April 2019

MTC aids big productivity gains Achieving best clamp load retention performance in extreme conditions T hreaded assemblies are the most important detachable parts used in machinery construction, installation and repair. Relaxation of tension and self-loosening is common for any machine but when it is operating in harsh environments, the need to minimise this deterioration with effective thread locking is even more important. Various methods are available but what are their respective strengths and failings? Mechanical devices such as split pins and tab washers are only suitable for preventing the loss of nuts and bolts. Friction devices give some resistance to vibration but do not perform well under extreme conditions. Locking devices, such as tooth flanged and ribbed flanged bolts, nuts and washers are effective at preventing self-loosening but can damage the contact surface, need larger flange-bearing surfaces and are expensive. Increasingly, thread locking adhesives are taking the place of traditional mechanical locking devices because they deliver the greatest all-round efficiency, especially when the going gets tough. As well as preventing unwanted movement, loosening, leaks and corrosion, they resist vibration. They are free-flowing liquids or semi-solid adhesives which completely fill the gaps between mating threads of fasteners and joints. To prove the performance of its thread locking system against other methods, Loctite submitted its products for independent testing in a transverse shock and vibration machine in which pneumatic hammers force relative movement of the stressed parts. At the same time, the existing pre-stress force was continuously measured for the number of load cycles. Characteristic clamp load retention curves of the various locking methods were then compared. While a similarly favourable load cycle performance was provided by the ribbed flange bolt, it does have other disadvantages. It’s expensive, requires a relatively large amount of space for the flange bearing and causes unavoidable damage to the surface of the clamped parts around the bolt bearing. A bolt with a saw-toothed flange also performed well but its teeth penetrated the bearings surface of the clamped material. The head and the nut were damaged during loosening, limiting their possible application to parts with hardened surfaces that cannot be reliably connected. As well as performing well, the Loctite thread lockers are able to cut costs by replacing expensive special locking bolts or nuts, allowing less costly standard assemblies to be used. Loctite thread locking adhesives are available in varying viscosities and strengths to meet the needs of a wide range of applications. They are single-component and semi-solid adhesives that cure at room temperature to a hard, solid thermoset plastic when applied between steel, aluminium, brass and most other metal surfaces. For more information please visit: www.henkel-adhesives.co.uk Maintenance Matters Problem Solver 20 | Plant & Works Engineering www.pwemag.co.uk April 2019 A family owned precision engineering company in Coventry has achieved a 10% increase in its forward order book and has made double-digit productivity gains with the help of experts from the Manufacturing Technology Centre (MTC). An SME team from the MTC’s Manufacturing Support Services operation worked with managers and operators from precision aerospace supplier Harris RCS and helped them make big advances in production planning, productivity and on- time schedules. Harris RCS, a progressive, well- established company based in Exhall, Coventry, approached the MTC to help the business reduce waste, improve set-up times and improve productivity in their CNC machining operations. MTC engineers, working with Harris RCS employees, began by replacing manual set- up processes with a digital solution. They captured data already available and made it visible to all operators so every machine could be monitored in real time. Machines are being digitally connected and a culture of continuous monitoring has been encouraged. Harris RCS managing director Graham Harris said the solutions arrived at added to the company’s reputation for quality and efficiency: “They took the big data we already had, made it more visible and linked our existing machine assets, building digital assets to make the processes more efficient. We are now able to handle more orders without having to bring in more resources, and we are investing in new technology where we really need it. “More importantly, they encouraged a culture of constant improvement. There is a real buzz about the place with our people coming up with new ideas all the time. Now working with the MTC forms an integral part of our strategy for improvement and innovation to meet our customer’s evolving needs,” he said. Dean Baker, director of the MTC’s Business Launch Centre and Manufacturing Support Services team, said the work with Harris RCS had demonstrated that as well as helping start-ups bring products to market, they could also use their expertise to improve productivity and competitiveness in established SMEs. He said, “We are able to provide a de- risked environment for SMEs with the support of our team of engineers, and through the MTC’s membership we can give companies the opportunity to draw on the wider manufacturing community to maintain a successful and sustainable business.” For further information please visit: www.the-mtc.org

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