| 摘要 |
<p>A blender (1) for deliver of blend additives to a plastics extrusion device has a mixing chamber (2) for reception of materials to be blended. Batches of blend materials are delivered to the mixing chamber (2) from material supply bins (36) via a weigh hopper (30). Within the mixing chamber (2), a mixing screw (3) circulates and mixes the blend materials prior to discharge through an outlet (4) to an extrusion process line. As material is discharged, a material level sensor 5 is uncovered and calls for a further batch of blend materials to be discharged from the weigh hopper (30) into the mixing chamber (2). The screw (3) has a pair of mixing blades (21, 22) of opposed pitch to direct material inwardly from outer ends of the screw (3) towards a centre of the screw (3) located above the outlet (4). Excess material above process demand requirements is delivered to the outlet (4) by the screw (3). This excess material is directed upwardly away from the outlet (4) and recirculated towards outer ends of the screw (3) and remixed with out material within the mixing chamber (2). <IMAGE></p> |
