Thermoplastic elastomer TPE / TPR foaming effect can often greatly reduce the material density, reduce costs, and some daily damping or water absorption and thermal insulation materials will be used foaming properties, we all know foaming agent For the physical foaming agent and chemical foaming agent, today mainly talk about the foaming principle and influencing factors.
The main factors that determine foaming are as follows:
1, foaming agent of gas and decomposition rate
General decomposition of low temperature foaming agent decomposition speed, the same kind of foaming agent, small particle size, processing temperature and high foaming speed.Generally large gas decomposition speed, the formation of large cells, easy to form Hole effect.
2, the impact of foam additives
Decomposition of the temperature higher than the TPE / TPR processing temperature of the foaming agent is the normal production can not be foamed, the need to add some additives to reduce the decomposition temperature of ZnO and other zinc salt the best.
3, rubber viscosity impact
Viscosity is too high, it limits the expansion of the gas, the internal pressure of the large aperture is small. If you do the hole effect can be done. The viscosity of the gas is too high, the gas is too fast, easy to overflow, not easy to produce bubbles. Rubber viscosity is small, closed-cell effect can increase the viscosity of the compound.
TPE / TPR foaming TPE / TPR foam TPE / TPR foam TPE / TPR foam TPE / TPR foam TPE / TPR foam TPE / TPR foam TPE / TPR foam TPE / TPR foam TPE / TPR (TPE / TPR) for foaming treatment, mainly based on its functional characteristics, such as slippers soles TPE / TPR, TPE / TPR, TPE / TPR, TPE / TPR, TPR, TPV / TPR to the development of the field, mainly to take into account the lightweight, many occasions need products Light weight, and other materials to the lightweight development, but also reduce the cost of raw materials.
TPE / TPR foam, foam alone is not enough, but also a crosslinking agent, in order to ensure the strength of foam products, such as tear resistance, toughness, etc. Because TPE / TPR applications usually associated with people fIELD direct or indirect contact, so for TPE / TPR compounded foamed material systems have high requirements, all components TPE / TPR, such as foaming agents, crosslinking agents need to consider environmental species, typically EVA shoes AC foam materials used, DCP cross-linking agent, used in TPE / TPR foam, to carefully consider how to make sure customers' environmental requirements.