Method for thermomechanically devulcanising a vulcanised elastomer
AssigneeRubbergreen Industrie
InventorsSaid SEGHAR, Olivier PRUD'HOMME
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Abstract
A method for thermomechanically devulcanizing an elastomer, comprising the steps of: providing a vulcanized elastomer in the form of particles; supplying said particles upstream of an extruder which comprises at least one twin-screw having at least one reverse-pitch screw element, and which extruder is configured to move the particles within it; thermomechanically treating said particles; and supplying said devulcanized material to an outlet in order to recover a devulcanized material.
Claims14
Method for thermomechanically devulcanising a vulcanised elastomer, comprising the following steps:
- Providing a vulcanised elastomer in the form of particles having a predetermined size distribution,
- Providing an extruder which comprises at least one twin-screw mounted rotatably, preferably co-rotatably, which extends into at least three sections of said extruder, a receiving section located upstream, a devulcanisation section and an outlet section located downstream,
- Bringing said particles upstream of said extruder which is arranged to move said particles within it following a rotational movement of said at least one twin-screw, downstream thereof, towards the outlet section,
- Optionally, crushing said particles in a crushing section so as to reduce the particle size,
- Thermomechanical treatment of said particles in the devulcanisation section to as to form a devulcanised material,
- Bringing said devulcanised material to the outlet section to recover said ready-to-use devulcanised material,
- characterised in that said at least one twin-screw extending into the devulcanisation section is provided with at least one reverse-pitch screw element that is arranged to allow the movement of the particles in the opposite direction, relative to the direction of movement of said particles brought upstream of said extruder, and to hold them for a sufficient period of time to allow devulcanisation and in that these particles brought in the opposite direction are thermomechanically treated after they have been in contact with said reverse-pitch screw element.
Extruder for thermomechanically devulcanising a vulcanised elastomer, comprising at least one twin-screw mounted rotatably, preferably co-rotatably, which extends in at least 3 sections, a receiving section located upstream, a devulcanisation section and an outlet section located downstream, said extruder being arranged to move the vulcanised elastomer in the form of particles within it following a rotational movement of said at least one twin-screw downstream thereof, in the direction of the outlet section, characterised in that said at least one twin-screw which extends in the devulcanisation section is provided with at least one reverse-pitch screw element which is arranged to allow the movement of the particles in the opposite direction, relative to the direction of movement of said particles brought upstream of said extruder, and holding them for a sufficient period of time to allow devulcanisation and in that these particles brought in the opposite direction are thermomechanically treated after they have been in contact with said reverse-pitch screw element.
Extruder according to claim 14, wherein said at least one reverse-pitch screw element constitutes the last screw element of the devulcanisation section, which is preceded by a kneading screw element designed to devulcanise the particles fed in the opposite direction and held by said at least one reverse-pitch screw element in order to perform devulcanisation.
Dependencies are inferred from the claim text.