Textar’s Technical Manager, Scott Irwin, discusses the types of noises made by the brake system – and why – as well as the shim technologies that dampen brake noise, including the manufacturer’s latest innovation, Textar Q+.
Automotive innovation has advanced to a point where cars are much quieter, showing little vibration and no brake squeal. Although there is a debate surrounding electric cars of the future being too quiet, there are technologies being developed to ensure the braking systems of today’s vehicles can keep up with ‘low noise’ expectations.
Brakes are not silent by their nature. However, they have become much quieter over the years thanks to extensive research and development. One of the technologies is the development of the shim, which works in conjunction with the brake pad to lower noise frequency. Brakes inevitably cause vibration when they are applied and, depending on their frequencies, these vibrations can be perceived in various forms.
A low frequency is often referred to as ‘creep groan’, ‘humming’ or ‘judder’, while medium to high frequencies can cause a ‘squeal’ or so-called ‘wirebrushing’. All of these are affected by a number of factors, including the friction coefficient of the pad or lining and counter material, friction speed, contact pressure, as well as the design of associated components and their natural frequency and dampening behaviour. Air temperature and humidity can also play an important role.
All components within the braking system and chassis, right down to the rubber car body mounts, are involved in noise generation, with the brake assembly taking a lead role and the discs acting as ‘loudspeakers’. Furthermore, the size, design and condition of the whole wheel – the rim and tyre – can also have an impact.
To eradicate this issue, TMD Friction is constantly developing its shim technology across its various brands globally, to effectively dampen noise and improve performance. One of the latest products to hit the market is the Q+ from Textar, the premium brake range within TMD’s portfolio.
Textar is the original equipment brand behind the majority of the world’s vehicle manufacturers and Q+ offers OE technology to the aftermarket. The lamination and composite nature of the product helps to eliminate noise through its layered design, along with a special adhesive that bonds the sections together and provides dampening properties. The layers are formed from rubber and metal and by their nature, help to change the frequency of the sound the brakes make, so humans are unable to hear it. Textar has also included an innovative textile-like texture on the Q+, which dampens and decouples the brake pad effectively from other braking components.
Comprehensive research, including a dynamometer test and on-the-road trial, showed significant comfort improvements with Q+. However, the best results were achieved when the Q+ brake pads were combined with Textar brake discs, as these components have been designed to complement each other.
With technology showing no signs of slowing down and with the possibility of electric vehicles on the horizon, it is important for manufacturers to be constantly innovating, to be ready for future developments.
Technical Team: 0330 0583 908