System and method for extruding complex profiles from elastomer mixtures

Patent metadata

Field	Value
Publication number	US-2021170661-A1
Application number	US-201917054220-A
Country	US
Kind code	A1
Filing date	May 13, 2019
Priority date	May 14, 2018
Publication date	Jun 10, 2021
Grant date	—

Abstract

The extrusion installation is configured for manufacturing a complex profiled-element strip, such as a tread, based on elastomer compounds by co-extrusion, and comprises multiple extruders feeding elastomer compounds to an extrusion head. The extrusion head receives a proportion of elastomer compound of between 2 and 25% of the total volumetric throughput of the installation from at least one Archimedean-screw extruder and the rest from positive-displacement extruders.

First claim

1 . An extrusion installation for the manufacture of a complex profiled-element strip such as a tread, based on elastomer compounds by co-extrusion, and comprising multiple extruders feeding elastomer compounds to an extrusion head, wherein the extrusion head receives a proportion of elastomer compound of between 2 and 25% of the total volumetric throughput of the installation from at least one Archimedean-screw extruder, and the rest from positive-displacement extruders.

2 . The installation according to claim 1 , wherein the flights of the screw of the Archimedean-screw extruder are shallow, the height of the flight being less than 0.2 the value of the diameter of the screw, for a short pitch, the value of which is less than 1.5 the value of the diameter of the screw.

3 . The installation according to claim 1 , wherein the length of the screw of the Archimedean-screw extruder is greater than 8 times the value of its diameter.

4 . The installation according to claim 1 , wherein the positive-displacement extruders are positive-displacement counter-rotating twin-screw extruders with intermeshing screw flights with mating profiles.

5 . The installation according to claim 1 , wherein the extrusion head comprises ducts for distributing the elastomer compounds coming from the extruders toward an outlet die, and the Archimedean-screw extruder is connected to the outlet die by a duct of a length less than that of the distribution ducts of the other extruders.

6 . The installation according to claim 1 , wherein the distribution ducts extend in a direction substantially perpendicular to the direction in which the flows of elastomer compounds coming from said extruders flow.

7 . The installation according to claim 1 , wherein the extruders are arranged on either side of the head with respect to a plane of symmetry (P) passing through the outlet orifice of the die.

8 . The installation according to claim 1 , wherein the extrusion head is connected to the extruders directly, without there being an elastomer-compound transfer duct between the two.

9 . The installation according to claim 1 , wherein the Archimedean-screw extruders are identical and in that the positive-displacement extruders are identical.

10 . The installation according to claim 1 , wherein the extrusion head comprises a collection of several removable plates arranged side by side.

11 . A method for the manufacture of a strip of a profiled element, such as a tread, based on elastomer compounds by co-extrusion, using an installation comprising multiple extruders feeding elastomer compounds to an extrusion head, wherein a proportion of elastomer compound of between 2 and 25% of the total volumetric throughput of the installation, coming from at least one Archimedean-screw extruder, and the rest coming from positive-displacement extruders, are passed simultaneously through the extrusion head.

Assignees

• Michelin & Cie

Inventors

• Hinc Henri
• Letocart Arnaud
• Ougier Christophe

Classifications

• B29C48/455

  Screws arranged to convey material towards each other, e.g. separate screws arranged after each other and feeding in opposite directions · CPC title

• B29C48/387

  using a screw extruder and a gear pump · CPC title

• B29C48/07

  Flat, e.g. panels · CPC title

• B29C48/388

  using a screw extruder and a ram or piston · CPC title

• B29K2021/003

  Thermoplastic elastomers · CPC title