“Give us affordable carbon fiber!”
Guest columnist Dan Pichler, managing director of CarbConsult GmbH, suggests that the we need a sustained, cooperative effort in the carbon fiber supply chain. Partnering is the key.
#outofautoclave #windblades #autoclave
The market for carbon fiber has doubled in a decade but customers continue to say it’s too expensive. Having been a producer of carbon fiber — I count myself in that category, given my extensive experience in starting up and commissioning carbon fiber lines — I know we have the ability to influence the market’s future growth, keeping in mind that market segments are sending different messages, based on different needs.
In the aerospace and high-end sporting goods sectors, performance is the key, and customers will pay for that performance. In the industrial segment, however, which includes energy and automotive, the message is, “We want carbon, and a lot of it, but we don’t want to pay more than €10/kg.” Wind blade producers certainly recognize that carbon fiber can reduce total system cost. If blades can be made lighter, then other components can be made lighter as well, including the gearbox, tower and foundation, for a lower total system cost. Automakers, on the other hand, haven’t forgotten the “$5/lb” message originally put forth by Zsolt Rumy of Zoltek Corp. (St. Louis, MO, US) in the late 1990s. Further, automakers say they want “kilos today, kilos tomorrow, and 10,000 MT in five years.” How can we meet such expectations?
I believe we can do it by examining all the opportunities in the carbon fiber value chain closely. First, world oil production is currently around 27 billion barrels per year. That breaks down to about 90 million MT of propylene per year and 7 million MT/yr of acrylonitrile. From there, about 2 million MT goes into acrylic fiber production, of which a small percentage is made into the polyacrylonitrile (PAN) precursor that subsequently becomes from 50,000 to 75,000 MT of carbon fiber today. That’s a very small amount compared to the enormous volume of upstream oil production — in other words, our industry has no influence on raw material cost.
So what other aspects of the supply chain can we affect? PAN precursor accounts for the largest chunk of carbon fiber cost. Each producer pays roughly the same price for acrylonitrile, but its cost of PAN precursor can differ depending on infrastructure, scale, labor and utilities costs. The same situation exists for carbonization cost, where conversion ratios are roughly the same but there are some significant differences in scale and infrastructure, and regional differences in utilities and labor costs.
Overall, the cost of carbon fiber dropped — a lot — since the 1980s, and then leveled off after 2000, despite the fact that raw material cost has moved up and down with the price of oil. I believe the price drop was a function of the industry scaling up and each producer becoming more efficient. Additional carbon fiber cost reductions of 10-20% or more could come from further incremental improvements and/or efficiencies in equipment, scale, labor and energy use. Volume is your friend in carbon fiber: The considerable investment necessary to scale up capacity can be raised with strong development partners and long-term customer supply agreements. Incremental cost savings can be realized by improving delivery options, using a lower-cost finish oil, running a single fiber product, optimizing sizings and employing automation where practical in new lines to reduce touch labor.
In the automotive sector, we also can reduce the cost of carbon fiber intermediates, that is, prepregs and woven fabrics, by improving material purchasing efficiencies, using the right process to make the product, and, perhaps most importantly, increasing conversion rates to minimize waste.
The reality is that regardless of carbon fiber cost, converting it and producing auto parts is rather expensive. Using resin transfer molding (RTM), for example, is certainly an advantage over hand laid, autoclave-cured prepreg. I believe that the cost of making a carbon fiber auto part — today, in the range of €85/kg (US$92/ kg) — will be reduced by 70% or more through better part design, automated near-net processing at an optimized scale, fewer processing steps and consumables, and lower-cost resins. Winning processes likely will include high-pressure RTM and compression molding systems optimized for part types (structural, semi- structural or Class A surface). These have the potential to deliver high-volume serial production parts at a cost of €20-€25/kg (US$23-US$28/kg).
To make this happen, we need a sustained, cooperative effort among carbon fiber producers, resin suppliers, equipment designers and manufacturers, automation experts and automotive OEMs. Partnering is the key, and from our end — the carbon fiber suppliers and the composites industry — we need to produce consistent fiber supply and continue to optimize processes to achieve high-quality, repeatable parts in short cycle times. We can make PAN carbon fiber, and carbon fiber parts, affordable.
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