EP4091963A1 - Pull cord bag made of a thermoplastic sheet material - Google Patents

Abstract

Drawstring bag made of a thermoplastic plastic film material comprising two side walls lying on top of one another, welded together at their lateral edges by lateral weld seams, which have folded-over sections at an upper edge bordering a bag mouth, which are each welded to the respective side wall by an upper weld seam running at a distance from the upper edge and drawcords disposed in the cord hems formed by the turned-up sections and the side panels and exiting from the ends of the cord hems, the lateral edges of the side panels each having a notch at the ends of the cord hems, the lateral edges in the region of the notches are not welded together and define through openings at the ends of the cord seams from which the drawcords exit.

Description

The invention relates to a drawstring bag made from a thermoplastic plastic film material.

Drawstring bags made of a thermoplastic plastic film material such as polyethylene (PE) or polypropylene (PP) are used in particular for packaging cotton pads, cotton balls or other cotton-wool products. For this application, they are often designed as bottom-filling bags, with the bag mouth being closed by an end wall and the bag being filled with cotton wool from the bottom side and being closed by a bottom weld. After opening the bulkhead, cotton can be removed. The drawstrings are used to hang up and to close the opened bag. Also known are drawstring bags for residual waste, organic waste or plastic with an open bag mouth that can be closed after filling by pulling the drawstring, which is usually designed as a drawstring.

the DE 42 44 024 describes a drawstring bag made of a thermoplastic, weldable film material in the form of a bottom-filling bag, which has a cord hem enclosing the bag mouth on the top side and delimiting at least one channel in which drawcords are accommodated. The channel is arranged between the outside of the respective film web and its outwardly folded parts forming the cord seam, the folded parts being welded to the film webs by longitudinal seam welds which are spaced apart from and approximately parallel to longitudinal welds running at the bag mouth. The drawstrings are made of a thermoplastic material which, with regard to environmental compatibility, is a plastic that can be recycled together with the material of the film webs without prior separation.

the DE 20 2019 005 520 U1 describes a resealable film package in which the front and back are each made of a plastic film, there being a front passageway with a plastic thread running through this at the upper edge of the front side and a rear passageway with a plastic thread running through this at the upper edge of the rear side. The side edges of the front are welded to the side edges of the back outside of the passages and are not welded in a portion of the passages. The front, the back and the plastic thread or the plastic cord are made of the same plastic, for example polyethylene, PE, or polypropylene, PP or recycled plastic of a plastic type. This should allow the film packaging to be recycled without separating the material. The side edges are tear edges or cut edges in the area where they are not welded. An apparatus for manufacturing the film package includes a sever-seal apparatus capable of producing the welded side edges of the front and back outside the passages by sever-seal continuous plastic film, sparing a portion of the passages from the sever-seal to sever the thermoplastic cord , which has a melting point similar to that of the film. For this purpose, a heated stamp has a thermally insulating cover or cutout, due to which the front and the back are not melted in the area cut out by the cut-off weld. The disadvantage is that the tear-off edges can cause process disruptions and an unclean tear-off of the film packaging. In addition, production is made more difficult by the fact that the cut edges in the non-welded area of the side edges have to be aligned precisely with the separating welds on the side edges so that the individual bags can be separated from the endless plastic film.

Proceeding from this, the object of the invention is to provide a drawstring bag that has more favorable manufacturing properties and allows the foil and cord to be recycled together without prior separation. Furthermore, a device for producing the drawstring bag is to be made available.

The object is achieved by a drawstring bag with the features of claim 1. Advantageous embodiments of the drawstring bag are specified in the dependent claims.

The drawstring bag according to the invention made of a thermoplastic film material comprises two side walls lying on top of one another, welded together at their lateral edges by lateral weld seams, which have unfolded sections at an upper edge bordering a bag mouth, which are each connected by an upper weld seam running at a distance from the upper edge on the respective side wall are welded, and drawstrings arranged in the cord hems formed by the folded portions and the side walls and emerging from the ends of the cord hems, characterized in that the lateral edges of the side walls at the ends of the cord hems each have a recess, the lateral Edges in the area of the recesses are not welded together and delimit through openings at the ends of the cord hems from which the drawcords emerge.

