The cell structure of sponge rubber is the main factor determining the performance of the product. For all kinds of sponge rubber, its cell structure can be classified into three types: open cell structure, closed cell structure and mixed cell structure.

Open cell structure

Open-cell sponge rubber, the cells are connected to each other, the walls between the cells are not completely closed, and the gas can pass freely between the cells. This sponge rubber has low resilience, high compression set, poor mechanical properties, poor thermal insulation performance, high water absorption and small apparent density.

Open-cell sponge rubber is widely used in vibration reduction, buffering, sound absorption and other occasions, such as carpet backing, cushioning pads, rubber pads, boxing gloves, sound insulation materials, etc.

Closed cell structure

The cells of the closed-cell sponge rubber have no openings, and there are complete cell walls between the cells. The bubbles generated by the decomposition of the foaming agent are discretely distributed in the rubber matrix. The gas in the cells cannot freely enter and leave the cells, and the surface of the product has a Layers of dense rubber crust. The closed-cell sponge has lower water absorption, higher resilience and good thermal insulation performance, and the apparent density is slightly higher than that of the open-cell sponge.