GB2275911A - Plastic carrier bags - Google Patents

Abstract

A plastic hag comprises a main section 20 for containing vegetables or other commodities and having two arm portions, 60, 70 the handles being provided by upper portions of the arm portions formed by punching out lower sections of the arms 28, 30 leaving an upper section in each arm portion to form the handle. A method is disclosed of making the bags from long flat plastic tubing. Two bags are formed at a time, initially joined by their respective upper portions. The double bags are then stacked to form a double block which is welded along the common upper edges of the bags, then severed to form two blocks. Finally the portions 28, 30, 50 are removed and perforations 42 and 44 and suspension holes 38, 40 formed. In a second embodiment of bag (Fig 3) the suspension holes are provided in a central bar block which bridges the two upstanding arms. <IMAGE>

Description

IMPROVEMENTS IN OR RELATING TO PLASTIC BAGS The present invention relates to plastic bags and to a method of manufacturing plastic bags.

A known type of plastic bag for use in a supermarket or similar store is provided in a stack or block of bags. The bags comprise a general rectangular shape and are removable from the block by means of a perforation line.

Such bags when removed from the block are rectangular and are not easily carried when filled with, for example apples or other vegetables.

It is an object of the present invention to provide a plastic bag suitable for carrying vegetables which has a handle for carrying by the purchaser and which has a simple but robust construction.

The present invention therefore provides a plastic bag comprising a main portion for carrying the contents to be placed in the bag, the main portion being provided with two arm members upstanding from the main portion, each arm member being shaped to provide a handle portion, the handle portion being formed by removal of a portion of the arm member.

Preferably the plastic bag is of the vest type, the removed portion comprising an arcuate region of the upper part of the arms.

Preferably the plastic bags are provided as a block of bags, the block being held together by heat sealing at the extreme ends of each arm and each bag being provided with perforation means across each arm to allow easy removal of the bag from the block.

Preferably each block of bags is provided with retention means for the block. In a preferred embodiment this comprises a hole formed through the block of bags intermediate between the heat sealed end and the perforation means.

The present invention also provides a method of manufacture of a plastic bag comprising the steps of: a) unrolling a length of lay flat plastic tubing; b) heat sealing in a lateral direction across a first portion of the plastic tubing and severing said plastic tubing at said first heat seal, c) heat sealing in a lateral direction across a second portion of the plastic tubing at a longitudinal distance from said first portion severing said plastic tubing at said second heat seal; d) heat sealing in a longitudinal direction along a third portion of the plastic tubing and severing said plastic tubing at said third heat seal; e) punching out first, second and third areas from said plastic tubing to form an opening for said plastic bag and also to form the handle portions of the plastic bag.

Preferably the plastic bags are manufactured in a block and following steps (a) and (b) a plurality of the heat sealed tubes are stacked prior to said third heat sealing and severing operation, the third heat sealing operation thereby joining the bags together to form the block of bags.

Preferably each bag is provided with perforation means to enable ease of removal from the block.

Preferably therefore the method comprises perforation in a longitudinal line adjacent and substantially parallel to the third heat seal, said perforation being effected by a serrated punch.

Preferably each block of bags is further provided with a through hole or holes by a further punching operation to enable the block to be suspended on appropriate rods.

The heat sealing operations may be carried out separately or alternatively more than one operation may be carried out simultaneously.

Also the punching operations may be carried out simultaneously.

Embodiments of the present invention will now be described, by way of example with reference to the accompanying drawings in which: Figure 1 shows in plan view a plastic bag according to the present invention; Figure 2 shows diagrammatically possible production sequence for a bag according to the present invention and Figure 3 shows in plan view an alternative design of plastic bag in accordance with the present invention.

With reference now to Figure 1, the bag 10 shown is of the vest type and is generally rectangular in outline shape. Other shapes could be provided.

The bag 10 comprises a main portion 20 for holding for example vegetables or other goods sold in shops, supermarkets etc.

The bag comprises a double layer of plastics material which is sealed along edges 22, 24, 26 as described hereinafter. Edges 24 and 26 are provided with cut out portions 28, 30 and with upper portions 32, 34.

In a preferred embodiment the bags are provided on a block of bags indicated schematically at 36. Support hole means 38, 40 are then provided as shown to enable the block of bags to be supported on support rods (not shown) in known manner.

If the bag is provided on a block of bags then preferably the block is provided with perforation means 42, 44 to enable individual bags to be readily removed from the block by the customer.

