GB1603900A

GB1603900A - Containers

Info

Publication number: GB1603900A
Application number: GB2500578A
Authority: GB
Original assignee: Bakelite Xylonite Ltd
Current assignee: BXL Plastics Ltd
Priority date: 1978-05-31
Filing date: 1978-05-31
Publication date: 1981-12-02

Description

(54) IMPROVEMENTS IN OR RELATING TO CONTAINERS (71) We, BAKELITE XYLONITE LIMITED, a British Company of 8 Grafton Street, London W1A 2LR, do hereby declare the invention for which we pray that a patent may be granted to us and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to containers and, in particular, to containers employed for dispensing interleaved paper tissues.

At the present time, the majority of interleaved paper tissues are packaged in cardboard cartons. These cardboard cartons generally have a face with perforations defining an opening. Access to the contents of the carton is achieved by rupturing the perforations and withdrawing a tissue through the so-formed opening. Once such cartons are opened they suffer from the disadvantage that they cannot be satisfactorily closed and the contents of the carton are thus not adequately protected against the entry of dust.

We have now devised a container having a panel comprising a sheet of flexible material which has a reinforced closable dispensing opening formed therein.

Accordingly, the present invention provides a container comprising a panel, which panel comprises a sheet of flexible material having an elongated dispensing opening defined therein, the panel having marginal pleat portions formed therein parallel to a longitudinal side of the opening and adjacent to the dispensing opening and a dual purpose flap being at least partially defined in the material between the marginal pleat portions, which dual purpose flap may, in use be manipulated internally of the container so that in one position the flap closes the dispensing opening and in the other position the flap reinforces one loneitudinal side of the dispensing opening.

The marginal pleat portions are pleated portions of the sheet which extend inwardly substantially from the edges of the sheet. In certain embodiments of the invention it may be found convenient if a weld extends through a marginal pleat portion.

In a particular embodiment of the present invention the marginal pleat portions comprise parts of a pleat extending across the sheet adjacent to the dispensing opening, at least one lower layer of the pleat being cut so as at least partially to define the dual purpose flap. In this case, when forming the flap in the panel it is preferred that the two lower layers of the pleat are cut. The length of the flap obtained by cutting the two layers of the material of the pleat enables the end of the flap, when in use, to be tucked securely under the opposite side of the dispensing opening.

It will be appreciated that in the case when marginal pleat portions only are formed, the flexible material between the marginal pleat portions enables a similarly long flap to be defined, which in use may likewise be tucked securely under the opposite side of the dispensing opening.

The flap preferably has a width which is less than the width of the panel and is centrally positioned so that the ends of the contents of the container are retained by margins of the panel at either end of the dispensing opening.

It will be appreciated that when the width of the flap is equal to the width of the panel the marginal pleat portions may form part of the flap instead of existing as separate entities on either side of the flap.

The dispensing opening and the flap are defined by cutting the flexible material fully, or by cutting the flexible material partially in the form of a plurality of broken-line cuts, or by perforating. When the broken-line cuts or perforations are employed to define the dispensing opening and/or the flap, the dispensing opening and/or the flap are then produced by the user by rupturing the material between the broken-line cuts or perforations.

The position of the cuts, whether full or partial, or perforations defines the position of the opening. The cuts or per forations do not necessarily form the side of the opening. As will be seen from the specific embodiment the side of the opening may be formed for example by folds or pleats under which the cut edges are pushed.

In a preferred container of the present invention, a pleat extends across the sheet of flexible material adjacent to the dispensing opening, the pleat being parallel to the marginal pleat portions.

The flexible material forming the panel may be any material such as paper or cloth, preferably rendered heat-sealable by, for example, a heat-sealable coating. Preferably, however, the flexible material is a thermoplastics material, for example a homopolymer or copolymer of ethylene, propylene or vinyl chloride. More preferably, the thermoplastics material is low density polyethylene. The sheet of flexible material preferably has a thickness of no greater than 250s, more preferably a thickness in the range of from 25,u to 125S.

The present invention also includes within its scope a method for producing a container of the present invention, which includes the steps of defining an elongated dispensing opening in a sheet of a flexible material, cutting the material adjacent to a first longitudinal side of the dispensing opening so as at least partially to define a flap and pleating the material so as to form at least marginal pleat portions parallel to one side of the dispensing opening at either side of the flap and adjacent to said first longitudinal side of the dispensing opening, the flap so defined being a dual purpose flap which may, in use, be manipulated internally of the container so that in one position the flap closes the dispensing opening and in the other position the flap reinforces said first longitudinal side of the dispensing opening.It will be understood that these three steps may be carried out in any order and that two or all of these steps may be carried out simultaneously.

