Plasan Carbon Composites used manufacturing intelligence software and analytics to cut high scrap rates and increase production volume by 6% on its new pressure presses.
Behind the glory of being an innovator is the arduous process of being the first to figure out how to deliver something new. Michigan-based Plasan Carbon Composites knows this firsthand as a supplier of carbon-fiber components for the automotive industry.
Carbon fiber has been around for decades but still is relatively new to mass automotive production. It is a composite material created from a base of plastics that are mixed, spun into fibers and carbonized through a heating process that can exceed 5,000°F.
Carbon fiber’s lightweight and high-strength characteristics have proven crucial to improving a range of advanced applications, from creating higher-performing wind-turbine blades to producing commercial aircraft that are 20% lighter than conventional, aluminum-based designs. Applied to automotive vehicles, carbon fiber can deliver savings in vehicle mass and gas mileage.
However, bringing carbon fiber to the automotive market has significant challenges. The raw material is expensive. During production, the curing process can be time-consuming, and environmental conditions must be watched and managed carefully. Additionally, scrap often cannot be reused or recycled. As a result, carbon fiber’s use in the auto industry has largely been limited to high-end, low-volume performance vehicles.
Only through continued maturing and refinement of carbon-fiber production processes will the material become feasible for higher-volume auto production. When that time comes, the potential for the automotive market is enormous. Lux Research estimates that, after 2020, “the onset of mainstream adoption in automotive will drive volumes that will dwarf other industries.”
Plasan Carbon Composites is helping lead this charge toward higher adoption. The company already produces carbon-fiber components such as hoods, roofs and side panels for popular performance vehicles, such as the Chevrolet Corvette, Dodge Viper and Ford Mustang. The company is using a mix of research and development, proactive development of engineered solutions and automated manufacturing processes to pioneer the mass production of carbon fiber.
Recently, Plasan Carbon Composites deployed its new pressure presses. This technology reduced carbon-fiber curing times significantly to help speed production. However, the presses introduced operational challenges, including higher than expected quality issues and scrap levels.
A Game-Changing New Process
Traditionally, large pressure vessels known as autoclaves have been used for curing carbon fiber. But their cycle times can be as long as 90 minutes, making them too inefficient to meet Plasan Carbon Composites’ growing production targets for vehicles like the Corvette Stingray.
As a result, the company deployed novel pressure presses at its new 200,000-square-foot production facility outside Grand Rapids, Michigan in 2012. The high-speed presses abandon the convection mass heating process used in autoclaves and instead use proprietary technology to heat the tool mold surface directly for faster heat transfer to the carbon fiber.
Once implemented, the proprietary pressure presses reduced curing time dramatically — from 90 minutes to less than 20 minutes. However, the launch was not without its challenges. The pressure presses introduced a number of new and complex process variables not associated with autoclave technology. With all the variability, the presses were unable to capture and log process data resulting in production personnel having no historical analysis of press cycles or ability to identify product issues with process data.
“Early on, the press process was highly variable, and we needed to straighten it out,” says Danny McKinnon, controls engineer for Plasan Carbon Composites. “My biggest challenge was being blind to what was happening on the off shifts. I couldn’t see what happened, and that limited my ability to troubleshoot and resolve issues.”
The challenges in the pressure presses led to a higher than expected production of scrap and quality defects within the parts. This slowed down production and created significant production losses, with scrap carbon-fiber components costing the company capacity and causing delivery issues.
A Retrospective Perspective
To get a better handle on quality issues in the pressure-press operations, Plasan Carbon Composites enlisted the support of Rockwell Automation. Plasan wanted to implement a software solution that could serialize and track each vehicle part going through the pressure presses, and record and report process parameters.
The mission was to drive scrap down from the historical 10% autoclave levels to below 4%. This change would result in millions of dollars in savings annually.
The FactoryTalk Historian SE software captures critical process variables as each product is sent through any of the facility’s seven pressure presses. Using a serial number created for each product by the Plasan manufacturing execution system (MES), the historian associates the process data to each part. The VantagePoint EMI software uses this information to deliver real-time quality and performance dashboards and Microsoft Excel®-based production reports.
McKinnon and others on the process and quality teams can use these capabilities to monitor products and 15 different pressure-press process settings. If a quality issue arises, they can go back and review the process settings to investigate and remedy potential issues. Additionally, operations personnel can use daily production reports for each pressure press to review key metrics, such as average cycle times and overall equipment effectiveness (OEE).
With the ability to track parts and processes in its pressure presses, Plasan has driven down scrap by more than 50%.
“There are so many variables to our process that it had seemed almost impossible to figure out,” McKinnon says. “The historian software helped our team track each variable to finally see a pattern as to why we were getting scrap parts. It’s greatly reduced our scrap in the press room and is setting a new standard for quality in our plant.”
In addition to better understanding issues in the pressure press, operators also are using the software to improve production coordination. They can review product cycle times to understand exactly how long parts should be in the presses and then use this information to set up schedules and staffing to meet daily throughput targets.
To date, more than 70,000 carbon-fiber vehicle parts have been serialized and stored since implementing the software. The insights available to plant personnel have been instrumental to helping produce more than 400 carbon-fiber vehicle components every day.
The company also is in the process of extending the benefits of the historian software to other areas of production. For example, the software is being used to track temperature and humidity in the plant. The carbon-fiber raw material must be kept cool and within specific temperature and moisture ranges. If these variables are not managed, the material can begin to dry out and become unusable.
“Temperature changes can create dry lines of the individual carbon fibers, which greatly affects part quality,” McKinnon says. “We then have to address these imperfections in our finishing area by dremeling out the dry lines and filling them back in, which is a long and tedious process. This is just another area where the historian software can help us refine our processes and drive up quality.”
For McKinnon, these additional uses for the software have been a bonus. “I initially wanted a historian solely so I could look at last night’s cycles to see what happened,” he says. “I wasn’t even thinking about what else historical analysis could do for us. But getting our hands on it and exploring its different uses has opened my eyes to what we can really do.”
The Journal From Rockwell Automation and Our PartnerNetwork™ is published by Putman Media, Inc.