The bag shown is of the vest type and is therefore provided with a central aperture 50 which may be of any convenient shape but in the embodiment shown is generally rectangular. This aperture provides the opening in the bag for the vegetables or other product.

In use the bag shape thus provides two arm like structures 60, 70 upstanding from the main portion 20. These arms provide carrying handles for the bag by means of the portions 32' and 34' which were not removed above the cut out portions 28, 30.

These arm like structures 60, 70 can be used either to carry the bag or they can be knotted together to effectively constrain the contents of the bag and the loose ends can also still be used to provide carrying handles.

If desired, but not essential to the operation of the bag further heat seals 82, 84 (shown chain dotted) may be provided adjacent to but underneath the perforation lines 42, 44. These heat seals would serve to seal together the two plastic layers forming the bag but would not sever the plastic. They would therefore provide further strength to the handles of the bag formed from the arm portions 60, 70.

The bag 10 may be manufactured by the steps diagrammatically illustrated in Figure 2.

A roll of lay flat plastic tubing 100 is rotatably mounted (not shown) and is pulled out in the direction indicated by arrow 102.

In a first position the edges 24, 26 are sealed and severed to form an elongate sealed bag 104 (which will eventually produce two bags 10).

If the additional heat seal 82, 84 is required it is preferably also provided at this stage.

The "double bags" 104 are then stacked to form the block of bags and then the stack of bags is welded together by heat sealing and severing the bags as shown at 106 to form two blocks of bags 104', 104".

The portions 28, 30 and 50 are then removed from each block of bags and the holes 38, 40 are inserted.

The perforations 42, 44 may be provided at this time or previously in the first operation.

The punching operation therefore provides the bag opening 50 and the arms 60, 70 handle portions 32', 34' in a simple manner.

With reference to the alternative embodiment shown in Figure 3, where applicable reference numerals are used to denote parts similar to those in Figure 1.

In this embodiment, the holes 38',40' for suspending the block of bags are formed in a central bar block 200, each bag being separable therefrom by serrations 82',84'. The bar block increases the rigidity of the block of bags.

Claims (14)

1. A plastic bag comprising a main portion for carrying the contents to be placed in the bag, the main portion being provided with two arm members upstanding from the main portion, each arm member being shaped to provide a handle portion, the handle portion being formed by removal of a portion of the arm member.

2. A plastic bag as claimed in claim 1 in which the bag is of the vest type, the removed portion comprising an arcuate region of the upper part of the arms.

3. A plastic bag as claimed in claim 1 or claim 2 in which the plastic bags are provided as a block of bags, the block being held together by heat sealing at the extreme ends of each arm and each bag being provided with perforation means across each arm to allow easy removal of the bag from the block.

4. A plastic bag as claimed in claim 3 in which each block of bags is provided with retention means for the block.

5. A plastic bag as claimed in claim 4 in which the retention means comprises a hole formed through the block of bags intermediate between the heat sealed end and the perforation means.

6. A method of manufacture of a plastic bag comprising the steps of: a) unrolling a length of lay flat plastic tubing; b) heat sealing in a lateral direction across a first portion of the plastic tubing and severing said plastic tubing at said first heat seal, c) heat sealing in a lateral direction across a second portion of the plastic tubing at a longitudinal distance from said first portion severing said plastic tubing at said second heat seal; d) heat sealing in a longitudinal direction along a third portion of the plastic tubing and severing said plastic tubing at said third heat seal; e) punching out first, second and third areas from said plastic tubing to form an opening for said plastic bag and also to form the handle portions of the plastic bag.

7. A method as claimed in claim 6 in which the plastic bags are manufactured in a block and following steps (a) and (b) a plurality of the heat sealed tubes are stacked prior to said third heat sealing and severing operation, the third heat sealing operation thereby joining the bags together to form the block of bags.

8. A method as claimed in claim 7 in which each bag is provided with perforation means to enable ease of removal from the block.

9. A method as claimed in claim 8 in which the method comprises perforation in a longitudinal line adjacent and substantially parallel to the third heat seal, said perforation being effected by a serrated punch.

10. A method as claimed in any one of claims 6 to 9 in which each block of bags is further provided with a through hole or holes by a further punching operation to enable the block to be suspended on appropriate rods.

11. A method as claimed in any one of claims 6 to 10 in which the heat sealing operations are carried out separately or alternatively more than one operation is carried out simultaneously.

12. A method as claimed in claim 10 in which the punching operations are carried out simultaneously.

13. A plastic bag substantially as described with reference to the accompanying drawings.

14. A method of manufacturing a plastic bag substantially as described with reference to the accompanying drawings.