Impression printing process

Chem. Descrip. Polyol carbonyl adduct Uses Insolubilizer for paper coalings incl. food-contact paper Fealwes Reacts with functional groups of coating binders reduces water sensitivity inc. number of impressions and print quality in the offset printing process Regulatory FDA approved Properties Dens. 10.7 Ib/gal pH 4.5 55% total solids SER-AD FA 153 [Sasol Servo BV ... 

Proof priif [ME, alter, of preove, ff. OE preuve, fr. LL proba, ff. L probare to prove] (13c) n. A test photographic print or total impression in a printing process taken for correction or examination. 

Among binders, styrene-butadiene latexes dominate beside modified starches. Styrene-acrylate dispersions are spedalties and of high importance for impressive prints. Additionally acrylate dispersions have an excellent brightness and ageing resistance and are less odorous. Future requirements of coating process conditions, on paper characteristics and printing technologies forced the production of tailor-made binders with very specific property profiles. 

Ma.ke-Rea.dy, Because pressure is needed for ink wetting and transfer and because the image elements in letterpress vary in size, the same amount of printing pressure or squeeze exerts more pressure on highlight dots than on shadow dots. This necessitates considerable make-ready to even the impression so that the highlights print correctly and do not puncture the paper. Precision plates and premake-ready systems have helped reduce make-ready time, but it is still appreciable for quaUty printing and is a reason letterpress has been largely replaced by other processes. 

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