BLC News
Footwear safety
19th January, 2011
Heel fatigue and footwear slip resistance are critical elements of the safety testing of footwear. As consumers become more aware of their rights there is an increasing chance of litigation, which can prove costly to retailers with significant compensation claims. BLC offers a wide range of footwear testing services.
Heel fatigue
When a heel snaps, causing injury to the customer, this can prove costly to retailers with significant compensation claims.
Stiletto design specifications vary. The heel needs to be high, tapered and thin with a tension pin running through it. It usually also has a top-piece which is 10mm or less across. This all contributes to the aesthetics for the wearer, but what about the safety implications involved with this design? The majority of tests carried out on high heels are deemed to be safety critical due to the chance of personal injury that can result from faulty items. The stiletto design leads to extreme repeated stresses being imposed on the heel and backpart during walking. During a normal walking cycle the heel will initially be pushed under the shoe as the tip of the heel comes into contact with the ground. The heel is then forced in the opposite direction as the forepart comes into contact with the ground and the weight is shifted forwards. The higher the heel, the higher the stress.
The (BS EN ISO 19956:2004) heel fatigue test simulates walking by subjecting the heel to repeated impacts. Failure can be due to incorrect choice of material, inaccurate reinforcement due to air cavities near the top of the tension pin, incorrect positioning of the tension pin or poor design of the heel stem (either too thin or too long).
Another crucial test for high heels is the attachment strength of the heel to the main body of the shoe (BS EN 12785: 2000). The repeated impacts caused by normal walking can cause weakening and loosening of the grindery attachment. The incorrect placement of the heel grindery, inappropriate choice of component or insufficient number of nails used can all contribute to one of the more serious causes of wear complaints.
It is also crucial that the top-piece is securely attached and does not twist inside the heel stem. BLC can carry out a series of tests which reproduce the failures often found in wear. The attachment strength of the top-piece to the heel can be measured using a tensile tester. This test can also help determine the security of the attachment between the top-piece and the spigot.
As well as testing the attachment in a tensile direction, the top-piece is also tested in a torsional direction. This is to ensure that the spigots and tension pins used are suitable and have been correctly fitted.
High heels can be fragile in wear, particularly if the basic safety critical tests have been ignored. Testing with BLC can help to ensure that all of these aspects are covered. A simple UKAS accredited heel fatigue test can be carried out at BLC to identify potential faults and failures.
Slip Testing
It is essential that footwear manufacturers test the slip resistance by measuring the coefficient of friction between the sole and different types of flooring under both wet and dry conditions. This test can be applied to all types of footwear, top pieces, sole units and soling materials
BLC offers a standard 4 day turnaround for slip resistance testing.
For further information contact info@blcleathertech.com or +44 (0) 1604 679999.
