Extrusion cooling method of pipe production line

Abstract

The invention discloses an extrusion cooling method of a pipe production line, comprising the following steps: a die of an extrusion die of an extruder is provided with a ring-shaped cooling device; the middle passage of the cooling device is communicated with the extrusion die; the circular wall of the cooling device is provided with a refrigerant passage; the products extruded out of the extrusion die can be quickly cooled by the refrigerant. The extrusion cooling method avoids the problem of lots of waste and defective products due to forming fluctuation of products under the high temperature condition, ensures that the production is carried out stably and continuously without changing the process or affecting the performance of the product, and improves the yield. The appearance and the internal dimension of the cooling device used for the cooling method are consistent with the appearance and the internal dimension of the die; furthermore, the appearance is designed as round, square, or rectangle, and the like, thereby being applicable to dies of various specifications.

Description

Technical field [0001] The invention relates to a method for continuously producing pipes, in particular to an extrusion cooling method on a pipe production line. Background technique [0002] At present, domestic pipe cooling devices generally use vacuum sizing and spray cooling methods. These methods start cooling after the pipe leaves a certain distance from the mold. However, for many materials such as ultra-high and ultra-high molecular weight polyethylene pipes, Due to the characteristics of the raw material itself, after the vacuum sizing and spray cooling method are used and the pipe is separated from the mold for a certain distance, serious phenomena such as cracks on the inner wall of the pipe and bulge on the outer wall often occur, resulting in the failure of the pipe to squeeze out or the poor quality of the extrusion, resulting in extreme Big waste. [0003] In recent years, thermoplastic materials such as PVC resin are being vigorously promoted and used in my count...

AI Technical Summary

Problems solved by technology

But for a long time, in the production process of the plastic pipe manufacturing industry, the cooling of extruded products has always been the method of rapid cooling. The high-temperature material at about 200 ° C extruded from the extrusion die directly enters the sizing machine located in cold water at about 25 ° C. The sleeve is quickly shaped, because the temperature difference is too large, the internal stress concentration of the plastic product is easy to occur, the product is brittle, the flexibility is poor, the product density is low, the strength is low, and when the sizing sleeve is vacuumed, the through hole provided on the sizing sleeve wall It is easy to cause the outer wall of the pipe to fluff and pack, and the outer wall is not smooth, which affects the use effect in places requiring beautiful appearance

[0004] In addition, with the increase of raw material prices, various manufacturers have adopted various methods to reduce production costs, especially in the field of PVC and PE plastic pipe production, adding a large amount of fillers and recycled materials to the production raw materials, adding plastic raw materials through the hopper The extruder is heated and plasticized, extruded through the extrusion die, cooled and shaped by the sizing sleeve cold water tank, pulled by the tractor, cut to length by the cutting machine, and finally packed into the warehouse. This method is very suitable for the production of adding a large amount of filler or recycled materials. The raw material adopts the same processing technology. Due to the high temperature of the die, the product is difficult to form and the pass rate is low. If the temperature of the die is lowered, the performance of the product will be affected.

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