Reasons and solutions for uneven foaming holes (too big or too small)

The foaming hole is too big, the hardness and density of the product are not standard, the closed hole will become joint hole, the micro-hole will become small hole, some parts will be collapsed or some parts will not be foamed up.
Cause.
(1) The foaming agent is agglomerated or the particles are too coarse.
(2) Uneven mixing.
(3) The water content of the compound is too high, and there is air or impurity mixed in the rubber material.
(4) Insufficient vulcanisation, continue to develop holes after leaving the mould.

Countermeasures.
(1) check the blowing agent, if there is agglomeration phenomenon should be sifted, the particles should be crushed, fully mixed (or thin pass) so that it is dispersed uniformly.
(2) with high moisture agent should be used after drying, remove the air or impurities in the rubber, so that it is fully vulcanised.