GB870800A - Improvements in or relating to infusion bags and method of making the same - Google Patents

Abstract

870,800. Infusion packages; making paper bags. NATIONAL TEA PACKING CO. Inc. March 13, 1958 [Aug. 23, 1957], No. 8130/58. Classes 94(1) and 94(2). An infusion package I, Fig. 16, is formed from a flattened tube by folding it to form a two compartment bag 20, 22 closing the compartments by a common top closure 90, securing a string S to the closure, and folding the top and bottom of the package to form expansion pleats 30 and 28 respectively. A filter paper is fed from a roll 38, Fig. 1, over a guide 40 and onto a former 42, cylindrical at one end and tapering to elliptical formation at the other end, to form a tube 44 which is then flattened by feed rolls 46. A thermoplastic strip 48 is sealed between the overlapping edges by a heated pressure roller 52. The resulting flattened tube 56 is then cut into lengths by knives 58 and 60, and each length passes between forming tools 64 and 66, Fig. 3, that fold the tube to produce a bag having two compartments 20 and 22. The tools 64 and 66 also form a bottom expansion pleat 28. As the tools 64 and 66 withdraw, the bag bottom is gripped between clamping plates 70 and 72, Fig. 6, and two spouts 76, 78, each having a blade 80 at its lower end, then descend to cause the blades to enter the compartments 20, 22, and hold them whilst they are opened by suction cups 84 and 86, after which the spouts 76 and 78 continue their descent into the compartments 20 and 22 and charge them with a product 88. The charge containers are sealed by a common thermoplastic strip 90 folded over the compartment ends before being subjected to heat and pressure. Next, a string S is fed through openings 74, 74, Fig. 9, in the clamping plates 70 and 72 and about the now formed bag I, to be attached by a staple 102 to the strip 90, after which the string is cut from its supply spool. Two clamp plates 108, 110 then engage the package near its upper end and two fingers 112, 114 move bag portions above the plates 108 and 110 through the formation shown in Fig. 9 to that shown in Fig. 10 to form a central pleat portion 30 and two expansion pleats 30a and 30b one on each side of the central portion 30. The top expansion pleats are compacted by clamping tools 116 and 118. The package I is finally gripped between forked members 120 and 122, Fig. 11, and a band of strip material 124 is fed beneath the package I. The package I and a severed strip 124 are then moved downwardly between blocks 132 and 134, to fold the strip 124 about the package I, the meeting edges of the folded strip 124 being stapled together and including the free end of the string S. The strip 124 holds the package in its flattened state and subsequently serves as a hand hold.