US3080102A - Valve bag - Google Patents

Description

March 5, 1963 A. F. OTTINGER VALVE BAG 2 Sheets-Sheet 1 Filed March 24, 1958 30 are 55 XXYKKXXX XXX XXXXX F's 2. 3 XXXXXXEZZXXX jib-U33 3/ %/55d /1 5? KJQ xxxxxxlxxg March 5, 1963 A. F.- OTTINGER VALVE BAG 2 Sheets-Sheet 2 xxxxxxxkxxxx XXXXXXXXXXXXX x k-xx- Unite This invention relates to bags, and more particularly to valve bags made of heat-scalable plastic such as polyethylene.

Among the several objects of the invention may be noted the provision of a bag made of heat-scalable plastic such as polyethylene having a valve at one corner of the bag including an inwardly extending valve extension for closing the bag after it has been filled; the provision of a bag of this class having such an extension, which may be essentially a paper sleeve, of a type which permits free flow of material into the bag from a filling spout inserted in the valve opening and which provides for tight closure of the bag upon removal from the spout after filling; the provision of a bag such as described which is of such construction as to allow for heat-sealing during manufacture without sticking any part of the valve opening and with complete sealing of the end of the bag at which the valve is located; and the provision of a bag of the class described in which the extension is of such character as to avoid contamination of the contents of the bag. Other objects and features will be in part apparent and inpart pointed out hereinafter.

The invention accordingly comprises the constructions hereinafter described, the scope of the invention being indicated in the following claims.

In the accompanying drawings, in which several of various possible embodiments of the invention are illustrated,

FIG. 1 is a perspective illustrating a bag having a valve of this invention as it appears prior to heat-sealing the bag closed at its valved end, parts being broken away;

FIG. 2 is a vertical cross section in the central plane of the valve, showing the bag provided with the heat seal across the valved end of the bag;

FIG. 3 is a view taken on line 33 of FIG. 2;

FIG. 4 is a perspective showing one way in which the valve sleeve may be initially applied to the bag;

FIG. 5 is a view taken on line -5 of FIG. 4;

FIG. 6 is a plan of the valve sleeve per se;

FIG. 7 is an enlarged cross section, with thicknesses exaggerated, taken on line 77 of FIG. 6;

FIG. 8 is a perspective, with parts broken away and shown in section, illustrating the valve sleeve in a semiflattened condition;

FIG. 9 is a view similar to FIG. 1 showing a modification; and,

FIG. 10 is a view similar to FIG. 2 showing the FIG. 9 modification.

Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.

Referring to the drawings, FIGS. 1, 2 and 8 show the valve corner of a heat-scalable plastic bag 1 provided with a valve of this invention. The bag 1 is shown as being formed from a flat seamless tube T of heat-sealable plastic such as polyethylene (see FIG. 4). The front and back walls of the tube T are designated 3 and 5. The side edges of the tube are constituted by folds 7 of the plastic. The lower end of the tube is closed by a transverse heat seal 8 (see FIG. 4). It will be understood that the tube may be a longitudinally seamed tube instead of a seamless tube.

The tube T is shown in FIGS. 1 and 2 as having at its 3,G&0,lll-Z Patented Mar. 5, 1963 upper right corner a valve formation comprising a tuckedin valve corner flap 9. Extending inward from this valve flap 9 is a flexible valve extension constituted by a valve sleeve 11. This projects from the inner end of the valve flap 9 into the bag. As shown best in FIGS. 6 and 7, the valve sleeve 11 comprises a blank of flexible paper 13 (such as kraft paper) coated on one face thereof with a layer 13a of heat-scalable plastic such as polyethylene, and coated on its other face with a layer 13b of a material which is infusible at the fusion temperature of the polyethylene or other heats salable coating 13a. Here it will be understood that coating 13b may be an infusible coating, such as an infusible lacquer, clay or starch or a coating of a material which is fusible but only at a temperature substantially higher than the fusion temperature of the plastic of the tube and the coating 13a, such as a high melting point wax, or a vinyl choride or acetate. The coatings 13a and 13b confine the fibers of the paper layer 13 thereby to provide protection against fibers from paper layer 13 contaminating the bag contents, and coating 13a additionally serves for heat-sealing the sleeve to the bag tube as will be made clear. The valve flap 9 (which in its entirety is of triangular form) has a central fold indicated at 17 and sleeve 11 is folded in half on a central fold 19 in line with andin extension of the fold 17, folds l7 and 19 being spaced from the upper end of the bag tube.

