VMI Group - Technology meets success

RETRAX

VMI developed the RETRAX retreading system to answer to our customers’ needs of the present and the future. The RETRAX employs the renowned cushion gum extrusion-smearing technology. This technology is used by a majority of bus- and truck tire retreaders in the USA and Europe.

Although based on the continuing development of the AZ Extrusion heritage, RETRAX is a true VMI product. Incorporating the commitment to innovation and automation that you would expect from any technology carrying the VMI name, it enables you to further automate your retread process.

The modular design of machines enables customers to choose between three extruder capacities. This allows the customer freedom to choose a specific output, depending on the number of tires which need to be produced and the method of tread application. Tread application can be done fully automatic or manually on the RETRAX or on a separate machine.

Product highlights

  • Uniform filling by extrusion-smearing technology
  • Save cushion gum costs by using single size feed strip
  • Lower labor costs through automatic skive filling

Operation

The RETRAX has been designed for application of extruded hot cushion gum on a “buffed” tire casing, in order to be able to apply a pre-cured, vulcanized cut to length tire tread.

“Buffed” means that remains of the old tread have been removed. The cushion gum is the layer of uncured rubber which will be cured and vulcanized at a later stage during the process. This will create a good bonding of the new tread onto the used tire casing. The RETRAX extrudes a cushion gum layer and smears it directly onto the buffed tire casing in one rotation of the casing and simultaneously fills skive holes.

The buffed tire casing is to be placed on the expendable rim, brought under pressure and moved towards the RETRAX extruder head. Thickness of the cushion layer can be controlled by combining the hub speed and extruder speed. The width is adjusted by movable slides. Wing formers are available for special shoulder build up, for wing tread or contour tread.

After the cushion gum layer application, the tire can be directly removed and further processed on a next station for tread application or the pre-cured tread can be manually or automatically applied whilst the tire is still on the RETRAX hub.

The RETRAX Program

Get advice

Contact VMI in your region

Select your

VMI Office:

Getting the best out of your solutions

Visit VMI Services