| 摘要 |
Method of extruding and a single, twin or multiscrew extruder. …<??>In the extruder, the thread of the screw or of each of the screws is partly left-handed and partly right-handed, so that the material to be processed is in part conveyed in a direction A and in another part conveyed in an opposite direction B. …<??>The method is a venting extrusion method and the extruder is a vented extruder: the following are provided… - a back venting arrangement (7, 22) at the end (8, 19) of the screw (1, 16) or screws (1, 16), if the material to be processed is led away from this end (8, 19),… and/or… - a back venting arrangement (41, 52) at the point between the thread sections of the screw (1, 16) or screws (1, 16) from where the material to be processed is led away in opposite directions B and A. …<??>According to the invention,… - continuous operation is possible,… - no dead zones and breakaway edges are formed,… - the back venting arrangement (7, 22, 41, 52) can be easily sealed against ingress of oxygen,… - thermally and oxidatively sensitive products, such as nylon 66, can also be processed without detriment and in continuous operation (example: synthetic fibre extrusion spinning). …<IMAGE>… |