The sleeve if, as shown, is similar, in shape, and also in respect to the inclusion of a check valve fiap, to the sleeve shown in the copenrling coassigned application of Russell J. Williams, Serial No. 558,542, filed January 11, 1956, issued as US. Patent 2,865,556, December 23, 1958. Thus, the sleeve 11 is shaped to have a base portion 21 (corresponding generally to the base portion 21 of the sleeve shown in said patent) but, in accordance with this invention, this base portion has a total width which is less than the total width of edge 23 of the valve flap 9, instead of having a total width corresponding to the total width of edge 23. The outer corners of the base portion of the sleeve 11 are cut off at a 45 angle as indicated at 25 to match the 45 folds 27 on which the valve flap 9 is folded in. The sleeve 11 is initially folded in half on fold line 19 with the heat-scalable coating 13a on the outside (see FIGS. 4 and 5). Then, so folded, it is inserted in the upper end of tube T as shown in FIG. 4 at the upper right corner of the tube, with the fold at 19 against the right side edge fold 7 of the tube. Then, heat-sealing bars (not shown) are applied to the front and back walls 3 and 5 of the tube to heat-seal the two side portions of the folded-in-half sleeve to the inside surface of walls 3 and 5 throughout the width of the sleeve as indicated at 29. With the nonsealing coating 13b on the inside of the folded-in-half sleeve, sticking together of the two halves of the sleeve by this heat-sealing operation is avoided. Then, the valve fiap 9 together with the sleeve 11 is tucked in, as illustrated in FIG. 1, the flap 9 being folded in half on line 17, and sleeve 11 being reversely folded on line 19 in relation to its folded condition of FIGS. 4 and 5 to assume the folded condition in which it is shown in FIGS. 1 and 2, wherein heat-sealing coating 13a is on the inside and nonsealing coating 13b is on the outside of the folded sleeve. The 45 corners 25 of the base portion 21 of the sleeve lie contiguous to the 45 folds 2.7 on which the valve flap 9 is folded llIl. Since the total width of the base portion 21 of the sleeve is less than the total width of the inner end edge 23 of the valve flap 9, the upper edges Zlle of the folded sleeve are spaced inward from (below) the upper edges 30 of the tube T.

The sleeve 11 has a reduced portion generally desig nated 31 projecting inward from the base portion 21. This portion 31 is folded in half on the central fold 19 of the sleeve. It is so shaped that, as folded in half in the bag,

its two halves have inclined edges 33 which converge toward the central fold 1% of the sleeve in inward direction (see FIGS. 1 and 2). These edges 33 intersect the edges Zlle of base portion 21 at points As shown, edges 33 preferably converge toward the central fold at an angle of 45 Portion 31 has a nose 3''? defined by its inner edge 39, which is cut oil at right angles to central told 19, and short side edges 41 paral el to the central fold 1?. The corners of the nose 37 are relieved by cutting them oil at an angle of 45 as indicated at 53.

The sleeve has a longitudinal slit 45 extending in outward direction from its inner end to a point spaced inward from the inner end 23 of the valve flap 9. he slit is located centrally in respect to the width of the sleeve in the line of the told 19. it is preferably made with its sides divergent toward the inner end of the sleeve so as to widen toward the inner end of the sleeve. The corners at the end of the slit are relieved by cutting them oil at an angle of 135 to the inner end of edge 3 as shown at 47. The slit 45 constitutes an opening for flow of material from the filling spout into the bag in a lateral (downward direction with respect to the length or" the sleeve. It is made of sufiicient length so that the inner end of the sleeve may open up Wide to allow for free how of material from the spout so as to avoid clogging.

