An Introduction To Free Radical UV Glue.
Optically clear glues!
UV cure glue offer an exceptionally easy way to glue materials. They are all single component product which require no mixing or measuring.
Quick and easy, it is the ideal glue choice in some specific applications.
UV cure glue is available in two specific cure mechanisms, cationic cure and free radical cure. This paper will refer to free radical cure systems only.
Unlike cationic sure UV glues, free radical cure glues cure very rapidly, usually in seconds. The reaction mechanism is quite simple. A chain reaction occurs when the photo-initiator within the glue decomposes upon exposure to UV light. Due to this chain reaction, free radical glues reach their optimum strength, once cured using the specific UV irradiation process.
One foible of free radical cure UV glue lies in its relationship with and reaction to oxygen. The presence of oxygen within the curing environment will quench the photo initiator and completely stop the chain reaction. The film of glue will feel soft and tacky with low to no strength.
How can oxygen poisoning be prevented? The best way is to bond in a nitrogen rich atmosphere. In the absence of this, a faster cure speed can reduce the impact of oxygen exposure in that the glue is curing faster than the quenching of the photo initiator can occur.
Don’t let this put you off! Overall, UV cure glues are the excellent choice for gluing applications where the optical clarity of the joint is important. They have reasonably good gap filling properties and offer aesthetically pleasing joints.
As Ireland’s only indigenous research based manufacturer and distributor of industrial glues, we have a UV cure glue to satisfy almost every job conceivable. Our laboratories are waiting for your call.