GB2350586A

GB2350586A - Improved sealing of bags for fine powders

Info

Publication number: GB2350586A
Application number: GB0013267A
Authority: GB
Inventors: Dermot Brady
Original assignee: Mach & Graphic Consultants Ltd
Current assignee: Mach & Graphic Consultants Ltd
Priority date: 1999-05-31
Filing date: 2000-05-31
Publication date: 2000-12-06
Anticipated expiration: 2020-05-31
Also published as: IE20000438A1; GB2350586B; GB0013267D0; IES991086A2

Abstract

A bag 10 manufactured from a tube 12 comprises one end folded and sealed to form the base 14 of the completed bag 10, wherein the folding operation is conducted in a number of stages, with an adhesive label or patch 20 being applied to the base 14 of the bag after the base is first formed and a final folding operation comprises folding the ends of the bag and label 20 over one another to form the final seal. Adhesive may be applied on the upper surface of the label 20 by an applicator prior to the final folding operation to form the final seal. The adhesive may be applied to the upper surface of the label 20 in two separate strips (41, Figure 8). The labels may be applied to the base of the bags from a roll (30, Figure 5a) of labels by a roller (31). The invention is useful for sealing bags for containing fine powder material such as flour, the improved seal totally sealing the base of the bag so no powder contents can sift out though the base of the bag.

Description

2350586 IMPROVED BAGS The present invention relates to bags, in particular

improvements to sealing bags for fine powder material such as flour.

Bags of flour when stocked on supermarket shelves tend to lose some contents as flour sifts out through the bottom of the bags and collects on the shelves. Therefore these supermarket shelves need to be cleaned regularly in order to maintain the cleanliness and hygiene requirements in modem supermarkets.

The present invention provides a bag in the form of a tube, with the tube having one end folded and sealed to form the base of the completed bag, characterised in that an adhesive label or patch is applied to the end of the bag after the ends are first formed, with the final folding operation comprising folding the ends of the bag and label over one another to 15 form the final seal.

In this way, the end of the bag is totally sealed and no powder contents can sift out through the end of the bag.

The final seal may be achieved by the use of adhesive or heat sealing.

Preferably, the adhesive is applied on the upper surface of the label prior to folding the ends of the bag.

Conveniently, the adhesive label may be supplied with adhesive only applied to a portion of the surface, with a non adhesive strip being provided, whereby the strip is applied over edges of the tube where the edges come together to form the end to prevent adhesive extending through any gap to contact the inner portion of the bag or products contained therein. 30 In one embodiment, the adhesive label has a narrowed or reduced width end portion and an extended or wide body portion. The wide body both increases the strength and improves the overall safety of the seal because of the increased surface area of the applied label, in contact with the end of the bag. The reduced width of the end portion of the label maintains the entire surface area of the label within the boundary of the end of the bag. As the lower surface of the label is covered in adhesive, the reduced width end removes the risk of the underside of the label becoming adhered to the bag during both the label fixing and the adhesive application process.

Conveniently, a unique indicator is provided on each label.

The invention also provides a method of manufacturing a bag comprising the steps of forming a sheet of material into a tube, folding one end of the tube to close one end of the bag, applying an adhesive label on the end of the bag from a roll of labels by a roller, applying adhesive to the upper surface of the label by an applicator, folding a first flap back onto the adhesive label and folding a second flap over onto the first flap to seal the 15 end of the bag.

The invention will hereinafter be more particularly described with reference to the accompanying drawings which illustrate, by way of example only, a number of embodiments of a paper bag according to the invention.

In the drawings:

Figure 1 is a perspective view of a bag with the end formed after the first stage of folding and an adhesive label being applied; Figure 2 is a view of the completed end of the bag from the inside of the bag; Figure 3 is a perspective view of the end of the bag; Figures 4a to 4d show the successive steps in completing the final folding stages to form and seal the end of the bag; G.

Figures 5a to 5d show a side view of the successive steps in completing the final folding stage corresponding to the respective views shown in Figures 4a to 4d; Figure 6 is a plan view of the bag prior to the final folding stage; Figure 7 is a plan view of an adhesive label having one surface completely coated with adhesive which is used to form the bag of the first embodiment; Figure 8 is a plan view of a second adhesive label used to form the bag of the second embodiment in which a centre strip is provided without any adhesive coating; Figure 9 is a plan view of a third adhesive label used to form the bag according to the third embodiment of the invention in which a reduced width end portion is shown; and Figure 10 is a plan view of the adhesive label of Figure 9 applied to the end of the bag.

Referring to the drawings, the first embodiment of bag 10 is formed into a tube 12 and the end 14 is formed to close the end of the bag. An adhesive label 20 is applied over the end 14 which is then folded over (see Figures 4a to 4d) to form a sealed bottom 16 for the bag 10.

Referring to Figures 5a to 5d, the adhesive label 20 is laid on the end of the bag 14 from a roll 30 of labels by a roller 3 1. Adhesive is applied to the upper surface of the label 20 by an applicator 32. After the application of adhesive, flap 13 is first folded back onto the adhesive label 20 and finally the flap 15 is folded over onto the flap 13 to form the fully sealed bottom 16.

C.

