New adhesive technology is bringing significant benefits to product assembly, especially where OEMs have multi-material and multi-substrate bonds that must meet stringent performance criteria
In some cases, the technical complexity of an application can constrain a manufacturer’s ability to boost productivity, but Henkel Loctite says that its new, patented hybrid technology is allowing many OEMs to address these issues with great success
Developed by Henkel, LOCTITE® HY 4090 is said to be a new breed of adhesive that combines the fixture speed of an instant adhesive (also known as a cyanoacrylate) with the durability of an epoxy. This unique combination has opened-up new application areas for an instant adhesives in structural bonding applications, especially those where production speed is a significant consideration.
A current example of this is in the assembly of battery packs for electrical devices. To meet the projected production rates of a new product, the manufacturer sought an adhesive that was able to bond polyamide (PA) with a thermoplastic polymer (ABS), and at speed. The resultant bond also needed to be resistant to operational fluctuations in vibration, temperature and humidity. In this case, LOCTITE HY 4090 proved to be the solution, a two-part hybrid which has the speed and material versatility of an instant adhesive plus high temperature-performance and moisture/chemical resistance. It is suitable for temperatures up to 150° Celsius and is well suited for bonding highly stressed joints and those that are exposed to vibration.
Having cleaned the battery pack parts with LOCTITE SF 7063 to remove moulding compounds that may inhibit final bond strength, LOCTITE HY 4090 is then dispensed from a dual cartridge pack using a manual hand gun with mixer nozzle. The hybrid adhesive fixtures in just three minutes, minimising any potential blooming from exposed fillets of the cyanoacrylate-based product.
Epoxy-based adhesives are proven to provide very good static and dynamic strength and are a frequent choice for demanding structural bonding applications such as this. However, this technology typically requires a minimal fixture time of ten minutes. By choosing LOCTITE HY 4090 the manufacturer has the best of both worlds – suitability for bonding load bearing parts and achieving handling strength in minimum time, qualities which are said to have allowed the manufacturer to significantly increase productivity whilst underpinning product quality.