Dispensing Automation Helps Defense Manufacturer Reduce Epoxy Bonding Time by 65%, Eliminating Cleanup Time

Success Story: L3Harris Embraces Automated Fluid Dispensing for Night Vision Goggles

Two-part epoxy is the modern manufacturer’s resin of choice. Thanks to its high strength, versatility, and excellent adhesion to a variety of surfaces, epoxy resins have gained wide acceptance in diverse applications — including coatings, electrical, casting resins, composites, etc. Despite the many advantages of this resin, working with epoxy is known to have some intrinsic challenges.

Operator Fatigue, Costly Cleanup, and Rework

For defense manufacturer L3Harris Technologies in Londonderry, NH, manual epoxy and room-temperature curing applications were creating waste and variance in many of their defense production operations. That’s because these processes were time consuming and created operator fatigue. Workers faced challenges from an epoxy pot life of 30 minutes to an exceedingly small difference between applying too little epoxy or too much epoxy to the product. As a result, the organization faced costly cleanup and rework with their hand-operated production process.

L3Harris builds sophisticated night vision goggles. The manufacturing process requires that multiple components are bonded inside the product. To achieve this, the company uses a two-part epoxy with a thermal curing mechanism to bond the parts together.

Operators needed to fill syringes, and then manually dispense the epoxy onto various components. With a working time of just 45 minutes, the epoxy viscosity increased over time, requiring pressure changes on fluid dispensers. In addition, the tolerances for dispensing epoxy beads were exacting.

Process Goals

L3Harris had been assembling night vision goggles using hand processes since the company started manufacturing the product. As the organization explored automated fluid dispensing technologies, the company set manufacturing goals for an automated fluid dispensing system. The company was seeking a faster application process, and to increase production efficiency. Also, they wanted to increase fluid dispensing accuracy, and improve application quality. Management wanted to automate the RTV dispensing and control the amount of RTV being dispensed to minimize the squeeze-out. Lastly, the organization desired a new fluid dispensing approach that would eliminate time-consuming fluid clean up and costly rework.

Seeking a more efficient, cost-effective solution, L3Harris Manufacturing Lead Lou Veiga approached Nordson EFD for solutions to the night vision goggles processing challenges.

Having collected extensive data from L3Harris about their processes, fluid specifications, and applications, the engineering services team at Nordson EFD swung into action. In the company’s East Providence, Rhode Island testing facilities, the team verified adhesive fluids, material substrates, and assessed automated fluid dispensing solutions. The time and energy invested at this phase of the process ensured that the client had a smooth technology adoption path as they upgraded their fluid dispensing process.

Recommendations

After evaluating the data, Nordson EFD recommended an automated dispensing process and, where the manufacturing goals warranted it, an integrated vision system. The Nordson EFD engineers focused on three technologies to meet L3Harris’ production goals. First, to resolve the challenges facing the two-part epoxy adhesive dispensing process, Nordson EFD recommended using two 797PCP-2K pumps with an E3V series robot. Second, for the one component RTV, the company recommended using one 797PCP pump on a 3-axis robot. To address precise fluid dispensing tolerances, Nordson EFD recommended employing the E4V automated dispensing solution with a simple vision pencil camera.

The 3-axis EV Series dispensing robots, with fully integrated simple vision systems and DispenseMotion software, provided vision-based programming and other standard features such as DXF import, part presence/absence, and wrong part identification.

Intuitive dispensing software integrated with the inexpensive pencil camera allowed users to program complex dispense patterns and arrays with high repeatability up to ± 8 µm (0.008 mm). The EV Series met L3Harris’ application requirements. The vision system ensured that components were in the right place and validated the parts were in alignment. The vision system would not allow dispensing fluids if it did not see the correct part in the proper location.

L3Harris Technologies started their automated dispensing system process enhancement with applications that were causing a high rate of operator fallout due to problems with the manual processes. Anything that was causing scrap and rework was scrutinized. With that in mind, L3Harris selected production lines with larger volumes because they would provide a faster return on investment, rapidly justifying the investment in a new production system.

65% Reduction in Process Time, Eliminates Cleanup, and Rework

In quick order the benefit of the automated dispensing approach became apparent. The new equipment reduced the 2K epoxy dispensing step by an average of 65%, and nearly eliminated the cleanup time for this process. It improved throughput time, plus the repeatable, high-quality epoxy application benefitted the manufacturing process. Specifically for the epoxy process, the automatic dispense system was configured to use the exact amount of fluid for each specific step and mixed the two-part epoxy in real time. This capability reduced waste. The Nordson EFD system also used a vision system to self-align the automated dispense system for predetermined tasks. This level of accuracy served to reduce the need for cleanup and prevented defects.

Mr. Veiga selected the Nordson EFD system primarily because of its software capabilities. L3Harris executives were impressed with the universality of the software package, enabling their staff to easily learn and use the automated systems. The software made it easy for L3Harris to program new applications, while maintaining repeatability and improving throughput time in the process. The automation benefitted the workers because it replaced the repetitive process requiring good fine motor skills. L3Harris Environment, Safety and Health manager Dave Collins noted that the Nordson EFD system scored highly on the ergonomics scale, as it replaced tedious manual tasks. In addition, the automated dispense system eliminated extended periods of seated bench work, as using hand dispensing tools while holding parts or fixturing to apply bonds is no longer necessary.

L3Harris considers the Nordson EFD automated dispense system an engineering best practice. They say that the new equipment allows for a better work experience for assemblers and operators, too. Within the organization, the fluid dispensing system has been highlighted as a successful case study about the process improvements possible from using an automated fluid dispensing system.

If you have any questions about how to improve your dispensing process, don’t hesitate to email us at [email protected].

About Claude Bergeron

Claude Bergeron is the Senior Global Product Line Manager of Jetting Systems at Nordson EFD. He uses his extensive application and product knowledge to lead the development of some of the most innovative dispensing valves on the market. Claude has more than 40 years of fluid dispensing experience. He joined Nordson EFD in 1981.