Abnormal problem

Causes

Solutions

1. The surface yellowing

Processing temperature or the head temperature is too high, and the stable component in the formula is insufficient

The machine can be adjusted to reduce the processing temperature and mold temperature, and then the stabilizer and lubricant in the formula can be appropriately increased

2. the external surface is dull

Low mold temperature or poor plasticization

Increase the die temperature, appropriately add high melting point PE wax or ACR, and moderately reduce the extrusion and traction speed

3. There are color-changing lines or color spots on the surface

The main reason is the shunt shuttle or die dead Angle caused by material delay and impurities in raw materials

Conduct thorough cleaning and identify raw material factors

4. The inner wall is rough

The main reason is low processing temperature and mold temperature and external lubrication caused by poor plasticization

Can be adjusted in this direction

5. Bubble on the tube wall

Material is too wet and vacuum failure or high head temperature causes material decomposition

Adjust the machine accordingly

6. Pipe bending

Uneven cooling, uneven pipe thickness, uneven temperature around the die, uneven discharge caused by the head, caliper sleeve, traction is not in a straight line or slip agent

Constant temperature, fixed in a straight line, uniform discharge

7. Uneven thickness of pipe wall

Die core rod may be different, traction speed is not stable, die temperature is not uniform resulting in uneven discharge speed, vacuum caliper vacuum degree is not stable, or formula caused by uneven discharge

Adjust the machine accordingly

8. surface black line

(1) Uncertain position, continuous linear or moire

(1) The dead Angle paste in the barrel, transition body, porous plate or mouth die.

(2) Oil seepage of the screw head or too much oil applied to the die.

(3) There are too many low molecular components in the formula, and they are not forced out at the exhaust port after decomposition

Can be adjusted in this direction

(2) The position has been intermittent line installation or moire on the lower surface of the pipe

(1) With the increase of calcium powder in the formula, the screw and barrel are seriously worn

(2) Lubrication system imbalance

To be polished and clearance readjust, serious to replace

Switch to late external lubrication (such as PE, etc.) or appropriately increase the amount.