Patent EA-003007-B1 (EA)
Title: Method for producing a resealable pouch
Inventor: HOLLOWAY STEPHEN JOHN
IPC: B31B50/64
Filed: 2000-01-06
Abstract: 1. A method of producing resealable filled pouches comprising the steps of: folding across part of its original width a length of thermoplastics sheet to produce a folded sheet having a fold portion running lengthways of the sheet having a folded edge which fold portion extends across part of the original width of the sheet and a non fold portion extending from the fold portion to the other edge of the sheet; in a direction at right angles to the folded edge and at regular intervals along the folded edge, welding the fold portion together to form individual pockets of equal size having welded wall edges along the length of the sheet; cutting the sheet, across the width of the sheet and along the line of the welds, to produce individual pouches each having a mouth, welded edges and an extended flap portion; filling each pouch, through its mouth, with desired contents and folding the extended flap over the mouth so as to form the flap around the pouch; characterised in that, at the time of forming the fold portion of the sheet, a resealable fastener is located on the sheet in a direction parallel to the edges of the sheet and in a position predetermined to be immediately below the mouths of the pouches wherein the resealable fastener comprises two interengaging closure strips in engaged position, each closure strip of which having a base portion, and in that the base portions of each of the two interengaging closure strips are, while the strips are engaged with each other, welded to the facing surfaces of the sheet respectively in the fold portion, and wherein after welding of the resealable fastener the closure strips are disengaged from each other, the closure strips being made to engage with each other after the filling of the pouch and before forming the extended flap over the pouch. 2. A method according to claim 1, wherein the thermoplastics sheet is a sheet of polyethylene. 3. A method according to either claim 1 or claim 2, wherein the sheet is a laminate of a thermoplastics material with one or more layers of similar or different thermoplastics material, a metalised or metal coated sheet material or a paper web. 4. A method according to any one of claims 1 to 3, wherein welding is carried out by ultra-sonic welding. 5. A method according to any one of claims 1 to 5, wherein the base of each of the closure strips is provided with one or more fanges. 6. A method according to claim 5, wherein the folded portion of the sheet is welded up to immediately below the flanges on the closure strip. 7. A method according to any one of claims 1 to 6, wherein the resealable fastener is cooled immediately following welding to the thermoplastic sheet. 8. A method according to any one of claims 1 to 7, wherein the extended flap of each individually formed pouch is folded over the pouch, after filling thereof, at a position between the filled pouch and the bottom of the fastener. 9. A method according to any one of claims 1 to 8, wherein the flap, after being folded over the mouth of the flap, is folded around the base of the pouch. 10. A method according to any on of claims 1 to 9, wherein the pouches are filled with tobacco. 11. A method according to any one of claims 1 to 10, wherein the thermoplastics sheet is supplied from a continuous reel. 12. A method according to any one of claims 1 to 11, wherein the thermoplastic sheet is folded such that the distance from the folded edge to the mouth of the pouch is equal to the distance from the mouth of the pouch to the edge of the extended flap.