To ensure that hook-and-loop fasteners deliver what they promise, standardised test methods are used to guarantee international industrial standards. The list of test methods carried out in the company's in-house laboratory is quite extensive. These usually involve peel and longitudinal shear strength, tear resistance, length changes in elastic tapes, weight per unit area, material thickness, and the curvature of hook and loop tapes – also known as the "banana shape" test. However, welding tests are also carried out, as well as tests to check the correct application quantity of adhesives or, for example, to ensure that seams are flawless.
"For us, quality management means taking responsibility."
For Andrea Schuhmacher, who is responsible for the relevant tests and certifications at kragoTEC®, the following is paramount in every single case: "For us, quality assurance means taking responsibility and using systematic procedures to ensure that our products are reliable, safe and durable." Using the example of a test on the effect of shear and peel forces on a hook-and-loop fastener system, she explains the relevance depending on the application: "Tensile strength, shear strength and peel adhesion are relevant performance characteristics, but they also depend on how many opening cycles a hook-and-loop fastener is expected to undergo in its application. A sports shoe, for example, should of course still be able to close properly, firmly and securely even after frequent and regular opening. The situation is completely different in areas of application that require a permanent – and therefore all the more secure – closure."
Accordingly, the test facility in our in-house laboratory tests longitudinal shear strength in accordance with DIN 13780, for example. In this process, individual strips of a hook-and-loop fastener are joined together and then separated at a constant speed using a "Zwick" device in such a way that the separation progresses along the length of the hook-and-loop fastener, parallel to the length of the strips forming the fastener and in the plane of the fastener.
In view of this description, which is complex for technical laymen, the laboratory employee explains: "What sounds complicated is indeed complicated – but the result is that, with regard to the test object in accordance with the DIN standard specifications and taking into account the product-specific data sheet, one systematically obtains information about whether a product meets the relevant requirements."
Tests are therefore carried out in accordance with international and industrial standards. However, "customers can also have individual parameters tested on request. Of course, these cycles and similar are also documented in our test reports," says the laboratory employee. Her daily work also includes documentation in the context of test equipment files as well as the calibration and adjustment of measuring instruments. "When it comes to reliable safety, clean documentation and flawlessly functioning test equipment are simply essential. We live and breathe quality from A to Z.
Andrea Schuhmacher smiles again: "Behind this name lies a test for measuring curvature in accordance with DIN EN 1416, which determines the relevant curvatures – i.e. slightly curved sections – within certain limits."
