Kevin Cook of Intertronics offers MachineBuilding.net a view on processes involving adhesives to improve productivity
Manufacturing output reached a record low in April 2020 amid the pandemic. There was a significant improvement in May, but there is still a difficult path ahead. During lockdown, the pressure on manufacturing companies mounted, and now things are back up and running, businesses are looking for ways to use their people and their equipment to be as competitive as possible in challenging markets.
For many British manufacturers, improving productivity is about giving employees the means to do their jobs productively — it is not always simply about speed, but often about improving accuracy, consistency, yield and material usage. In a bonding or coating process, many of these improvements can be achieved with dispensing and application equipment.
The first steps to process improvement
There is no one-size-fits-all method for adhesives application process improvement — our recommendation would ultimately depend on your process, and what you are trying to achieve. A good understanding of the adhesives process and what the pain points are is key and, for many companies, a Six Sigma approach is a starting point. This measurement-based methodology provides a framework to improve processes, by identifying causes of defects and coming up with methods to eliminate them. Even if not in a Six Sigma environment, companies can identify specific areas for improvement — it may be that production times are slow, work in progress is high, process control is poor, or results are unpredictable. Once identified, the manufacturer should take steps to overcome each specific issue.
Upgrading manual processes
Improving productivity may be as simple as buying a simple time-pressure dispenser to help with a manual process. For example, an operator may experience issues with physical strain or discomfort while manually dispensing viscous liquids like silicones. Switching to a pneumatic-driven machine would lead to an immediate increase in productivity, as the operator works more steadily and efficiently, and the risk of repetitive strain injury (RSI) is mitigated.
If a manufacturer is experiencing problems with consistency, either with an individual operator or between operators, it may be that the application can be replicated using a small benchtop robot. The programming might copy the operator’s methodology, since she/he may very well have naturally developed the most efficient system, but a robot will take out the operator variability, remove human error and will often be quicker. It is also possible to combine multiple processes using a robot, for example dispensing and curing, or dispensing on an array of parts so that larger batches can be produced more quickly. The operator’s skills can be redeployed into tasks that cannot easily be automated and ones that add more value.
One successful example is our work with GJD Manufacturing, a motion detection system manufacturer, whose manual silicone dispensing process was time-consuming, ergonomically unsatisfactory and resulted in material waste and clean ups. The company purchased a Fisnar Dispensing Robot with a pneumatic dispensing valve fed from a cartridge, which substantially improved efficiency. GJD then opted for further process improvement by upgrading to a preeflow ecoPEN 600 precision volumetric positive displacement pump, which offers >99% repeatability and ±1% accuracy.
It is important to remember that automation is not always the answer — a process needs to balance. Opting to automate part of a process without a clear understanding of the bigger picture could increase work in progress.
Manufacturers who mix multiple materials together may find that manual mixing is another source of inconsistency and process woe. Switching from a manual process to a mixing machine like Thinky Mixer can improve mix uniformity as well as save time. For example, using it to evenly disperse epoxy resin, hardener and aluminium powder before application, or to mix ingredients for cosmetic products.
If there is an issue with poor adhesion resulting in a high reject rate and a lower number of saleable products, it may be possible to improve productivity with surface treatment prior to bonding. Plasma pre-treatment, for example, improves the surface’s wettability, which can increase adhesion and ultimate bond strength, and therefore increase the number of QA passed products going out of the door. Plasma surface treatment is an easy process to automate, so it can help to improve production efficiency if replacing an existing pre-treatment process, and potentially remove a wet chemical process.
Process friendly packaging
Manufacturers can purchase material in a range of containers, from very small syringes to large pails. Package size availability and selection are contributory factors, with the need to balance shelf life, batch sizes, handleability, and so on. The type of container can help optimise your dispensing process and reduce material waste. Single part materials supplied degassed in dispenser-friendly syringes or cartridges can add to accuracy and line efficiency, as well as chemical handling. Purchasing in bulk containers can reduce material costs, but can add challenges to the dispensing process. Material can be supplied in specialised packaging, such as pre mixed and frozen in syringes, to add process simplicity when working with two-part materials.
Now is a better time than ever to think about improving your productivity, as the manufacturing landscape experiences some significant changes. Small improvements to a process can have a big impact on yield, speed and waste. For best results, manufacturers should work closely with an experienced adhesives and dispensing equipment supplier, who can determine the appropriate equipment for what you are trying to achieve, as well as install, configure, and customise it, as well as provide the training you need to optimise its use and get a quick return on your investment.