There are more kinds of drinking water pipes in use now,one of which is high-density polyethylene drinking water pipe,which is also produced by an extruding machine.The polyethylene pipe is usually milky white and is a flexible and non-toxic plastic pipe,The high-density polyethylene drinking water to be discussed in this paper is made of HDPE pipe material.The author has prepared some information and hopes to give you some help.The specific process operation points are as follows:

1.The plastic factory takes about 30 times the thickness of the pipe wall when designing the length of the shaped section of the pipe forming mold produced by the extruder.The inner diameter of the mouth die should be slightly less than the inner diameter of the calibration sleeve(the reduction value is less than 10%),the pipe blank of the extrusion die of the plastic extruder is drawn to draw about 1.2,and the roughness R of the working face of the shaping section of the forming die should not be greater than 0.32μm.

2.The inner diameter of the cooling calibration sleeve used by the plastic extruder needs to be slightly larger than the outer diameter of the finished pipe,generally about 3%,and the length of the cooling calibration sleeve can generally be determined by about 4 times the diameter size of the pipe

3.When we use an extruder to carry out the cooling of a high-density polyethylene pipe after extrusion from the die mouth,the cooling speed can be adjusted according to the circumstances,and the pipe blank needs to be cooled slowly.It can effectively avoid the stress concentration of the pipe or the tarnish phenomenon of the pipe surface.Fast cooling,low crystallinity,and fine grain are beneficial to improve the strength of products.

4.Sometimes we will use the inner diameter compressed air shaping method,and we need to pay attention to the compressed air pressure control in the range of 0.02~0.04MPa;But if we use a vacuum calibration sleeve,the vacuum calibration sleeve degree should be controlled in the range of-0.08~-0.06mpa.The inner diameter of the vacuum calibration sleeve is plated with a hard chrome layer,the surface is smooth,the diameter of the pores is the same,and the layout is uniform and reasonable.