The fact that in the drawstring bag according to the invention the lateral edges at the ends of the cord hems each have a recess, ie have a punched or otherwise separated from the plastic film material area, the drawstring bag needs after Separation welding of the lateral welds not to be torn from the endless film web. There is also no need to make cuts in the area of the drawstring hems that are aligned exactly with the lateral edges of the side walls or the cutting lines between the lateral weld seams in order to separate the drawstring bag from the endless plastic film. In contrast to cuts, the cutouts can be made relatively imprecisely in the plastic film material, since they have a certain extent, which makes it possible to ensure that the cutouts are arranged above the lateral edges. In particular, the recesses can be produced in the plastic film material before the sections are folded over at the upper edge of the side walls. The recesses also eliminate the need for a cut-off welder to extend to the top of the sidewalls. Rather, to form the lateral edges and lateral welds, it is sufficient to form the cut-off sealer so that it extends just to the bottom edge of the recesses, thereby preventing physical proximity of the hot sealer to the thermoplastic cord. It is also not necessary to control the use of the cut-off welding device in such a way that there is only a partial cut in the area of the hems and the drawstrings are not damaged or fixed at the ends of the hems. The recesses can be formed as punched-out portions. These can easily be stamped into the plastic sheet material. The cutouts can be punched together with other punches, for example with the punching of ventilation holes, so that no additional effort is required as a result. The drawstring bags can thus be produced in a particularly fast, stable and less fault-prone process. The drawcords freely exit the ends of the drawstring hems. The drawcords can easily be pulled out of the unsealed through-openings of the hems because the Extraction is not impeded by welds reaching up to the drawcords.

According to one embodiment of the invention, the cavities are rectangular. In the area of the recesses, the lateral edges of the side walls are offset inwards or the lateral edges at the ends of the hems have a shoulder.

According to another embodiment, the recesses are concave. This counteracts tearing of the plastic film material at the cutouts during production or when the drawstring bag is pulled closed or carried. According to a preferred embodiment, the recesses are in the shape of a quarter of a circle. Quarter circle shaped cutouts can be made at adjacent seam ends of two adjacent drawstring bags formed from the plastic film material by stamping circular cutouts.

According to another embodiment, the drawstrings are made of a thermoplastic material or of cotton. The use of a thermoplastic material is possible without any problems, because the drawstrings do not run the risk of being welded to the lateral edges due to the recesses. When using the thermoplastic material for the drawstrings, it can be achieved that the drawstring bag can be recycled without separating the material. In the case of cotton drawstrings, these can be easily pulled out through the through openings so that the drawstring bag can be disposed of separately from the drawstrings.

According to a preferred embodiment, the drawstrings are made of a plastic material that is recyclable with the plastic material of the side walls.

According to another embodiment, the side walls are made of polyethylene, especially LDPE, and the drawstrings are made of polyethylene, especially HDPE, or of polyethylene terephthalate, or of polypropylene.

Cords are strings twisted together from several threads. In the present application, the term "draw cord" is understood in a broader sense. According to one embodiment, the drawstrings are plastic threads or ribbons. According to a further embodiment, the drawstrings each consist of a single thread made of plastic or of several single threads made of plastic twisted together. According to another embodiment, the drawstrings consist of a plurality of yarns twisted together, which are themselves already twisted and twisted. In this way, in particular drawstrings made of cotton can be formed.

According to another embodiment, the drawcords emerging from adjacent ends of the hems are knotted or welded together. The fact that the drawstrings are made of thermoplastic material allows them to be easily welded together. As a result, the use of devices for knotting the drawstrings can be eliminated. This can increase the speed and stability of the manufacturing process and reduce its susceptibility to failure. Both plastic threads and plastic straps can be connected to one another by welding.

The connected ends of the drawstrings running in the front and back drawstring hems form loops that allow the drawstring bag to be hung up.

According to a further embodiment, the mouth of the bag is closed by an end wall which is folded inwards between the two side walls when the bag is lying flat and which is welded to the two side walls via weld seams spaced apart from the upper edge. In this way, a bottom-fill bag can be formed. According to a further embodiment, the end wall has a tear-off perforation or another opening aid. This makes it easier to open the bag. The tear-off perforation is, for example, a perforation line (perforation seam). This extends, for example, from one side edge to the other side edge across the end wall. According to another embodiment, the end wall is connected to the lower edge of the folded portions of the side walls. This enables production from a single sheet-like plastic film material.

According to a further embodiment, the drawstring bag has ventilation holes in the area of the side weld seams. The ventilation holes make it easier to ventilate the drawstring bag when it is filled with cotton wool or another product, and a high production speed is made possible because the air can escape to the outside through the ventilation holes. This is particularly advantageous for drawstring bags with an end wall.

Furthermore, the object is achieved by a device according to claim 12. Advantageous embodiments of the device are specified in the dependent claims.

The device according to the invention for producing a drawstring bag according to one of Claims 1 to 11 or one of the previously described types of embodiment from a sheet-like plastic film material has a separating welding device which is designed and set up to weld the side walls together at the lateral edges and to separate them from one another and to not to weld and separate the ends of the cord hems in the area of the recesses.

