| 摘要 |
PURPOSE: To increase the area of the contact with a film in sealing it by a heat-sealing roller so as to free the operation of defective sealing. CONSTITUTION: The subject relates to a vertically sealing device in a packing machine which holds the ends of a tubular film to be superposed one upon the other between a pair of revolving heat-sealing rollers 31, 32 in sealing the film vertically. The circumferential surfaces of the heat-sealing rollers 31, 32 between which the ends of the tubular film to be joined as above are held are formed in undulations 35 consisting of a series of ridges 37 and furrows 36 each shaped substantially in an arc and the two heatsealing rollers 31, 32 are linked in a manner of enabling the ridges 37 and furrows 36 engaged together to hold the ends to be joined under a specified pressure therebetween. The ridges 37 and furrows 36 are formed at a minute furrow-to-ridge height ofΔr and at a furrow-to-ridge pitch (p) that jointly enable forming a vertical sealed part of the ends to be joined in a substantially flat joint free of waviness.
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