Automotive Weight Reduction Expo 2013 (Report 2)

CFRP and other plastics improve weight reduction



 Below is the second part of the report on the technologies exhibited at the Weight Reduction Expo held January 16-18, 2013, in Tokyo. Report 2 focuses on the use of carbon fiber reinforced plastics and other plastics for weight reduction.

Related report: Automotive Weight Reduction Expo 2013 (Report 1): 3D additive manufacturing and lightweight metal use (posted February 2013)

* Click on the photo for a larger image.

Carbon fiber reinforced plastics (CFRP)

 Toray Industries, Inc. exhibited three automotive body components in which its CFRP (carbon fiber reinforced plastics) was used; the hood on the Lexus LFA, the roof on the Subaru Impreza WRX STI tS, and the trunk lid on the Mercedes-Benz SL 63. Toray also introduced Torayca Pellet containing thermoplastic resin, a material that is more easily moldable for making a broad range of products, compared to the conventional CFRP made of thermosetting resins.

 Mitsubishi Chemical Holdings exhibited the EV concept, APTSIS.

CFRP components exhibited by Toray CFRP components exhibited by Toray; hood on Toyota Lexus LFA (left), carbon roof on the Subaru Impreza WRX STI tS (center), and trunk lid on the Mercedes-Benz SL (right)

APTSIS EV concept "APTSIS" (with CFRP-made chassis) exhibited by Mitsubishi Chemical Holdings

Sheet frame bracket on Yamaha YZF-R1 Sheet frame bracket on Yamaha YZF-R1 using long filament carbon fibers of Toray's Torayca Pellet

Resin-made gears, PPS-CF and PA66-CF Resin-made gears, PPS-CF and PA66-CF, enhanced with short filament carbon fibers, exhibited by Toray

Carbon Fiber Reinforced Plastics (CFRP)

CFRP body and outer panels made of thermosetting resins
Toray Hood on Lexus LFA  CFRP-made hood used on Toyota Lexus LFA. Toyota ended in December 2012 the limited production of LFA after producing 500 units, but the technology acquired in the process of development and production, especially the production know-how of the CFRP components, will be inherited to a broad range of Lexus models.
Carbon roof on WRX STI tS  Limited production and sales of 400 units of Subaru Impreza WRX STI tS by Fuji Heavy Industries began in December 2010. Toray exhibited its roof made of carbon fiber composite material, jointly developed by Toray and Fuji Heavy, which contributed to reducing the vehicle weight, lowering the center of gravity, and increasing the steering stability.
Trunk lid on Mercedes-Benz SL  Toray exhibited the CFRP-made trunk lid used on Mercedes-Benz SL 63 (launched in 2012). In June 2011, Toray and Daimler jointly established a company, Euro Advanced Carbon Fiber Composites, dedicated to the manufacturing and sales of automotive components made of composite CFRP material.
Mitsubishi Chemical Holdings Corporation EV Concept APTSIS  "APTSIS" is an acronym for Mitsubishi Chemical Holdings' business mottoes, "Agility, Principle, Transparency, Sense of Survival, Internationalization, Safety, Security and Sustainability." It is the name of the concept car exhibited by the group.
 The concept car assumes generous use of components built by the group's cutting-edge technologies such as the CFRP chassis, organic thin film solar panels on the roof (to supply electric energy while the engine is inactive with the start/stop system), PC glazing (substitute for glass), the body formed by low linear expansion resin, underbody shield and LED illumination.
Application to racing bikes
KODAKA SEIMITSU Front-wheel shaft for bike  Kodaka Seimitsu, a CFRP manufacturer, exhibited the CFRP-made front-wheel shaft manufactured and supplied by KYB for Honda's downhill racing mountain bike.
 Kodaka Seimitsu also exhibited the CFRP-made front-wheel shaft delivered by Showa Corporation for Honda's road-racing bike. Aluminum is used in the shaft's inner surface and part of the outer surface to reduce costs.
Torayca Pellet containing thermoplastic resins
TORAY Sheet frame bracket for motorcycles (long-filament type)  Toray exhibited a carbon fiber thermoplastic resin, Torayca Pellet, said to contribute to weight reduction and that may be used to make cases for electric components because of the outstanding radio shielding characteristics. The material is available in long-filament and short-filament types.
 The long-filament type contains 10 to 30% carbon fiber and has high strength, impact resistance and flexural capacity. Toray exhibited the sheet frame bracket, made from the long-filament Torayca Pellet, used in Yamaha motorcycles (YZF-R1, 998cc engine).
Resin gear (short-filament type)  Toray exhibited resin gears made of the short-filament type of the company's thermoplastic CFRP. The gears are made of polyphenylene sulfide (PPS) and PA (nylon) 66 containing 8 to 30% reinforcing carbon woven in matrix state. According to the exhibitor, the plastic gears exert less risk of damaging the mating gear.



