1. What is weight reduction?

Lightweight, this concept originated from motorsports, and aims to bring better power and maneuverability by reducing the weight of the car itself. As the concept of "energy saving and environmental protection" has taken root in the hearts of the people in recent years, more and more car manufacturers have also begun to research on lightweight. Numerous new materials have also come into the sight of our ordinary people.

2. Substituting plastic for steel, the background of lightweight

In 1953, the world's first FRP (glass reinforced plastic) car was born in GM Corvette, marking that polymer matrix composites became a new force in the automotive industry.

¡ñIn 2014, BMW launched a pure electric model BMW i3, using 200-300 kg of carbon fiber composite materials from BASF, and the overall weight is 250-350 kg lighter than the previous design

¡ñIn 2016, DSM launched a new polyamide product ForTii? Ace to replace metal die-casting parts and expensive high-performance thermoplastic engineering plastics.

¡ñIn 2017, Chery eQ1 used Saudi Basic Industries Corporation (SABIC) engineering polyolefin materials, which reduced the weight of the internal structure of the tailgate panels of electric vehicles by 40%.

Lightweight has undoubtedly become the focus of new car research and development today. In order to achieve lightweight goals, in addition to optimizing structure and process design, most of them focus on the selection of materials. Among them, "plastics instead of steel" is the general trend.

3. Advantages of replacing steel with plastic

1) The biggest advantage of using plastics is to reduce the weight of the car body.

Lightweight is the goal pursued by the automotive industry, and plastics can show their power in this respect. The specific gravity of general plastics is 0.9~1.5, and the specific gravity of fiber-reinforced composite materials does not exceed 2. Among metal materials, the specific gravity of A3 steel is 7.6, brass is 8.4, and aluminum is 2.7. This makes plastics the preferred material for lightweight cars.

2) Plastic molding is easy.

This makes it very convenient to process parts with complex shapes. For example, when the instrument panel is processed with steel plates, it is often necessary to first process and shape various parts, and then assemble or weld them with connectors, which requires many procedures. The use of plastic can be molded at one time, the processing time is short, and the accuracy is guaranteed.

3) The elastic deformation characteristics of plastic products.

It can absorb a large amount of collision energy, has a greater buffering effect on strong collisions, and protects vehicles and passengers. Therefore, plastic instrument panels and steering wheels are used in modern cars to enhance the cushioning effect. The front and rear bumpers and body trim are made of plastic materials to reduce the impact of objects outside the car on the sound of the car. In addition, plastic also has the function of absorbing and attenuating vibration and noise, which can improve the comfort of riding.

4) The plastic has strong corrosion resistance.

Local damage will not corrode. However, once the paint surface is damaged or the anti-corrosion is not done well in the steel production, it is easy to rust and corrode. The corrosion resistance of plastics to acids, alkalis, and salts is greater than that of steel plates. If plastics are used as body covers, they are very suitable for use in areas with greater pollution.

5) Plastic modification performance.

According to the composition of the plastic, plastics with the required properties can be prepared by adding different fillers, plasticizers and hardeners, and the mechanical strength and processing and forming properties of the plastics can be modified to meet the requirements of different parts on the car. For example, the bumper must have considerable mechanical strength, while the cushion and backrest must be made of soft polyurethane foam. What's more convenient is that the color of plastic can jump out of different colors through additives, saving the trouble of painting. Some plastic parts can also be electroplated. For example, ABS plastic has good electroplating performance and can be used to make decorative strips, signs, switch knobs, wheel decoration covers, etc.

4. Application of replacing steel with plastic

With the improvement of engineering plastic modification technology, "plastics to replace steel" has become an international trend, and the excellent performance of plastics to replace steel has been widely used in various fields. Compared with general-purpose plastics, replacing steel with plastic can meet higher requirements in terms of mechanical properties, durability, corrosion resistance, heat resistance, etc., and it is more convenient to process and can replace metal materials.

¡ñMechanically, replacing steel with plastic can be used for mechanical parts such as bearings, gears, screw nuts, seals, and mechanical structural parts such as housings, covers, handwheels, handles, fasteners and pipe joints.

¡ñIn electronics and electrical appliances, using plastic instead of steel can be used for insulation materials such as wire and cable coating, printed circuit boards, insulating films, and electrical equipment structural parts.

¡ñIn household appliances, plastics can be used to replace steel in refrigerators, washing machines, air conditioners, televisions, electric fans, vacuum cleaners, electric irons, microwave ovens, rice cookers, radios, combined audio equipment and lighting appliances.

¡ñIn the chemical industry, replacing steel with plastic can be used in chemical equipment such as heat exchangers, chemical equipment linings, and pipes, pipe fittings, valves, pumps and other chemical pipelines.

¡ñIn the automotive industry, the use of plastic instead of steel is mainly used in bumpers, fuel tanks, instrument panels, body panels, interior trim parts, lamp covers, fuel pipes, radiators, and automotive related parts.