| 摘要 |
528,833. Packaging. PAD-Y-WAX CO., Inc. May 16, 1939, No. 14569. Convention date, May 25, 1938. [Class 94 (i)] A method of packaging commodities consists in feeding a web of material to a device which seals it along its margins and along spaced transverse areas to form a succession of sealed envelopes, and in introducing the commodity into each envelope during and prior to the completion of the sealing-operation. A web, preferably of any suitable flexible transparent material that can be sealed by heat, is led from a roll 26, Figs. 1 and 12, beneath a horizontal bar 39 and then upwards and over the surfaces of two conical formers 31 to fold it into a U-shape around a filling duct 37, through which the commodities are delivered into the packets as they are formed. The folded web is drawn downwards by pairs of motor-driven rollers 50, 51 which crimp the edges of the folded web and seal them together, the shafts of the rollers being heated electrically, if required, to assist the sealing. The rollers are joined by transverse members 52, Fig. 8, which seal the web transversely along a narrow zone, and one of the members 52 may be provided with a blade to weaken, perforate, or separate the web between the filled and completed packages. The delivery of an article, or of a predetermined quantity of solids or liquids, is controlled by two valve members 63, 64 which are operated by any suitable means such as a cam on one of the shafts of the rollers 50. 51. A narrow tearing- strip of flexible material or thread 76, to facilitate opening the packages, is inserted between one of the longitudinal folds of each packet by a needle 77 which is reciprocated by a cam. Instead of the formers 31 being fixed cones they may consist of separate elements rotated on their axes. The edges of the web may be doubled, as it passes the bar 39, in order to provide four thicknesses of material at the sides of the packages. A strip of metal foil may be embodied also on the doubled edges to provide more rigid edges for packages which have to be closed again,after the first opening. Two single webs may be used instead of a single web, and in this case the formers 31 may be replaced by means for bringing the two webs into contact with one another. The filling-duct 37 may be inclined or horizontal instead of being vertical, and may be provided with a positively-driven feeding device. Also, the packets may be of double thickness, an inner lining of heat - sealable material and an outer layer which may be of different material glued to the lining.
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