Abstract: Thermoplastic web treating apparatus, particularly adapted for the fabrication of flexible bags and comprising, in combination, a web treating station along with means for intermittently advancing webs through the station. The treating station includes thermal welding or sealing apparatus with a welding bar and sealing pad combination for forming spaced seals in the web, and a cutting blade for cutting or shearing the web. The apparatus is designed to provide tension during cutting operations, and to eliminate tension prior to and during sealing operations to permit "relaxation" of the film prior to formation of the seal, as well as to break away any bond which may form between the thermoplastic web and the sealing pad from the sealing operation. This break-away of the bond is accomplished through an initial short duration reversal of the web draw rolls prior to each web advance.

Abstract: An aqueous solution for alkaline stripping of metallic surfaces having a resist coating on at least a portion of the surface thereof, the resist coating normally being based upon polyvinyl chloride, such as polyvinyl chloride contained in a base emulsion for a photo resist material. The alkaline stripper solution is based upon a mixture of potassium hydroxide and ammonium hydroxide, together with a chelating agent consisting of the sodium salts of ethylenediaminetetraacetic acid, acetic acid, and ethylene glycol monobutyl ether.

Abstract: A stacking system for thermoplastic film products, such as polyethylene bags or the like. The stacking system is arranged to be employed in combination with a product conveyor which receives finished articles or products from a thermoplastic film converting machine, the arrangement employing stacking wheels disposed along the terminal portion of the conveyor, and wherein the drive means for the stacking wheels are arranged to impart rotary motion to the stacking wheels in timed relationship to the movement of thermoplastic film product therethrough, and with means being provided to intermittently retard the rotational velocity of the stacking wheels at a point generally coincident with the passage of the trailing edge of the film product through the stacking wheels so as to frictionally retard the rate of speed of travel of the film product.

Abstract: A mechanically sound electrically stable substrate for use in an electrical laminate wherein the substrate supports at least one electrically conductive metallic layer. The substrate portion comprises a woven glass cloth base pad which is interposed between a pair of outer substrate layers of a polyester mat. The polyester mat comprises a mat of spunbonded continuous filament polyester fibers, preferably polyethylene terephthalate fibers, calendered, with the fibers including a mixture of bulk fibers of relatively high melting point retained in place or bonded by a binder fiber of essentially the same polyester material but with a relatively lower melting point. In fabrication, the mat, along with the glass cloth, is saturated with a curable resin, for example a heat curable resin, preferably polybutadiene, which is cured in-situ.