| 摘要 |
A vaporisation intaglio process is provided which includes treating the surface of an acrylic sheet by successively applying a series of heated dies (5) to the surface of the sheet to form a product sheet (8) carrying a plurality of cavities (9) at its treated surface, the successive die applications bringing the dies (5) into repeated contact with cavities (9) partly formed by a previous die application, whereby the cavities (9) are deepened at each successive application and wherein each partly formed cavity is cooled after each successive die application, characterised in that water is added into each partly formed cavity prior to at least some of the successive die applications. Apparatus for use in this process and including means to add water to each cavity after cooling is also provided. |
