Patent GB-1436676-A (GB)
Title: Method and apparatus for compressing material and enclosing the same in a plastics film
IPC: B65B27/12
Filed: 1974-01-30
Abstract: 1436676 Seaming JOHNS-MANVILLE CORP 30 Jan 1974 [23 Feb 1973] 04308/74 Heading B5K [Also in Division B8] Cotton, hay, straw, felt or glass fibre insulation batts are compressed between convergent endless conveyers 74, 76 having back-up plates 96 and 98 at a compression station 24 and are enclosed between opposed plastics webs 152, 154 whilst maintained in the compressed condition by opposed conveyers 104, 106 having back-up plates 138, 140 in a sealing station 26. The webs are welded together about the batt by pairs of reciprocating longitudinally extending welding members 116, 118 and by reciprocating transversely extending welding members 202 and 204, rails 124, 126 being provided to prevent the side edges of the compressed batt extending between the pairs of welding members 116, 118. Each batt is fed by an inclined conveyer 42 at a loading station 22 to the compression station past a pair of piston operated gates 32, which are subsequently closed on actuation of a photo-cell (232), Fig. 13 (not shown), by the leading edge of the batt being compressed, to permit another batt to be placed on the conveyer 42. During compression of the batt between the conveyers 74, 76, the batt is retained against lateral expansion by triangular side plates (100), (102), Fig. 3 (not shown). The compressed batt is then sandwiched between the webs and held compressed by the conveyers 104 and 106 whilst being fed thereby between the webs. The leading edge of the batt trips a second photo-cell (234) which causes halting of the conveyers 104, 106 and actuation of the welding members 116, 118, 202, and 204, the members 202, 204 forming both the transverse trailing weld of the preceding packaged batt on an off-load conveyer 216 and the leading transverse weld of the batt being packaged between the conveyers 104, 106. The batt being packaged is then moved between the off-loading conveyer 216 and roller 226, which separates the packaged batt from the subsequent batt along the trailing transverse seam, the plastics of the sheets being weakened during the formation of this seam. The side edge portions of the webs are guided between rails 112, 114 through the sealing station whilst the longitudinal guide rails 122, 124 constrain the lateral side edges of the batts from contacting the welding members 116, 118. After welding of the side edges of the webs, the formed welds are cooled by compressed air fed from perforated tubes 210, 212 affixed to the guides 122, 124. Each pair of welding members 116, 118 includes an anvil (190) having a rubber insert (192) and a heating member having a resistance wire or ribbon (172) extending along the edge of an insulating block (168) and connected to a supply through thermal expansion compensating springs (174), Figs. 10 and 11 (not shown). The transverse welding members 202, 204 are similarly constructed but may not extend across the complete width of the webs so that, on separation of the packaged batt along its trailing transverse weld from the preceding batt, corner vents are provided in the package, to allow the escape of air on recompression of the package when packed with others in a larger container. In a modification (not illustrated), the welding members may be replaced by heated sealing rollers, glue applicators and pressing rollers, or stitching heads.