Solar Shingle Dispensing, Simplified

Case Summary

Installing solar energy systems at home offers numerous benefits, such as reducing utility bills, boosting property value and promoting sustainability. However, conventional solar panels often appear bulky and unsightly on residential properties. In response to the growing demand for aesthetically pleasing residential solar power solutions, manufacturers worldwide are enhancing the design and functionality of solar panels. GP Reeves collaborated with a manufacturer to develop solar panels that resemble standard roofing shingles. These innovative panels can generate energy from any light source, with direct sunlight being the most efficient.

As our customer’s production capacity increased, their existing material application process began to create a bottleneck, impacting overall efficiency. To address this challenge, we developed and implemented an automated RTV (room temperature vulcanizing) material dispensing system, seamlessly integrating it into their existing assembly line.

The Problem

The customer’s solar shingles were designed to seamlessly integrate with the roof’s style, making the appearance and integrity of each unit a major concern for the manufacturer. Each solar shingle featured tabs for connecting the electrical components, mounting brackets for attaching them to the roof, and a junction box to protect the tabs and electrical components from environmental exposure.

RTV was used to seal two key components to the solar shingle: the junction box and the mounting bracket. In their previous process, the junction box or bracket was loaded into an offline fixture for material dispensing. Following this, a jig was used to manually place the components onto the shingle. This manual step introduced the potential for human error, increasing the likelihood of smeared RTV material on the components. Incorrect material placement could compromise the seal, leading to potential water leaks and, in turn, damage to the panel or even equipment failure.

The Challenge

Working with RTV presents unique challenges due to its material properties. RTV is thick and has a relatively fast cure time, forming a strong bond upon application. Consequently, our system needed to operate with both speed and precision. The viscosity of thick materials often necessitates higher pressures for movement, so our equipment had to handle the required pressure and curing characteristics effectively.

Our task involved integrating our system into an existing conveyor line. The customer previously utilized a standalone gantry dispense system that did not scale well for production. The complexity of this transition required extensive collaboration, which is one of our core strengths. We coordinated with multiple groups globally, as manufacturing takes place in the USA, while the company’s headquarters and the conveyor manufacturer are located overseas.

The Solution

The customer initially intended to integrate their offline system into the new assembly process. However, we proposed an alternative approach that had not been previously considered. Our vision was to develop a completely automated system that would not only apply RTV directly to the shingle but also detect and address broken or misaligned tabs that could compromise the unit’s quality.

In the enhanced process, a shingle moves along the conveyor to our automated dispensing cell, which is equipped with a vision system. This system identifies the data marking on the panel to verify its location, accounting for slight positional variations between cycles. It then inspects the two tabs on the panel to ensure they are correctly positioned and aligned for the junction box attachment. If the system detects any potential issues, it sends an error signal, allowing for immediate corrective action.

After confirming the positioning of the panel and tabs, the robot uses information captured by the vision system to determine the precise dispense locations. The robot then dispenses RTV in two specific areas on the shingle: around the tabs to seal the junction box and along a path to attach the mounting bracket.

Given the properties of RTV, it is essential to use equipment capable of handling its characteristics. We utilize AA7 Servo Dispensers to manage the material volume while maintaining the moisture-cure RTV in an airtight environment. An ACED Dispense Valve is employed to accommodate the thicker material with minimal restriction and ensure a robust flow, facilitated by a Teflon-braided stainless-steel hose designed for high working pressure. A total of 8.5 ccs of material is dispensed in the paths for both the brackets and the junction box. Once the dispensing process is complete, the conveyor is signaled, allowing the panel to move on, and the dispense cell prepares for the next shingle in the sequence.