Pre-setting supporting assembling die for plastic extruder

Abstract

The invention belongs to plastic extruders for producing plastic pipes, in particular to a pre-setting supporting assembling die for a plastic extruder. The die comprises a neck ring mold and a core rod and is characterized in that the outlet end face of the core rod is longer than the outlet end face of the neck ring mold, and a supporting section M is formed between the outlet end face of the neck ring mold and a calibrating sheath; the outlet end face of the core rod is arranged in the calibrating sheath, and the core rod forms a coincidence section with the calibrating sheath; and the outlet end face of the neck ring mold is provided with a cooling medium cavity as well as a medium inlet and a medium outlet which are communicated with the cooling medium cavity. The invention can be used for producing various plastic pipes made of PVC, PE, PPR, and the like. The invention has the advantage that the production rate is obviously enhanced and the yield is greatly enhanced without changing the original production technology, equipment and material formulation; in addition, produced products have good flexibility and high pressive strength and do not have fluff and protuberance, and the outer walls of the products are smooth and have good brightness.

Description

technical field [0001] The invention belongs to a plastic extruder used for making plastic pipes, in particular to a pre-shaped support combination mold for a plastic extruder. Background technique [0002] In recent years, thermoplastic materials such as PVC resin and other synthetic materials are being vigorously promoted, developed and used in my country, and their processing equipment and processing technology are gradually improving and improving. Especially in terms of plastic pipe products, new plastics such as PVC, PE, and PPR are rapidly replacing original metal pipes with their excellent advantages. With the increase of the power of the plastic extruder and the addition of recycled plastic granules to the raw material formula of the product, higher requirements are placed on the extrusion stability of the extruder during the production process, and the production yield also needs to be improved. [0003] In the existing plastic extruder, the die at the outlet end ...

AI Technical Summary

Problems solved by technology

[0003] In the existing plastic extruder, the die at the outlet end of the extrusion die is substantially flush with the end face of the mandrel, the die is also called the outer die, and the mandrel is also called the inner die; in the continuous production process, The transition distance between the discharge port of the extrusion die and the feed port of the sizing sleeve is generally 20 cm, and the high-temperature re-product plastic pipe extruded from the extrusion die at about 200 ° C goes through a transition distance of about 20 cm and then directly enters the pipe located at 25 cm. The sizing sleeve in cold water around ℃ is rapidly shaped, because the temperature difference is too large, the internal stress concentration of the plastic product is easy to occur, the product is embrittled, the flexibility is poor, the density is low, and the strength is low; when the sizing sleeve is vacuumed, the sizing sleeve The through holes on the wall are easy to cause the outer wall of the pipe to fluff and pack, and the outer wall is not smooth; the most important thing is that as recycled plastic is added to the raw material formula of the product, the recycled plastic inevitably contains a small amount of impurities. When the pipe wall is thin, impurities will produce small holes on the pipe wall of the high-temperature reprocessed pipe, allowing air to enter the pipe. Since there is no support in the pipe, this section of pipe enters the sizing sleeve and will be sucked flat under the action of vacuum. As a result, a pile of materials is formed between the discharge port of the extrusion die and the feed port of the sizing sleeve, resulting in waste products. Although the waste products generated during the production process can be recycled and put into production, it leads to low production efficiency and low production speed. Increase the production cost of the manufacturer and reduce the economic benefit

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