1, poor plasticization of rubber extrusion

General poor plasticization important performance: plug power cord extrusion layer with toad skin-like; plastic surface black, no luster, and there are small cracks; extrusion layer in the glue at the obvious line seams; caused by the important reasons are:

1) The rubber is mixed with other plastic particles of different nature;

2) Temperature control is too low, especially in the material nozzle area;

3) There are quality issues with the plastic itself;

4) The screw rotates too quickly and the plastic is not fully plasticized;

For the above reasons, attention should be paid to the reasonableness of the extrusion temperature control; the quality of the rubber material to improve the requirements; can not just pursue the output and increase the speed of extrusion; strengthen the custody of raw materials, especially in the plastic drying process; reasonable with the mold to adapt to the injection molding machine discharge.

2, Glue burning

Rubber burning is a common quality defect in the process of rubber extrusion, its attention to the performance of: the temperature display is too high; head die mouth has a large amount of smoke, a strong irritating smell, and in serious cases there is a bursting sound; extrusion of the plastic layer of charcoal particles; the glue seam at the continuous bubbles; the most important reasons for the emergence of:

1) The screw has not been cleaned for a long time and the accumulated burnt material is extruded with the molten plastic;

2) The temperature control is too high to reach the thermal degradation temperature of the rubber;

3) The extruder cooling system is not open or faulty, resulting in overheating of the rubber shear friction.

4) The temperature control instrument is out of control or inaccurate, resulting in high temperature decomposition;

5) The heating or downtime is too long, so that the rubber inside the machine is decomposed by long-term heat;

Therefore, in the extrusion process, we should check whether the heating and cooling system is working properly; the setting of extrusion temperature should be based on the provisions of the process as well as the rotational speed of the screw; the time of adding temperature should be reasonably controlled, and the extrusion system should be cleaned regularly.

3, plug power cord extruded cladding section with air holes or bubbles, the important reason for its generation:

1) Excessive moisture in the rubber material;

2) The temperature control is too high (especially in the feed section);

3) High humidity in the natural environment;

4) Long downtime, decomposition of plastic is not eliminated cleanly;