| 摘要 |
A method of reducing wastage during the start-up phase of an extrusion device used to produce extruded profiles such as tread strips for vehicle tires from a plurality of mixtures is disclosed. The extrusion device comprises a plurality of extruders each extruding a component of the profile and each extruder has its own drive means. The outlets from the extruders communicate with a template member having flow channels formed therein which lead into a common extrusion port. The drive means are actuated simultaneously and the pressure of each of the components is monitored in the outlet region of each extruder. These pressures are compared with a pre-determined desired pressure by a control device, which device switches-off the appropriate drive means as each desired pressure is attained. When all desired pressures have been attained, all of the drive means are re-actuated simultaneously by the control device. In a minor modification of the method, the drive means for the final extruder to reach its desired pressure is not switched-off and the other drive means are simultaneously re-actuated when the final desired pressure is attained.
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