Thermosets thin-wall molding

Blow molding cannot be used to produce hollow rubber parts from conventional thermoset rubbers. These must be injection molded over a manually removable collapsible core to form thin-walled rubber shapes such as boots, bellows, and covers. Blow molding is uniquely suited to TPEs as a material for hollow, thin-waUed rubber articles. 

Molds for thermoplastics are often cooled to a temperature well above ambient. The mold temperature is controlled such that it will cool the material in the cavity at the fastest rate possible without causing it to harden before it totally fills the cavity. Molds are often made of metals more easily machined than steel, such as beryllium copper, that will afford optimal heat transfer to the molding material. Cavity surfaces are generally not chrome plated, because thermoplastics are less abrasive than thermosets. Overall cycle times, especially for thin-walled products, are often below 10 s. 

---