GB670230A - Process for the production of relief pictures for making ready for the printing of illustrations - Google Patents

Abstract

670,230. Printing. FIEG, A. Dec. 30, 1949 [Jan. 12, 1949], No. 33392/49. Class 100 (ii). Make-ready arrangememts.-In preparing make-ready sheets by sprinkling a powder onto a sticky print on a flat base and fixing it, the powder used is a fine readily pourable mixture of globular grains solid at normal temperature. Grain diameters of 0.3 to 0.01 mm. are referred to, e.g. at most equal to the dimensions of the smallest screen dots of the print; a coarse grained powder may be applied first, followed by a finer grained powder. Suitable powder materials are (a) copolymers of vinyl chloride and vinyl acetate, polymeric mixed esters of acrylic acid and derivatives thereof, or other thermoplastic powders softenable below the destruction point of the strong paper or synthetic sheet base (e.g. 150‹ C.), or (b) high melting point materials such as fine glass globules. The sticky print may be of black or bright book printing ink, with or without a fixative, or of a thick paste or other binding agent, p6wder (a) being fixed by heating to its melting point and powder (b) by spraying with lacquer; other print materials for use with (b) are: a precondensate of a hardenable synthetic resin e.g. phenol urea resin; a readily polymerisable compound e.g. allyl ester; a solid adhesive in a solvent that may be evaporated by heat. For increased relief two or more make ready sheets may be stuck together or the sticky print and powder may be applied to both sides of the base.