Plasticising and injection unit for rubbers and plastics

摘要

A plasticising and injection unit for an injection moulding machine with a non-return valve includes a sieve-like filter (28) covering the entire flow cross-section in front of the non-return valve (27) in the flow direction. The filter (28) moves in unison with the screw (13) and the non-return valve (27). Pref. the filter (28) is interchangeable. Both screw (13) and cylinder (14) move together into the space (5) in front of the screw (13) enclosed by a cylinder block (6). The filter (28) and non-return valve (27) are held on the cylinder end by a cap-like extension (21). Filter (28) positioning in the extension (21) is by stops. Filter (28) construction comprises wire mesh grids (33) one behind the other, located in a common recess (32) of a holder (30, 31) with openings (29) for passage of polymer.