According to one embodiment, the separating and sealing device has a heating and separating element to be arranged on one side of the web-shaped plastic film material and a counter-pressure element to be arranged on the other side, with either the heating and separating element or the counter-pressure element or both the heating and separating element and the counter-pressure element being did not extend over areas of the plastic sheet material designed to form the lateral recesses.

According to a further embodiment, the recesses are produced in the plastic film material before the cut-off welding, preferably before the drawstrings are applied to the plastic film material.

According to a further embodiment, the recesses are formed as punched-out portions or by laser cutting or laser separating in the plastic film material, preferably as circular recesses.

Fig. 1

einen Kordelzugbeutel in einer Seitenansicht;

Fig. 2

den Kordelzugbeutel in einem Vertikalschnitt;

Fig. 3

eine Kunststofffolienbahn zum Herstellen des Kordelzugbeutels von Fig. 1 und 2 in der Draufsicht;

Fig. 4

eine Kunststofffolienbahn zum Herstellen eines alternativen Kordelzugbeutels in einer Draufsicht.

The invention is explained in more detail below with reference to the accompanying drawings of exemplary embodiments. In the drawings show:

1

a drawstring bag in a side view;

2

the drawstring bag in a vertical section;

3

a plastic film web for making the drawstring bag of Figures 1 and 2 in top view;

4

a plastic film web for manufacturing an alternative drawstring bag in a plan view.

According to Figures 1 and 2 comprises a drawstring bag 1 two side walls 2, 3, which are welded together at their lateral edges 4, 5 by lateral welds 6, 7.

The upper edges 8, 9 of the two side walls 2, 3 delimit a bag mouth 10.

The side walls 2, 3 have, at their upper edges 8, 9, portions 11, 12 which are folded over onto the insides of the side walls. These are each welded to the respective side wall 2, 3 by an upper weld seam 13, 14 running parallel to and at a distance from the upper edge 8, 9.

The lower edges 15, 16 of the folded portions 11, 12 are connected to one another in one piece via an end wall 17 which is offset downwards with respect to the upper edges and closes the mouth 10 of the bag.

Between the folded portions 11, 12 and the side walls 2, 3 cord hems 18, 19 are formed. The lateral edges 4, 5 of the side walls 2, 3 each have a recess 20, 21 in the form of a quadrant at the ends of the cord hems 18, 19. At the ends of the cord seams 18, 19, the lateral edges 4, 5 of the side walls 2, 3 are not welded together. In the field of Recesses 20, 21 delimit the lateral edges 4, 5 through openings 22, 23 at the ends of the cord hems 18, 19.

Drawstrings 24, 25 are arranged in the two cord hems 18, 19, which emerge at the ends of the cord hems through the through openings 22, 23 to the outside and further protrude from the lateral edges 4, 5 of the side walls 2, 3 to the outside. The drawstrings are connected to one another or knotted or otherwise connected to one another at two adjacent ends by welded connections 26 , 27 , resulting in a closed band that lies in the cord seams 18 and 19 .

According to Figures 1 and 2 the drawstring bag 1 is open at the bottom. The drawstring bag 1 can be filled, for example, with cotton pads or other objects to be packaged through a lower opening 28, and after it has been completely filled, the lower end of the bag is closed, for example, by a lower weld seam.

The side walls 2, 3 consist of a thermoplastic plastic film material, for example a polyethylene, in particular LDPE. The thermoplastic plastic film material enables the weld seams 6, 7, 13, 14 to be formed.

The drawstrings 24, 25 are made of a thermoplastic material which allows them to be welded together at the ends, for example polyethylene, in particular HDPE. Preference is given to synthetic materials that can be recycled together with the film material without prior separation. The drawstrings 24, 25 can in particular be formed from plastic threads or plastic strips, with each drawstring being able to be only a single plastic thread or can consist of several plastic threads twisted together.

According to 3 the drawstring bag 1 is formed from a single, quasi-endless web-like plastic film material 29 . In order to form the recesses 20, 21, two series 30, 31 of circular punched-out portions 32, 33 are present therein at regular intervals. Furthermore, the plastic film material has holes 34 for positioning the bags on a bag filling system.

In the running direction L of the plastic film material 29 through a production plant, two quasi-endless drawstrings 24, 25 are applied to the upper side of the plastic film material 29. Also running in the running direction L are lines 35, 36, 37, 38 for forming upper weld seams, which are shown in dashed lines. The cord hems 18,19 are formed by folding the plastic sheet material around the drawcords 24,25 and welding the plastic sheet material along lines 35,36 and 37,38.

