Leak tightness and technical cleanliness in screw fastenings 15 December 2022

Here, Arnold addresses the relationship between technical cleanliness and leak tightness, which the company believes plays a crucial role in the reliable performance of fastenings in the electric vehicle sector. To ensure this balance, Arnold offers its Cleancon concept which guarantees technical cleanliness throughout the entire process.

The fastening solutions manufacturer, based in Forchtenberg, Germany, believes that it is important to create an awareness that certain requirements for leak tightness also require a defined degree of cleanliness. The requirements for technical cleanliness were first set by the automotive industry and today, general regulations establish a standardised framework to achieve technical cleanliness.   Arnold Umformtechnik GmbH offers two leak tightness test stands through its Cleancon concept, one which measure leaks with test gas, another which uses water as its test medium and can produce an IPX7 certificate.  

For the cleanliness analysis, Arnold believes it is important to determine the specific particle load present, so contaminating particles are detached and gathered inside an extraction cabinet. There are several different ways of making the necessary analysis that follows. For example, the part can be analysed under an optical microscope used to determine the length and width of any contaminating particles, and these can be categorised as metallic bright or non-metallic bright. Laboratory scales can also provide information on particle mass. Arnold has recently acquired a scanning electron microscope, which can determine the chemical elements that make up a contaminating particle. It can also draw conclusions about the source of error. Moreover, the company has a residual magnetism test stand.

The company has also acquired a scanning electron microscope which can determine the chemical elements that make up a contaminating particle. At Arnold, the focus is on leak tight applications such as battery cases, final assembly and installation. Clean fasteners are essential when used in any oil conducting systems as well as for the sensor technology in autonomous vehicles. The aim of the company’s ‘clean and tight’ analyses is to guarantee a reliable evaluation of the leak tightness of the fasteners within the context of the customer’s application. As well as ascertaining how leak-proof a component is, the analysis should also include long-term effects, such as corrosion or environmental influence. Using these analyses methods, fastening solutions are ensured to meet leak tightness requirements.

Becca England Assistant Editor t: +44 (0) 1727 615 413

Becca is the latest member to join our team and is eager to get stuck into the world of fasteners. She brings an enthusiastic and fresh outlook on what we do editorially and will be leading our social media activity – including sourcing material, editing articles and posting online.