A point well made on syringe needle bonding

In addition to their mechanical bond strength, the adhesives used for bonding needles into syringes must be compatible with high-precision production, deliver permanent joining and be able to withstand various sterilisation methods and processes. Panacol’s UV light curable Vitralit® adhesives offer all these attributes and more says Eurobond. The company’s Vitralit® adhesives are available in various viscosity ranges to suit various designs of the needle hub and to fill the gap between the hub and the needle. 

The material of which the hub and needle are manufactured can also affect the choice of the adhesive according to the experts at Eurobond. Many adhesives are UV-curing, which requires the use of transparent and UV-permeable materials, but for materials that block UV light, (such as polycarbonate), long-wave LED curable adhesives are recommended. All Vitralit® adhesives which Eurobond recommends for needle bonding are solvent-free and are also certified USP Class VI and/or ISO 10993 for use in medical equipment. In addition, high needle extraction forces were measured with all needle bonding adhesives even after several sterilisation cycles. For visual quality inspection, fluorescent versions of Vitralit® medical grade adhesives are also available.

The adhesive of choice will also require a matching dispensing system as well as a UV light curing system for reliable and precise dispensing in a rapid production environment. Handily, Eurobond Adhesives are also UK distributors of the latest products from German UV light manufacturer Hönle AG. The company’s LED Powerline LC UV light source is claimed to guarantee high-intensity irradiation for fast curing and short cycle times. The irradiation time can be precisely selected from a range from 0.01 – 99.99 seconds to match precise process requirements. Further, Eurobond confirms that Hönle LED Powerline heads have a compact design for straightforward integration into most production lines. The high-intensity, water-cooled LED-UV light source is also said to be suitable for clean room operations.