The sleeve 11 is provided with a flexible flap #9 con stituting a check valve member adapted to permit how of material through the slit 45 during the filling of the bag and adapted to close back upon the slit: when the has been filled. As shown, this flap 49 cots of a rectangular piece of paper with coatings 49a and 4% corre sponding to coatings 13a and 13b having a length greater than the length of the slit and less than the distance from the inner end of the sleeve to the inner end of the valve flap. It is secured to the sleeve on one side of the slit 4-5 as by adhesive 51 to that surface 131) of the sleeve which is on the outside of the sleeve in the folded condition of the sleeve. The flap 4 9, as secured to the sleeve, projects laterally with respect to the length of the sleeve from the portion of the sleeve on the stated side of the slit in the direction away from the edges 30 (downward as viewed in F168. 1 and 2). The flap 49 extends from a point between the inner end 23 of the valve flap 9 and the outer end 53 of the slit 45 to the inner end of the sleeve. With the sleeve in its flat unfolded condition as illustrated in FIG. 6, the flap d9 extends completely across the slit 45 to overlie the portion of the sleeve on the other side of the slit. The flap 4? is also adapted to over" lie this portion of the sleeve when the sleeve becomes flattened on filling the bag (see PEG. 8). When the sleeve is initially folded with coating 13a on the outside (FISS. 4 and for application to the tube T, the flap lies between the two halves of the folded sleeve.

Atiter the valve flap 9 and the attached sleeve 11 have con tucked in, the front and back walls- 3 and 5 of the tube T are heat-sealed together by a heat seal 55 (see FIGS. 2 and 8) constituting an end closure for the tube extending tnansversely across the upper end :of the tube. As shown, this seal 55 is a seal of substantial Width, and is located so that its lateral mar-gin 55a toward the end of the tube is outward .of the side edge portions lie or" the sleeve its other lateral margin 55b is inward of side edge portions 212. Accordingly, despite the nonsealing character of coating 13b on the outside of the sleeve, the walls of the tube are directly sealed together by the portion 550 of seal 55 which lies outward of edges 312 so that the upper end of the tube is completely sealed. Also, the heat-sealing at 55 results in heat-sealing together of the two upper side margins of the sleeve by portion 55d of the seal 55 along edges 21a by reason of fusion of the coating 13a (between the two halves of the folded sleeve) adjacent edges 21c. Thus, the portion of the sleeve extending inward from the valve flap is of tubular form. It will be understood that instead of having seal 55 looated as shown in FIG. 2, it could, for example, be

cated nearer the upper end of tube T and formed with a wider portion at the valve corner to effect the heat-sealing together of the upper margins of the sleeve.

T he bag is filled with finely divided or pulverized material by entering :a filling spout (not shown) into the valve flap 9 and delivering the material through the spout into the bag. The material flows tireely into the bag through the sleeve 11 in the direction of the length of the sleeve and also in .a lateral direction through the slit 45. The flap or check valve member 49 :does not impose any perceptible obstruction to fiow of material into the bag. As the bag is filled, the sleeve flattens out in the manner illustrated in FIG. 8. When the bag is completely filled, the flow of material is cut oil and the bag is taken off the spout. The flattened sleeve is pressed closed by the contents of the bag. The flap 49 is pressed closed against the sleeve effectively to block the slit and prevent escape of material through the slit. The provision of the flap 49 makes possible the use of a relatively long slit to ensure tree flow of material into the bag while avoiding the possibility of leakage through such a slit as may occur without the flap. It will be observed that there is full overlap of the flap throughout the len th of the slit.

It will be understood that where there is no necessity for insuring against contamination of the contents of the bag by paper fibers from the sleeve, it is not necessary that the sleeve have the coating 1311. Also, in such case, it is not essential that sleeve 11 have heat-sealing coating 13a throughout its entire area. It may have a heat-sealing coating only on the outer end portion thereof which laps the valve flap 9. Under such circumstances, there is sufiicient sticking of the upper edges of the sleeve to the bag walls at seal by tusion of the heat-scalable plastic of the bag walls to the paper of the sleeve to provide the tubular form for the sleeve by reason of the upper edges of the sleeve being caught in the seal 5'5.

t will be further understood that the sleeve '11, instead of being made of coated paper as above described, may be made of heat-scalable plastic. For example, it could be made from sheet polyethylene, and flap 4 also made of polyethylene and heat-sealed thereto. If so made, sticking together of the sides of the folded sleeve may be avoided during the heat-sealing of the sleeve to the tube T by inserting a sheet of nonheat-sealing material, such as Teflon, between the sides of the folded sleeve when inserted in the tube T as in FIG. 4.