In preferred embodiments of the process the cutting step precedes the pleating step.

The present invention includes within its scope a method for producing a container which method comprises defining an elongated dispensing opening in a sheet of flexible material, forming a pleat in the material parallel to one side of the dispensing opening and adjacent to one longitudinal side of the dispensing opening and extending substantially to the edges of the sheet and cutting the material of at least one lower layer of the pleat so as at least partially to define a dual purpose flap which may, in use, be manipulated internally of the container so that in one position the flap closes the dispensing opening and in the other position the flap reinforces one longitudinal side of the dispensing opening.

The present invention further includes within its scope a method for producing a container which method comprises forming a parallel sided pleat in a sheet of a flexible material defining an elongated dispensing opening adjacent to the pleat, and cutting the material of at least a lower layer of the pleat so as at least partially to define a dual purpose flap which may in use, be manipulated internally of the container so that in one position the flap closes the dispensing opening and in the other position the flap reinforces one longitudinal side of the dispensing opening.

The material of the panel may be different from the material of the rest of the container but it is preferred that the material of the panel and the material of the rest of the container are the same.

A preferred container in accordance with the invention has gussets formed in the longitudinal side walls thereof.

In a preferred embodiment of the present invention containers having a panel as hereinbefore described are formed from a flat sheet of flexible material by a process in which containers are formed, filled and sealed in a substantially continuous manner.

In one such process, which is often referred to as the "form and fill" process, flat sheet material, preferably a thermoplastics material, is supplied from a reel and formed into a back-seamed tube by drawing it around a vertically arranged hollow former or cylinder and bonding the longitudinal edges of the material, for example by heat sealing, to form the back seam. The tube thus formed is advanced through the apparatus by pulling on the tube and a transverse seal is made to seal the forward end of the tube. The product which is to be packaged is dropped through the hollow cylinder into the tube below and the tube is then sealed above the product to enclose it in a sealed bag which, simultaneously with the sealing operation, is cut from the formed tube.

This latter sealing operation not only seals the top of the bag but also seals the bottom of the next bag to be produced. The material is normally progressed intermittently through the apparatus by the transverse sealing jaws to which a reciprocating action is applied.

In another such process, a flat sheet material, preferably a thermoplastics material, is fed to a conveyor machine and the product to be packaged is placed on the material which is then formed into a tube around the product and the longitudinal edges of the material heat sealed together above the product. The leading edge of the tube thus formed is then transversely sealed and the tube behind the product is also similarly transversely sealed. The seal also serves to seal the tube ahead of the next product and should therefore be sufficiently broad to allow it to be cut through without destroying the seal on the completed pack or the new leading end of the tube.

In both of the above-described processes the flat sheet material is drawn off from a supply and is converted into tubular form by means of guides. In order to form the marginal pleat portions, or a pleat of which the marginal pleat portions form part or from which speciflc marginal pleat portions may be formed (as explained below) and any other pleats it is desired to form in the panel of the container of the present invention when employing such processes, suitable guides are introduced at appropriate stages of the pack production which automatically introduce any such marginal pleat portions or pleats into the material as the material is drawn over the guides.

The cuts to be made in the material to define the dispensing opening and the flap are preferably made in the material prior to subjecting the material to the pleating operation since this not only simplifies the making of the cuts but it is also found when the cut material is pleated in the manner described above the action of pleating may cause a fully cut flap to be tucked into the tube automatically and itself avoid being pleated. If desired, the positioning of the flap may be controlled at various stages of the process by prQviding air jets or additional guides. The cutting of the material to define the dispensing opening and flap is preferably effected using a suitably profiled rotary cutter or perforator between which and a back-up member the material is caused to pass.The back-up member may be, for example, an upper portion of the cylinder employed in the above-described "form and fill" process.

The preferred container of the invention also possess side gussets which are introduced before the transverse seals are made.

The gussets are preferably introduced, by the use of suitable guides, after the introduction of marginal pleat portions, or a pleat from which the marginal pleat portions may be formed or form part together with any additional pleats required.

It will be understood that container blanks sealed at one end may be produced from flat sheet material using apparatus similar to that described above with reference to the "form and fill" process, by operating the transverse severing mechanism only alternately with the conjoint operation of the transverse sealing and severing mechanism.

