US2373340A - Bag and method of filling same - Google Patents

Description

April 10, 1945. H. A. ROHDIN BAG AND METHOD OF FILLING SAME Filed Nov. 12, 1942 Patented Apr. 10, 1945 UNITED STATES PATENT. OFFICE BAG AND METHOD or FILLING SAME HowardA. Rohdin, Glen Ridge, N. .1.

Application November 12, 1942, Serial No. 465,337 3 Claims. (Cl. 229-425) Figure 1 is a perspective view showing a preferred construction of filling tube for insertion into a bag;

Fig, 2 is a section through an empty bag showing the conditions of the parts prior to the filling operation;

Fig. 3 is a plan view showing the condition of the mouth during the filling operation;

Fig. 4 is a section on the line 4-4 of Fig. 3;

Fig. 5 is a view similar to Fig. 4 but showing the parts in sealed condition;

Fig. 6 is a section on the line 66 of Fig. 5; and

Fig. 7 is a view similar to Fig. 6 showing the application of my invention to a different form of bag.

In the last few years heat sealing has become of increasing importance as a means of closing various types of bags. When, however,such bags are filled either' with liquids or With finel divided solids of a fiuffy" nature such, for example, as cocoa, there is a tendency for the material entering the bag to form a film over the portions of the bag wall which are to be joined by heat sealing and such films may prevent the formation of perfect seals. It is true that in the case of certain heat sealable materials an elfective seal can be formed even though a considerable film of liquids, such as oil or milk, but it is also true that where such conditions are encountered the percentage of defective closures will be greater than would be the case were the sealing area completely uncontaminated.

In the packaging industry it is axiomatic, first, that there is no difficulty in producing a single perfect closure and, second, that it is impossible to produce millions of perfect closures without producing some defective closures. The test of a closure is the percentage found defective in the formation of hundreds of millions of such closures.

It is a further characteristic of the packaging industry that the manufacture of packages;

though utilizing fundamentally the same operations, is, as a whole, radically different fromthe closure of filled packages; This difference is due to many factors. In the manufacturing process there is a higher degree of continuity of operations than in the closing of filled packages. The

speed of operation is greater in manufacturing and, in general, the package manufacturer, due to greater'speed and continuity, is able to afford a greater investment in machines and a higher grade of supervision than is a packer who 15,0105- ing filled packages. 'On the other hand, packages are classified as defective after they are filled and it matters not at all whether the defect occurred during manufacture or during the filling and closing stages. It is, therefore, most essential to design a package so as to facilitate as much as possible the formation of perfect closures on the filled package and improvements in this respect yield the maximum dividends in the way of decreasing theultimate percentage of defectives.

My invention is applicable to any type or style of bag in which it is desired to effect a perfect heat seal closure at one end. Purely for manufacturing reasons under the limitations of existing equipment, my invention is probably best adapted to bags of the double side seam type but,

so far as the construction and operation of my invention is concerned, the type of bag is absoitself and sealing the meeting edges 3| and 32 together toform a fiat fin or seam 33. This tube is made of sufiicient cross sectional size to accommodate whatever filling spout is to be encountered by the final bag. The tube should be formed of some material which will be satisfactory for the particular purpose. If, for example, the tube is to be used to convey oil or asoline into the bag, it should be formed from one of the impervious synthetic films such, for example, as those sold under the trade name of P1iofilm" or "Koroseal and in such case the bag itself would be formed of similar material, at least so far as its inner surface is concerned."

In Fig. 2 I show a cross section through a fiat non-gusseted bag 40. As previously stated, for manufacturing reasons and under present conditions this should preferably be of the double side seam type and a bag particularly suitable for this use is disclosed in my co-pending application, Ser. No. 419,628, filed November 18, 1941. The tube 30 is inserted in the bag 40 with one end of the tube approximately even with the mouth of the bag. If desired (and for some uses it will be desirable) the tube may have its upper end projected beyond the mouth of the bag. It should not, however, come much below the mouth. The tube 30 is secured to one wall of the bag ll by a seal 34, preferably in the area of the seam 33 of the tube 30 and the seal should be as small as is consistent with the necessary strength. This seal should lie below the edges of the mouth of the bag but above the intended. level of the contents when filled. The lower end ll of the tube 30 should approach the bottom I of the bag II but should always be clear of the intended ultimate plane of the bag bottom, since otherwise the tribe might be bent and choked 119011 distension of the bag II. In the course of manufacture the mouth of the bag 4. is partially sealed in areas II and 42, extending inwardly from the sides of the bag but terminating so as to clear the tube 3|. These areas of sealing 4i and 42 are desirable, particularly for extremely wide mouthed bags, but are not indispensable in the use 01' my invention.

