1. What are the processes involved in the plastic extrusion of products?

Raw (mixed) material → charging → extrusion → shaping and cooling → hauling → cutting → inspection → packaging → storage and stacking.

2. What does a filter plate (porous plate) do?

a) Establish the head pressure;

b) Change the material in the head of the screw from spiral flow to axial flow along the filter hole.

3. What kind of machines require the use of filter plate?

Single screw extruder and some twin screw extruder require the use of filter plate, depending on their structure, plasticizing capacity, and the actual situation.

4. What is the purpose of the cooling water unit?

Prevent the material from being heated and agglomerated, resulting in the material at the feeding section of the screw cannot be transported forward in time.

5. What factors are involved in the plasticization of the material in the barrel？

The plasticization of the material in the cylinder is related to the heat and the shearing effect of the screw rolling. Under the same conditions, the higher the temperature of heat, the greater the shear strength, the better the plasticization.

6. What factors determine the wall thickness dimension of a product?

It is determined by the gap between the bush and the pin and the haul-off speed and extrusion speeds (output)

7. To what extent is the screw normally filled with material from the barrel?

Material filling screw 2/3 is good. If the filling material is too little, it will lead to screw upward, friction with the barrel, so that the screw and barrel will damage. it will also lead to poor plasticization of the material, affecting the quality of the product. If the filling is too much, it will cause the material to wrap around the screw, even from the venting hole, also affecting the quality of the products.

8. What are the benefits of using a reverse setting for barrel temperatures?

a) To promote the PVC material in the exhaust section before the partial plasticization, conducive to the escape of water vapor volatiles, but plasticization is too good, is not conducive to the full exhaust.

b) To avoid the dry powder in the exhaust section to be pumped away.

c) To avoid high temperature adhesion of the material barrel.

9. What measures can be taken if the sizing sleeve is prone to plugging? What are the side effects of the change?

a) Check whether the shaping cooling water is blocked; drip solution or speed up the traction speed;

b) Reduce the vacuum pressure or shut down the vacuum pump to reduce traction resistance.

10. What factors can cause wall thickness deviation of products? How to resolve?

a) The bush and the pin center are not correct, which need be adjusted.

b) Check whether the heating ring is wrapped tightly or whether it is partially damaged;

c) The molten material in the head of the decomposition of stagnant material, should be cleaned up.