Leverkusen, Germany - Bayer MaterialScience has developed a new high-performance crosslinking agent for the coating of temperature-sensitive textile fibres, such as those used in swimwear and athletic clothing.
The polyurethane dispersion, called Imprafix 2794 XP, is suitable for coating elastic polyamide fibres, used in athletic attire, underwear, tights and shoes. Bayer says the blocking agent in the dispersion enables formulations with extremely long pot life, which means they can be stored "almost indefinitely" before they are used.
A temperature of around 125°C is sufficient for deblocking and initiating the crosslinking process, which means the formulations can be used to coat elastic polyamide fibres without damaging them. Bayer said in a February news release that conventional blocked cross-linking agents require higher temperatures of around 150°C, which can cause textile fibres to experience a loss of elasticity.
The company added that Imprafix 2794 XP can also be used to coat perfume bottles or fine dining glassware. Typically performed at temperatures above 180°C, the blocking at these temperatures is associated with clearly perceptible yellowing, Bayer claims, adding that its new dispersion avoids this. The cross-linker can also be used for baking coatings in automotive OEM coating applications.