Plastic stretching method and apparatus for use in vacuum forming techniques

摘要

Machine and method for stretching and then vacuum forming acrylic sheets. Machine has clamping bars (1-4), each of which has a plurality of secondary clamps (5) which move along the clamping bars proportionately to the stretching of the plastic sheet as it stretches but act to prevent bowing of the plastic sheet. Primary clamps (13, 14) hold the edges of the sheet in place after stretching during the vacuum forming process.