VMI launching new Flexx belt builder in February

Dutch tyre manufacturing equipment maker VMI Group has announced plans to launch a new “Flexx” belt builder in February. According to the company, this technology offers the ability to produce OE quality belts for products up to UHP tyres in “a flexible and cost effective way.” VMI reports that one way it does this is by utilizing an extrusion process rather than calendaring.

The adoption of traditional extrusion based systems in place of calendaring was generally considered to be a compromise due to limitations with regard to the achievable belt quality. Now however, VMI reports that by adopting advanced extrusion, maximum flexibility, maximum quality and maximum economy for both small and large batches, it can finally be delivered by the VMI machine. 

VMI also reports that the Flexx belt maker is a fusion of the latest breakthroughs in cutting and feeding technology, high-speed vision systems and extruder gear pump technology. A high level of splice accuracy is said to have been achieved with a modern servo driven magnetic placement conveyor, combined with state of the art vision technology for control over the high accuracy splice. The use of VMI’s own gear pump extruder technology is designed to ensure “both dimensionally stable and accurate strip as well as high volume low temperature extrusion at the high pressures necessary for high quality strip.”

The Dutch company reports that it developed and optimized the machine’s basic principles under the code name ‘Baldwin’. The technology has reportedly already been utilized in “various highly advanced ‘in-line’ car tyre belt making systems”, according to VMI, and even in various very flexible ‘off-line’ OTR tyre component making lines – although these applications have so far been limited.     

In the ‘in-line’ FLEXX systems for car tyre belts, two highly accurate reinforced strips of 30mm width are extruded at the same time through the same extruder-gearpump head to produce the two belts required for radial passenger tyres. The belts of varying length and width are produced within the tyre building cycle time and applied to the tyre building drum. The challenges in ‘of-line’ FLEXX systems for OTR tyre were the thicknesses of the cords and the components to be produced and the necessary flexibility of the whole system, enabling it to produce all steel cord reinforced components, needed for a given all steel OTR tyre production. “It appeared that this flexibility was what the OTR tyre makers were really yearning for and is now the main reason of the success of VMI’s FLEXX OTR tyre component maker,” company representatives wrote in a statement announcing the release of the news machinery.

Therefore this technology has now been adopted and refined for endless ‘off-line’ production of car tyre belt material, where high levels of output are achieved by extruding a single reinforced strip of 250 to 300 mm wide.