Smart system solution for needle bonding 05 March 2021

A main field of application for adhesives in medical systems is needle bonding and syringe assembly in high volume production. Optimally matched processes are essential for reliable bonding. Panacol, Hönle and bdtronic work together to ensure that precise adhesive dosing, capillary flow and curing in seconds with UV light work hand in hand.

As the needles are produced in large quantities rapid and reliable bonding is essential. In addition to their mechanical bond strength, the adhesives used must allow high-precision production and permanent joining and must withstand various sterilization methods. Panacol’s UV curable Vitralit® adhesives exactly meet these requirements. Vitralit adhesives are available in various viscosity ranges to perfectly fit the design of the needle hub and fill the gap between the hub and the needle. The material of the hub and needle also affects the choice of the adhesive: Many adhesives are UV-curing, which requires the use of transparent and UV-permeable materials. For materials that block UV light, such as polycarbonates, long wave LED curable adhesives are recommended.

All Vitralit adhesives recommended for needle bonding are solvent-free and 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 sterilization cycles. For visual quality inspection, fluorescent versions of our medical grade adhesives are also available.

The choice of the adhesives requires a matching dispensing system for reliable and precise dispensing in a rapid production environment. The high quality demands required for medical devices, as this needle bonding application, confirms the choice for bdtronic’s volumetric dispensing equipment. With the mini-dis solution provided by bdtronic, dispensing in microliter range is made easy, regardless of the adhesive viscosity. Thanks to the continuous volumetric dispensing, the dispensing is pulsation free ensuring optimal process speed, repeatability and accuracy.

Finally, the choice of the UV curing equipment depends on the adhesive and the wavelength which triggers polymerisation. For needle bonding with Vitralit  products either UV-A or visible LED light can be used. Due to a special LED assembly and an own optimised electric power supply, Hönle LED Powerline LC guarantees a high intensive irradiation for fastest curing and shortest cycle times. In addition, the irradiation time can be selected in a range of 0.01 – 99.99 sec and thus precisely adapted to the process requirements.

Claire Aldridge Editor t: +44 (0) 1727 743 889

Having spent a decade in the fastener industry experiencing every facet – from steel mills, fastener manufacturers, wholesalers, distributors, as well as machinery builders and plating + coating companies, Claire has developed an in-depth knowledge of all things fasteners.

Alongside visiting numerous companies, exhibitions and conferences around the world, Claire has also interviewed high profile figures – focusing on key topics impacting the sector and making sure readers stay up to date with the latest developments within the industry.