Tougher than steel: Japan looks to wood pulp to make lighter auto parts

DaikyoNishikawa

14/08/2017 23:00

By Naomi Tajitsu and Maki Shiraki 
    KYOTO, Japan, Aug 15 (Reuters) - The global push among 
carmakers to make ever lighter vehicles is leading some auto 
suppliers in Japan to turn to what seems like an unlikely 
substitute for steel - wood. 
    Japanese researchers and auto component makers say a 
material made from wood pulp weighs just one fifth of steel and 
can be five times stronger. 
    The material - cellulose nanofibres - could become a viable 
alternative to steel in the decades ahead, they say, although it 
faces competition from carbon-based materials, and remains a 
long way from being commercially viable. 
    Reducing the weight of a vehicle will be critical as 
manufacturers move to bring electric cars into the mainstream. 
Batteries are an expensive but vital component, so a reduction 
in car weight will mean fewer batteries will be needed to power 
the vehicle, saving on costs. 
    "Lightweighting is a constant issue for us," said Masanori 
Matsushiro, a project manager overseeing body design at Toyota 
Motor Corp. 
    "But we also have to resolve the issue of high manufacturing 
costs before we see an increased use of new, lighter-weight 
materials in mass-volume cars." 
    Researchers at Kyoto University and major parts suppliers 
such as Denso Corp  6902.T , Toyota's biggest supplier, and 
DaikyoNishikawa Corp  4246.T , are working with plastics 
incorporated with cellulose nanofibres - made by breaking down 
wood pulp fibres into several hundredths of a micron (one 
thousandth of a millimetre). 
    Cellulose nanofibres have been used in a variety of products 
ranging from ink to transparent displays, but their potential 
use in cars has been enabled by the "Kyoto Process", under which 
chemically treated wood fibres are kneaded into plastics while 
simultaneously being broken down into nanofibres, slashing the 
cost of production to roughly one-fifth that of other processes. 
    "This is the lowest-cost, highest-performance application 
for cellulose nanofibres, and that's why we're focusing on its 
use in auto and aircraft parts," Kyoto University Professor 
Hiroaki Yano, who is leading the research, told Reuters in an 
interview. 
    The university, along with auto parts suppliers, are 
currently developing a prototype car using cellulose 
nanofibre-based parts to be completed in 2020. 
    "We've been using plastics as a replacement for steel, and 
we're hoping that cellulose nanofibres will widen the 
possibilities toward that goal," said Yukihiko Ishino, a 
spokesman at DaikyoNishikawa, which counts Toyota Motor Corp 
 7203.T  and Mazda Motor Corp  7261.T  among its customers. 
    Automakers are also using other lightweight substitutes. BMW 
uses carbon fibre reinforced polymers (CFRPs) for its i3 compact 
electric car as well as for its 7 series, while high-tensile 
steel and aluminium alloys are currently the most widely used 
lightweight options because they are cheaper and recyclable. 
     
    "SPRUCE GOOSE" 
    Yano said he was inspired in his research by a photo of the 
"Spruce Goose", a cargo plane made almost entirely of wood in 
1947 by U.S. billionaire entrepreneur Howard Hughes. At the 
time, it was the world's largest aircraft. 
    "I thought that if Howard Hughes could find a way to use 
wood to build a massive plane, why not use wood to make a 
material that was as strong as steel," he said. 
    The cost of mass producing a kilogramme of cellulose 
nanofibre is currently around 1,000 yen ($9). 
    Yano aims to halve that cost by 2030, which he says will 
make it an economically viable product, since it would be 
combined with plastic, and so competitive against high tensile 
steel and aluminium alloys, which currently cost around $2 per 
kg. 
    Industry experts anticipate that carbon fibre prices will 
fall to around $10 per kg by 2025. 
    Analysts say high-tensile steel and aluminium will be the 
more popular alternative for many years to come, considering 
parts makers would need to overhaul production lines and figure 
out ways to fasten new materials like cellulose nanofibre onto 
other car parts. 
    Anthony Vicari, an applied materials analyst at Lux Research 
in Boston, said it "would be a big deal" though if Yano's 
projections prove to be correct. 
    But for now, it remains "a very big 'if'", he said. 
 
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GRAPHIC: Outlook for lighter materials in vehicles    http://tmsnrt.rs/2hBjFII 
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 (Reporting by Naomi Tajitsu and Maki Shiraki: Additional 
reporting by Yuka Obayashi; Editing by Neil Fullick.) 
 ((naomi.tajitsu@thomsonreuters.com; +81364411078; Reuters 
Messaging: naomi.tajitsu.thomsonreuters.com@reuters.net)) 
 
Keywords: AUTOS JAPAN/WOOD