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Raw material problems
Moisture or low molecular volatiles (e.g. solvents, plasticisers) are mixed in the rubber material. Uneven mixing, there is air or impurity inside the rubber material. Improper storage of rubber materials, moisture or expiry date.
Moisture or low molecular volatiles (e.g. solvents, plasticisers) are mixed in the rubber material. Uneven mixing, there is air or impurity inside the rubber material. Improper storage of rubber materials, moisture or expiry date.
Improper curing process parameters
Vulcanisation temperature is too high or too low: too high a temperature leads to premature vulcanisation of the surface of the rubber, the internal volatiles can not be discharged; too low a temperature leads to insufficient vulcanisation, gas residues. Insufficient vulcanising pressure: unable to discharge the gas in the rubber or compressed residual air. Insufficient vulcanisation time: the rubber is not fully cross-linked and the gas is not sufficiently escaped.
Vulcanisation temperature is too high or too low: too high a temperature leads to premature vulcanisation of the surface of the rubber, the internal volatiles can not be discharged; too low a temperature leads to insufficient vulcanisation, gas residues. Insufficient vulcanising pressure: unable to discharge the gas in the rubber or compressed residual air. Insufficient vulcanisation time: the rubber is not fully cross-linked and the gas is not sufficiently escaped.
Mould design or use problems
Unreasonable mould exhaust structure (e.g. insufficient number of exhaust slots or blockage). Complicated mould cavity design, the rubber flow path is long, the gas can not be discharged in time. Mould surface contamination (oil, release agent residue) resulting in adhesive flow obstruction.
Unreasonable mould exhaust structure (e.g. insufficient number of exhaust slots or blockage). Complicated mould cavity design, the rubber flow path is long, the gas can not be discharged in time. Mould surface contamination (oil, release agent residue) resulting in adhesive flow obstruction.
Operation Problems
Improper loading method: the adhesive does not fully fill the cavity, forming air pockets. Unreasonable shape or size of pre-moulded rubber, resulting in air being trapped when the mould is closed. Unstable pressure or insufficient holding time of the vulcanising machine.
Improper loading method: the adhesive does not fully fill the cavity, forming air pockets. Unreasonable shape or size of pre-moulded rubber, resulting in air being trapped when the mould is closed. Unstable pressure or insufficient holding time of the vulcanising machine.