Referring now to Figures 6 to 8, when the label 20 is laid down onto the end 14, it covers two edges 19. If the two edges do not fully meet, a slight gap (not shown) may be present.

To avoid the adhesive label sticking to material behind the gap, use can be made of a modified label 40 of the second embodiment of bag which has two areas of adhesive 41 separated by a strip 42 having no adhesive. When the label 40 is applied, the strip 42 lies over the edges 19.

Referring now to Figures 9 and 10 there is shown a third embodiment of a bag in accordance with the invention. A label 50 is shown with a reduced width end portion 51 and an enlarged main label portion 52.

In use, when the label 50 is rolled from the roller 3 1 onto the bag 10 the width of the end 51 is such that no part of the label 50 extends beyond the flap 13. It will be understood that a non-adhesive strip 42 (as shown in Figure 8) may also be incorporated into this embodiment of adhesive label. The increased width allows a larger portion of the end of the bag 14 to be covered and both increases the strength and overall safety of the seal because of the increased surface area of the applied label. At the same time, the reduced width of the end portion of the label maintains the entire surface area of the label within the boundary of the end of the bag thereby facilitating application. The reduced width end portion of the label removes the risk of the underside of the label becoming adhered to the bag during both the label fixing and the adhesive application process.

In other modifications to the invention the labels 20, 40 and 50 can be pre-coated with adhesive on both sides.

The material used to manufacture the bag can be any material used in the packaging industry such as paper, coated paper or polymeric packaging material. The labels used can be of any suitable material but paper labels are effective.

In a farther modification to the invention an unique indicator such as a token, lucky number or prize award is applied by printing or other means to the face of the labels 20, 40 and 50. Such a unique indicator may be used for the purpose of awarding customers rewards or prizes so as to encourage the purchase of products contained within the bags of the invention.

It is to be understood that the invention is not limited to the specification details described above which are given by way of example only and that various modifications and alternations are possible without departing from the scope of the invention as defined in the appended claims.

P-

Claims

CLAIMS:

1. A bag (10) in the form of a tube (12), withthe tube (12) having one end (14) folded and sealed to form the base of the completed bag (10), characterised in that an adhesive label (20) or patch is applied to the end of the bag (10) after the ends are first formed, with the final folding operation comprising folding the ends of the bag (10) and label (20) over one another to form the final seal. 10

2. A bag (10) as claimed in claim 1, characterised in that the final seal is provided by adhesive.

3. A bag (10) as claimed in claim 1, characterised in that the final seal is provided by heat sealing.

4. A bag (10) as claimed in claim 1 or claim 2, characterised in that adhesive is applied on an upper surface of the label (20) prior to folding the ends of the bag (10) and label (20) over one another to form the final seal.

5. A bag (10) as claimed in any preceding claim, characterised in that the adhesive label (40) may be supplied with adhesive only applied to a portion of the surface, with a non adhesive strip (42) being provided, whereby the strip (42) is applied over edges (19) of the tube (12) where the edges (19) come together to form the end (14) to prevent adhesive extending through any gap to contact the inner portion of the bag (10) or products contained therein.

6. A bag (10) as claimed in any preceding claim, characterised in that the adhesive label (50) has a narrowed or reduced width end portion (5 1) and an extended or wide body portion (52) thereby increasing the strength and improving the overall safety of the seal due to the increased surface area of the applied label (50).

4a.

7. A bag (10) as claimed in any preceding claim, characterised in that the labels (20), (40) and (50) are pre-coated with adhesive on both sides.

8. A bag (10) as claimed in any of the preceding claims in which a unique indicator is 5 provided on each label (20), (40) and (50).

9. A method of manufacturing a bag (10) comprising the steps of forming a sheet of material into a tube (12); folding one end (14) of the tube (12) to close one end of the bag (10); applying an adhesive label (20) on the end of the bag (14) from a roll (30) of labels by a roller (3 1); is applying adhesive to the upper surface of the label (20) by an applicator (32); folding a first flap (13) back onto the adhesive label (20); and folding a second flap (15) over onto the first flap (13) to seal the end of the bag (10).

10. A method of manufacturing a bag (10) as claimed in claim 9, characterised in that the label (40) comprises two areas of adhesive (41) separated by a strip (42) having no adhesive (4 1) and lies on edges (19) of the end (14) of the bag (10) to be scaled.

11. A method of manufacturing a bag (10) as claimed in claim 9, characterised in that the label (50) comprises a reduced width end portion (5 1) and an enlarged main label portion (52), whereby in use the label (50) is rolled from roller (3 1) onto the bag (10) wherein the width of the end portion (51) is such that no part of the label (50) extends beyond the first flap (13).

Q

12. A method of manufacturing a bag (10) as claimed in claim 11, characterised in that the label (50) comprises two areas of adhesive (41) separated by a strip (42) having no adhesive and lies on edges (19) of the end (14) of the bag (10) to be sealed.

13. A method of manufacturing a bag (10) as claimed in claims 9 to 12, characterised in that the labels (20), (40) and (50) are pre-coated with adhesive on both sides.

14. A bag (10) with an adhesive label (20), (40) and (50) or patch applied to its end substantially as herein described with reference to and as shown in accompanying drawings.

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