Need a fast curing plastic adhesive? Choose next-gen Permabond UV643

Permabond UV643: Fast curing on rigid plastics

Permabond UV643 is a high-performance UV light-curable adhesive specifically formulated to bond both rigid and flexible thermoplastics at very high speed. It bonds extremely well to a wide variety of substrates, including polycarbonate (PC), polymethyl methacrylate (PMMA), polyethylene terephthalate glycol (PETG), polyethylene terephthalate (PET), acrylonitrile butadiene styrene (ABS), and polyvinyl chloride (PVC). In addition to plastic-to-plastic applications, UV643 also performs excellently when bonding dissimilar materials. It facilitates metal to plastic bonding, making it a highly versatile choice for design and manufacturing engineers.

A next-generation, exceptionally fast-curing UV adhesive 

UV643 cures at very high speed. When bonding glass to glass, full cure can be achieved in less than a second under appropriate UV conditions. These conditions include a lamp intensity of 150 mW/cm² or higher, within the 365–420 nm wavelength range. One of the key advantages of this adhesive, however, is its efficiency even when using lower-powered lamps. Curing still occurs rapidly due to its advanced photoinitiator system. Containing multiple photoinitiators, UV643 is capable of curing across a range of UV wavelengths. This occurs even with UV-stabilized plastics that typically slow down the curing process.

Other benefits that make UV643 stand out from older UV adhesives are its consistent tack-free finish, as well as a lower hazard rating. This puts UV643 in a similar category to Permabond UV6260 and Permabond UV6357, UV curing adhesives that launched earlier this year. Both of these products also cure tack-free very quickly and offer unique benefits – UV6260 cures through coloured glass and tinted substrates, whereas UV6357 offers outstanding cold resistance. All of these products, including UV643, have a better safety profile than some older UV adhesives. This includes not having the so-called ‘exploding man’ hazard pictogram on their safety data sheets. They also have improved resistance to harsh environmental conditions such as heat and humidity.

Rheological and Handling Benefits

UV643 is thixotropic and has a higher viscosity than many competing products. Its controlled flow properties allow for precise dispensing and clean application, which makes it easier to handle prior to curing. These features also enable the adhesive to form fillets and perform exceptionally well in complex or irregular joints, providing both functional strength and aesthetic quality in finished assemblies. The adhesive surface cures to a tack-free finish.

Exceptional Durability and Environmental Resistance

Permabond UV643 has been rigorously tested to ensure long-term performance. It successfully passes 85/85 accelerated life testing, during which samples are subjected to 85°C and 85% relative humidity for up to 1,000 hours. This demonstrates its outstanding resistance to both heat and moisture and showcases its suitability for outdoor and harsh-environment applications.

The adhesive also exhibits excellent resistance to thermal cycling on plastic assemblies. Internal testing has shown that bonded substrates often fail before the adhesive itself. In addition, UV643 resists yellowing and discoloration, maintaining a clear, professional finish over time. This is particularly important for optical and aesthetic applications.

Typical Applications

The versatility and reliability of Permabond UV643 make it ideal for a wide range of industries and uses, including:

• Electronic components and PCB assemblies
• Automotive parts and lighting
• Plastic window and display bonding
• Household appliance manufacturing
• Optical and precision assemblies

Because of its tack-free surface cure and strong mechanical properties, UV643 is suitable for coating or encapsulation applications. For instance, conformal coating of printed circuit boards (PCBs). Additionally, its low-hazard SDS makes for a safer working environment compared to many alternative UV-curable products.

If you’d like to learn more about Permabond UV643 or to discuss how it could be used in your project, please contact us.