Assessing slip resistance for the Chinese market
Describing SATRA’s work into testing to the revised GB standard.
by Peter Allen
For several decades, SATRA has developed test methods and test machines to evaluate footwear for slip resistance. These originated from human subject tests in the 1930s and 1940s, which were followed by extensive laboratory tests – including force platform and high-speed camera work. SATRA scientists studied the biomechanics of walking and slipping to develop SATRA TM144 – ‘Friction (slip resistance) of footwear and floorings’ test method and the forerunners of the machine we manufacture today – the SATRA STM 603 slip resistance tester.
SATRA TM144 is a mechanically accurate test that replicates the speed and angle with which an average foot meets a ground surface just before slip takes place.
This test realistically simulates the conditions at the moments during a normal walking step when slip is most likely to commence. Unlike many other methods, it uses realistic loading forces representing an adult walking gait, in addition to realistic floor contact angles, static contact time and sliding speed. It is based on biomechanical studies of humans walking normally or slipping, and the method is true to normal confident gait on a level surface. Being a machine-based method it is, therefore, definable and consistent every time.
A basis for national and international standards
SATRA is active in the fields of standardisation and SATRA TM144 has influenced many slip standards around the world. For example, international (ISO) European (EN), Canadian (CSA), Japanese (JIS) and US (ASTM) standards all use the SATRA test methodology and test machine derivatives.
More recently, standards makers developing China’s GB standards have been considering the subject of slip resistance for domestic footwear, and a new 2017 version of GB/T 3903.6 (‘Footwear – Test methods for whole shoe – Slip performance’) has been released. SATRA engineers have revised SATRA’s slip resistance machine software to enable this method to be included, along with the existing test methods incorporated in the STM 603 slip resistance tester.
One of the characteristics required by the GB test method is to report the static (pre-movement) coefficient of friction between the footwear sample and the floor surface. This is reported separately, in addition to the sliding coefficient of friction.
The inclusion of the GB/T 3903.6-2017 test method in the selectable tests incorporated within the SATRA STM 603 slip resistance tester makes this the global solution for testing slip resistance.
How can we help?
Please email firstname.lastname@example.org for further information on SATRA’s STM 603 slip resistance tester.
This article was originally published on page 14 of the September 2018 issue of SATRA Bulletin.