Curing, rubber engine mount

Reversion is defined as the softening and weakening of natural rubber vulcanisate when the curing operation has been continued too long. This article describes experimentation carried out on a natural rubber engine mount with a reversion-resistant polychloroprene coating. Materials and methods are detailed, results are presented and discussed, and conclusions drawn. 18 refs. 

Components such as engine mounts and bearing pads, must be clamped or otherwise compressed during bonding. A compression ratio of 5 to 10% based on the initial dimensions of the rubber component will give optimum bond performance. Compression must be maintained throughout the PV bonding cure cycle and until the bonded component assembly has cooled to below 50 °C, see Table 3.5. 

Butyl rubber is used to make innertubes and curing bladders (see Butyl Rubber). Butyl polymers are about eight times more resistant to air permeability compared to natural rubber and have excellent resistance to heat, steam, and water. This accounts for its use in gaskets and diaphragms for hot water and steam services. In addition, butyl rubber can be compoimded to have low resilience properties and has found use in high damping mounts for engines, motors, and similar devices (6,17,18). 

---