Causes and prevention methods of scorch in Automotive Wiring Harness Protection Sleeve

The scorch of the Automotive Wiring Harness Protection Sleeve is a kind of advanced vulcanization behavior, that is, the phenomenon of early vulcanization occurs in various processes before vulcanization, so it is also called early vulcanization. Scorching will lead to difficulties in post-processing and easy disconnection of product joints, which will affect the physical properties of the product and the smoothness of the appearance surface.

First, the cause of scorching phenomenon
① Improper production formula design, unbalanced configuration of vulcanization system (excessive dosage of vulcanizing agent and accelerator).
②The roller temperature of the rubber mixing machine or other roller devices is too high and the cooling is not enough.
③ For some rubber types that need to be masticated, the mastication does not meet the requirements, the plasticity is too low, and the rubber is too hard, which leads to a sharp rise in temperature during the rubber mixing.
④ When the mixed rubber is unloaded, the sheet is too thick, the heat dissipation is not good or it is not cooled, so it is stored in a hurry, but the warehouse is poorly ventilated and the temperature is too high, which will cause heat accumulation and cause scorching.
⑤ Poor management of Cable Sleeve during storage. After the remaining scorch time is exhausted, they are still stacked and unused, resulting in natural scorch.
Second, the method of preventing scorching
①The design of the Cable Sleeve should be appropriate and reasonable, such as: the accelerator should be used in combination as much as possible to suppress scorching.
②In order to adapt to high temperature, high pressure and high speed rubber mixing process, an appropriate amount (0.3-0.5 parts) of anti-scorch agent can be used in the formula.
③Strengthen the cooling measures for the Cable Sleeve in the rubber mixing and subsequent processes, mainly by strictly controlling the machine temperature, roller temperature and ensuring sufficient cooling water circulation, so that the operating temperature does not exceed the scorch critical point.
④Pay attention to the management of semi-finished Cable Sleeve, each batch of materials should be followed by a flow card, implement the "first in, first out" storage principle, and stipulate the longest storage time for each vehicle of materials, which must not be exceeded.
⑤ The warehouse should have good ventilation conditions.