Find your application
- iCOM® continuous mixing
- Gear pump systems
- Tire retreading
- TPE / TPV compounding
- Steel belt extrusion
- Apex Extrusion
- Pin Extrusion
- Small scale extrusion
- Vacuum extrusion
- Miscellaneous solutions
Tire retreading
VMI-AZ Extrusion offers a wide range of machines for retreadingtruck- and earth mover tyres
• Cushion gum extruder (CTC)
• Retread systems for earth mover tires
• OTR Strip Builder for Treads
Cushion gum extruder (CTC)
The VMI-AZ Extrusion CTC (Cushion-To-Casing) system, with (optional) building machine for pre-cured treads, uses an extruder to directly extrude hot cushion gum onto the buffed casing surface, thus directly replacing the process of wrapping calandered sheet cushion gum around the buffed casing. Single size extruder feed strip is drawn into the extruder feed section, heated up by being plastisized in the mixing section of the extruder and then forced through the 420 mm wide CTC extrusion head directly onto the buffed casing.
Since the CTC skive filling action is an automatic process, it is far more reliable than the skive filling operation as performed by an operator with a hand held extruder. Cushion gum width is adjusted by moveable slides, which change the die opening width of the extrusion head. Specially shaped quick-change side-dies are also available so that cushion gum can be partially extruded on the casing shoulder in order to accomodate pre-cured tread with sings or contour sides.
The VMI-AZ Extrusion CTC system comes in two models, i.e.: The extruder builder CTC-SB I and the extruder builder CTC-SB VII.
The main features of the extruder builder CTC-SB I are:
- Optimized for big shops
- 80-160 tires per 8-hour shift
(cushion gumming and pre-cure tread building) - PLC controlled, with touch screen HMI
- Automatic stretching of tread for precise splice matching
- Saves labor costs by automatic skive filling
- Saves cushion gum costs by using just one size of feed strip
- Saves cement spraying costs with correctly formulated cushion gum
- Increases product quality
- Optimized for small to big shops
- Up to 140 tires per shift
- PLC control operation, with touch-screen HMI
- Saves labor costs by automatic skive filling
- Saves cushion gum costs by using just one size of feed strip
- Saves cement spraying costs with correctly formulated cushion gum
- Increases product quality
- Discounted versions available without stitching unit and laser arm, for cushion gum application only
- Start saving costs today!
Retread systems for earth mover tires
VMI-AZ is one of the market leaders for retread systems for truck and passenger tires. Based on this experience a new system has been developed to enable retreading of earth mover tires. Main components of this system are the base constructor and the strip builder.
The base constructor consists of three PIN-Extruders attached to a special retread extrusion head that supplies rubber to the tire carcass. This set-up smears rubber onto the tire carcass while the carcass is rotating. The so called cushion to casing technology is already well known from VMI-AZ retread machinery.
If the base is built-up by the base constructor the tire can be moved to the strip builder position. At the strip builder a hot extruded rubber strip is supplied to the tire carcass for building-up the new tread. To ensure high precision the Shark® extruder gear pump system is used for extruding the strip.
OTR Strip Builder for Treads
The Strip Builder builds-up the tread of OTR tires. This VMI-AZ strip building systems consists of a gear pump extruder system, a tire stand and the control system.
Thanks to the volumetric gear pump the strip is extruded onto the carcass directly. The strip apply position and the tread build-up is controlled by the laser sensor and the software program. Customers’ different tread requirements can be stored in the HMI.
VMI-AZ Strip Builder offers the following advantages:
- Direct strip apply – no calender required
- Gear pump delivers high output precision
- Close distance between die and tire surface
- Gear pump allows usage of short screw – low temperature
reduces risk of scorching - Different strip sizes possible by just changing the die
