|국가/구분||United States(US) Patent 등록|
|미국특허분류(USC)||156/382 ; 156/228 ; 156/245 ; 156/285|
|우선권정보||DE-3840542 (1988-12-01); DE-3905177 (1989-02-20)|
|발명자 / 주소|
|출원인 / 주소|
|인용정보||피인용 횟수 : 54 인용 특허 : 0|
Cold-stretchable sheet material is isostatically formed at an operating temperature beneath the softening temperature of the sheet material by means of a fluid pressure medium at a pressure of more than 20 bars so as to produce a deep-drawn formed plastics piece. Forming may take place abruptly. The sheet to be formed may be provided with a coating such as an ink imprint. The resulting thin-walled deep-drawn piece may be backed and reinforced by injecting further plastics material.
Apparatus for forming a plastic sheet comprising a mold that includes two halves, a lower half having a mold cavity with side walls and a bottom surface, and an upper half comprising a pressure bell connected to an air compressor by a pressure conduit, the bottom surface extending between the mold side walls and consisting of a spring mounted plate extending between the mold side walls over the entire bottom surface, the spring mounted plate having a pressure-loaded position which exposes a maximum volume of the mold cavity, and an unloaded elevated posi...