. Fig. 3 shows the bag ll! with the mouth of the bag in' condition for filling. The p rtion of the mouth lying between the sealed areas It and 42 is opened up to permit an expansion of the tube 30 and filling is done through the tube. Fig. 4, being a section through the bag in the condition illustrated in-Fig. 3, shows the tube 30 with its lower end 30 clear oi the plane of the ultimate bottom of the bag indicated at the line d-d. The line c-c indicates the ultimate level of the contents, and the area in which the final seal will be applied lies between the lines a--a and b-b. The tube 30 is sealed to the bag 40 by the seal 34 which preferably-lies above the line c-c and below the line 12-17.

In Fig. 5 the bag 40 is shown in cross section after being filled and with the mouth fully collapsed and sealed. The upper end 38 or the tube 30 has been folded down so as to clear the collapsed mouth, the seal of which has been completed between the lines a-a and bb. Fig. 6 illustrates the location 01' the final seal 46 relative to the pre-i'ormed seals ll and 42 in the bag mouth. It is clear, however, that seals I and 42 may be dispensed with, in which case the seal 45 will extend across the entire mouth.

Fig. '7 is a. view similar to Fig. 6 but illustrating my invention as applied to a gusseted bag 50. The bag 50 has gusset tucks 5| and 52 at each side and its mouth is preferably partially closed by sealed areas 54 and 56 at each corner, which sealed areas preferably should extend inwardly beyond the extremities of the gussets 5| and 52. The tube 30 is inserted and secured by a seal M and in all respects has the same relationship to the parts of the bag as in the case of the flat bag of Figs. 2-6. The mechanics of filling and of closing the mouth are the same in either case, except that if the seals 54 and 55 be utilized in a structure suchv as that of Fig. '7 the mouth would never be extended beyond the closing section of the bag.

While my filling tube would discharge its function of preventing contamination of the mouth of the bag, even though the bottom of the filling tube should extend only slightly below the point of attachment of the tube to the bag wall, in handling fiuids it is advantageous to have the lower end of the tube extend as nearly as practicable to the plane of the ultimate bag bottom, since by so doing the tendency of the entering liquid to foam is greatly reduced. I have recommended securing the tube to the bag wall below the line of ultimate sealing of the bag mouth and above the ultimate level of the contents and a study of Fig. 4 will indicate that this is the most desirable point of attachment. It is, however, within the purview or my invention to attach the tube to the bag wall at any, point alon the length of the tube or even throughout its length, since any foreshortening oi the tube 00- casioned .by attachment to the has well at a point below the level oi the contents could readily be compensated for by permitting the tube to project beyond the mouth of the bag when the bag is in flattened condition.

. So far as the attachment oi the tube to the bag wall is concerned and the partial sealing of the bag mouth during manufacture, heat scaling is preferable. and ordinarily will be resorted to as a matter or convenence but I do not intend to be limited to heat sealing. since adhesive sealing could be resorted to if desired. The basic idea is to improve the likelihood of securing perfect heat seals in the ultimate closing operation on the filled bag and whether the preliminary steps be,

accomplished by adhesive sealing or heat sealins is immaterial. I

For some purposes it may be desirable not to attach the tube to the bag wall; in such case the tube may be inserted in the bag at the time of filling. The basic idea is to fill through a collapsible tube which is then thrust into the bag. out of contact with the line of ultimate sealing. Withdrawal of the tube from the bag, after fillins, would create precisely the difilculty which my invention seeks to avoid, namely, contamination of the sealing area. My invention, therefore, is not merely a new form oi package, but a new process of filling and sealing packages.

The entire object of this invention is to fill a bag without contaminating the surface of the material of which it is made in the area which will ultimately be closed by heat sealing. It is only convenience which dictates the securing of the tube to the wall of the bag. when very large bags areto be filled, it may be more convenient to use an unsecured tube. Such a tube will have the same relative length as those shown secured in the drawings. It will be inserted in the bag, a filling spout will then be inserted into the tube. and the bag will be filled without the slightest danger of contaminating the bag mouth. When the filling operation is complete, the spout is removed. It the tube were then to be withdrawn from the has, its lower end would almost certainly contaminate the bag mouth. The tube is, therefore, treated just like a secured tube. It is thrust into the mouth of the bag below the line of sealing, and the sealing step is then completed. Once the bag has been filled and sealed, the tube has completed its entire function, and it is wholly immaterial whether it is secured or free.

What is claimed is:

l. A flexible walled bag having a heat sealable inner surface at least adjacent its mouth; a flexible filling tube extending into said bag, extending longitudinally of the bag and having its outer end extending across said heat scalable substantially above to substantially below the in-.

the mouth of the bag and its lower end near the bottom of the bagbut clear of the intended ultimate plane of the bag bottom when filled said tube being secured to one wall of the bag by a seal lying below the intended line of sealing of the mouth of the bag but above the intended level of the contents when filled.

3. A method of filling and closing a flexible walled bag having at least a portion 01' its inner surface, adjacent its mouth thermoplastic so as to be capable of being closed by heat sealing, said method comprising inserting a, tube into the mouth of the bag until the tube extends from walls.

HOWARD a. ROI-IDIN.

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