Changing the Auto Industry
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 is still 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 degrees Fahrenheit.
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 percent 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 carefully watched and managed. 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 significantly reduced carbon-fiber curing times to help speed up production. The presses also 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 first-of-their-kind pressure presses for a 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 directly heat the tool mold surface for faster heat transfer to the carbon fiber.
Once implemented, the proprietary pressure presses dramatically reduced curing time – from 90 minutes to less than 20 minutes. For the production of Class A, carbon-fiber, vehicle components, that’s among the fastest – if not the fastest – curing time in the world.
But 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 had no means of capturing and logging process data resulting in production personnel having no means of doing historical analysis of press cycles or identifying product issues with process data.
“Early on, the press process was highly variable, and we needed to straighten it out,” said 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. Their goal was to implement a software solution that could serialize and track each vehicle part going through the pressure presses, as well as record and report process parameters within the presses. The mission was to drive scrap down from the historical 10 percent autoclave levels down to below 4 percent. This change would result in millions of dollars of savings annually.
To accomplish this, they implemented the FactoryTalk® Historian Site Edition (SE) and FactoryTalk VantagePoint® EMI enterprise manufacturing intelligence software from Rockwell Automation.
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, overall equipment effectiveness (OEE) and more.
Reducing Scrap
With the ability to track parts and processes in its pressure presses, Plasan Carbon Composites has driven down scrap by more than 50 percent.
“There are so many variables to our process that it had seemed almost impossible to figure out,” McKinnon said. “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 better coordinate production. 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 improved insights available to plant personnel have been instrumental to helping the plant 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 unmanufacturable.
“Temperature changes can create dry lines of the individual carbon fibers, which greatly affects part quality,” McKinnon said. “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 said. “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.”
