
US Patent No: 4,221,621
Number of patents in Portfolio can not be more than 2000
Process for preparing a foamed article of thermoplastic resin and a die therefor
Stats
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Sep 9, 1980
Issued date -
Sep 11, 1978
filing date -
05/940,893
serial no -
Expired
status
Importance
Abstract
A process and die are disclosed for preparing a foamed article of thermoplastic resin having a particular cross section configuration. The die of the invention is provided with a plurality of apertures in its face through which the resin is discharged. The apertures in the face of the die are distributed in a shape corresponding to the cross section of the foamed article which is produced. The apertures are further divided into a plurality of groups in which there is at least one zone which is void of apertures so that the apertures in the same group are actually restricted to a narrow band. The zone on the surface of the die which is void of apertures has a thickness more than twice the average distance between two adjacent apertures belonging to the same group.
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