US3439468A - Method of manufacturing bag closures - Google Patents

Description

April 22, 19.69- E, 50K

METHOD 0F MANUFACTURING BAG cLosUREs Filed Nov. 2, 1964 sheet of 3 IIHHHIIHHIHIIIII WIW/P f WMV/F0 50K Semmesandsemmes rfa/P/)- YS April22,1969 5550K 3,439,468

METHOD OF MANUFACTURING BAG CLOSURES Filed Nov. a, l1994 sheet L of s /3/ wr l /2 l n [l l l /l April Z2, 1969 Y E. BOK

I METHOD OF MANUFACTURING BAG CLOSURES sheet Q lof s Filed Nov. 2, 1964 INVENTOR- EDwARD 50K BY M U from/fm United States Patent O Int. CI. B651) 61718, 9/12, 51/30` U.S. Cl. 53--14 3 Claims ABSTRACT OF THE DISCLOSURE The present invention relates to a bag closure and method of manufacture, particularly a method of manufacturing a resealable 4bag using pressure sensitive adhesive as a resealing means and including tear strip pressure sensitive cutting means and reinforced pull tab opening means.

The invent-ion relates to a closure for a bag having a flat mouth the outer sides whereof are provided with adhering adhesive tape, strips whereof protrude opposite to each other beyond the mouth edge and close the bag by the adhesion of the adhesive layers to each other.

In the practical application of this type of bags there is a desire to have them delivered from the packing factory filled with Sweeties provided with a solid air tight closure such that this closure after opening cannot be reshaped to its original state, showing clearly that the bag has been opened. Such type of closure constitutes at the same time the seal of the manufacturer and a means to ensure that the filled bags can be stocked during a long period without any damage that the contents will be attacked by influence of the surrounding atmosphere.

On the other hand it is very desirable that the buyer of the package can open it and reclose it in a satisfactory air tight manner after taking a part from the contents.

It is an object of this invention to meet these desires by means of a closure comprising adhesive tape and to bring a solution which is not too expensive in manufacturing on automatic machines designed in correspondence with the features of the new closure.

Further objects in the working out of the invention areto make the means for opening and closing the bag p-ractical for the user, trustworthy and at the same time ready for manufacture in the automatic machine, wherein the whole of the closure is made and that as a part added to the filling machine for the bag and working with the same capacity and without necessity for additional operator handling.

A still further object of the invention is to develop means for opening the original outer closure destined for maintenance during stocking periods, by which the opening can be executed quite sure without damaging the neat appearance of the remaining closure parts during the application thereof by the buyer.

These and further objects in mind and the manner in which they are obtained according to the invention and developments thereof will be described now hereinafter with reference to the drawing and the most essential features thereof will be defined in claims.

In the drawing:

FIGURE 1 is a side view of a filled and sealed bag according to the invention,

FIGURE 2 on a larger scale a detail cross section along the line II-II of FIGURE 1,

FIGURE 3 on a somewhat reduced scale with respect to FIGURE 2 a schematic side View of the upper part of a bag, wherein those parts of the adhesive sealing tape ICC where extra pressure is applied in the sealing process are specially outlined,

FIGURE 4 is a side view corresponding to FIGURE 3, but on a smaller scale showing the bag in a preliminary stage of manufacture of the closure, before sealing tape has been applied,

FIGURE 5 a cross sectional detail along the line V in FIGURE 4 but on a larger scale, showing at the same time schematically machine parts used in this stage of manufacturing,

FIGURE 6 a view corresponding to FIGURE 4, but after application of sealing tape,

FIGURE 7 a schematic side view of a transport mechanism for the bags from a filling machine to the sealing machine,

FIGURE 8 a schematic top view on a device by which the adhesive tape closure is applied to the bags.

