摘要 |
<p>A die is fed with two polymer streams (S1, S2), one of which is split into two outer streams (S2.1, S2.2), which are then extruded together to form a multi-layered composite sheet (G). The outer streams are fed through gaps in the walls of the passage for the central stream. The gaps are formed between the wall and wedges pointing in the flow direction. A die is fed with two polymer streams (S1, S2), one of which is split into two outer streams (S2.1, S2.2), which are then extruded together to form a multi-layered composite sheet (G). The outer streams are fed through gaps in the walls of the passage for the central stream. The gaps are formed between the wall and wedges pointing in the flow direction. The wedges can be rotated from the outside through a lever and calibrated screw in order to control the gap width. The pivot for rotating the wedge is formed by a thicker, circular section of the component. The wedges can be rotated to a closed position to give a smooth wall when only one material is extruded. Several wedges fed from an internal distribution channel are provided to cover the width of the sheet. For extruding more than two outer layers, several sets of wedges can be placed in succession in the flow direction.</p> |