Blowing agent selection

  Foaming agent is the most critical link in the production of foamed rubber, and its selection is closely related to work efficiency and work quality. Generally speaking, to produce foamed products with good performance, it is necessary to choose a scientific and reasonable foaming agent, and the amount and method of use of the rubber foaming agent must meet the current social development requirements. At present, foaming agents mainly include organic foaming agents and inorganic foaming agents. Among them, inorganic foaming agents mainly refer to sodium bicarbonate, ammonium bicarbonate, urea, etc. These foaming agents have the advantages of fast decomposition speed and low temperature in application, and their foaming performance is relatively good in theory. Because the gas produced by this technology in the application is mainly carbon dioxide and ammonia, etc., the existence of these gases makes the rubber structure have a large permeability coefficient, making it difficult to produce closed-cell foamed rubber, and the quality of the produced foamed rubber is low. , low strength, large shrinkage, and easy deformation, so it is very easy to use alone in work, and generally can be used as an organic foaming agent.

In the current work, our commonly used blowing agents mainly include nitrogen diformamide, nitroso, diphenylsulfonyl hydrazide ether, etc. The decomposition temperature of these materials is above 200°C in application, and other foaming aids, such as urea, magnesium oxide, zinc oxide, etc., need to be added in the production process, so the decomposition is greatly reduced, and the thermal decomposition The gas produced mainly includes nitrogen, carbon dioxide, ammonia, etc. These gases are not only non-toxic and odorless, but also have the advantages of not polluting the environment and not changing color. The rubber foam products made with foaming agent have larger pore size and larger shrinkage rate; when foaming agent is used, foaming aids include stearic acid, alum, etc., and the decomposition temperature of foaming agent can be significantly reduced after adding to 130-150°C.