WHILE the adhesives industry has made major advances in recent years, the manufacturing industry has been slow to endorse these new adhesives as an alternative to mechanical fasteners in their assembly operations.
Gavin Williams, technical service engineer with 3M Australia, says there are major benefits of using adhesives in the manufacturing process. “The end product can be lighter, with a lower total mass than with mechanical fasteners.
“You can bind similar materials same as with rivets or weld, but you can also join dissimilar materials such as plastic to a foam or polystyrene to a metal. Things you could never bind with a rivet. This is where adhesives come into their own.
However Williams says manufacturers are missing out on these advancements. “They are not getting us involved early enough in the design process.
“It’s important for us to get involved early because all too often the items are designed without adhesives in mind. There are certain ways you need to design the joints to achieve highest possible performance and strength, whereas if you try to put an adhesive into something that’s already been designed to be mechanically fastened then it may not perform as well as it could,” he told Manufacturers’ Monthly.
Williams said that because manufacturers are failing to get them involved they are failing to exploit the latest innovations. He added that 3M’s main focus recently has been in the area of bonding tapes for the construction industry.
“We have developed systems for bonding panels on building facades without cutting and folding, by just using tape. 3M’s VHB tape has been around for 25 years but it’s only been in the last 15 years that it’s been pushed and promoted in Australia. We have always known how durable it is and in recent years it has really started to take hold.
“In Canberra they are using the tape to attach panels to many new constructions. It basically turns a task that has a lot of steps into a simple peel and stick process,” he said.
“Some manufacturers are moving away from traditional curing types of adhesives to a pressure sensitive adhesive tape in order to increase productivity,” Williams said there is also a move to water-based adhesives that are environmentally friendly.
“It’s not as big in Australia as it is in the US, where they have limits to the volatile organic compounds that can be contained in different adhesives but I think we will eventually follow.
“There is also the issue of employee safety with solvent-based systems. People have to be kitted up with respiratory gear and all the systems have to be in place to evacuate the fumes.
“The drawbacks with water-based adhesives is that they take so long to dry, but 3M has a water-based adhesives that enable fast bonding yet are safe,” he said.
Williams makes the point that some manufacturers don’t want to know about improved environmental properties and workers safety if it’s going to affect the bottom line by taking twice as long to manufacture.
Cost of some adhesives is another issue, says Williams.
“Manufacturers are often worried that a role of VHB tape may cost more than rivets and other mechanical fasteners.
“But they are failing to look at the potential savings from more efficient production by using tapes and adhesive, as well as aesthetic and performance improvement of goods produced.
“They need evaluate how much longer it takes a worker to do the job using traditional fastening compared to tapes and adhesives,” Williams said.
Stuart Blacket, managing director of Henrob Australia, is not so sure saying there will always be a place for fasteners in the manufacturing process.
“We have seen a steady consistent growth in the application of fasteners and expect this will continue,” Blacket told Manufacturers’ Monthly.
“We are seeing with our self-pierce rivets, a focus on improved productivity, in the face of increasing overseas competition, and the use of a lower skills base to compensate for labour shortages,” he said.
“Increasingly the manufacturing base is being exported to our lower labour based neighbours so this in turn requires control of the assembly solutions to ensure repeatable quality,” he said.
Regarding new applications for fasteners, Blacket said there is an increasing use of high strength steel and stainless steel requiring a new range of rivets for joining dissimilar materials such as plastics to aluminium.
“Also a worldwide switch in coatings away from the use of chromium 6 has involved extensive research into new coatings for steel fasteners.
“Henrob has improved the corrosion performance and the temperature resistance for coated steel rivets that are applied to steel and aluminium products,” Blacket said.