Method for manufacturing speed control unit, involves injecting material into mold at selected pressure and selected temperature, where predetermined quantity of material is placed in melt state to define walls of casing

摘要

The method involves injecting a material into a mold (MB) at selected pressure and selected temperature, where a predetermined quantity of the material is placed in melt state with gas molecules to define walls of a casing (BC), which comprises the skin having density, and a core having density. The core is surrounded by the skin, where the density of the core is less than that of the skin. The skin and the core are adapted to absorb noise. The material is produced by mixing an inflating agent (AG) and plastic pellets (GP) made of polyamide. The inflating agent includes bicarbonate and derivative of citric acid.