Production technology for heat shrinkable polyester film

Abstract

The invention discloses a production technology for a heat shrinkable polyester film and relates to the package material field. The production technology comprises the following technologies: slicing, vacuum drying, melt extrusion, quenching slice casting, biaxial tension, cooling and rolling slitting. Amorphous polyethylene glycol terephthalate is selected as a raw material, amorphous polyethylene glycol terephthalate is easy to recycle, nontoxic and odourless, has good mechanical properties, and meets environment protection requirements. Heat is transferred to materials to be dried through a drier shell under the vacuum environment, and therefore the purpose of drying reinforcement is achieved. The softening point of polymers is raised effectively, adhesion and agglomeration of resin particles are avoided during the drying and melt extrusion processes, moisture in resins can be removed, and hydrolytic degradation and bubble generation of polymers containing ester groups are prevented during the melt extrusion process. The ways of segmented heating and segmented processing are beneficial for fusion of molecules, and avoid material deterioration caused by too fast heating. the intensity of the produced shrinkable film is raised, and the shrinkable film has impact resistance.

Description

technical field [0001] The invention belongs to the field of packaging materials, and more specifically, the invention relates to a production process of heat-shrinkable polyester film. Background technique [0002] Heat-shrinkable plastic films are often used in the packaging of convenience foods, beverages, electronic appliances, metal products, daily commodities, etc., especially shrink labels are the most important application fields. Heat-shrinkable plastic films are generally made of amorphous plastics. Such as polystyrene, polyvinyl chloride, PVDC, the invention patent application number is CN03129658.0, which has the characteristics of low thermal shrinkage rate, low haze, good friction performance, smooth winding, etc., but its raw materials contain elements such as chlorine , is not conducive to recycling and does not meet environmental protection requirements; moreover, the shrink film produced by this production process has low strength and is not impact resistan...

AI Technical Summary

Problems solved by technology

[0002] Heat-shrinkable plastic films are often used in the packaging of convenience foods, beverages, electronic appliances, metal products, daily commodities, etc., especially shrink labels are the most important application fields. Heat-shrinkable plastic films are generally made of amorphous plastics. Such as polystyrene, polyvinyl chloride, PVDC, the invention patent application number is CN03129658.0, which has the characteristics of low thermal shrinkage rate, low haze, good friction performance, smooth winding, etc., but its raw materials contain elements such as chlorine , is not conducive to recycling and does not meet environmental protection requirements; moreover, the shrink film produced by this production process has low strength and is not impact resistant; in addition, it is easy to stick to each other during drying and extrusion during the production process Hydrolytic degradation and generation of bubbles