In the embodiment of FIGURE 1 the first closure consists in a Weak heat seal 3 of small width `whichis applied to the end 2 of the filled bagl 1, where the walls of the bag are brought flat against each other. The second and third closure are indicated as a whole by 4. Two strips 18 and 19 of one adhesive tape length 5 are folded one on each side of the bag mouth 2 on the outer side of the walls thereof and they adhere thereto by single pressing themI thereon in the area indicated -by 24 in FIGURE 3. This cannot be seen in FIGURE 2, because the cross section is taken along the middle of the pull lips strip 6. A tear wire 7 is embedded in the adhesive layers of the sealing strips 18, 19 at their parts protrud ing beyond the edge of the bag mouth 2, where the adhesive layers thereof adhere to each other and shape the second closure (see also FIGURE 3).

The tear string 7 extends at the Side of the bag, where it is enclosed by the tape part 9, which is provided with a small notch 8 on each side in order to facilitate tearing open the bag for the first time without damaging the adhesive tape seal.

In FIGURES 2 and 3 it can clearly be seen that the third, solid closure is formed at 17 by a fold line of the strips 18, 19 of the adhesive tape length, which is applied from a tape roll through a folding device as will be shown hereinafter. It is this fold 17 which is torn open by the tear string 7. According to FIGURE 2 the pull lips 12 and 13 are parts of one single adhesive tape length 13, folded at 20 within the fold 17, and the ends of these lips are folded inwardly and thus the pull parts 12 and 13 are double walled and strong the two walls adhering to each other by their adhesive layer in the planes indicated by 21 and 22. The parts 15 and 16 of this adhesive surface adhere at 10 and 11 to the respective sides 10 and 11 of the bag, and the parts of the pull tape sides 15 and 16 protruding beyond the mouth edge ensure the bag sealing in the same manner as the strips 18 and 19 of the sealing tape 5 running along the length of the mouth edge (second closure). The strips 18, 19 adhere at the same time to the outer sides of the pull tape parts 15 and 16 so that the connection of the pull lips to the bag is strengthened thereby. A normal polyethylene adhesive tape can be used as well for the pull lip strip as for the sealing strip tape and after the solid (third) closure 17, 20 has been ripped open by means of the tear string 7 the adhesive layer closure (second closure) will still shape an airtight seal which however can be opened by means of the pull lips 12 and 13.

It will be clear that on cutting the fold 17 by means of the wire 7 the fold 20 of the pull tape `6 is at the same time cut and strip parts 18 and 19 are separated thereby at their top so that on pulling these lips outwardly in opposite directions, the bag mouth Walls 10 and 11 are removed from each other, then the weak heat seal 3 is broken along `its length, starting in the middle thereof and further on the adhesive seal is broken in the zone above the area 24 in FIGURE 3, starting in the middle part thereof and proceeeding to both sides.

After a part of the contents of the bag 1 is taken therefrom it can easily be reclosed airtight by means of the above mentioned adhesive zone beyond the mouth edge by taking the mouth of the bag between the two fingers of one hand at the left hand side of the line II-II in FIGURE 1 `and with two fingers of the other hand on the right hand side of this line and then moving the hands away from each other along the outer sides of the sealing tape strips 18, 19 to the side edges of the bag.

In FIGURE 3 a zone 25 is shown shaded n the direct proximity of the fold line where the adhesive tape strips 18 and 19 are pressed with extra force onto each other in order to obtain a sharp crease, which can easily fbe cut by wire 7. The device by `which this is obtained in the manufacture of the closure will be described further on.

The non-shaded surfaces of the adhesive tape closure are only lightly pressed onto each other, in the manufacturing process, so that an easy moving of the tear string 7 by the user between the sides of the adhesive tape is made possible.

In FIGURE 4 and in the cross section of FIGURE 5 a filled bag 34 is shown, provided with a weak or non completed closure (first closure) 65 being the stage of manufacture wherein it leaves the heat sealing and cutting unit 36 (FIG. 7) of the filling machine 33. It is quite normal in such a machine, that such a unit at the outlet side of a filling machine provides a heat seal across a tube, above the lower part of the tube which has lbeen lled and shaping at the same time the bottom of the next part of the tube to be filled, whereupon the filled bag 34 is cut off by cutting the sealed area in two parts as schematically shown in FIGS. 5 and 7 at 36.

