Practical testing for a productive process
01 July 2021
Up front evaluation of the performance of materials & equipment for a manufacturing process to establish how they will perform in the real world can greatly reduce the risk of problems later down the line.
The full version of this article was originally featured in the July 2021 issue of EPDT magazine [read the digital issue]. And sign up to receive your own copy each month.
One of the stepping stones to productivity is a simple, efficient and error-free process when first setting up production. Here Kevin Cook, Technical Manager at adhesives specialist, Intertronics discusses how practical testing can help give electronics manufacturers confidence when investing in an adhesives process.
Considered evaluations and pre-production methods mean businesses can start full manufacturing with more confidence and less risk. Though the adhesive or equipment manufacturer will have done extensive testing to determine the basic datasheet parameters, it is vital to evaluate products in a real-world application, ideally on production parts, so manufacturers can be sure that they function adequately on their unique assemblies. Part of the practical evaluation process in selecting an adhesive, and the accompanying application and curing technology, will be understanding overall process costs; often, these costs outweigh material costs on a per part basis. Choosing a process where costs are optimised will impact on the overall economic calculation for the assembly, the associated return on investment (ROI) estimate, and ultimately the investment decision.
While product datasheets are a useful way of shortlisting adhesives and other materials to test, we do not recommend selection based on the datasheet alone. Published product parameters are usually determined from laboratory testing or under ideal circumstances. It is important to verify that the expected performance is achievable on the intended parts, with their particular surfaces and geometries, as well as in the proposed use environment.
The datasheet will not answer every question the user has; for example, the list of which substrates it can bond may not be exhaustive. An experienced adhesives supplier will have a wealth of knowledge from real world applications to help you interpret and understand the datasheet in practical terms. Nevertheless, this is still no substitute for testing. The evaluation process translates the datasheet onto your real-life application.
Always a compromise, never perfect
It is important to remember that, when evaluating a material, there is no such thing as the perfect adhesive — there will always be some level of compromise. Often, this revolves around ultimate functionality versus practical processability. Over-specifying parameters like operating temperature range or solvent resistance will limit adhesive choice, and potentially add to costs. Keeping this in mind will ensure that the test results are interpreted pragmatically, and that an unachievable standard is not being pursued. The evaluation should take a holistic approach, with an understanding of which selection factors are set in stone, and which can have their tolerances widened in order to arrive at a dependable product which can be used efficiently and at an appropriate cost.
Practical testing can establish that the assembled part can withstand whatever environmental conditions it will be operating in. Environmental testing involves subjecting the finished product to the conditions it will likely face in its lifetime to see how it performs, when exposed to the relevant humidity and temperature extremes and changes.
Testing will confirm that the chosen bonding methodology will meet the requirements of the assembly and production line in terms of accuracy and repeatability, meeting quality and productivity needs. Examples include the measurement of a number of deposited shot sizes from proposed equipment, using statistical analysis to confirm the required precision; the assessment of a UV curing function to ensure that it complies with the overall takt time; or the determination of the minimum and maximum adhesive quantities in a bond, which still produce the required strength...
Read the full article in EPDT's July 2021 digital issue...
Contact Details and Archive...