Process to apply a plastic foil fleece sleeve to a plastic preform core by combination of heat shrink and form tools

摘要

In a process to manufacture a plastic pre-form a plastic fleece foil (1) is drawn over a positive form (4) while exposed to heat and presented as a sleeve (2) to a preform core and form tool (3) under tension. Exposure to heat is sustained until the sleeve has shrunk to the positive form dimensions to form a skin on the preform core. The plastic pre-form is then removed from the positive form. The sleeve is presented in seamless condition. The positive form is essentially of circular or oval cross-section. The process allows for two or more plastic products to be manufactured from the same length of sleeve in a single process step. Heat is supplied to the shrink-wrap process by radiation from one or more electrically heated sources, electro-magnetic radiation, infrared radiation, an electrically heated quartz tube.