1. The shrinkage of the product increases with the increase of the rubber content.
2. The shrinkage of the product changes into a saddle shape with the hardness after vulcanization. It rises sharply from 78 ° to 88 ° and then rises to 95 ° and is about the same as 35 °.
3. For the same mold production, the greater the weight of the rubber material, the smaller the shrinkage will be, but the change will not be too great, see Figure 2.
4. For the same mold production, the higher the pressure used, the higher the density of the product and the smaller the shrinkage rate, but the change will not be too great, see Figure 3.
5. The higher the vulcanization temperature, the larger the shrinkage (about every 10 °, the shrinkage increases by 0.06 ﹪ -0.14 ﹪), as shown in Figure 4.
6. The greater the distance the rubber flows in the mold, the greater the shrinkage of its corresponding position.
7. The greater the plasticity of the rubber, the smaller the shrinkage of the product.
8. The shrinkage of thin products (收缩 3㎜) is 0.2 ﹪ -0.6 ﹪ larger than thick products (﹥ 10㎜).
9. The order of shrinkage of different rubber compounds is: fluorine rubber> silicone rubber> EPDM> NR> NBR> CR.
Remarks: a. The shrinkage of the product changes with the lead time of the rubber;
    b. In the multi-cavity mold, the shrinkage rate of the product extruded from the middle cavity is slightly smaller than the product extruded from the edge cavity.