July 2014 | Page 24

Brake Technology TRW achieves a braking first TRW has introduced Cotec - an innovative coating for its brake pads. Independent tests have proven that Cotec achieves significantly shorter stopping distances for the first stops after leaving a garage following a brake pad change. In the normal bedding in process there is a period at the beginning where the friction co-efficient is lower than usual. D rivers can find it difficult to adjust to the difference in performance during these first stops. TRW Cotec brake pads address this issue by improving the contact between the brake disc and pad. TRW has made the decision to coat all of its brake pads with Cotec. The changeover is already underway with 450 of the fastest moving references, covering 90% of the European car parc, already Cotec coated. Scorching is also a vital part of the manufacturing process and involves heating the brake pad material to 600700°C. Scorching allows the evacuation of gases and resins, trapped inside the friction material at the mixing stage. This helps to reduce the bedding in time to a minimum. Not all aftermarket suppliers carry out scorching, which means that the bedding process is extended. TRW utilises advanced heat plate scorching. Not only is this the OE standard, but it is more effective and uses less energy than conventional scorching techniques. During the process of advanced heat plate scorching, the friction material of the brake pad is pressed to a heated plate. This heats the matrix of the friction material, allowing carbonisation to occur to the first 0.5 to 1.5mm of its surface. The friction material is the most important part of a brake pad. All TRW brake pads contain the optimum mix of raw materials from rubber to graphite. TRW has made a significant investment over the years to ensure the perfect mix. The ingredients ensure a stable friction coefficient and the safest braking performance in all temperatures, at all speeds and under all conditions. Another important part of the brake pad is the back plates, which are high-quality steel plates that carry the friction material required for the braking function. The friction material is bound to the disc-facing surface of the back plate. The backing plate is powder coated which protects the back plate from rust. The backing plates used by TRW are designed, patented and produced in-house to OE specification. They are fitted to the friction material with a unique adhesive compound which can withstand high temperatures and resists extremely high shear strengths. All TRW brake pads undergo a rigorous set of tests during production and on the road and the aftermarket testing mirrors OE procedures. Many aftermarket suppliers in Europe consider their adherence to ECE R90 | words in action 22 july 2014 specifications as a mark of excellence, but for TRW, this is a minimum. TRW goes the extra mile with its testing procedures and its brake pads undergo a further shear strength test during production control to ensure that the pad material will not separate from the backing plate. In addition, TRW places great emphasis on noise reduction and its brake pads are fitted with high quality shims which act as a damper between the friction material and the brake caliper. The friction components are tested in NVH (noise vibration harshness) laboratories and on the road. But TRW is taking things to the next level. For the best possible performance, TRW now uses a fibre glass material instead of rubber for its shims. And where at an OE level, vehicle manufacturers use a metal shim held in place with special adhesive, TRW aftermarket parts follow suit. And for the best possible noise reduction, many TRW pads have integrally moulded shims and a multi-layer construction.