EN
With precision manufacturing, lack of consistency is the enemy of quality. The uniformity of the application process is what makes the sealing of an electrical enclosure, bonding of an automotive battery cover or installation of a gasket on an air filter reliable. Manual dispensing is a very variable process, prone to human fatigue, hand wobbling and judgement errors. That is where glue dispensing equipment come in, changing the way bonding is done by ensuring a repeatable, accurate and consistent result with each and every cycle. We have worked with more than 20 years of experience to develop this technology to assist manufacturers from over 60 countries in getting to perfection for the consistency.
The Challenge of Manual Dispensing
It is important to realise the benefits of automation before the understanding of the limitations of manual application. If sealant or glue is applied manually using a worker, the amount of material applied will vary as a result of the squeeze pressure and the speed of the worker's hand. The width of the path is not consistent; the beginning and end of the path can create a gap or overfill.
This is even scarier for industries employing two part polyurethane (PU) materials. A wide range of resin to hardener ratio can cause the seal to not cure completely, or it can become brittle and crack when shaken. Manual processes do not have real-time feedback to ensure an accurate A:B ratio, resulting in reworked parts and material waste. The automated glue dispensing equipment overcomes these variables by controlling output to the milliliter by using servo-driven glue pumps and flow meters.
How Automation Ensures Unwavering Precision
Automated dispensing systems use a mixture of hardware and software to ensure that all bonded parts are the same. It is usually fitted with a programmable controller, a positive displacement pump (typically a gear or piston pump), and a motion platform, which is typically a 6-axis robot.
Closed loop flow control is the major way to ensure consistency. Unlike an open-loop system, which uses only air pressure, the flow of material that comes out of the nozzle is measured with computer-controlled glue dispensing equipment and adjusted in real time to the speed of the pump. The system adjusts automatically to compensate for any changes in the material viscosity caused by temperature changes (typical of PU resins).
Moreover, the work piece is at a constant standoff distance from the nozzle, thanks to the robotic path planning. When it comes to the gasket height of parts such as inner door handles on automobiles, or housings for LED luminaires, it is important that the height be the same throughout for a good IP67 waterproofing rating. Combined with our patented mixing heads, KAIWEI's six-axis manipulator systems are capable of delivering the sealant with a complex 3D path without deviation, placing the sealant within a millimeter of the CAD file definition.
Eliminating Waste and Reducing Rejection Rates
Financial benefits are realized in the consistency of bonding. With strict control on the amount of glue dispensed there is no over-application (saving waste of expensive glue) and no under-application (preventing leaks and failures). One of the significant benefits of automated glue dispensing systems is that they can significantly reduce a manufacturer's waste rate.
Furthermore, programs for various products can be saved and recalled as needed, significantly reducing set-up time. The operator changes from a sealing refrigeration door to a transformer cover by clicking on the pre-saved program. The equipment automatically optimizes the dosage amount, robot speed and material temperature, thus guaranteeing the same quality bonding consistency from production to production and shift to shift. This is especially useful to manufacturers who have a variety of product lines.
Conclusion
To truly achieve consistency in component bonding, it is not about training the operators to become robots, it's about introducing the appropriate robotic tools. Manual glue dispensing methods are not capable of providing the precision, repeatability and control that automated glue dispensing machines can. Manufacturers can gain a competitive advantage by providing accurate mix ratios, consistent bead geometry and perfect path tracing, which adds to the product quality, lower material costs and perfect reliability. At KAIWEI, our intelligent sealing solutions are engineered to achieve this performance and meet the technology demands of our global partners to compete in the smart manufacturing era.
