| 摘要 |
1,184,231. Extrusion - blow moulding. REXALL DRUG & CHEMICAL CO. 28 Feb., 1967 [28 Feb., 1966], No. 9585/67. Heading B5A. Hollow articles are formed by extruding plastics material to form a tubular parison having longitudinal grooves ("strial") and blow-moulding the parison in a mould cavity having a minimum radial dimension greater than the maximum radial dimension of the parison. The grooves may be on the exterior of the parison, the interior being smooth, or on both walls. Fluorescent material or other pigment may be included in the plastics, giving the article a rippled effect wherein the apparent depth of the ripples or grooves is greater than the actual depth. Air may be supplied through the extruder mandrel, which may be vertically reciprocable to vary the parison wall thickness. |
