Abstract: A method for forming an extruded plastic sheet with vacuum pressure and without mating dies. The plastic sheet is extruded onto a heated portion of a supporting bed which maintains the sheet in a soft condition. The bed also includes a cooled portion adjacent to the heated portion with a plurality of parallel grooves which extend continuously through the cooled portion and at least partially through the heated portion. A vacuum pressure is provided within the grooves between the bed and sheet thereby pulling the sheet downwardly into the grooves. The residual heat within the sheet is then removed by the cooled portion of the bed to maintain the formed condition of the heated sheet. Various means are provided to maintain the vacuum pressure between the bed and sheet.
Type:
Grant
Filed:
May 28, 1974
Date of Patent:
January 6, 1976
Assignee:
General Plastics Corporation
Inventors:
Richard H. Erlewine, Charles W. Richter, III, Arthur J. Calpha, Jr.