MOLDING PRETREATMENT OF RESIN SHEET

摘要

PURPOSE: To heat and soften a resin sheet having such a characteristic that the end part in one of the opposed direction and orthogonal direction of two sides of the resin sheet is shrunk in shrinkage factor larger than that of the other end part at the time of heating and softening so that the shrinkage quantities of both end parts of the resin sheet become equal in a method for heating and softening the resin sheet in such a state that two opposed sides of the resin sheet are grasped before the feed of the resin sheet to a molding process. CONSTITUTION: Two opposed sides of a resin sheet 1 are clamped by clamp members C and the resin sheet is set to a vertical posture so that one end part 2 large in shrinkage factor thereof is turned downwardly to be heated and softened. The shrinkage of one end part 2 is suppressed by the effect of gravity and the shrinkage quantities of one end part 2 and the other end part 3 are made equal.