In the .present case however heating parts of the lower pair of sealing jaws are limited to two areas providing a heat seal only at the surfaces 67 (FIG. 4) on the sides of the bag mouth and/ or eventually a weak heat seal of small Width in the Zone indicated by 3 in FIGURE l.

In the present embodiment however the weak seal 3 is not a heat seal but by means of two inserted heat insulated lower jaw parts `68, 69 a profile 65 is provided in the walls of the flat bag mouth. In this way a weak closure 65 (first closure) is shaped as well which is protected at the sides of the mouth =by the solid heat seal parts 66 and 67 and in this way it is obtained that the bag can be transported upside down to the apparatus where the second and third closure parts are provided, without danger that the articles filled into the lbag will pass the mouth. This first, protective closure continues its same protective purpose in the closure when completed and when the filled bag is in use by the buyer after opening ofthe outer, solid closure by means of the tear wire 7.

FIGURE 6 showing the closure completed will easily be understood after the explanation given hereabove already with respect to FIGS. 1 and 2. The notches 8 in the tape 9 (one in view) are positioned in this embodiment just inside the side border of the bag 34 and further a perforation 68 is provided somewhat to the left above the notch 8 in the fold line 17 of the sealing tape 9. It has been found that this is the most sure way to rip the sealing tape between the notches 8 and the perforation 68 when the tape end 9 with the tear string 7 enclosed therein is pulled upward for cutting the fold 17 avoiding any danger that the sealing type would be pulled fromthe bag walls.

In FIGURE 7 it can further be seen that the lled and cut off bag 34 is transported to the closure manufacturing device 42 by a transport device 28.

The bags 34 attained from the bag forming and filling machine 33 are temporarily held by means of a clamping device 35 against a slide until the jaws 36 of the machine 33 after finishing their sealing action move upward again in order to pull a following tube length downward. The moment of opening the clamping device 35 is timed with the start of the said upward movement so that a uniform discharge of the bags to the transport device 39 is assured.

When the bag 34 is released by the clamping device 35 it lands in the guide trough 37 through which it is transported by the conveyor belt 29 to a slide trough 30, 40, which is mounted with an adjustable inclinement to the trough 37 and is made of such thin elastic material, that it can deflect under the weight of the filled bag 34 so that the latter lands with its end 38 against the stop block 31 upon the conveyor belt 32 in the trough 41.

If empty bags arrive on the slide 30 -because of any default in the filling machine the slide trough 30 practically does not deflect and these empty bags are delivered behind the stop block 31 and thus do not arrive on the conveyor 32.

It will be clear that the filled bags 34 arrive at the closure machine table 42 with their permanently closed bottom end 38 turned away from this device but with the end bearing only the preliminary weak closure part (fi-rst closure) turned to the device 43 on the table 42 whereat the bag mouth lands against a stop block 34. On the way from the filling machine 33 to the closure table 42 the direction of movement of the bags 34 has been reversed for this purpose in the manner as described hereabove.

A sensitive electric switch is built into the stop block 44, which `works as soon as the end of the filled bag 34 causes the upper end of a stop pin 146 to move, which happens just before the forward end of the bag 34 lands against the stop surface 147 of the block 44.

The switch 45 then sends an electric impulse to an impulse sender on the closure table 42, by which the applying of the adhesive tape closure to the filled bag is initiated in a way to be described further on.

Now the device 42 for applying the adhesive tape closure 4 to filled bags 34, mentioned already hereabove as the closure manufacturing table 42, will be described with reference to FIGURE 8.

