| 摘要 |
1,072,203. Making screw extruders. WERNER & PFLEIDERER. Feb. 23, 1966 [March 13, 1965], No. 7987/66. Heading B3A. A screw element of a screw extruder for plastics is cast from a hard abrasion - resistant material, such as "Stellite" (Trade Mark). An axially extending recess 2 is filled with a softer steel 4 and a keyway 1 is machined by slotting or broaching. The part 5 of the bore, the external threads and end faces of the element are finished by grinding. The bore may be polygonal in cross-section or be provided with a plurality of axial slots (Figs. 3 and 4, not shown), in which case the entire bore surface is " Stellite " coated. |
