Offset printing involves the transfer of ink from the image areas of the printing plate to the paper through an intermediate blanket. The blanket is usually composed of synthetic fiber materials (e.g. nylon). Blanket-paper-ink characteristics contribute to limits of printing quality and mechanical press operation. Paper and blanket physical surface characteristics and also ink tackiness contribute to adhesion between the paper and blanket. If the adhesion is sufficiently large, the force required to separate the paper from the blanket may cause deterioration of print quality or press operational problems. Deterioration of the printed quality may include picking of coating from the paper surface (leaving holes in the image) or misregistration of succeeding color overlays due to distortion of the paper. Measurements of blanket release characteristics have been done in the laboratory (Hull) and on sheet-fed presses (Beecroft and Farrell). In both cases, evaluation was done by measuring paper parameters after completion of the printing operation by an indirect method. This study has led to development of methods for direct measurement of blanket wrap during operation of a high speed web press. A visual technique allows numerical rating of blanket release for objective comparison of blankets or printing parameters. High speed cinematographic techniques allow analysis of the transient characteristics of blanket release. Samples of data gathered by both techniques are given. Recommendations for further work and standardized blanket test procedures are presented.
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Department, Program, or Center
School of Photographic Arts and Sciences (CIAS)
Griggs, Joseph and Sandford, Ronald, "Optical Measurement Techniques for Blanket Release Characteristics on Web Presses" (1972). Thesis. Rochester Institute of Technology. Accessed from
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