Foaming principle and application of thermoplastic elastomer TPE

The main influencing factors that determine foaming are as follows:

1. The gas generation and decomposition rate of the Foaming Agent

Generally, the foaming agent having a low decomposition temperature has a high decomposition rate, and the same foaming agent has a small particle diameter and a high processing temperature and a high foaming speed. Generally, the decomposition rate of a large amount of gas is high, and the formed cells are large, and the opening effect is easily formed.

2, the impact of foaming agent

The normal production of foaming agents with a decomposition temperature higher than the TPE/TPR processing temperature cannot be foamed. It is necessary to add some additives to reduce the decomposition temperature of ZnO and other zinc salts.

3, the viscosity of the rubber compound

Viscosity affects the rate at which the gas diffuses in the compound. The viscosity is too low, the gas diffuses too quickly, it is easy to overflow, and bubbles are not easily generated. If the viscosity is too high, the gas expansion is limited, and the internal pressure has a large pore size. If the opening effect is made, the viscosity of the rubber compound can be adjusted to be small, and the closed cell effect can increase the viscosity of the rubber compound.

Common thermoplastic elastomers TPE/TPR foaming such as slippers soles TPE/TPR foaming, wine stoppers TPE/TPR foaming, etc. In recent years, some cushions, anti-slip mats, sealing strips TPE/TPR products have also begun to move. The direction of foaming is considered. According to the product requirements, the expansion ratio (foaming effect) is different, and there are high foaming and micro foaming points. TPE/TPR is foamed, mainly based on its functional characteristics. For example, the slippers sole TPE/TPR is mainly considered to be lightweight, and it has a soft effect when stepped on. The wine bottle stopper foaming is mainly considered to be light in weight. In fact, the development of TPE/TPR in the foaming field is mainly due to the consideration of light weight. In many occasions, the product needs to be light in weight, and the material development to light weight can also reduce the cost of raw materials.

The foaming of TPE/TPR is not enough for single foaming, and it also has the function of Cross-Linking Agent to ensure the strength of foamed products, such as tear resistance and toughness. Since the application of TPE/TPR is usually in direct or indirect contact with humans, there is a high requirement for TPE/TPR foaming compound compounding systems. All components of TPE/TPR, such as foaming agents, are crosslinked. Agents need to consider environmentally friendly varieties, usually AC foaming agent for EVA shoe materials, DCP cross-linking agent, applied to TPE/TPR foaming, should be carefully considered, to confirm the customer's environmental requirements.