Abstract: The present invention relates to methods and apparatus for forming seamless cylindrical photosensitive elements of uniform thickness on flexible sleeves. The apparatus for forming a seamless cylindrical photosensitive element of uniform thickness on a flexible sleeve, comprises a mandrel, a mandrel support assembly, a calendering assembly, a drive system and at least a heating element. The methods comprise forming seamless cylindrical photosensitive elements of uniform thickness on flexible sleeves from a stream of molten photopolymerizable material, or a solid or molten sheet of photopolymerizable material. The seamless cylindrical photosensitive elements are formed on polyester sleeves for use on a printing cylinder.

Abstract: A porous material of a polytetrafluoroethylene (PTFE), which can retain at least 90% of 0.109 .mu.m latex spheres and has a flow rate (IPA flow rate) of at least 0.6 ml/cm.sup.2 /min as measured with isopropyl alcohol under a differential pressure of 1 kg/cm.sup.2. A process for the production of a porous material of PTFE, which comprises, after forming a molded article from fine powder of PTFE by paste extrusion, (1) sintering the molded article, (2) rolling up the molded article thus sintered and heat-treating it at a temperature lower than the melting point of the polytetrafluoroethylene in a state as rolled up, and then (3) stretching the molded article thus heat-treated in at least an uniaxial direction. The porous material of PTFE according to the present invention has micropores and good permeability and particularly is excellent in performance of retaining fine particles.

Abstract: The invention concerns a roll or cylinder or roll coating for a pulp machine, paper machine, or paper finishing machine, in which application the roll or equivalent comprises a cylinder mantle of cast iron or steel or any other, equivalent metal, which bears the mechanical loads. On the rollor cylinder mantle, fixed to the outer face of the frame mantle, there is a resilient polymer coating, and onto said polymer coating a coating is fixed which is by several orders thinner than the radial thickness of the polymer coating. Said coating fixed onto the outer face of the polymer coating is a metal, ceramic, or cermet coating or a plastic coating. The invention further concerns a method for the manufacture of a roll coating in accordance with the invention as well as the use of such rolls and coatings.

Abstract: A platen roller producing process includes the steps of coating the circumferential wall of a core metal with a rubber material, inserting the core metal coated with the rubber material into a cylindrical mold and subjecting the mold to a heating treatment.

Abstract: Compact discs are continuously mass produced by continuously rotating a master roller about whose periphery a plurality of optical disc patterns are sequentially arranged in order to form inverse patterns on an elongated film fed to the roller at successive contact locations spaced apart of one another lengthwise of the film during each rotation. Each optical disc has a metallized layer which is protected from damage by the provision of sheets of non-negligible thickness.

Abstract: A method of roller forming thermoplastic sheet material to form large parts includes providing a form having a surface of predetermined curvature. A sheet of thermoplastic material is overlain on the form surface and heated until pliable. Pressure is provided on the thermoplastic sheet using a roller so that the sheet conforms to the shape of the form.

Abstract: A cloth take-up mandrel is fabricated by cutting pipe of a thermoplastic polymeric material (e.g. PVC) to a desired length, heating the ends of the pipe to a temperature at which the polymeric material softens (as by insertion into a bath of glycerine), inserting end caps into the thus softened pipe ends (having a cross-sectional dimension greater than the dimension of the pipe), and cooling the ends with the end caps inserted therein. The invention avoids problems such as splintering associated with conventional wooden mandrels.

Abstract: A heatable winding drum construction for use in the manufacture of thermoplastic tubes and receptacles comprises an internal supporting structure for an elongated cylindrical wall with an insulating layer between the supporting structure and the wall.

Abstract: A method for molding elongated workpieces wherein the mold is comprised of three vertically oriented quadrants and a fourth quadrant pivotally mounted relative to the three quadrants between a mold open position and a generally vertically oriented mold closed position. A workpiece is loaded into the mold by positioning end plates on the workpiece and locating the combination on the fourth quadrant by positioning of the end plates on locating pins projecting from a frame member or tilt beam associated with the fourth quadrant. Slide assemblies are then moved into workpiece engaging positions on each end of the workpiece to accurately locate the workpiece relative to the fourth quadrant. The fourth quadrant with the workpiece locked thereon is then moved into a mold closed position for molding.

Abstract: A process for preparing photosensitive resin cylinders which-comprises winding a photosensitive resin sheet on and around the surface of a cylinder without any material overlapping of or spaces between the edge portions of the wound resin sheet, and applying to the cylinder under rotation a roll rotating in contact with the surface of the resin sheet while heating so as to join the edge portions of the resin sheet to one another by melting and to make uniform the thickness of the resin sheet.