| Résumé : |
The promise of increasing manufacturing productivity by bonding and coating with light curing adhesives has not been fully realized because some clear substrates do not transmit ultraviolet light. Additionally, UV adhesive not directly exposed to light does not cure.
Now, special resins are available that cure synergistically by combining UV and visible curing mechanisms. As a result, almost any transparent or translucent plastic, glass or ceramic can be bonded. Cure speeds with these new resins are faster, and the new UV/visible curing technology enhances the capacity of secondary cure mechanisms to augment and complement cures in shadowed areas. This capability broadens the number of applications where the advantages of photocuring can increase productivity, lower costs and enhance manufacturing competitiveness (see Table I).
The new "expanded spectrum" light curing technology combines the curing energy of both ultraviolet and visible wavelengths. Offered by the Dymax Corp. under the trade name Ultra Light-Weld, these new UV/visible light curing aerobic acrylic adhesives provide faster, and in some cases, deeper cures with lamps emitting longwave UV and visible wavelengths. The faster and deeper cures possible with the new UV/visible curing technology enhance the synergistic effects of secondary curing mechanisms, thus expanding the capability for cure in shadowed areas. The encapsulation of microelectronic assemblies is an example of this capability where even black, opaque encapsulants cure rapidly in depths to 50 ml, and adhesive in shadowed areas will cure completely. |
Aller sur edunet
Accueil
Expanding capabilities with UV/visible light curing adhesives in ADHESIVES AGE, Vol. 38, N° 4 (04/1995)
