Abstract: A feed conveyor arrangement is disclosed for horizontally unwinding zipper-equipped sheet packaging material from a supply roll and turning back a flap portion of the sheet material for reception of product prior to delivery into a form, fill, and seal machine. The feed conveyor utilizes a special guide wheel device for maintaining the zipper, and hence the sheet material, in an aligned flow path and holding down the flap portion only adjacent the zipper. A subsequent flap turning wheel device turns the flap portion away from the remaining panel area of the sheet below the zipper line, pivoting the flap about the hold down area of the guide wheel device. The guide wheel device is in the form of skewed wheels acting on the upper surface of the flap at opposed sides of the zipper. The flap turning wheel device includes an offset wheel which applies both upward and horizontal forces to the upturned inner surface of the flap to open up the sheet material.

Abstract: The method of making flexible plastic bags with integral pressure interlocking rib and groove elements on the confronting top edges, comprises the steps of extruding a continuous tube with pairs of closely spaced interlocking elements on the surface of the tube, the total pairs being a multiple of 2 with at least 4 pairs on the tube, slitting the tube lengthwise between profiles of alternate pairs, and folding the tube between each adjacent pair and bringing the profile adjacent the slit over onto the closest profile of the pair which has not been slit.

Abstract: A method and apparatus is provided for forming an abrasion resistant sheet from a sheet of orientable thermoplastic polymer material in one continuous process which can be effected by a single continuous production line apparatus. A method and apparatus is also provided for treating the surface of an oriented sheet with heated rolls for creating a fused surface layer on each side of the sheet. A method and apparatus is also provided for slitting a wider sheet into a plurality of strips at elevated temperatures with the strap under tension and with a staggered array of fixed blades. Further, a method and apparatus is provided for treating an oriented strip having a non-uniform thickness so as to conform the surfaces of the strip in a substantially uniformly flat and parallel configuration.

Abstract: Apparatus is provied for forming an abrasion resistant sheet from a sheet of orientable thermoplastic polymer material in one continuous production line apparatus. Apparatus is also provided for treating the surface of an oriented sheet with heated rolls for creating a fused surface layer on each side of the sheet.