FIGS. 9 and 10 illust nate a modification in which the sleeve (designated 61 to distinguish it from the sleeve 11) has an outer end portion 63 of triangular shape corresponding to the triangular shape of the valve flap 9. End portion 63 laps the valve flap on the outside surface of the tube T (instead of the inside surface of the tube as in FIGS. 1 and 2). Also, instead of having the heatsealable coating 13a on the inside of the folded sleeve and coating 13b on [the outside, this relationship is reversed, coating =13a being on the outside and coating 1123]] being on the inside. Flap 49 in this instance is secured to the surface 13a of the sleeve, instead of surface 13b, and this securement may be by heat-sealing if so desired. The triangular end portion 63 of the sleeve 61 is secured to the valve flap 9 as by heat-sealing along its three sides, as indicated at 65. This triangular end portion serves to stiffen the valve flap. The end of the tube is closed by a heat seal 55 the same as that previously de scribed, the only difference being that (the upper side margins Zle of the sleeve, instead of being heat-sealed directly together, are caught in the seal 55, being heat-sealed to the tube walls 3 and 5 by reason of fusion of the coating 13a to the tube walls at 55d. This provides the tubular form for the portion of sleeve 61 which extends in ward from the valve flap.

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

' As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

I claim:

1. A valve bag comprising a heat-scalable plastic tube, said tube having an intucked valve flap at one corner thereof, said flap having a central fold spaced from the respective end of the tube, a flexible sleeve extending inward from the valve flap, said sleeve being folded in half on a generally central fold in line with the central fold of the valve flap, the outer end portion of the sleeve lapping and being secured to the valve flap, the total width of said sleeve being less than the total width of the inner end edge of the valve flap and the sleeve having side edge portions spaced inward from the respective end edges of the tube, and said tube having its walls heat-sealed together by a heat seal constituting an end closure for the tube extending transversely across said end of the tube and including a portion located outward of said side edge portions of the sleeve and a portion located inward of and adjacent said side edge portions of the sleeve, the latter portion of said heat seal constituting a heat seal for said side edge portions of the sleeve.

2. A valve bag comprising a heat-scalable plastic tube, said tube having an intucked valve flap at one corner thereof, said flap having a central fold spaced from the respective end of the tube, a flexible sleeve extending inward from the valve flap, said sleeve being folded in half on a generally central fold in line with the central fold of the valve flap, the outer end portion of the sleeve lapping the valve flap, said sleeve being of heat-scalable character at least where its outer end portion laps the valve flap and being heat-sealed to the valve flap, the total width of said sleeve being less than the total width of the inner end edge of the valve flap and the sleeve having side edge portions spaced inward from the respective end edges of the tube, and said tube having its walls heat-sealed together by a heat seal constituting an end closure for the tube extending transversely across said end of the tube and including a portion located outward of said side edge portions of the sleeve and a portion located inward of and adjacent said side edge portions of the sleeve, the latter portion of said heat seal constituting a heat seal for said side edge portions of the sleeve.

3. A valve bag comprising a heat-scalable plastic tube, said tube having an intucked valve flap at one corner thereof, said flap having a central fold spaced from the respective end of the tube, a flexible sleeve extending inward from the valve flap, said sleeve being folded in half on a generally central fold in line with the central fold of the valve flap, the outer end portion of the sleeve lapping the valve flap, said sleeve being of heat-scalable character throughout the entire area of one face thereof, said one face of the sleeve engaging the valve flap, said sleeve being heat-sealed to the valve flap and being heat-sealed to the inside surface of the tube and folded with its said one face on the inside, the total width of said sleeve being less than the total width of the inner end edge of the valve flap and the sleeve having side edge portions spaced inward from the respective end edges of the tube, and said tube having its walls heat-sealed together by a heat seal constituting an end closure for the tube extending transversely across said end of the tube, said end closure being of substantial width and located so that its lateral margin toward said end of the tube is outside of said side edge portions of the sleeve and its other lateral margin is inward of said side edge portions, the portion of said end closure heat seal lying inward of said side edge portions of the sleeve constituting a heat seal for securing together the side margins of the sleeve.