It will furthermore be understood that pleated tubular film may be produced with the use of suitable guides, for example by inflating the tube against such guides. In such cases, definition of the flap can be achieved by perforations small enough to allow the tube to be inflated being made prior to inflation with the tube in the flattened condition. Gusseting of the tube may be achieved simultaneously with pleating. Container blanks may be readily produced from such pleated, cut, and gussetted tubing by applying intermittent transverse seals and severing cuts.

If a line of weakness is made adjacent to transverse seals intermittently made then rolls of tear-off blanks may be produced.

The present invention will be further described with reference to the accompanying drawings, in which: Figure 1 is a plan view of an unfilled container in accordance with the invention; Figure 2 is a cross section of the container of Figure 1 along the line A-A; Figure 3 is a cross section of the container of Figure 1 along the line B-B; and Figure 4 is a cross section of the partially filled container of Figure 1 along the line A-A.

The container illustrated with reference to Figures 1 to 4 is a polyethylene film bag 1 having gussets 2 formed in the side walls thereof, a pleat 3 and marginal pleat portions 3c formed in the top panel. The pleat, marginal pleat portions and gussets are formed in a polyethylene film in tubular form or in some form which is a precursor to a tubular form, but in either case before applying a transverse heat weld seal to one end of the tube and thereby to one end of the bag. The other end of the bag is similarly sealed after filling.

The end welds 6, which extend through the material of the pleat, marginal pleat portions, and gussets, serve to retain the pleat, marginal pleat portions and gussets in position. The inner limits of the side gussets are indicated by reference numberals 2a in Figure 1. The inner limits of the pleat and marginal pleat portions and the outer limits of the pleat and marginal pleat portions are indicated by reference numerals 3a and 3b, respectively.

A flap 4 is formed by cutting through the material between the marginal pleat portions and slightly beyond along lines 5a-5b, 5c-5d, and 5b-5d. For clarity, lines 5a-5b and 5c-5d are shown to be of the length that would be required for cutting through the material between the marginal pleat portions when it is itself pleated and the lower two layers of the pleat are cut. But it is preferred that the flap is formed by cutting the material in the unpleated state.

The cut 5b-5d defines one longitudinal side of the dispensing opening 7 which is reinforced by the material of the pleat 3.

The cut 5b-5d preferably underlies the outer limit of the pleat 3, although for the sake of clarity this preferred position has not been shown. Referring to Figure 4, the container is partially filled with tissues 9 and a tissue 8 ready to be withdrawn from the container is shown. The flap 4 is folded back on itself, thus opening the dispensing opening and reinforcing the other longitudinal side of the dispensing opening.

Suitable apparatus for introducing pleats into sheet material in the continuous pr ductions of containers in accordance with the invention is described with reference to Figures 5 to 9 of the accompanying drawings, in which: - Figure 5 is a front view of the face of a forming member; Figure 6 is a side view of a pleating former; Figure 7 is a front view of the pleating former of Figure 6; Figure 8 is a section taken along the line A-A of Figure 5 but showing the pleating former assembled with the forming member in relation to which the direction in which in use the sheet is moved is indicated by 15; and Figure 9 is a section along the line B-B of Figure 5 showing the configuration of material between the forming member and the pleating former.

Referring to Figure 5, a forming member 10 for use in the "form and fill" process described above comprises a hollow cylinder having a slot 11 cut in the wall thereof. The slot 11 is on the opposite side of the cylinder to means (not shown) for forming the back seam in the tube formed from the sheet material. A pleating former 12 having a material entry guide 13 is fitted in relation to slot 11 as shown in Figure 8. The material entry guide 13 is uppermost and extends outwardly of the cylinder through slot 11.

The pleating former 12 is supported in this position by means of a narrow lug (not shown) projecting through the slot 11 indirectly and indirectly attached to a base member (not shown).

A sheet material of a suitable width, such as low density polyethylene, is fed around and down the forming member 10. During this operation the sheet material is at least partially cut or perforated to define the dispensing opening and the flap (both not shown). The uncut portions of the pleat to which the flap is attached which extends on either side of the flap constitute the marginal pleat portions. The sheet material is caused, during its movement in the direction 15 indicated in Figure 8, by the pleating former 12 to take up the configuration 14 shown in Figure 9. When this operation has been effected the back weam is formed in the sheet material and the "form and fill" process continues in the manner described above.

