1. The size of the extruded package is not up to the standard, which is manifested as eccentricity; the thickness or outer diameter of the sheath is poor; the main reasons are: the extrusion and traction speed are unstable;
1) The outer diameter of the cable core changes too much;
2) Excessively high extrusion temperature leads to a decrease in extrusion volume;
3) Too many impurities in the plastic block the filter screen to reduce the plastic flow;
4) The tension of the take-up and take-up line is unstable;
5) The mold core is selected too large (extrusion type) or the length of the core line area is too short and the core is eccentric;
6) The mold spacing is not suitable;
7) The temperature of the extruder head is uneven;
8) The concentricity of the extrusion die is not well adjusted;
9) The temperature of the feed inlet is too high to make the feed difficult and affect the material flow;
For the above reasons, the outer diameter of the sheath should be measured and adjusted in time; the extrusion die should be selected and adjusted reasonably; the tension of the take-up and take-up line should be adjusted in time; the temperature control should be consistent with the specified requirements;
2. The bonding strength of the longitudinal tape is not up to the standard, the main reasons are:
1) The temperature of the extrudate is too low;
2) Too much filling of ointment overflows;
3) The production line speed is too fast, so that the sheath is quickly cooled;
4) The temperature of the hot water tank is too low and it is close to the mold opening;
5) The stretch ratio of the matching mold is too small, or the matching mold is unreasonable, making it loose;
6) The melting point of the longitudinal tape composite film is too high; according to the above reasons, pay attention to the mold matching requirements and adjust according to the cable core if necessary; the sheath cannot be quickly cooled to improve the bonding ability; the sheath shape should not be improved To reduce the temperature of the machine head excessively because of its ability; pay attention to the filling amount of the ointment, and it is better to touch the cable core with your fingers to scrape a thin layer.
3. The appearance of the extruded package does not meet the standard, and the appearance of the extruded package does not meet the standard. The specific manifestations are scratches on the surface of the extruded layer; roughness with trachoma or micro cracks; any defects caused by inadequate plasticization. The main reasons are:
1) The selection of the extrusion die sleeve is unreasonable. Too small will cause hemp pattern; too large will cause disjointed or squeezed loose;
2) Impurities in the extrusion die sleeve are stuck and scratch the surface of the sheath.
3) Extruder head heating temperature is too high to cause roughness, or temperature is too low to cause micro cracks;
4) The die sleeve sizing area is damaged;
5) The sheath is scratched in the sink; for the above reasons, defects can be eliminated or prevented in production. In actual production, in addition to the above defects and causes, there are also problems such as wiring problems, overlapping widths of longitudinal bags, and slub-shaped shapes. We observe and summarize more in production, grasp the main and essence of the problem, and we will solve it easily and make the quality level of the cable better.
