Problem 1: Insufficient foaming holes
1. There may be a problem with the quality of the foaming agent. If this happens, we should first check the service life of the foaming agent to see if it is within the service life.
2. It may be that the strength of the rubber material is too low. At this time, we need to check whether the plasticity of the rubber material is within the standard range. If the plasticity is too low, it should be supplemented and mixed to increase the plasticity and increase the number of foaming holes.
3. The rubber material has been placed for too long or in a high temperature place, causing the foaming agent to volatilize. In this case, the rubber material should be reprocessed.
4. The rubber material vulcanizes very quickly. At this time, the formula of the rubber material should be adjusted to coordinate the critical temperature of the vulcanizing agent and the decomposition temperature of the foaming agent so that the speed of the two can cooperate with each other to slow down the vulcanization speed.
Problem 2: Insufficient filling mold
1. The amount of rubber used is insufficient. At this time, the rubber strips should be weighed one by one to ensure that the weight of the rubber material meets the standard.
2. The mold may not be smooth enough or the mold has been used for a long time without corresponding cleaning, so that the rubber is subject to resistance when it flows. In this case, we should find a way to reduce the resistance and enhance the fluidity of the rubber.
Problem 3: The foaming holes are too large or too small and uneven
1. The foaming agent is agglomerated. The solution is to sieve the agglomerated particles, crush the coarser particles, and then mix them thoroughly to make them evenly dispersed.
2. The compound contains too much water or air and other impurities mixed in the rubber. In this case, the excess water in the compound should be removed first, and the air and impurities in the rubber should be fully removed to fully vulcanize them.
3. It may be due to insufficient vulcanization that the phenomenon of continued pores appears after the pattern is formed. At this time, the conditions of the vulcanization process should be adjusted accordingly, and the amount of vulcanizer used should be increased to meet the corresponding standards.
Question 4: Over-vulcanization or under-vulcanization
1. Over-vulcanization generally causes surface discoloration, smaller holes, higher hardness, and cracked edges. The causes are improper operation, too high temperature, too long vulcanization time, or instrument failure. Check whether there are any problems with the valves and instruments, and then strictly follow the operating rules.
2. Under-vulcanization When the vulcanization is insufficient, the internal pressure of the pores is greater than the external pressure after demolding. If the rubber material continues to pore, it will cause low hardness, poor strength, and large deformation at the least; or the holes will burst. Check whether there are any problems with the instruments and valves, and strictly follow the operating rules.
Note: Quality control indicators for foam products (1) Apparent density, the smaller the better; (2) Mechanical strength is generally 0.5-1.6Mpa; (3) Static compression permanent deformation; (4) Hardness; (5) Impact elasticity; (6) Continuous dynamic fatigue; (7) Aging test (70 degrees * 70 hours; 100 degrees * 24 hours); (8) Low temperature test.