High-performance resins

 Victrex (headquartered in the U.K.) exhibited high-performance resins that are used in a broad range of automotive components. Igus (a German corporation) and BNL (a U.K. corporation) exhibited plastic bearings.

Plastic slide bearings exhibited by Igus Plastic slide bearings exhibited by igus

High-performance resins

Victrex High-performance resins  Victrex manufactures high-performance resins including Victrex PEEK. The company has its head office and production base in the U.K. and operations in more than 30 countries.
 The company exhibited the bearing retainers for PHV, guide rings for brakes (ESC), rod seals for ABS, ring seals for ABS/ESC, thrust washers for transmissions, etc. Among the exhibited components, 70 to 80% are CF-reinforced and display blackish appearance.
Impellers for turbochargers  Victrex exhibited the impellers for turbochargers. According to the company, the use of the high performance resins not only increases functionality and the freedom of moldability compared to the conventional metal-made components but also contributes to cost reduction from volume production.
 The conventional metal parts cost less in material but require extra labor and cost for cutting and other machining processes that lead to cost variation. The resins developed by Victrex are expensive in terms of material cost but require no additional processing. This makes them affordable in large-scale production once initial investments are paid up for.
Plastic bearings
igus Plastic slide bearings  Igus, a German manufacturer of plastic bearings, has been producing and selling plastic bearings since 1983. In Japan, the company has a production site in Tochigi Prefecture and has warehousing and assembly sites in several locations.
 Igus has developed a high-performance polymer "iglidur" that consists of base polymers, fillers and solid lubricants. The company produces and sells iglidur-made slide bearings. Unlike the conventional metal bearings, they do not require lubricants and their low coefficient of friction allows extended use while the high thermal conductivity ensures faster heat dissipation.
 The material is used in making a broad range of automotive components such as seats, pedals, steering, throttle body, hinge systems and wipers.
 In 2007, igus launched "xiros" ball bearings made of high-performance polymers called "xirodur." This material is used in medical, pharmaceutical and textile industries but is currently considered unfit for automotive use because of the relatively low durability and other properties.
BNL Plastic bearings  BNL, a British corporation, has been making plastic bearings for more than 40 years. Headquartered in the U.K., BNL has production sites in the U.K., U.S. and Thailand (since 2008). Plastic bearings deliver several benefits that include weight reduction, freedom of design, small rotational torques, ease of assembling and cost reduction.
 Since plastics are smooth material and slide easily, plastic bearings do not require lubrication as do the steel-made bearings. According to BNL, however, plastic bearings are rarely used as a substitute for ball bearings because of the extra cost required in polishing and they do not contribute much to weight reduction.
 BNL's plastic bearings are currently used by GM, Ford and Audi in their automotive components such as the steering columns, roof racks, and revolving lights (used for warning after an accident). Today, plastic bearings are used in more than five million cars around the world.



Use of foamed plastics and other plastics for weight reduction

 A wide range of products and components are made in various combinations of the material, structure (foamed plastics, hollow, integrated with the skin, sandwiched core, complex shapes, etc.) and their manufacturing techniques. In addition to weight reduction, these products and components often deliver excellent benefits such as high rigidity, thermal insulating properties and sound absorbing qualities.

Door inner panels Door inner panels made of foamed plastics and other materials (used on Japanese RVs, exhibited by Ube Industries)

High-fill sandwich moldings High-fill sandwich moldings (exhibited by Ube Industries)

Cross section of TWINCONE Cross section of TWINCONE by Ube Nitto Kasei (reproduced from the company's product catalog)

Air ducting Air ducting made by foam blow molding (exhibited by Kyoraku)

Air ducting for turbocharged engines Air ducting for turbocharged engines (exhibited by Altech) made by Kautex, a German company, by suction blow molding (ideal for manufacturing products having complex shapes)

Plastic fuel tank Plastic fuel tank used on Toyota Aqua (Prius c) (exhibited by Mitsubishi Chemical Holdings Group, manufactured by FTS)