The bag grip 43 is moved laterally by means of an air cylinder 146 during the applying of the adhesive tape closure 4 to the bag 34. A separate set of grip jaws 43 is provided on the bag grip 43, gripping the outer end 9 of the adhesive tapelength and taking it along with the bag and at the same time the tape 48 is folded about the mouth edge of the bag 34 and provisionally brought to adherence therewith by means of the folding device 49. This sealing tape 48 is supplied from a roller. In FIGURE 8 the supply track is shown just below the device, indicated by the reference number 50 at the right hand side of this figure.

By means of the device 50 pull lip material, to be as well adhesive tape, is pulled from a roller 51, strips 6 are cut off, folded at their outer ends and attached crosswise to the adhesive tape 48 in an apply station 52 at distances from each other corresponding to the successive sealing lengths of the sealing tape 48 to be applied to the bags.

At the same time tear string material 53 is taken along from a roller 54 with the movement of the bag grip 43 and pinched between the tape 48 in the folding device 49 for the latter. v

It is to be understood, that in FIGURE 8 the bag 34 is shown in a position just before it is carried away by the right hand group of three bands of a conveyor moving it outward from the table 42 to a delivery station after the closure has been completed. Therefore the plunger of cylinder 46 takes its fully shoven out position. The bag 34 had been transported onward to the table 42 in a foregoing phase on the left hand group of the bands belonging to a conveyor moving in opposite direction to the tirst-mentioned conveyor. In that stage the abovementioned plunger took its inward position and the grip device 43 was situated opposite the end of the lastmentioned conveyor.

When now by filling one end of the air cylinder 46 with air under pressure the grip 43 is moved to the right the bag will thereby be carried in a sideward direction and the sealing tape 48 as well as the wire 53 are pulled along through the folding device 49 (FIG. 8) and the crosssectional part of the sealing tape near its fold with the tear Wire 53 enclosed therein Will be attached to the outer edge of the bag mouth.

What I `claim is:

1. A method for providing a filled at-mouthed bag from advancing tube stock with a combined first heat seal closure; a second reclosable sealing tape closure Iand a third solid tearable closure comprising:

(A) heat sealing said tube at opposed edges thereof to provide a first rudimentary heat seal closure to the mouth of a filled bag;

(B) simultaneously and adjacently heat sealing transversely yacross said tube so as to form a heat sealed bottom of the next bag to be lled;

(C) cutting said tube transversely intermediate heat sealngs, so as to dene a bag mouth;

(D) closing a median portion of said bag mouth with a strip of pressure sensitive adhesive as `an opening tab extending from one lip, over the bag mouth and onto the opposed lip so that opposed portions of pressure sensitive adhesive extend inwardly towards each other above said bag mouth;

(E) forming a second reclosable sealing tape closure by applying a folded strip of pressure sensitive adhesive over both top edges of the bag mouth so that the -opposed edges of said pressure sensitive adhesive strip extend over said opening tab and onto the mouth edges for adherence thereto, while the closed end of said folded strip presents opposed sur-- faces of pressure sensitive adhesive above said bag mouth.

2. Method as in claim `1, including the step of inserting a tape-tearing means across the mouth of said bag and beneath both said opening tab and said reclosable sealing tape closure, said tape tearing means being capable of cutting through the closed ends of opening tab and the folded pressure sensitive adhesive forming said second reclosable sealing tape closure.

3. Method as in claim 1, including cutting said reclosable sealing tape closure at its lower open ends adjacent one edge of said bag so ,as to provide a notch for opening said closure by said tape-tearing means.

References Cited UNITED STATES PATENTS 3,045,890 7/ 1962 Swanson 229-66 3,116,009 12/1963 Williams et al. 229-66 2,929,180 3/ 1960 Abrams et al. 53-29 2,977,729 4/ 1961 Frechtmann et al 53-29 2,740,244 4/ 1956 Belli 53-137 3,021,652 2/ 1962 Greisman 53-137 3,173,232 3/1965 Merier 53-137 THERON E. CONDON, Primary Examiner. NEIL ABRAMS, Assistant Examiner.

U.S. Cl. X.R.

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