The areas adjoining the outside of the lines 35, 38 furthest apart form the side walls 2, 3. The end walls 16 are formed between the two lines 35, 36. The welding and separating seams 39, 40 on the two lateral edges 4, 5 of the side walls 2, 3 are shown as dotted lines, which run perpendicular to the running direction L of the plastic film material 29.

Around the central axis between the series 30, 31 of circular perforations 32, 33 the two middle parts of the plastic sheet material 29 are folded against each other and the parts outside the outer fold lines 35, 38 from the outside against the folded middle parts. The parts of the plastic film material 29 are welded together and separated from one another at the welding separation seams 39, 40. There is no welding and separation within the punched-out areas 32, 33.

The drawstrings 24, 25 are pulled slightly out of the ends of the drawstring hems 18, 19 of the severed drawstring bags 1 and adjacent ends are welded or otherwise connected together.

After filling the drawstring bag 1, the lower end of the bag is sealed.

the 4 shows a sheet-like plastic film material 29 for forming alternative drawstring bags 1. These differ from the previously described in that the recesses 20, 21 are designed as slots. Each slit has a certain width in the running direction L of the plastic film material, as a result of which it is distinguished by a simple cut through the plastic film material 29 .

reference list

1

drawstring pouch

2, 3

Side wall

4, 5

lateral edge

6.7

lateral weld

8, 9

upper edge

10

pouch mouth

11, 12

section

13, 14

top weld

15, 16

lower edge

17

bulkhead

18, 19

drawstring hem

20, 21

recess

22, 23

passage opening

24, 25

drawstring

26, 27

welded joint

28

lower opening

29

sheet plastic film material

30, 31

series

32, 33

circular punch-out

34

Hole

35-38

line

39, 40

weld and parting seam

Claims (15)

Drawstring bag made of a thermoplastic film material comprising two side walls lying on top of one another, welded together at their lateral edges by lateral weld seams, which have folded-over sections at an upper edge bordering a bag mouth, which are each welded to the respective side wall by an upper weld seam running at a distance from the upper edge and drawstrings arranged in the cord hems formed by the turned portions and the side walls and emerging from the ends of the cord hems, characterized in that the lateral edges of the side walls each have a recess at the ends of the cord hems, the lateral edges im Area of the recesses are not welded together and delimit through openings at the ends of the cord hems from which the drawcords emerge. A drawstring bag according to claim 1, wherein the recesses are rectangular or concave. A drawstring bag according to claim 2, wherein the recesses are quadrant shaped. A drawstring bag according to any one of claims 1 to 3, wherein the drawstrings are made of a thermoplastic material or cotton. A drawstring bag according to claim 4, wherein the drawstrings are made of a plastics material which is co-recyclable without prior separation from the plastics sheet material of the side walls. Drawstring bag according to Claim 4 or 5, in which the side walls are made of polyethylene, in particular LDPE, and the drawstrings are made of polyethylene, in particular HDPE, or of polyethylene terephthalate or of polypropylene. A drawstring bag according to any one of claims 1 to 6, wherein the drawstrings are plastic threads or ribbons. A drawstring bag according to any one of claims 1 to 7, wherein drawcords exiting adjacent ends of the seams are knotted, glued or welded together. Drawstring bag according to one of Claims 1 to 8, which is closed at the mouth of the bag by an end wall which is folded inwards between the two side walls when the bag is lying flat and which is welded to the two side walls via weld seams running parallel to the upper edge, the end wall preferably having a tear-open perforation . A drawstring bag according to claim 9, wherein the end panel is connected to the bottom edge of the unfolded portions of the side panels. Drawstring bag according to one of Claims 1 to 10, which has ventilation holes in the area of the lateral weld seams. Apparatus for manufacturing a drawstring bag according to any one of claims 1 to 11 from a sheet-like plastic film material, the apparatus having a separating welding device which is constructed and arranged to weld and separate the side walls together at the lateral edges and at the ends of the drawstring hems not to be welded or separated from each other in the area of the lateral recesses. Device according to Claim 12, in which the cut-off welding device has a heating and cutting element to be arranged on one side of the web-shaped plastic film material and a counter-pressure element to be arranged on the other side, with either the heating and cutting element or the counter-pressure element or both the heating and cutting element and the counter-pressure element does not extend over areas of the plastic film material which are designed to form the lateral recesses. Apparatus according to claim 12 or 13, wherein the recesses are formed in the plastic sheet material prior to the cut-off welding, preferably prior to the application of the drawcords to the plastic sheet material. Device according to one of Claims 12 to 14, in which the recesses are formed as punched-out portions or by laser cutting in the plastic film material.

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