GB1355046A - Die - Google Patents

Abstract

1355046 Extruded section IMPERIAL CHEMICAL INDUSTRIES Ltd 19 July 1971 [24 July 1970] 35986/70 Heading B5 [Also in Division E1] An extruded section comprises a flat sheet 32 extruded from a stationary outlet and fused thereto a sheet 33 of an undulating configuration imparted by angular oscillation of a further outlet from which it is simultaneously extruded. A pair of stationary outlets provides the Fig. 3 configuration, and there may also be provided a plurality of adjacent oppositely oscillating outlets the extrudates from which intermittently contact and fuse together downstream of the outlets to produce a honeycomb structure. The flat and undulating configurations, may be of the same, or of a different resin. One or more such oscillating outlets may be provided in combination with one or more stationary outlets, as in the Fig. 1 embodiment, wherein the oscillating outlet is provided by an oscillating member 13 located within a rectangular die bore 12 and from which the undulating extrudate 33, Fig. 3, is fused to exterior planar sheet extrudates 31, 32, issuing from stationary outlets 17 of material from the same extrusion source. Where the undulating extrudate issues from an outlet which -does not discharge in sufficient proximity to the sheet extrudates to ensure contact and fusion, the sheet extrudates may be inwardly deflected by angled plates or rolllers, or by a narrowing of the bore of the die 11 into which the extrudes issue. With an outlet oscillating about a greater radius than in the Fig. 1 embodiment and discharging downstream of and between a pair of stationary sheet outlets, Fig. 2 (not shown), the undulations may be of a substantially linear configuration which may also be enhanced by having a greater velocity of the oscillating outlet intermediate, than at the ends of, its traverse. With different resins from different extrusion sources, and using a modified, Fig. 2, extrusion die the undulating sheet may comprise a rubber-resin blend with the planar sheet extrudate being of glass filled resin. In the Fig. 4 modification of the Fig. 2 embodiment, the flat sheet outlets are interconnected to produce a planar channel section 41, 42, 44 internally connected by an undulating web 43. The rectangular die passages of this embodiment preferably comprise rounded corners, and the section extruded may be modified by extending one side 42 beyond the base 44 to form a section suitable for a window or door frame. A T-section may also be extruded (not shown) with a flat horizontal limb, optionally having outward facing flanges, e.g. for attachment purposes, and an undulatory vertical limb. A constant relationship of the planar and convoluted extrudates is maintained by oscillating the die outlet by means of a drive from that rotating the extruder screw, or reciprocating the extruder ram, e.g. by a rack and pinion through a unidirectional clutch, such as a ratchet and pawl.