths, to the top of the bag. These channels I'I afford a passage from the bag for the entrapped air in the material I5, which passes through the porous paper layer 2. They are not clogged up by the material I5 itself, because the paper layer 2 substantially prevents the passing of said powdered material therethrough.

It has been found that bags constructed in accordance with this embodiment of the invention may be readily and quickly filled with the most puffy material, and that while the filling goes on, the material packs down firmly, allowing the immediate escape of all entrapped air, and permitting the bag to be solidly and completely filled and closed all in one immediate sequence of `op erations.

From the above it will be seen thatV the broader concept of the invention is the provision of a double bag, the outer bag material being substantially impervious and sift-proof, while the inner bag material is porous to lair, and the provision by non-matched surfaces between said two materials of an interfacial region having passages or spaces permitting the outiiow of air from the bag.

Within this broad description, many other embodiments of the invention are possible. For example, in Fig. 4 there is illustrated a construction in which the paper liner 5 of the outer bag laminated material is smooth-surfaced, such as would be obtained when a kraft or similar calthe market, in appearance.

endered paper is used as the liner. 'In order to provide an efcient bag within the present invention, when employing such a liner, it is desirable that the bag layer 2 be formed of fluted porous paper. The flutes are indicated by numeral I8. 5 They provide passages I9, of regular shape and direction, for conducting the released air from the bag.

It is not even entirely necessary that the spaces corresponding to the passages I'I of the Fig. 3 embodiment and I9 of the Fig. 4 embodiment be intentionally provided for. For example, if the smooth-surfaced liner 5 of the Fig. 4 embodiment is used with a relatively smooth-surfaced porous paper layer 2, such as shown in the Fig. 3 embodiment, and said layer 2 is made of sufliciently stiff stock, it will be found that when the two bags are telescoped together, the natural stiffness of the bag 2 prevents it, even when being filled, from lying flat against the paper liner layer 5 at all points. 'Ihere is always provided, by the natural stiifness of the paper, a suilicient number of small spaces or regions of non-juxtaposition to provide for the release of the air.

It is not necessary that the outer bag I be 25 formed of the laminated fabric material heretofore described. In Fig. 5, for example, there is illustrated an embodiment wherein the outer bag may be formed of a material described and claimed in my copending application, Serial Number 17,584, led April 22, 1935, which comprises a fabric layer 20 having an inner layer 2I of the Goodyear 'Iire and Rubber Companys product Plioiilm securely adhered thereto. The Plioflm layer 2l is of similar character to the transparent cellulose nlm or sheet now available on It is absolutely waterproof in the combination with fabric as shown. It also provides a smooth inner surface. With this type of laminated material, it is desirable to use a iluted inner porous paper layer 2, as shown in Fig. 5, and which is similar to the analogous layer in the Fig. 4 embodiment.

The outer bag may also be made of impervious materials such as paper lacquered onits outer surface for appearances sake. It is not necessary that the outer layer embody a fabric in order for it to constitute a. part of the present invention. Y

The word tu is used herein to describe the inner envelope of the combination. It will of course be understood that the inner tube may have a. closed end, or (in the lled bag) ends. and thus comprise as much an envelope as the outer envelope. 55

In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

As many changes could be made in carrying out the above constructions without departing 6 from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting,85

with a plurality of passages whereby air can escape to the mouth of the bag.

2. A bag of the class described comprising an outer envelope' and a tube assembled therein, said outer envelope being relatively waterproof, and said inner tube being porous to air, the interfacial region between the inner surface of said outer envelope and the outer surface of said inner tube being provided with a plurality of air passages to the mouth of the bag.

3. A bag as set forth in claim 2, in which the outer envelope is provided with an inner liner of creped paper, while the inner tube has relatively smooth outer surfaces.

4. A bag as set forth in cl 2, in which the outer envelope is formed of a laminated material l0 comprising an outer layer of fabric, and an inner layer of smooth-surfaced paper secured to said outer layer by a layer of adhesive..

CHARLES V. BRADY.

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