New thermoplastic film replaces metal
Hofheim, August 24, 2011
A high performance thermoplastic film developed by Victrex Polymer Solutions and Italian company ROJ Electrotex was selected to replace metal, which suffered from mechanical decay and inconsistent braking performance.
The innovative thermoformed cones designed with Victrex Aptiv 1000 series films made from Victrex Peek polymer are used as part of a brake on industrial weaving machines to equip the weft feeders, which are the electromechanical systems located between the loom and the spool on which the weft is wrapped.
The weft feeder conveys the weft under ideal tension to the loom picking devices (pliers or fluid spouts), in order to carry out the weaving process.
“Previously, the brake cones were produced by using a metal cone placed on rubber supports but ROJ faced two critical areas in need of improvement: from a material performance perspective, the mechanical decay of the rubber component was unacceptable; further, the metal cone created an inconsistent braking performance,” explained Cesare Brovarone, an aeronautical Engineer responsible for new technology at ROJ.
“The brake constancy is a key feature as it adjusts and maintains the optimum tension of the weft, which the weft feeder provides to the loom at the same level.”
‘It also allows a more consistent yarn tension at every desirable tension level, while the tension depends on the pressure applied by the APTIV film cone on the weft feeder yarn running surface, thereby eliminating defects in the cloth,” added Brovarone.
ROJ used Aptiv films in three different thicknesses (150, 250 and 500 microns) selected according to the required tension and weft characteristics. ROJ has already produced and tested thousands of the Victrex Peek polymer-based Aptiv film braking cones and forecasts the production of ten thousand per year.
The unique range of properties displayed by Aptiv films allows total accuracy in the production of the cones, which are made using high-pressure forming technology by the German company Niebling HDVF in Penzberg.
“This process has been a key aspect for component quality as the strict tolerance needed by the cone shape allows the required braking consistency. We are really satisfied with this development, and we decided to patent not only the structure but also the use of Aptiv films for this specific application,” added Brovarone.
Aptiv films are the most versatile, high performance films available, providing all the performance properties of Victrex Peek polymer in a thin flexible format, a statement said.
They offer a unique combination of properties, including high temperature performance, mechanical strength, chemical resistance, electrical insulation, excellent wear and abrasion resistance, purity, radiation resistance, and low moisture absorption, it added.
Aptiv film is a technology enabler to facilitate meeting the demand for reduced systems cost and improved product performance, while also providing increased design freedom and ease of processing to achieve product differentiation, according to the statement. – TradeArabia News Service