Multi-dimensional analysis of automotive lightweight

Nowadays, with the release of new cars, “lightweight” has become the absolute focus! In the product introduction, descriptions such as “lightweight body technology” and “10% weight reduction of the entire vehicle” are indispensable. To achieve lightweight, in addition to optimizing the structure and process design, most of them are centered on material selection.

The specific gravity of general plastics is 0.9-1.6, and the specific gravity of glass-reinforced composites is within 2.0, while A3 steel is 7.6, brass is 8.4, and aluminum is 2.7. Therefore, although the strength is not as good as carbon fiber or metal material, the light weight effect of plastics is the best from the aspect of the specific gravity, and it can be said that the material of choice for automotive lightweighting. The use of plastic can reduce the weight of parts by about 40%, while the power, comfort and safety of the car are improved. The future of its innovative applications may subvert the traditional car.

Three ways to make the car lose weight <br> <br> newly revised national mandatory standards "passenger car fuel consumption limits", will be implemented from January 1, 2016, will set the standard fuel consumption value per year, until the The average fuel consumption of passenger cars in 2020 fell to 5.0 liters/100 kilometers. The increasingly stringent fuel consumption regulations have prompted all automakers to spare no effort to develop lightweight automotive technologies.

Lightweight car is not a simple weight loss, it needs to take into account the product features, cost and quality. There are three main approaches to the "plastic steel replacement": optimizing material quality; modularization and integration; structural optimization design.

The most critical high-performance materials <br> <br> foreign car brands now have large-scale use of high-performance engineering plastics and plastic composites. In the future, the doors, roofs, seat parts, hubs, and structural components of automobiles and even the body of automobiles may use engineering plastics. The body made of fiber-reinforced composite plastic material can reduce the weight by 35% compared with that of the steel body. If the carbon fiber reinforced composite material is adopted, the weight can be reduced by more than 60%.

Honeycomb sandwich structures have been widely used in automotive interiors, including trunk floors, roof linings, and rear window sill. The new Mercedes-Benz smartfortwo uses BASF's Elastoflex E polyurethane foam in its honeycomb sandwich roof. Its canopy module consists of a honeycomb sandwich and a fiberglass liner. It is about 30% lighter than a conventional canopy but still maintains good strength and resistance. Bending stiffness.

The TEpexynalite, a polypropylene-based continuous fiber-reinforced composite material introduced by Bond-Laminates, a LANXESS subsidiary, also presents significant opportunities in lightweight automotive production, especially in large-scale components with high strength requirements, such as: backup Box bottom plate, electric vehicle range extender housing and seat assembly, etc.

<br> <br> modular production has become a trend in modular, integrated aspect, the plastic has a very distinct advantage. At present, many components and systems, such as side door systems, instrument panel systems, and engine systems, have achieved modular production. The front end structure of the integrated module reinforced with a plastic frame and partial metal insert can achieve a 30% weight reduction effect, and can greatly reduce the number of parts and improve assembly efficiency. It is reported that many European and American companies such as BMW, Mercedes-Benz, General Motors, Renault, and Mark have applied the front-end module and door module technologies.

Structural optimization can not be ignored <br> <br> lightweight design is also an important way to structure optimization, structural shapes and sizes designed to meet the technical requirements under the premise of. For example, the thin wall of the bumper development, the conventional design for the 3.0MM wall thickness, the use of ordinary PP talcum powder material, single weight 4-5kg. According to Xiong Fei, chief engineer of the Geely Automobile Research Institute, Geely uses 2.5mm wall thickness design, high rigidity PP material, and the weight loss of single piece is 10%-15%. At the same time, he pointed out that to achieve lightweighting can not be limited to materials, only the depot's material department to participate in the vehicle design can effectively promote the application of new materials and new processes. In other words, performance and design are fundamental to the car. Materials must be developed around these two points. On this basis, light weight is achieved, and better fuel efficiency and performance attributes of the vehicle are achieved.

Innovative processes escort density <br> <br> long glass fiber reinforced composites, carbon fiber-reinforced composite materials, and modified micro foamed, thin-walled plastic material is a material research hotspot of the vehicle. The development and application of these materials are inseparable from the support of innovative processes.

Long fiber injection molding is an innovative process for lightweight structures. The long fibers developed by Arbug are directly injection moulded, and the fibres are fed directly into the molten plastic by means of a servo motor-driven feed device. The continuous fibres can be cut into 15-50 mm lengths. The two-stage screws ensure melting of the plastic particles. At the same time, the fibers are fed to ensure even mixing and the purpose of increasing the strength is achieved. Taking the long-fiber direct injection molding of the airbag housing as an example, the direct injection molding using 16mm glass fiber can make the length of 50% glass fiber more than 2mm, which is much better than the injection molding of long fiber pellets.

Ingers Mould Manufacturing (China) Co., Ltd. has exhibited its new FLEXflow servo-driven valve gate system at the CHINAPLAS2015 exhibition, which is especially suitable for automotive large plastic parts, high-quality optical parts, high-performance engineering materials, and narrow process windows. Injection molding applications. In terms of cost savings, it is possible to reduce the clamping force by about 20% and reduce the weight of plastic parts by up to 5%.

MuCell micro-foam injection molding technology is increasingly used in automotive manufacturing. According to media reports, Land Rover plans to use MuCell technology in all models by 2017. Microcellular foaming refers to the use of thermoplastic materials as the matrix, through a special processing process, so that the middle layer of the product has a closed size from ten to tens of micrometers. The MuCell process is particularly advantageous in terms of weight reduction. It can reduce the weight by up to 10% on the premise of ensuring the structural strength of the parts. The cycle time is reduced by 50% and the average cost is reduced by 16%-20%. As early as 2000, based on cooperation with MIT, Trexel first used this technology to achieve commercial applications. Many world-renowned equipment and raw material manufacturers, including Arbug, Demag, Engel, Husky, and Dupont, have purchased patents for this technology. To achieve the goal of lightweighting, the future MuCell will still be the industry's competing technology.