using perforated rollers or discs

Full Title

Presses specially adapted for forming shaped articles from material in particulate or plastic state, e.g. briquetting presses, tabletting presses (for clay or mixtures containing cement B28B; for plastics materials B29) > Extrusion presses; Dies therefor (extruding by the use of roller-and-ring machines B30B11/20) > using perforated rollers or discs