Use of foamed plastics and other plastics for weight reduction

Ube Industries Group Engineering plastics  Ube Industries group supplies engineering plastic components that are used in various parts of cars. The group had display panels introducing polyamide 6, 66 (UBE NYLON), polyamide 12 (trade name UBESTA), synthetic rubber (trade name UBEPOL BR/VCR) and other products.
Foamed door trims  As a manufacturer of injection molding machines, Ube Industries proposed weight reducing techniques that use the company's molding machines. These include up to 10% weight reduction by thin wall design, up to 40% reduction by foaming technique using mold expansion process, and over 40% reduction by other techniques.
 The company exhibited door trims representing 30% weight reduction compared to conventional products. The door trims were manufactured by the mold expansion process (material is injected into the cavity and the mold is stretched after it reaches a specific pressure to increase the cavity volume for foaming).
High-fill sandwich moldings  Recycled material is sandwiched between skins to meet both the cost and cosmetic requirements. The company exhibited parts made of TPS (styrene-based thermoplastic elastomers) foamed by the mold expansion process and sandwiched between PP skins. This technique meets requirements for high cosmetic and performance qualities (thermal insulation, temperature absorption and vibration damping) and the company plans to build new business on this technique.
UBE NITTO KASEI TWINCONE (4-layer hollow honeycomb structure)  TWINCONE is a four-layered hollow honeycomb structure with two sheets of polypropylene sheets in which cones are arranged in a grid-like design and capped by surface materials (as shown in the photo). It has a number of advantages. The symmetrical construction along the direction of thickness resists warping and the connecting hollows provide ample space for air. It is more rigid than the corrugated plastic cardboards. These benefits make it ideal for making interior components in cars.
 (Note) Corrugated plastic cardboard is made of PP. It has a cross-section similar to that of the corrugated cardboard sheet and has spaces at regular intervals like a harmonica. They are often used as cushioning material to protect walls in buildings and elevators.
KYORAKU Foam ducting  The foam blow molding technique has made it possible to have heat insulation along the air ducting while reducing its weight. The ratio of foaming and the resulting wall thickness can be determined according to the customer's need. Higher heat insulation is obtained from a higher ratio of foaming (thicker wall) assuming that the weight is the same.
 Kyoraku is a volume manufacturer of ducting on many models including the ceiling ducting on the Toyota Alphard and ducting behind the instrument panel on Daihatsu Move/Mira e:S and Honda N-One.
Energy absorbing (EA)material  The company exhibited blow-molded bumper absorber made of multi-purpose polypropylene. The blow-molding has achieved weight reduction from the steel counterpart that weighs 1,250g to only 600g. The blow-molded bumper absorbers are mass produced for Suzuki Escudo, Kizashi and Jimny.
FLP Lite  FLP (Fabric Laminated Plastic) is a technique in which the skin fabric is preset in the mold so that the component is molded and the skin bonded to the component in a single action. Kyoraku introduced two products, FLP Lite and FLP Lite S.
 Other than the skin integrated molding, FLP Lite is made by thin wall molding and core insert technique that contributed to weight reduction and high rigidity that was not available from the conventional blow molding method. The unwoven skin cloth, the sandwiching parison (molten tube-like material) at both sides and the core insert are preset in the mold for integrated molding. The core may be foamed material, originally developed core material or reinforcing material.
 This process is used for volume production of deck boards for Toyota's new RAV4 (parts are supplied by Toyota Boshoku) and the sliding luggage boards (delivered to Suzuki Kasei) for Suzuki WagonR.
FLP Lite S  The skin integrated molding is combined with the thin-wall blow molding to achieve significant weight reduction to the same level as the corrugated plastic cardboard manufacturing method. The new process also provides a high freedom of design that was not associated with the plastic corrugation method. If it is used to manufacture cargo floor lids, Kyoraku will have the lightest cargo floor lids. The company plans to put the new components on the market in 2013.
 Other than the cargo floor lids, the company will propose the use of FLP Lite S for making roof trims, seat back boards, back door trims, sun-visors, etc.
ALTECH Air ducting for turbocharged engines  Altech introduced the 3D suction blow molding process developed by KAUTEX MACHINENBAU, a German corporation. The process offers an ideal solution to making air-conditioning ducts having complex three-dimensional shape, especially the air ducting for turbocharged engines that are subjected to higher temperatures than the naturally-aspirated engines.
 This process starts with the parison being sucked in the closed mold until it reaches the far edges of the mold cavity. Then the cavity is closed at both ends and air is blown inside for molding and cooling (when suction is not used, the mold is opened and the parison is guided into the mold by a robot, etc.).
STARLITE Underbody shield  Starlite introduced the underbody shield that uses Seeberlite developed by Roechling, the company's German affiliate. Seeberlite is a PP material with approximately 25 to 40% glass fiber content. It offers a number of benefits that include lighter weight, high strength, excellent sound absorbing property, and heat insulation. This material is used extensively in Volvo XC40.
 The company has also developed complete undershielding that covers the hot area directly under the engine and exhaust piping. The tire cover being supplied to Mercedes-Benz AMG SL 63 was exhibited at the show.
Mitsubishi Chemical Holdings Corporation Plastic fuel tank  Mitsubishi Chemical Holdings Group exhibited the plastic fuel tank used on Toyota Aqua (Prius c), and the tank itself is manufactured by FTS. The plastic fuel tank is preferred to the conventional metal tank because of lighter weight, durability, rust resistance and freedom of shaping. The tank was exhibited by Japan Polyethylene, one of the group companies. The company also had a panel showing the fuel tank used on the Prius made of the same material.
 The tank is of a six-layer construction and high-density polyethylene (HDPE) is the main ingredient that makes the outer and inner layers. The barrier layer used to prevent the fuel from gasification and evaporation is made of Soarnol (ethylene vinyl alcohol copolymer) that has 2,000 to 3,000-folds higher barrier properties than HDPE. The birth of plastic fuel tanks owes solely to the development of Soarnol (exhibited by Nippon Synthetic Chemical Industry, a Mitsubishi Chemical Holdings Group company).
Luggage box  The Group proposed a luggage box made of GMT (Glass Mat reinforced Thermoplastic) and GMTex, an additionally reinforced grade of GMT. They both are composite materials in which thermoplastic resin is reinforced with continuous glass fiber mat. The material delivers a number of benefits including approximately 20% weight reduction, excellent impact energy absorbing property, rust resistance and freedom of design. The luggage box was exhibited by Quadrant Plastic Composites Japan.



