Importance

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Abstract

Disclosed is an overvarnish unit for applying varnish to a web of printed material as a protective overlay. The overvarnish unit includes a varnish fountain for receiving paste varnish, a form roller, and a plurality of rollers intermediate the fountain and form roller. The form roller engages an impression cylinder roller forming part of a printing assembly. The varnish is transferred from the fountain to the form roller by the intermediate rollers which also mill the varnish as it is being transferred to reduce its viscosity. The form roller is driven at a peripheral speed greater than the linear speed of the web over the impression cylinder roller. This form roller overspeed provides a smearing action in applying the varnish to the web rather than a one to one or line by line printing action thus achieving control over the thickness of the applied varnish and the appearance of the final product.

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First Claim