The apparatus illustrated in Figures 5 to 9 may also be used in the other process described in detail above. In this case the forming member 10 is flat and situated so that the pleats are formed in the flat film before the film reaches the conveyor when the product to be packaged is placed on the pleated film.

It will be appreciated that, whilst the present invention has been described in relation to a container having a dispensing opening, the container of the invention may be used in a manner where the dispensing opening is not necessarily employed as a means through which the contents of the container are dispensed, but merely to provide access to the inside of the container.

The present invention includes within its scope such containers when intended for use in this manner.

WHAT WE CLAIM IS: - 1. A container comprising a panel, which panel comprises a sheet of a flexible material having an elongated dispensing opening defined therein, the panel having marginal pleat portions, parallel to a longitudinal side of the opening and adjacent to the dispensing opening, a dual purpose flap being at least partially defined in the material between the marginal pleat portions, which dual purpose flap may, in use, be manipulated internally of the container so that in one position the flap closes the dispensing opening and in the other position the flap reinforces one longitudinal side of the dispensing opening.

2. A container as claimed in claim 1 wherein the marginal pleat portions comprise parts of a pleat extending across the sheet adjacent to the dispensing opening, at least one lower layer of the pleat being cut so as at least partially to define the dual purpose flap.

3. A container as claimed in claim 2 wherein the two layers of the pleat are cut.

4. A container as claimed in any one of the preceding claims wherein the flap has a width which is less than the width of the panel.

5. A container as claimed in any one of the preceding claims wherein the dispensing opening is defined by a plurality of broken-line cuts or perforations.

6. A container as claimed in any one

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. lower two layers of the pleat are cut. But it is preferred that the flap is formed by cutting the material in the unpleated state. The cut 5b-5d defines one longitudinal side of the dispensing opening 7 which is reinforced by the material of the pleat 3. The cut 5b-5d preferably underlies the outer limit of the pleat 3, although for the sake of clarity this preferred position has not been shown. Referring to Figure 4, the container is partially filled with tissues 9 and a tissue 8 ready to be withdrawn from the container is shown. The flap 4 is folded back on itself, thus opening the dispensing opening and reinforcing the other longitudinal side of the dispensing opening. Suitable apparatus for introducing pleats into sheet material in the continuous pr ductions of containers in accordance with the invention is described with reference to Figures 5 to 9 of the accompanying drawings, in which: - Figure 5 is a front view of the face of a forming member; Figure 6 is a side view of a pleating former; Figure 7 is a front view of the pleating former of Figure 6; Figure 8 is a section taken along the line A-A of Figure 5 but showing the pleating former assembled with the forming member in relation to which the direction in which in use the sheet is moved is indicated by 15; and Figure 9 is a section along the line B-B of Figure 5 showing the configuration of material between the forming member and the pleating former. Referring to Figure 5, a forming member 10 for use in the "form and fill" process described above comprises a hollow cylinder having a slot 11 cut in the wall thereof. The slot 11 is on the opposite side of the cylinder to means (not shown) for forming the back seam in the tube formed from the sheet material. A pleating former 12 having a material entry guide 13 is fitted in relation to slot 11 as shown in Figure 8. The material entry guide 13 is uppermost and extends outwardly of the cylinder through slot 11. The pleating former 12 is supported in this position by means of a narrow lug (not shown) projecting through the slot 11 indirectly and indirectly attached to a base member (not shown). A sheet material of a suitable width, such as low density polyethylene, is fed around and down the forming member 10. During this operation the sheet material is at least partially cut or perforated to define the dispensing opening and the flap (both not shown). The uncut portions of the pleat to which the flap is attached which extends on either side of the flap constitute the marginal pleat portions. The sheet material is caused, during its movement in the direction 15 indicated in Figure 8, by the pleating former 12 to take up the configuration 14 shown in Figure 9. When this operation has been effected the back weam is formed in the sheet material and the "form and fill" process continues in the manner described above. The apparatus illustrated in Figures 5 to 9 may also be used in the other process described in detail above. In this case the forming member 10 is flat and situated so that the pleats are formed in the flat film before the film reaches the conveyor when the product to be packaged is placed on the pleated film. It will be appreciated that, whilst the present invention has been described in relation to a container having a dispensing opening, the container of the invention may be used in a manner where the dispensing opening is not necessarily employed as a means through which the contents of the container are dispensed, but merely to provide access to the inside of the container. The present invention includes within its scope such containers when intended for use in this manner. WHAT WE CLAIM IS: -

1. A container comprising a panel, which panel comprises a sheet of a flexible material having an elongated dispensing opening defined therein, the panel having marginal pleat portions, parallel to a longitudinal side of the opening and adjacent to the dispensing opening, a dual purpose flap being at least partially defined in the material between the marginal pleat portions, which dual purpose flap may, in use, be manipulated internally of the container so that in one position the flap closes the dispensing opening and in the other position the flap reinforces one longitudinal side of the dispensing opening.

