| 摘要 |
<p>A raster-like coating is applied by screen printing to flat flexible material. The web is e.g. a lining for clothing items, the melt adhesive coated as two overlying rasters onto the product. The coating has a base layer unaffected, or only slightly affected by heat, and a melt adhesive layer over it. The latter is more readily affected by heat. In the novel process, the screening stencil (1) perforations are each filled by paste (2) of a soln. or pref. dispersion of the thermally inactive plastic mass. The screen is then brought into contact with the web (3) and the doctor blade (4) adds to the externally coated paste, the melt adhesive (5) paste, which is pressed into the perforations. On removing the coated web structure (8) the resulting double layer is dried and sintered together. Also claimed is the corresponding equipment for the process. Pref. part filling of paste in all perforations, is applied externally to the drum by means of the blade (6), resting on the screen stencil from the outside. The wiping edge is sharply ground and presents an obtuse angle of 120 degrees -150 degrees to the stencil on the paste (2) feeding side. This filling is aided by an internal support (7) reaching over the full width of the screen and resting with its two blades (7a) which conform to the screen inner surface. The base layer paste applied by the outer blade contains polyurethane, polyacrylate, polybutadiene acrylonitrile, polybutadiene-styrene-acrylonitrile or acetate copolymer. The outer coating paste contains a fine grain powder of melt adhesives, PVC, mineral fillers and additionally fatty acid salts, softening agents, thickeners, coagulants, paraffins or waxes. The melt adhesive paste (5) applied by the inner blade is based on copolyamides, copolyesters, low pressure polythene or polyurethane.</p> |
