Common Problems and Solutions of Silicone Rubber
1. Raw gum eats powder slowly
Reason:
1. The molecular weight of raw rubber is high.
2. Silicone Rubber Raw Rubber with Trifunctional Groups in DMC
Handle:
1. Choosing the appropriate molecular weight of raw rubber or reducing the molecular weight of raw rubber
2. Appropriate addition of 500cs~1000cs dimethyl silicone oil or low molecular weight or water in mixing


2. Poor transparency of mixtures
Reason:
1. Silica particles are coarse and difficult to disperse.
2. Low molecular weight is not removed, and there is mist in vulcanizate.
3. Insufficient roll-wrapping times
4. Dirt Storage in Raw Materials
5. Poor sanitation
6. The sealing of equipment is poor. When vacuum is pumped, dirt enters the glue.
7. Short high temperature time in hot smelting
8. improper operation of nitrogen charging


3. The appearance of glue is inconsistent
Reason:
1. Color difference between batches of silica
2. Inconsistent Refining Time
3. The appearances of accessories are different.
Handle:
1. The heating time and temperature should be unified.
2. Pay attention to the color difference between batches of silica and replace it in time after it appears.
3. The rubber should be sent out at the same time to prevent the rubber from discoloring due to long storage time and reaction with air.
4. Unification of raw materials


4. Rubber roll-free
Reason:
1. High Plasticity Value of Rubber Material
2. Low Roll Temperature
Handle:
1. Increase roll temperature and close cooling water
2. Controlling the proper mixing time
3. Adding appropriate auxiliaries


5. Resilience difference
Reason:
1. Irrational Vinyl Formula of Raw Rubber
2. Excessive additives
3. Insufficient refining time, poor infiltration of silica and raw rubber
4. High Refining Temperature
Handle:
1. Proper addition of polyvinyl silicone oil to improve vinyl content
2. Appropriate Dispersion Dose
3. After eating the silica, the refining time is extended to 45 minutes.
4. Guarantee Refining Temperature


6. Poor tearing strength
Reason:
1. Unreasonable Vinyl Groups of Raw Rubber
2. Silica is coarse and its specific surface area is small.
3. Unripe vulcanization
4. Rubber brittleness
Handle:
1. Adjusting Vinyl Content with Polyvinyl Silicone Oil or Vinyl Raw Rubber
2. Replacement of silica fillers, selection of silica with large specific surface area and good performance, replacement of high-quality products
3. Adjusting the dosage and time of vulcanization
4. Reduce vinyl, adjust with methyl silicone oil or low vinyl raw rubber
7. Adhesion
Reason:
1. Bad polymerization of raw rubber, excessive low molecular weight or low molecular weight of raw rubber
2. Poor vacuum pumping
3. Overdose
4. Less release agent
5. Unripe vulcanization
6. Mould cleaning is not clean
Handle:
1. Exchange or dispatch of high molecular weight raw rubber for blending
2. Proper vacuum control
3. Reduce the dispersing dose and mix the glue with the glue
4. Adding release agent
5. Increasing vulcanizate temperature and prolonging vulcanization time
6. Regular cleaning of moulds
7. Use of alternative release agents


8. Large permanent deformation
Reason:
1. Unreasonable mixing ratio, excessive low molecular weight and low vinyl rubber
2. Low Vinyl
3. Poor vacuum
4. Short vulcanization time
Handle:
1. Adding high vinyl raw rubber to increase vinyl content or adding additives appropriately
2. Extending Vacuum Time
3. Extending kneading time at high temperature


9. Rubber yellow
Reason:
1. Raw gum contains NH2 and CL-ions
2. Silica contains more Fe3+
3. Insufficient high temperature and short vacuum time
4. The choice of silica is unreasonable and the appearance is yellow.
5. Poor vacuum or nitrogen filling
Handle:
1. Adding hydrogen-containing silicone oil and other anti-yellowing, the purpose is to react with NH2 and CL-ions to produce NH3 and HCL when vacuum is pumped out.
2. Guarantee high temperature time and temperature, otherwise the reactions of additives with NH2 and CL-ions are insufficient.
3. Change to other brands of silica
4. Guarantee Vacuum and Nitrogen Filling Time