Why does the extruder have poor plasticization?

Writer： admin Time：2020-02-24 14:33 Browse：℃

In the production process, the plastic extruder sometimes has poor plasticization. What is the reason for this? The following may help you.

Ⅰ. Scorch

1.Scorch phenomenon

(1) The temperature reflects the extremely high temperature, or the temperature control instrument fails, causing the plastic to become extremely hot and scorched.

(2) The glue outlet of the machine head has a large smoke, a strong pungent odor, and a crackling sound.

(3) Granular scorch appears on the plastic surface.

(4) There are continuous air holes at the glue joint.

2.Causes of Scorch

(1) Plastic scorch caused by ultra-high temperature control.

(2) The screw has been used for a long time without cleaning, and the scorched material is accumulated and extruded with the plastic.

(3) If the heating time is too long, the plastic deposits will be heated for a long time, which will cause the plastic to deteriorate and scorch.

(4) The parking time is too long, and the machine head and screw are not cleaned, causing the plastic to scorch.

(5) Change the mold or color several times, causing the plastic to scorch.

(6) The gland of the machine head is not compressed, and the plastic is degraded inside.

(7) The temperature control instrument fails, causing scorch after ultra-high temperature.

3. Methods to eliminate scorch

(1) Regularly check whether the heating system is normal.

(2) Regularly clean the screw or machine head and thoroughly clean it.

(3) Heating according to the requirements of the process, the heating time should not be too long, if there is a problem in the heating system, you should find relevant personnel in time to solve. (4) Change the mold or color in a timely and clean manner to prevent noise or scorching of glue.

(5) After adjusting the mold, the mold cover gland should be pressed tightly to prevent the glue from entering.

(6) The head and screw should be cleaned immediately when scorch is found.

Ⅱ. Poor plasticization

1. Bad plasticization

(1) There is a toad skin phenomenon on the surface of the plastic layer.

(2) The temperature control is low, the meter pointer reflects that the temperature is low, and the actual measured temperature is also low.

(3) The surface of the plastic is black and has small cracks or small particles that are not plasticized.

(4) The plastic glue is not well stitched, and there is an obvious mark.

2. Reasons for poor plasticization

(1) The temperature control is too low or inappropriate.

(2) There are resin particles that are difficult to plasticize in plastic.

(3) Improper operation method, the screw and traction speed are too fast, and the plastic is not completely plasticized.

(4) The plastic is not uniformly mixed or the quality of the plastic itself is bad during granulation.