AUTOMOTIVE PLASTICS
China focuses on lightweight materials to meet 2015 fuel economy standard / Recent CPRJ conference
Further weight reductions in passenger vehicles are needed to meet new fuel economy standards in China. From 2015, passenger vehicles in the country have to reach an average fuel consumption of 6.9 litres per 100 km, compared with previous standards of 8 litres/100km. Further efforts will be required to develop new materials and processing technologies to achieve the necessary reduction in vehicle weights, says Wan Xinming, vice president of China Automotive Engineering Research Institute (Chongqing; http://en.caeri.com.cn).
Speaking at a conference organised by Plasteurope.com cooperation partner China Plastic & Rubber Journal (CPRJ), Wan highlighted long fibre reinforced thermoplastics (LFT), which are widely used in Europe and USA, as one of the most important trends in automotive lightweight construction. This is expected to be a major material of choice because carbon fibre reinforced plastics (CFRP) are still too expensive for mass production, he said.
Speaking at a conference organised by Plasteurope.com cooperation partner China Plastic & Rubber Journal (CPRJ), Wan highlighted long fibre reinforced thermoplastics (LFT), which are widely used in Europe and USA, as one of the most important trends in automotive lightweight construction. This is expected to be a major material of choice because carbon fibre reinforced plastics (CFRP) are still too expensive for mass production, he said.
 Plastic wheel fenders can reduce weight by 40%, Geely's Xiong Fei told confence participants. |
Replacing metals with plastics can provide multiple benefits. For example, in 2008 a front-end module made of metal comprised 15 parts, while in 2014 an all-plastic frame with metal parts reinforcement structure can result in a 30% reduction in weight, as well as reducing the number of parts, said Xiong Fei, chief engineer at Geely Automobile (Hong Kong; www.geelyauto.com.hk/en). Similarly, a vehicle cross-beam made of plastic composite can weigh just 2 kg, 50% less than its metal counterparts while offering the same safety performance, he told conference delegates. And a wheel fender made of plastics can reduce the weight by 40% while providing the same level of protection for pedestrians.
Shang Hongbo, chief engineer in the non-metal material department of the Beiqi Foton (www.foton-global.com) Automotive Engineering Research Institute, noted that an oil tank made of plastics can reduce weight by one third, as well as offering higher efficiency, design freedom and corrosive resistance. It is also anti-static with a long life.
Refining part structures is another way to reduce vehicle weight. Traditional bumpers made of general PP with talc powder usually have a wall thickness of about 3 mm and weigh 4-5 kg. Currently some parts with a 2.5 mm or even 2 mm thickness are achievable. For high strength PP, Geely uses a 2.5 mm design that reduces weight by 0.8 kg, or 10-15% per part, said Fei.
On the machinery side, new solutions are being developed for fibre reinforced plastics, including both glass and carbon fibres. Fibres help to improve stiffness and heat resistance, but adding fibres into plastics affects melt flow and demands higher injection temperature and pressure. Cedar Yang, from the design department at Zhejiang Hengdao Keji, pointed out that a hot runner system is effective at optimising the melt flow.
Other developments discussed at the conference include the use of thin-walled or foamed plastics. Honeycomb structures, in which a PU structure reinforced by glass fibre is sandwiched between two honeycomb panels, are becoming increasingly popular. The honeycomb structure provides high structural strength, strong mechanical properties and low VOC emissions, and can be produced efficiently and bonds well with woven materials.
Advancements in plastics allow the materials to be used in difficult environments such as engine compartments, including air inlet systems. Edi Degasperi, GM of Radici Plastics (Suzhou) (www.radicigroup.com) noted that demand for PA in engine compartments is particularly strong in China. In terms of energy consumption and machinery performance, PA 6 and PA 6.6 offer the best result compared with PP, LDPE, HDPE and PC, he said.
Miniaturisation is another growing trend in engine development. A small engine needs an even more compact turbo charging system, leading to higher temperatures inside the engine compartment. This requires high heat materials, said Ricky Liu, key account automotive sales representative at Ems-Chemie (Suzhou) (www.ems-group.com). Replacing metal with PA reduces cost and the vehicle’s weight. For example, air pipe made of the PA can reduce weight by 39% and cut costs by 27% for turbo charging air inlets, he added.
This article was first published by CPRJ on www.adsalecprj.com/Publicity/lang-simp/HomePage.aspx
Shang Hongbo, chief engineer in the non-metal material department of the Beiqi Foton (www.foton-global.com) Automotive Engineering Research Institute, noted that an oil tank made of plastics can reduce weight by one third, as well as offering higher efficiency, design freedom and corrosive resistance. It is also anti-static with a long life.
Refining part structures is another way to reduce vehicle weight. Traditional bumpers made of general PP with talc powder usually have a wall thickness of about 3 mm and weigh 4-5 kg. Currently some parts with a 2.5 mm or even 2 mm thickness are achievable. For high strength PP, Geely uses a 2.5 mm design that reduces weight by 0.8 kg, or 10-15% per part, said Fei.
On the machinery side, new solutions are being developed for fibre reinforced plastics, including both glass and carbon fibres. Fibres help to improve stiffness and heat resistance, but adding fibres into plastics affects melt flow and demands higher injection temperature and pressure. Cedar Yang, from the design department at Zhejiang Hengdao Keji, pointed out that a hot runner system is effective at optimising the melt flow.
Other developments discussed at the conference include the use of thin-walled or foamed plastics. Honeycomb structures, in which a PU structure reinforced by glass fibre is sandwiched between two honeycomb panels, are becoming increasingly popular. The honeycomb structure provides high structural strength, strong mechanical properties and low VOC emissions, and can be produced efficiently and bonds well with woven materials.
Advancements in plastics allow the materials to be used in difficult environments such as engine compartments, including air inlet systems. Edi Degasperi, GM of Radici Plastics (Suzhou) (www.radicigroup.com) noted that demand for PA in engine compartments is particularly strong in China. In terms of energy consumption and machinery performance, PA 6 and PA 6.6 offer the best result compared with PP, LDPE, HDPE and PC, he said.
Miniaturisation is another growing trend in engine development. A small engine needs an even more compact turbo charging system, leading to higher temperatures inside the engine compartment. This requires high heat materials, said Ricky Liu, key account automotive sales representative at Ems-Chemie (Suzhou) (www.ems-group.com). Replacing metal with PA reduces cost and the vehicle’s weight. For example, air pipe made of the PA can reduce weight by 39% and cut costs by 27% for turbo charging air inlets, he added.
This article was first published by CPRJ on www.adsalecprj.com/Publicity/lang-simp/HomePage.aspx
19.01.2015 Plasteurope.com [230095-0]
Published on 19.01.2015