Pelleting extruder for FEP powder

Abstract

The invention discloses a pelleting extruder for FEP powder, which comprises two parallel screws, a machine barrel which is arranged outside the screws, a heating system, a cooling system and a vacuumizing and de-volatilizing system, wherein a fluorine gas charging port is formed on the machine barrel. The invention aims to provide the dual-screw extruder for the FEP powders, which can shorten anFEP production and processing flow, simply and efficiently remove unstable end groups in products, control volatile matters of the products and has the advantages of high-temperature resistance, corrosion resistance and long service period. The double-screw extruder of the invention can efficiently remove the unstable end groups in molecular links and control the volatile matters of the products;and meanwhile, the machine barrel has corrosion resistance and high-temperature formation resistance and is very suitable for processing the FEP powder.

Description

technical field [0001] The invention relates to a FEP powder processing equipment, in particular to a special granulation extruder for FEP powder capable of ensuring stable terminal groups and low volatile content. Background technique [0002] The full name of FEP is polyperfluoroethylene propylene. It is a fluoroplastic with excellent performance. It has excellent electrical properties, thermal stability and mechanical and physical properties. It is widely used in the wire and cable industry. [0003] FEP is a high molecular polymer produced by the copolymerization of TFE (tetrafluoroethylene) and HFP (hexafluoropropylene). In the production process of FEP, the initiator such as ammonium persulfate (APS) or persulfuric acid used in the aqueous phase polymerization reaction system Potassium (KPS), etc., will produce a lot of unstable terminal groups in the reaction, and these unstable terminal groups will cause adverse effects on the product during the melt processing of th...

AI Technical Summary

Problems solved by technology

Under normal circumstances, fluorine gas fluorination is carried out as an independent process using special fluorination equipment, with high processing temperature and long processing time, and high requirements for equipment (such as requiring high temperature resistance, corrosion resistance, and high safety) ), the processed powder will be granulated by a twin-screw extruder, and the production and processing process is lengthy

[0011] In addition, in the process of extrusion and granulation production, the twin-screw extruders used by most manufacturers generally use corrosion-resistant special alloy steel to inlay the barrel shell in terms of barrel structure design. Although this structural design is simple to process, Easy to mass produce, but has major flaws

Under the high temperature and corrosion conditions of FEP processing, the barrel will expand or contract due to high temperature, so it is difficult to avoid the gap between the insert and the shell, or the crack of the insert, and the corrosion of the shell, which seriously affects the product quality and quality. Normal production of extruder

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