Cooling process for deep drawn thermoplastic sheet - in which liquid gas is distributed over component surface after forming and decreases cooling period

摘要

Plastic sheet is held horizontally in a frame, heated to softening temp. and a forming tool is pushed upwards from below the frame into the softened plastic sheet. Vacuum is also applied between the tool and the deformed sheet to draw it onto the tool surface before cooling occurs. A more rapid cooling method leading to increased prodn. envisages the use of a super-cooled fluid e.g. liquid nitrogen which is distributed evenly over the component upper surface. USE/ADVANTAGE - The process enables faster cooling of deep drawn thermoplastic components and allows use of cheaper tooling.