ISSUE 011 Autumn 2021 Candela C-7 hydrofoil speedboat dossier l In conversation: Robert Hoevers l Battery recycling focus l Vehicle dynamics insight l ZeroAvia hydrogen-electric aircraft digest l Motor materials

leaking can be expected. Programmed with a material model of the polymer from which the gasket is made, the simulation can show graphically and numerically how it reacts to increasing pressure that, by design, will change its shape and improve the sealing performance, right up to the point at which it starts to go wrong. With too much pressure, the gasket itself can start to be extruded through the tiny gaps it is supposed to seal, followed by the oil or coolant itself. Simulation is particularly important for vehicle and subsystem manufacturers when they are trying to find a seal material that will do the job at a low cost, allowing them to try out many materials virtually and very quickly. The same applies when weight savings are pursued through making subsystems and components smaller, as that means sealing surfaces also get smaller, so it is critical to ensure that a proper seal can be formed. If this is done early in the design process it can save a lot of time and money later. In seal manufacture, how the material flows into a mould, how quickly and completely the mould fills, where the flows of material meet and the temperature at which all this happens are all simulated. This allows material parameters and design details to be refined and problems ironed out before committing to production. The in-service performance of seals has to be balanced against their ease of manufacture, application and cost, which is more of a challenge. The specifics of each application in terms of sealing performance and resistance to aggressive media drive different chemistries and cost levels, and define the space in which solutions can be optimised. In battery manufacture, for example, the industry is rapidly improving its processes in terms of cycle time and cost, with a growing reliance on automating sealant and adhesive application in particular. As bead widths and thicknesses get smaller, it is critical to keep the relationship between them (known as the aspect ratio) stable during application, because key performance requirements such as chemical resistance, permeability and pressure resistance depend on the adhesive’s footprint. Also critical is the sealant’s ability to retain its heat resistance up to high temperatures without losing adhesion or its cured properties, while curing at lower temperatures. Lower curing temperatures make application easier and increase production rates, but they can affect cured properties. Liquid application In car plants these days, many sealants are applied in liquid form by robots during assembly. A sealing compound that is usually highly viscous and thixotropic (meaning that viscosity is reduced under mechanical stress over time) is applied to the components along a specified 2D or 3D contour. The flow characteristics of the liquid sealants and their inherent adhesion-promoting characteristics help to keep the cured bead in place and retain its dispensed profile and size. Compared with traditional die-cut gaskets, wet-dispensed gasketing allows flexibility in component design and significantly reduces waste. There is often a wide variety among the designs Some suppliers of seals and sealants Germany bdtronic +49 7934 104 0 www.bdtronic.com Elring Klinger +49 712 372 40 www.elringklinger.de Freudenberg Sealing Technologies +49 6201 800 www.fst.com Henkel +49 211 797 0 www.henkel.com Trelleborg +49 711 7864 0 www.trelleborg.com/en/seals ThreeBond Europe +49 2103 688 4384 www.threebond-europe.com Viscotech +49 8631 92740 www.viscotec.de UK Eastern Seals +44 1670 840529 www.easternseals.co.uk Hylomar +44 1942 617000 www.hylomar.com USA 3M +1 888 364 3577 www.3m.com deVan Sealants +1 314 858 5657 www.devansealants.com Graco +1 612 623 6000 www.graco.com HB Fuller +1 833 672 1482 www.hbfuller.com Nordson +1 760 431 1919 www.nordson.com Seal Methods +1 562 944 0291 www.sealmethodsinc.com :ealants adOesives NaW Ällers and tOerTal interface Taterials coTWleTent one anotOer in ,= batteries Wower conversion electronics and electrical TacOines (Courtesy of /) -uller) 70 Autumn 2021 | E-Mobility Engineering