| 摘要 |
A filter for removing solid contaminants from plastic melt as well as homogenizing the plastic melt prior to injection, including a generally cylindrical filter screen having an inlet passage receiving the unfiltered plastic melt. Axially arranged series of relatively large diameter holes extend between the inlet passage and filter grooves formed in the surface of the filter screen. A first stage, coarse filtration is achieved by flow through the holes radially outwardly from the inlet passage into each of the filter grooves. A second stage, fine filtration occurs by flow from the filter grooves through circumferential clearance spaces located between each of several lands separating the filter grooves and the interior of the filter cavity. Filtered plastic is collected in axially extending discharge grooves also formed in the filter screen surface intermediate the pairs of filter grooves. Each discharge groove is in communication with a discharge passage collecting the flow of filtered plastic melt from each of the discharge grooves. Flow through the clearance spaces and discharge grooves affords linear flow paths, enhancing the homogeneousness of the plastic melt and uniformity of density in the molded product.
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