Henkel Corporation has developed two new highly flexible instant adhesives, Loctite 4902 and Loctite 4903, that offer elongations up to 155% and provide high-strength bonds in seconds. Both cyanoacrylate adhesives bond reliably to plastics, rubbers, metals and other substrates and offer ISO 10993 biocompatibility for use on disposable medical devices.
These one-part, low-viscosity instant adhesives flow easily onto any substrate and typically fixture to handling strength in 5 seconds or less. Loctite 4902 is the more flexible of the two, with an elongationof 155% and a modulus of 57,900 psi. Loctite 4903 offers 85% elongation and a modulus of 78,100 psi. In comparison, conventional cyanoacrylates offer limited elongations of less than 2% and moduli of greater than 200,000 psi.
Loctite 4902 and Loctite 4903 are designed for use on close-fitting,flexible parts and can easily bond dissimilar substrates from plastics to elastomers. The flexibility of these new instant adhesives rivals those of acrylic and urethane adhesives. Both adhesives are available in either 20-gram or 1-pound packages. Loctite 770 or 7701 primers can be used to enhance bond strength on difficult-to-bond substrates such as polyethylene or polypropylene.