US 4,324,493 AGranted

Mixer-cooler device for the extrusion of thermoplastic foams

AssigneeLavorazione Materie Plastiche L.M.P. S.p.A.

InventorRoberto Colombo

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Abstract

A mixer-cooler device for the extrusion of thermoplastic foams comprising: a pair of radially foraminous tubular cylindrical blocks, clamped in axial alignment against opposite faces of a barrier disk by means of a headplate for connection with an extruder barrel and a headplate for connection with an extrusion head, the disk having an axial circular aperture; an advancement screw sealingly rotatable within the blocks, connectable with a screw of the extruder to constitute an extension of this latter screw, the advancement screw having an intermediate barrier section sealingly rotatable in the aperture of the disk; a tubular casing sealingly connecting the two headplates to form a tubular collector channel embracing from the outside the foraminous zones of the two blocks; and a system of passages in the headplates, blocks and disk for the circulation of a coolant liquid for the two blocks.

Claims9

Dependent claims

A mixer device for the extrusion of thermoplastic material comprising:

a barrier disc having a central axially extending circular aperture,
a pair of cylindrical blocks having axially extending circular apertures disposed in axial alignment against opposite faces of said disc, each of said blocks having a plurality of radial holes extending therethrough,
a tubular casing surrounding said disc and said blocks in concentric spaced relation to define a collector channel,
a pair of head plates having central axially extending circular apertures connected to opposite ends of said casing and clamping said blocks against said disc,
an advancement screw rotatably mounted in said circular apertures and having an intermediate barrier section sealingly rotatable in said barrier disc whereby material conveyed by said advancement screw from one end of said device to the other is forced outwardly through the radial holes in one block, axially over the outer periphery of said disc and inwardly through the radial holes in the other block, and
passage means extending through said headplates, blocks and disc for the circulation of a coolant fluid.

3 more elements

Dependencies are inferred from the claim text.

Facts

Application: 06/166,874Filed 8 Jul 1980
Priority: IT 68617 A/796 Aug 1979
Granted: 13 Apr 1982
Term ends: Not estimatedThe source records don’t support an estimate.

Classification15 codes

B29C 48/834
Heating or cooling the cylinders: cooling
B29C 48/267
Component parts, details or accessories; Auxiliary operations: intermediate treatments, e.g. relaxation, annealing or decompression step for the melt
B29C 48/42
Using two or more parallel screws or at least two parallel non-intermeshing screws, e.g. twin screw extruders: non-identical or non-mirrored screws
B29C 48/515
With internal flow passages, e.g. for molten material: for auxiliary fluids, e.g. foaming agents