Question: We use an acrylic UV adhesive to bond and coat a complex medical device, and get areas where there is incomplete curing. How can we improve this?
Answer: First, you need to ensure that you measure the intensity of the UV light in various parts of the device and ensure that you use the optimum dose of radiation (intensity x time). Special versions of UV adhesives incorporate additives, such as isocyanate functionality, which cure by atmospheric moisture to solve those “shadow” areas where the UV radiation might not reach. One technique that I have seen used successfully is to cure the part in an enclosure that has mirrored surfaces. This way, the reflected UV light can often reach areas that direct radiation might miss.