Common problems in the production of chlorinated polyethylene cable - cured rubber.

Cured rubber is a more frequent problem in the production process of chlorinated polyethylene cable, and this phenomenon is more prominent in summer. The influencing factors are extrusion temperature, steam pressure, coke time of mixing rubber, and the mixing of impurities.

(1) The extrusion temperature is set too high or the temperature measuring device is not accurate, resulting in abnormal temperature setting, and the actual temperature exceeds the temperature limit of the rubber. This problem occurs more in smaller cable manufacturers, thermocouples or mercury thermometers are placed at different depths, and some even have no temperature measuring device, the operation depends on the feel, and the temperature control is unstable and easy to produce ripe glue.

(2) The temperature of the extruder is not good, and the friction accumulation heat cannot be eliminated in time. The cooling of extruder includes several parts, such as fuselage, screw, head and die. Cooling water pipeline blockage, cooling water flow is not enough, water temperature is too high will lead to poor cooling effect, rubber friction heat accumulation, can not be eliminated in time will exceed the burning temperature of the rubber and mature glue phenomenon. Some small business head, mouth die can not be cooled, and even the screw has no cooling water, the production of natural styrene butadiene rubber and other low viscosity, low heat rubber is okay, chlorinated polyethylene rubber material is hard, friction heat, if the adjustment of the temperature is not good, the probability of cured rubber will increase.

Due to the poor cooling of the mold, the cured rubber produced by the mold is relatively slight, and the cured rubber particles will appear on the surface of the protective layer, and the abnormal cooling will be eliminated in time, and the measures will be aggravated until the scratch or the sheath is broken. When the screw cooling is not good, it is easy to produce cured rubber in the extruder barrel, and once it is found, it will be more serious, and it can only be stopped if the cooling is not timely.

The production lines of large enterprises are more advanced, and the cooling and temperature control are relatively better. The extruder has a large length-diameter ratio, and the screw structure is complex, which can provide high extrusion pressure, make the rubber material dense, the cable protective layer surface will be smoother, and the technical indicators are more guaranteed. However, the friction heat generation of the extruder of this structure is faster, and there will be the problem of cooked glue, and the imported cable production line needs more attention. To solve these problems, you can start with adjusting the formula, but you should also pay attention to cooling efficiency.

(3) When the small size cable is extruded, the air pressure before the vulcanization tube is too high at the connecting part of the traction line and the extrusion core, and cured rubber is easy to appear. The thinner the line, the more likely this problem is to occur.

(4) Add superheated rubber or accidentally mix cured rubber during glue feeding operation. Workers in some companies will directly add the hot hose generated during driving operation to the feeding port for cable extrusion, which is easy to produce cured rubber. Summer temperatures are high, and it is even more important to avoid this problem.

When feeding rubber, the cured rubber such as the vulcanized sheath rubber will appear, which is characterized by no regularity and continuity, and it is destructive.

(5) The mixed rubber has been produced or mixed with cured rubber during the production. It can be solved by adjusting the formula vulcanization system and strengthening the process control.

(6) The burning time of the mixing rubber is short, which exceeds the safe operation time. There are two scenarios for this question:

One is individual, that is, when the rubber is produced, a certain train is caused by an error in ingredients or a timeout.

Second, the quality of the whole batch of rubber fluctuates. It can be solved by adjusting the vulcanization system and strengthening the control of mixing process. If the rubber has been delivered to the cable manufacturer, it must be used in order to meet the deadline, and qualified products can be produced by adjusting the extrusion process. Control key points are: reduce the pressure and extrusion temperature, slow production.