Injection moulding tool, for making e.g. CD's or DVD discs, has dosing gap formed in flow control means for injected polymer when the tool sections are brought closer together to compress the polymer

摘要

A radial dosing gap is formed between the protruding part and cavity forming a flow control means for polymer entering the mould cavity (4, 5) when the two closed mould tool sections (2, 3) are brought closer together to compress the polymer. An injection moulding tool (1) comprises two tool sections defining a mould cavity, each tool section being provided with a means for controlling the flow of polymer out of the injection tube (11, 12) into the cavity when the tool is closed. The flow control means cooperate with other and comprise a cavity and a protruding part inserted into the injection tube. This part extends in the tool section closure direction at an axial distance from the cavity when the tool sections are brought together, and lies inside the cavity when the tool sections are brought closer together. In this second position, a radial gap is formed between the protruding part and the cavity in which it is located.