Others: Biomass fibers, seat material with heat adjusting function, etc.

Seat finished with special fabrics Seat finished with special fabrics (warm in winter, cool in summer) exhibited by Toray

Biomass fibers, etc.

Toray Biomass fibers for interior use  Toray has established interior material designing technology using biomass fibers (polymer modification, textile design). The technology was used to manufacture seats, ceilings and door trims for Toyota SAI that was launched in 2009 (components were fabricated by Toyota Boshoku).
 The technology was established after the development of polylactic acid fibers (PLA, having a dry draping finish and excellent coloring property), 3GT fibers (poly trimethylene terephtalate, having a soft touch) and bio-PET fibers (polyethylene terephthalate, having the same properties as petro-derived PET). The new technology was used to manufacture roof head lining, trunk door trims and sun-visors for Toyota SAI.
Impact absorbing nylon honeycomb  Toray developed the industry-first impact absorbing resin having a structure that deforms like rubber when impact is applied. The impact absorbing property has been increased further by inserting an impact absorbing resin honeycomb structure between the two skins. This has led to a large total energy absorbing capacity and the least risk of damaging the object being hit. The company plans to develop new applications for the material in such areas as outer panels, panels and passive safety components.
Seat fabric with temperature adjusting function  The seat fabric has a vapor absorbing property that will make the cabin warm in winter and cool in summer, thereby reducing the need for the air conditioning in HVs and EVs. The ultimate aim is to increase the car's fuel efficiency and cruising range.
 In wintertime, the moisture-absorbent polymer in the fiber absorbs the moisture from the warm air from the air ducting. The kinetic energy of the vapor is converted into thermal energy in the process and the temperature rises by approximately 2°C (the use of air conditioning is assumed in summer and winter alike). The seat fabric works in the same principle as the Uniqlo "HEATTECH" that Toray developed jointly with Uniqlo.
 In summertime, the moisture absorbent polymer releases the moisture to the cabin that it had absorbed from the cooler. The temperature decreases by approximately 2°C as the heat in the cabin is lost in the process of evaporation.
Metal-less metallic luster film PICASUS  The company has developed a polyester film, PICASUS, a non-metal material that gives metal-like luster and design flexibility that allows light to transmit through it. With conventional plastic material, the plastic molding had to be plated, coated or metal vapor-deposited to get metallic sheen. The PICASUS film is used in the overhead consoles and center consoles of Daihatsu Tanto Exe (parts are supplied by Toyota Boshoku).
 PICASUS contains highly refractive polymer and least refractive polymer overlapping each other. This causes interference reflection in the visible light range and produces metallic luster without the presence of metal. The film also allows transmission of light. A light source may be installed underneath to illuminate the film in the same color.
Fluoro Coat Fluororesin coating  Fluoro Coat is a company that specializes in fluororesin coating as used in frying pans and other products. Fluororesin is a thermoplastic polymer made up of fluorine (F) and carbon chain. Its benefits include (1) non-stickiness, (2) thermal resistance, (3) slipperiness, (4) chemical resistance, (5) water and oil repellency, (6) wear resistance and (7) electrical characteristics.
 Fluororesin coating has been used with rubber, resin, titanium, ceramics and other lightweight materials. The company plans to extend its use to magnesium alloys, composite CFRP materials and metal matrix composites (MMC) to add value and support the use of these lightweight materials in increasing demand.
 The fluororesin coating is used on sealing parts in the brake boosters. Slipperiness is an important property as the seal comes in contact with other parts and slides when the booster is activated.

Source: Exhibits, panels and printed materials distributed at the Automotive Weight Reduction Expo 2013

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