1, rubber products mold
(1) Rubber products in the design of the mold must be easy to demoulding, to conform to the outline of rubber products, shape, structure to simple, reasonable, easy to operate, to meet the technical requirements;
(2) The mold should be maintained frequently to observe its cleanliness, deformation, positioning is firm, surface is smooth, etc.
2, rubber products structure unfavorable rubber products in the design should pay attention to its shape, thickness, release slope, which release slope is the main factor. After the product is out of the oven, due to the product cooling and centripetal contraction, in the core or pin to produce a great holding force, thus hindering demoulding. If the demoulding slope is increased, this resistance can be significantly reduced, and defects such as tearing caused by no slope can be avoided.
3, the product formula is not reasonable in the curing agent, accelerator is not enough, or curing temperature, time design is not reasonable, resulting in less sulfur; Or rubber raw rubber content too much, accelerator curing agent too much can also lead to release difficulties.
4, production process in the production process of rubber molding products, injection pressure, pressure holding, curing temperature, curing time, etc., will also affect the difficulty of release. For example, the injection pressure is too high, will make the mold parts produce elastic deformation and cause extrusion pressure, the pressure retaining injection force is too high, the time is too long, will lead to increased pressure in the mold cavity, produce large internal stress, cause the mold parts deformation or produce flying edge between the mating surface, make the demoulding more difficult.
The second is the demoulding method through the analysis of demoulding factors, we can use the following methods to avoid the demoulding problem or solve the demoulding problem.
1, the mold structure is reasonable, as far as possible to improve the mold stiffness; Timely mold maintenance work, such as cleaning (electroplating, tetrafluorospray, sand blasting).
2, the structure design of rubber products should be easy to demoulding, and have enough slope.
3, choose a reasonable and appropriate viscosity formula. Appropriate adjustment of vulcanization system, especially rubber products, increase the amount of accelerator; Add carbon black to strengthen or adjust the original formula.
4, immature curing can increase curing time, improve curing temperature and other ways to solve; For the more complex structure of the product especially pay attention to the demoulding method, improve the demoulding workers operating level.
5, reduce the frequency and dosage of release agent, which can effectively avoid the release agent pollution mold cavity surface, resulting in difficult to stick mold.
6. Use a certain amount of release agent.
