VMI’s Extrusion Smearing Technology

VMI Extrusion, together with its skilled technicians and designs, has been part of VMI since 2004. Extrusion is a dedicated business unit of VMI and builds on more than 20 years’ experience with retread cushion-gum extrusion smearing technology, using the lessons learned from the more than 1200 systems containing this technology it has supplied worldwide.

Retreading replacement 2 528x352 VMI’s Extrusion Smearing Technology

The AZ-RETRAX Program

Now VMI has taken AZ Extrusion technology to the next stage with the AZ-RETRAX program. By keeping AZ in the title we underline the continuing development of the AZ-Extrusion heritage, but this is a true VMI product, incorporating the commitment to innovation and automation that you would expect from any technology carrying the VMI name.

AZ Retrax 6005 528x353 AZ RETRAX 6005

Product range

The AZ-RETRAX is available in three different types, each with a different extruder capacity.

The AZ-RETRAX can be provided with stitcher rolls and high speed on the wheel hub. This makes the AZ-RETRAX suitable for manual pre-cured tread application, with successive automatic stitching.

The smallest machine in the AZ-RETRAX product family.
Click here for detailed info (at VMI´s homepage)

Workhorse of the AZ-RETRAX family.
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Top of the AZ-RETRAX product range.
Click here for detailed info (at VMI´s homepage)


Key benefits

Compared with the more traditional use of calendered cold cushion gum, freshly extruded hot cushion gum application offers the following advantages:

  • Lower cost single size feed strip instead of calendered strip in different widths
  • Better tackiness which reduces or eliminates use of cement sprays, reducing costs and eliminating the fire and health threats caused by these materials

Key features

VMI’s smearing technology cushion application is a major advance on all methods that use extruded strip winding, offering:

  • Automatic skive filling for lower labor costs, while delivering the right quantities of gum on the right spots
  • The smearing principle pushes out the air much better

Thickness of the cushion layer can be controlled by the hub speed and/or extruder speed.

The width is adjusted by movable slides. Wing formers are available for special shoulder and sidewall cushion application.