SATRA revises footwear test machines

Investigating improvements to the range of SATRA test equipment.

A number of footwear-related tests require materials to be flexed at low temperatures. SATRA provides a range of machines that incorporate a low temperature cabinet to enable tests to be carried out to determine the suitability of materials when assessed at temperatures below 0°C.

Several of SATRA’s low temperature test machines – including the STM 141F Ross flexer, STM 184F whole sole flex machine and STM 477F Bally flexer – have recently been revised. These revisions include updated and simplified drive mechanisms in order to reduce machine noise.

The Ross flexer has also been adapted to accept flexing at 60 degrees as called up in a number of specifications. Ninety-degree flexing is still available to suit test methods such as SATRA TM60:1992 – ‘Ross flex test – resistance to cut growth on flexing’. A new motor has also been fitted to machines that were previously manually jogged, so introducing a push-button jog facility.

To ensure maximum operator safety, SATRA’s low temperature cabinets have the electrical control and drive systems outside the freezer area, where moisture cannot impair electrical safety. The control system incorporates a digital temperature controller that can be set to achieve the desired temperature (from ambient down to -20°C), plus a counter to indicate the number of flexes carried out. The counter can be preset to stop the drive mechanism when completed.

Perforation resistant insert test machine updated

Both metallic and non-metallic inserts incorporated into the soles of safety footwear to prevent nails penetrating through to the foot need to be assessed for their flex resistance. This is an important requirement for safety footwear standards such as International/European standard EN ISO 20345.

SATRA has been manufacturing and supplying a suitable insert flexing machine for over 20 years. This equipment, designated STM 441, has recently been the subject of a major noise reduction review. As part of this update, higher-grade pivot point bearings have also been incorporated to increase periods between maintenance.

STM 441 is a six-station machine with two banks of three stations on either side of the central body of the machine. The angle of flex can be adjusted to meet the appropriate standard, and a timer is provided to stop the machine once the required number of flexes has been reached in order for the inserts being tested to be inspected. The machine is designed to operate at 16 cycles/second.

Click here for comprehensive information on SATRA's range of test equipment.

Publishing Data

This article was originally published on page 14 of the November 2017 issue of SATRA Bulletin.

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