摘要:
A method of making a polypropylene printing plate using a paper matrix in which a roll and an opposing member are prepared, a paper matrix is attached to one of the roll and opposing member, a crystalline ethylene-propylene copolymer having a MFI (melt flow index) of 3.about.10, containing ethylene less than 20% by weight and tensile yield strength of 220.about.330 kg/cm.sup.2 is continuously fed under molten state between the roll and the opposing member, and then the crystalline ethylene-propylene copolymer is pressed and cooled to be hardened.Further, a reproducing printing plates consists of a crystalline ethylene-propylene copolymer whose melt flow index is selected in a range of 3.about.10, which contains ethylene less than 20 weight % and which has the tensile yield strength of 220.about.330 kg/cm.sup.2.
摘要:
The present invention relates to a pad capable of high liquid retention and capable of self-metering of liquid from the pad upon application of pressure. Such pads are highly desirable in lubricating applications and serve well as printers and ink reservoir for computers, markers and printing machines. The process comprises mixing a void former, typically a non-reactive salt of a size range chosen between 2 and 450 microns with a polymeric material in a weight ratio of 2.5:1 to 10:1 salt to polymer. The polymer is heated and the salt dispersed therein to form a salt-polymer composite. The composite is fed to an extruder and extruded to a desired shape, a dense skin being formed on the surface of the extruded polymer. Subsequently, the extruded polymer is cut, the salt is leached from the polymeric matric with a suitable solvent, and the leached extruded polymeric matrix is dried. The skin layer has narrower channels and a lower void volume than the adjacent reservoir column. The pad thus formed is then filled with liquids using conventional methods.
摘要:
A method for manufacturing an ink-containable stamp used for a printer of a computer or the like is disclosed, wherein a number of printing types and a drum or plate are moulded from a mixture comprising synthetic resin consisting of polyvinyl acetate resin and polyolefin resin, fillers, stabilizers, plasticizers and pigments, irradiated with gamma-rays, immersed in an enzymatic solution and then in an acid solution. The type and drum or plate are then assembled to form a printing element.
摘要:
A first portion of a sheet of thermoplastic material is placed on the face of an engraved master plate, and the plate and sheet are positioned between the platens of a hydraulic press. The first portion of the sheet and the master plate are pre-heated and are then pressed together to mold an impression of the face within the first portion of the sheet. The master plate and sheet portion are cooled while the pressure is maintained, after which the pressure is released and the sheet is shifted laterally a precise predetermined distance relative to the master plate while maintaining the angular orientation of the sheet, to position a second portion of the sheet over the face of the master plate. The steps of pre-heating, pressing, cooling and releasing are then repeated to produce a flexible mat having a pair of identical impressions in precise spaced relation and corresponding angular orientation. One or more metal layers are electrolytically deposited on the mat, and the resulting thin sheet of deposited metal is separated from the mat and laminated to a pre-curved reinforcing plate which is trimmed along its edge.
摘要:
AN IMPROVED METHOD FOR PROCESSING A COMPOSING MEMBER HAVING A HEAT SENSITIVE POLYMER DISPERSION COATING ON A STABLE BASE SUCH AS PLASTIC, USING INFRARED RADIATION AND NO SOLVENTS OR ETCHANTS TO FORM A RELIEF PRINTING PLATE. INFRARED ABSORBING INDICIA ARE PLACED IN THERMAL CONTACT WITH THE COATING AND THE COATING IS THEREBY SELECTIVELY HEATED THROUGH THE APPLICATION OF NEAR INFRARED RADIATION. THE COATING, NOW HAVING FUSED PORTIONS CORRESPONDING TO THE INDICIA, IS PLACED IN PHYSICAL CONTACT WITH A PICK SHEET AND IN THERMAL CONTACT WITH A TOTAL INFRARED ABSORBING MEDIUM. THE COATING THE PICK SHEET AND THE TOTAL INFRARED ABSORBING MEDIUM ARE ARRANGED SUCCESSIVELY OUTWARDLY FROM THE INFRARED SOURCE.
THE PREVIOUSLY UNFUSED PORTIONS OF THE COATING FUSE AND ADHERE TO THE PICK SHEET. WHEN THE PICK SHEET IS PEEDED OFF, THE PREVIOUSLY FUSED PORTIONS CORRESPONDING TO THE INDICIA, REMAIN ADHERE TO THE BASE TO FORM A RELIEF PRINTING MEMBER. THE PREVIOUSLY UNFUSED PORTIONS ARE NOW FUSED TO THE PICK SHEET AND MAY BE USED AS AN INTAGLIO PRINTING MEMBER, IF DESIRED.
摘要:
PRINTING PLATES EXHIBITING MINIMAL THERMAL SHRINKAGE ARE MADE BY MOLDING A LAMINAR PRINTING PLATE BLANK AGAINST A MATRIX. THE WORKING FACE (THE TOP LAMINATION) CONTAINS CARBON BLACK OR A CONDUCTIVE SUBSTANCE, AND IS SUBSTANTIALLY THINNER THAN THE SUPPORTING LAMINATION USUALLY FORMED OF THE SAME RESIN BUT CONTAINING NO CONDUCTIVE SUBSTANCE. MOLDING PREFERABLY TAKES PLACE IN A CHAMBER AT REDUCED ATMOSPHERIC PRESSURE. HEATING IS ACCOMPLISHED BY HIGH FREQUENCY ELECTRIC CURRENT. SINCE ONLY THE FACE CAN BE HEATED IN THE DIELECTRIC FIELD AND THE THICKER BASE REMAINS COOL, SHRINKAGE IS GREATLY REDUCED.
摘要:
A hydraulic press supporting a lower press member including a center and end sections each having an internal passageway and with an engraved master plate mounted on the center section, an automatically controlled system for circulating cooling fluid through the passageways in the end sections and alternately circulating cooling and heating fluid through the passageway in the center section for preheating and cooling the plates, a thermoplastic sheet of material pressed against the preheated plate by an upper press member having a resilient blanket and held until the plate and sheet are cooled, and a frame slidably mounted on the lower press member for shifting the sheet a predetermined distance to form a flexible mat having a pair of identical impressions in precise registration for use in producing a two-on plate for a letterpress.
摘要:
A PRINTING PLATE BLANK HAVING A DIFFERENT DIELECTRIC LOSS FACTOR THROUGH ITS THICKNESS MAY BE FORMED INTO A PRINTING PLATE BY DIELECTRIC HEATING SO THAT THE HIGH DIELECTRIC LOSS ZONE MELTS AND IS MOLDED TO THE TYPE FORM WHILE THE LOW DIELECTRIC LOSS ZONE REMAINS DIMENSIONALLY STABLE. A GRINDING LAYER MAY BE APPLIED TO THE SIDE OPPOSITE THE PRINTING FACE TO ENABLE PRECISE GRINDING OF THE PLATE TO CORRECT DIMENSIONS.