Abstract: A system for continuously and configurationally heat soldering layered sheets of plastic, concomitantly with embossing a distinctive pattern across at least one face of the heat soldered seam. The disclosed system has at least one pressing face that includes the mirror image of the pattern to be embossed across a face of the seam, engraved therein. Pressing faces embedding electrical heaters provide for embossing a changeable content across the faces of the seam. Sealing band a pattern engraved across a face of which provides according to the present invention for embossing distinct three-dimensional geometrical shapes across the faces of the heat-soldered seams. A seam that is heat soldered according to the present invention continuously extends across two-dimensional contours of significant widths. Three-dimensional features having distinct sectional shapes protrude off the seam at least towards one direction.

Abstract: A system and method for imprinting distinct patterns along a seam by which two or more layered plastic sheets are mutually attached to each other is provided. The disclosed method comprises (i) heating selected contours located across a surface of the layered plastic to a predefined temperature, and (ii) forcing a molding head against the heated surface, wherein the molding member has a face from which a plurality of pressing faces extend towards a common direction, the footprint of which features the desired pattern. A soldering head of the disclosed system has at least one molding member having a plurality of fingers. The footprints of the fingers are geometrically shaped in accordance with the pattern to be imprinted along the seam. Some of the fingers may have sharpened tips. A soldering head optionally comprises a pressing member for pressing against peripheries of the footprints of the fingers located across the surface of the layered plastic.

Abstract: A process for producing bubble-pack. Bulges are formed in a first sheet by a combination of mechanical pressure, vacuum and air pressure, without using the high temperatures associated with the prior art processes. A second sheet is sealed to the first sheet, opposite the bulges, by contacting the sheets and heating them only along the area of contact. The process of the present invention is suitable for forming bubble-pack from a wider variety of materials, notably HDPE, and bubble-pack with a lower weight per unit area, than are the prior art processes.

Abstract: A tamper-evident envelope has a first layer of paper-containing material and a second layer of paper-containing material attached to each other along a number of seams. Each seam includes a pattern embossed and/or perforated through both layers along a major part of the seam. If the envelope is opened and resealed along one of these seams, the embossed or perforated pattern is corrupted, thereby making the unauthorized opening of the envelope readily apparent to an intended recipient.