EDITOR ’ S CHOICE ROI ON A UV BONDING PROJECT
INTERTRONICS
The considerations for establishing ROI in a UV bonding process
Light curable adhesives have applications in the assembly of products in medical devices , automotive , aerospace , consumer electronics , appliances and more . The materials provide a way to reduce costs without sacrificing product quality . Once you have established criteria for performance and the application requirements to determine if a UV curing material might be suitable for your application , there are multiple considerations to get the best out of your investment . Here Simon Gibbs , Product Specialist at adhesives supplier Intertronics , shares insight on achieving return on investment ( ROI ) from a UV curing process .
When designing a UV curing process , it is critical that you understand both the process and how it can deliver on your objectives , so that you can choose a material and equipment that meets your requirements . It is typical practice to narrow down the adhesive choice first , and then pair your material with a curing lamp with the correct spectral output , intensity and size . A robust process also requires comprehensive testing to prove process capability and ensure that the parts of the system work optimally together .
There are several factors governing the ROI of a UV curing investment , including financial , environmental , materials , resources , quality and process considerations . UV curing equipment may be a larger upfront investment than other available technology , so it is important to understand the process and how you may be able to achieve financial savings over time .
ENHANCING QUALITY AND MINIMISING RISK
UV curing materials offer good toughness , durability , shock and moisture resistance and structural integrity . As well as the properties of the adhesive , potential quality benefits can come from the UV curing process , which has characteristics that enable manufacturers to reduce chances of defects due to improper dispense or cure . Firstly , UV curable materials cure on demand in seconds . Manufacturers can therefore control the process so that cure is only initiated when the substrates are correctly positioned .
UV curing materials can easily be combined with technology that makes in line inspection easy , such as See-Cure technology , which changes colour once the material has cured , building a visible safety factor into the assembly process . This can be further combined with Ultra Red™ fluorescence technology to streamline post-cure bondline inspection . This technology means the adhesive remains clear until exposed to low-intensity black light , at which point it fluoresces bright red , particularly useful when bonding plastics that naturally fluoresce blue .
UV curing materials offer good toughness , durability , shock and moisture resistance and structural integrity .
The potential improvement in yield and ability to identify and remove defective products can help deliver a good ROI , although it is difficult to quantify the confidence and subsequent reputation gained by both you and your customers when you consistently deliver high-quality products .
REDUCING COSTS
The ability to achieve a near-instant light cure means manufacturers can increase their production rates and reduce labour costs . Compared with that of a two-part material , the process can be simpler . For two-part products , the extended cure time will require more fixtures and space in the factory . A thermal cure may be required to speed up the process and reduce WIP , with the extra energy of an oven and load / unload overhead . The working life of the mixed two-part product needs to be managed to prevent excess waste or application equipment blockage .
UV curing adhesives may present inherent material savings when the process and waste is taken into consideration . For example , leading adhesive-manufacturer Dymax compared the cost of a UV curing adhesive with a two-part , urethane adhesive that had a lower cost per gram . Once the higher material usage , as a result of purging , improper mixing and general waste in the mixing system , was considered , the material cost benefit for the two-part material vanished .
UV curing adhesives are 100 % solids , include no solvent carrier and produce no volatile fumes ; usually , there is no requirement for special venting in the facility .
IMPROVING EFFICIENCY AND PRODUCTIVITY
UV curing adhesives provide fast cure times that enable shorter cycle times and reduced work in progress . Their small process footprint means space can be freed up for other tasks — there is no racking or heating required , saving time and floor space .
UV curing processes are well suited to automation , meaning the manufacturer can benefit from the typical automation benefits such as improved repeatability and precision , and the fact that robots do not get tired or need breaks .
TWO DIFFERENT UV TECHNOLOGIES
Part of the ROI calculation will be the cost of a UV curing lamp . For optimal results and to get the full benefits of the technology , an industrial unit with the correct output is required . It is always a false economy to use UV sources which do not meet a minimum recommended intensity or output non-optimal wavelengths — incomplete cure being the most obvious result . A good supplier will work with you to choose and evaluate appropriate curing equipment .
There are two types of UV curing lamp , based on fundamentally different technologies . The traditional light source used during UV curing is a mercury-based arc lamp , which emits broad spectrum light .
28 PECM Issue 51