6. A container as claimed in any one

of the preceding claims wherein the flap is defined by a plurality of broken-line cuts or perforations.

7. A container as claimed in any one of the preceding claims wherein a pleat extends across the sheet of flexible material adjacent to the dispensing opening to reinforce a second side of the dispensing opening, the pleat being parallel to the marginal pleat portions.

8. A container as claimed in any of the preceding claims wherein the flexible material is a thermoplastic material.

9. A container as claimed in claim 8 wherein the thermoplastics material is a homopolymer or copolymer of ethylene, propylene or vinyl chloride.

10. A container as claimed in claim 9 wherein the thermoplastics material is a low density polyethylene.

11. A container as claimed in any of the preceding claims wherein the sheet of the flexible material has a thickness no greater than 250,u.

12. A container as claimed in claim 10 wherein the sheet of the flexible material has a thickness in the range of from 25,a to 125A.

13. A container as claimed in any of the preceding claims wherein the material of the panel is different from the material of the rest of the container.

14. A container as claimed in any one of claims 1 to 12 wherein the material of the panel is the same as the material of the rest of the container.

15. A container as claimed in any one of the preceding claims wherein the thickness of the panel is the same as the rest of the container.

16. A container as claimed in any one of the preceding claims wherein gussets are formed in opposed side walls thereof.

17. A blank for a container as claimed in any one of the preceding claims.

18. A method for producing a container which method comprises defining an elongated dispensing opening in a sheet of a flexible material, cutting the material adjacent to a first longitudinal side of the dispensing opening so as at least partially to define a flap and pleating the material so to form at least marginal pleat portions parallel to one longitudinal side of the dispensing opening at either side of the flap and adjacent to said first longitudinal side of the dispensing opening, the flap so defined being a dual purpose flap which may, in use, be manipulated internally of the container so that in one position the flap closes the dispensing opening and in the other position the flap reinforces said first longitudinal side of she dispensing opening.

19. A method for producing a container which method comprises defining an elongated dispensing opening in a sheet of a flexible material, forming a pleat in the material parallel to one longitudinal side of the dispensing opening adjacent to one longitudinal side of the dispensing opening and extending substantially to the edges of the sheet and cutting the material of at least one lower layer of the pleat so as to at least partially define a dual purpose flap which may, in use, be manipulated internally of the container so that in one position the flap closes the dispensing opening and in the other position the flap reinforces one longitudinal side of the dispensing opening.

20. A method for producing a container which method comprises forming a parallel sided pleat in a sheet of a flexible material, defining an elongated dispensing opening adjacent to the pleat and cutting the material of at least one lower layer of the pleat so as at least partially to define a dual purpose flap which may, in use be manipulated internally of the container so that in one position the flap closes the dispensing opening and in the other position the flap reinforces one longitudinal side of the dispensing opening.

21. A method as calimed in claims 19 or 20 wherein the two lower layers of the pleat are cut.

22. A method as claimed in any one of claims 18 to 21 wherein the dispensing opening is defined by a plurality of brokenline cuts or perforations.

23. A method as claimed in any one of claims 18 to 22 wherein the flap is defined by a plurality of broken-line cuts or perforations.

24. A method as claimed in any one of claims 18 to 23 wherein a pleat is formed in the sheet of flexible material so that it extends across the sheet adjacent to the dispensing opening to reinforce a second longitudinal side of the dispensing opening, the second pleat being parallel to the marginal pleat portions.

25. A method for producing a container substantially as hereinbefore described with reference to figures 5 to 9.

26. A container whenever made by a method as claimed in any one of claims 18 to 25.

27. A container substantially as hereinbefore described with reference to and as illustrated in Figures 1 to 4 of the accompanying drawings.

28. A container as claimed in any one of claims 1 to 16, 26 or 27 which is filled with interleaved paper tissues.