Abstract: Disclosed is a process for producing a multiple-layered sheet of film comprising at least two thermoplastic materials by coextrusion through a slot die, comprising the steps of heat plastifying a first, second, third and fourth thermoplastic material; joining a stream of the first heat plastified thermoplastic material and a stream of the second heat plastified thermoplastic material to form a first combined stream having a generally rectangular cross-section and having an upper layer of the first thermoplastic material and a lower layer of the second thermoplastic material mechnically anchored together by means of profiles formed on the contact surfaces of the two layers; joining a stream of the third heat plastified thermoplastic material and a stream of the fourth heat plastified thermoplastic material to form a similar second combined stream, reducing the width of the first and second combined stream; joining the first and second combined streams in edge-to-edge fashion in a single plane to form a composi

Abstract: Disclosed is a device for the surface treatment of film webs by means of an electrical corona discharge, comprising: at least one grounded counter-electrode comprised of a point electrode; at least one roll electrode rotatably positioned adjacent to said counter-electrode, the roll electrode comprising an outer tube comprised of dielectric material, an inner tube comprised of dielectric material fitted coaxially inside of the outer tube and a plurality of electrodes carried by the inner tube; and a supply of A.C. voltage for the electrodes.

Abstract: A corona discharge device is disclosed in which a cylindrical shell made of a dielectric material is mounted around a rotatable axle. Electrodes are arranged inside and outside of the shell so as to provide a corona discharge across a material to improve its surface qualities. A method of corona discharge treatment with the above apparatus is also disclosed.

Abstract: Apparatus for coating moving web material includes an open trough containing a fluid coating agent over which a tensioned web to be coated travels. A pair of rotatable doctor rods are supported by the narrow edge areas of open channels across which the rods lie, the channels and the doctor rods extending widthwise parallel to the trough and adjacent each side thereof, with the rods forming upright extensions of the opposite sidewalls of the trough, so that the web contacts the rods sequentially as it traverses the trough. The rod on the far side of the trough relative to the moving web wipes the coating picked up from the trough by the web to desired thickness, and the channel support for the rod enables the rod to be wiped and cleaned by the narrow edge areas, which may be made from replaceable thin doctor strips that extend beyond the channel sidewalls.

Abstract: A corona apparatus comprising at least one roller electrode assembly, a supporting surface acting as a counter electrode, and a generator for generating an alternating current voltage for said electrode assembly characterized in that the roller electrode assembly comprises: a central shaft, an electrode, means for mounting said electrode to said shaft, a tube, means for mounting said tube for rotation about said shaft, said electrode contained within said tube, means for electrically connecting said electrode to said generator and means for supporting said shaft whereby said tube is positioned adjacent to said counter electrode.