4. A valve bag comprising a heat-scalable plastic tube, said tube having an intucked valve flap at one corner thereof, said flap having a central fold spaced from the respective end of the tube, a flexible sleeve extending inward from the valve flap comprising a blank of paper having a coating of heat-scalable material on the entire area of one face thereof and a fiber-confining coating entirely covering its other face, said sleeve being folded in half in a generally central fold in line with the central fold of the valve flap, the outer end portions of the sleeve lapping the valve flap, said one face of the sleeve engaging the valve flap, said sleeve being heat-sealed to the valve flap and being heat-sealed to the inside surface of the tube and folded with its said one face on the inside, the total width of said sleeve being less than the total width of the inner end edge of the valve flap and the sleeve having side edge portions spaced inward from the respective end edges of the tube, and said tube having its walls heat-sealed together by a heat seal constituting an end closure for the tube extending transversely across said end of the tube, said end closure being of substantial width and located so that its lateral margin toward said end of the tube is outward of said side edge portions of the sleeve and its other lateral margin is inward of said side edge portions, the portion of said end closure heat seal lying inward of said side edge portions of the sleeve constituting a heat seal for securing together the side margins of the sleeve.

5. A valve bag comprising a heat-scalable plastic tube, said tube having an intucked valve flap at one corner thereof, said flap having a central fold spaced from the respective end of the tube, a flexible sleeve extending in ward from the valve flap, said sleeve being folded in half on a generally central fold in line with the central fold of the valve flap, the outer end portion of the sleeve lapping the valve flap, said sleeve being of heat-scalable character throughout the entire area of one face thereof, said one face of the sleeve engaging the valve flap, said sleeve being heat-sealed to the valve flap and being heat-sealed to the outside surface of the tube and folded with its said one face on the outside, the total width of said sleeve being less than the total width of the inner end edge of the valve flap and the sleeve having side edge portions spaced inward from the respective end edges of the tube, and said tube having its walls heat-sealed together by a heat seal constituting an end closure for the tube extending transversely across said end of the tube, said end closure being of substantial width and located so that its lateral margin toward said end of the tube is outward of said side edge portions of the sleeve and its other lateral margin is inward of said side edge portions, the portion of said end closure heat seal lying inward of said side edge portions of the sleeve constituting a heat seal securing the side margins of the sleeve to the tube walls.

References Cited in the file of this patent UNITED STATES PATENTS 2,034,217 Verwys Mar. 17, 1936 2,437,693 Hartman Mar. 16, 1948 2,676,745 Geisler Apr. 27, 1954 2,708,067 Paton May 10, 1955 2,799,314 Dreyer July 16, 1957 2,865,556 Williams Dec. 23, 1958

Claims (1)

1. A VALVE BAG COMPRISING A HEAT-SEALABLE PLASTIC TUBE, SAID TUBE HAVING AN INTUCKED VALVE FLAP AT ONE CORNER THEREOF, SAID FLAP HAVING A CENTRAL FOLD SPACED FROM THE RESPECTIVE END OF THE TUBE, A FLEXIBLE SLEEVE EXTENDING INWARD FROM THE VALVE FLAP, SAID SLEEVE BEING FOLDED IN HALF ON A GENERALLY CENTRAL FOLD IN LINE WITH THE CENTRAL FOLD OF THE VALVE FLAP, THE OUTER END PORTION OF THE SLEEVE LAPPING AND BEING SECURED TO THE VALVE FLAP, THE TOTAL WIDTH OF SAID SLEEVE BEING LESS THAN THE TOTAL WIDTH OF THE INNER END EDGE OF THE VALVE FLAP AND THE SLEEVE HAVING SIDE EDGE PORTIONS SPACED INWARD FROM THE RESPECTIVE END EDGES OF THE TUBE, AND SAID TUBE HAVING ITS WALLS HEAT-SEALED TOGETHER BY A HEAT SEAL CONSTITUTING AN END CLOSURE FOR THE TUBE EXTENDING TRANSVERSELY ACROSS SAID END OF THE TUBE AND INCLUDING A PORTION LOCATED OUTWARD OF SAID SIDE EDGE PORTIONS OF THE SLEEVE AND A PORTION LOCATED INWARD OF AND ADJACENT SAID SIDE EDGE PORTIONS OF THE SLEEVE, THE LATTER PORTION OF SAID HEAT SEAL CONSTITUTING A HEAT SEAL FOR SAID SIDE EDGE PORTIONS OF THE SLEEVE.

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