Improvements in or relating to a method and machine for producing cylinder coatings for applications to graphical industries in paper making, textile industry, mechanography and the like

摘要

705,298. Coating cylinders by extrusion. LIEVREMONT, H. G. June 21, 1951 [June 22, 1950], No. 14811/51. Class 87 (2) In .a process for the production of cylinder coatings for graphical industries a trued metal cylindrical core provided on its surface with protrusions or recesses is held between two centres connected with each other and moving in line with each other on a table or bench, the metal core being thus caused to go through a box containing plastic coating material such as a polymerization product of vinyl chloride'which is subjected to a pressure ensuring its extrusion through an annular aperture round the core, the driving of which, with the two centres, is caused by the coating material extruded from the box and adhering to the core. The protrusions may be studs or screw threads, about onetenth of a millimetre in height. The cylinder 9 to be coated is mounted between centres 2, 3 which are connected by means (not shown) that can be adjusted to alter the distance between them. To facilitate the adherence of the plastic material a preliminary coating of collodion is applied to the cylinder from a distributer (not shown). Cellulose acetate or aceto-butyrate may also be used. One end of the cylinder is placed in the chamber 10, which has, in one wall, a hole corresponding in diameter to that of the cylinder and in the opposite wall a slightly larger hole to give the annular aperture 8b. The plastic material is placed in the hopper 6 of a machine 4 for forcing the material into the chamber 10, the machine being driven by a motor 5 Heat is applied to the end 11 of the chamber and the extrusion end is cooled at 12. The material is extruded through the aperture 8b and takes the cylinder 9, to which it adheres. with it. For larger cylinders a drive, in synchronism with the drive from the motor 5, may be applied to the movement of the centres 2, 3. The driving, heating and cooling means are controlled from a board 14.