| 摘要 |
A new extrusion plant comprises main extruder (1), auxiliary injection extruder (2) and interconnecting three-way valve (3). A mixing section (5) in the main extruder, follows the point of injection (4) from the auxiliary. Also claimed is a method holding mixed melt coloration constant. The melt in the auxiliary extruder has concentrated colouration; that in the main extruder has none. In-line colour measurement determines the mixture colour. Should this value deviate, the mixture is adjusted by extruder speed control, restoring it. Also claimed is a method accelerating change-over between colours. The three-way valve is operated to cause the colouring mass to be flushed out, afterwards reverting to the original setting, to feed in the new colour. |
