VMI-AZ launches extruder for giant tyre retreading

ERJ staff report (DS)

Epe, Netherlands -- VMI has introduced a large extruder system aimed at off-road mining tyres. The system was introduced at a recent OTR-Retreading Conference held at VMI in Epe, Netherlands, and which was organised by the VMI Group and Kraiburg from Austria.

At the event, VMI -AZ based in Runding Germany, demonstrated an extruder and strip builder aimed at the giant tyre retread sector.

The base constructor consists of three pin-extruders attached to a special retread extrusion head that supplies base rubber to the tyre carcass. This set-up smears rubber onto the tire carcass while the carcass is rotating. Simultaneously skive holes are filled and the shoulder is automatically built at the same time. The technology is based on VMI-AZ's existing retread systems.

Once the base constructor's job is done, the carcass is moved to the strip builder. The strip builder provides a hot extruded rubber strip that is supplied to the tyre carcass to build up the new tread according to a menu controlled pattern and shape. The strip is directly applied and compacted onto the carcass, avoiding any air entrapment.

The OTR base constructor and strip builder are designed to retread tyres up to 63” rim size, 4000mm outer diameter and 1200mm width. VMI said the systems are also suitable for the building of new OTR tyres