| 摘要 |
<p>This invention relates to the surface treatment of paper webs and particularly to an improved treatment particularly suitable for paper used for security documents. The method provided by the invention involves passing a paper web between opposed surfaces moving counter to each other, one of the rolls having an abrasive or cutting means on its surface, and the other roll having a base surface, at least one raised profile pad in the shape of a predetermined pattern. These are dimensions such that the surface of the web will be reduced in thickness throughout an area coincident with the predetermined pattern when the abrasive or cutting means is opposite the raised profile pad. An apparatus is also provided for carrying out the foregoing method. The invention also comprises the web produced which has uniform density but a thickness reduced to a uniform extent throughout a predetermined pattern, with the portion of reduced thickness exposing internal fibers of the web.</p> |
