Full double-screw extruder and BOPET thin film extrusion process using same

Abstract

The invention relates to a full double-screw extruder and a BOPET thin film extrusion process using the same, and belongs to the technical field of plastic thin film machining. The extruder comprises a screw cylinder, a double-screw body arranged in the screw cylinder, a feeding opening, an exhaust opening and a metering pump. The feeding opening, the exhaust opening and the metering pump are arranged on the screw cylinder. The extruder is applied to plastic thin film machining and has the advantages of being short in machining procedure time, simple in equipment, high in machining efficiency, high in raw material utilization rate and the like.

Description

technical field [0001] The invention relates to a full twin-screw extruder and a BOPET film extrusion process thereof, belonging to the technical field of BOPET film processing. Background technique [0002] Biaxially oriented polyester film, also known as BOPET film, is widely used in packaging work in various fields due to its good characteristics. In the traditional BOPET production line, both the main extruder and the auxiliary extruder adopt the single-screw serial extrusion method, which has the following defects: [0003] 1. The requirements for raw materials are relatively high. All raw materials entering the extruder must be thoroughly removed from moisture and dust, which requires that the raw materials must be subjected to strict dry crystallization pre-treatment, and the dry crystallization process is a very large and complex process that requires a lot of work. In the process of power heating and air delivery, poor control of any link will affect the quality of...

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Problems solved by technology

[0003] 1. The requirements for raw materials are relatively high. All raw materials entering the extruder must be thoroughly removed from moisture and dust, which requires that the raw materials must be subjected to strict dry crystallization pre-treatment, and the dry crystallization process is a very large and complex process that requires a lot of work. In the process of power heating and air delivery, poor control of any link will affect the quality of the melt in the extruder, resulting in poor film forming effect or failure to form film after subsequent stretching, and also consumes a lot of electric energy;

[0004] 2. In the single-screw tandem extrusion method, a large number of side materials will be separated during drafting and winding. These side materials must be re-granulated, and they must be dried and crystallized before they can be recycled. Consumption also increases;

[0005] 3. The screw of a conventional single-screw extruder is an integral structure. When a certain part of a screw is worn out, in order to ensure the extrusion quality of the melt, the whole screw must be replaced with a new screw. The utilization of the screw low rate

[0006] Although some auxiliary extruders can be partially replaced with a twin-screw structure due to their smaller specifications, the twin-screw structure of the main extruder cannot be realized due to the larger specifications and dimensions of the main extruder.

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