Shall we make car panels entirely of plastic instead of metal?

Of course yes!
Usually the lightweight of automobile needs to start from materials and technology. With the development of technology, the combination of new materials, new structures and new processes has given birth to a special lightweight body structure: the integrated body.

1.the weight can be reduced by 60%

The common car body is generally composed of a series of parts such as door panel, top cover, front and rear wing sub-plate, side cover plate, floor and so on. After steel plate stamping, plate welding, body in white painting and final assembly, the whole car is formed. As a bearing part, the body is the main source of the weight of the car and plays a protective role in the safety of the occupants. In our mind it looks like this.
The body of one body is completely different from the surface, and it has a more unexpected name – plastic body.

As the name suggests, the body is mostly made of a lightweight roll plastic, a type of plastic. This body structure is different from the traditional body manufacturing method, using polymer material instead of steel, and the use of rotational plastic integral molding process to manufacture the body, because the raw material can be toned, the body will no longer need to paint processing, omitted stamping and spraying processes, this is “rotomolding
Plastic is widely used in cars, but would an all-plastic body come as a surprise? Such processes and materials can make the vehicle significantly lighter.

Due to the characteristics of light weight and simple structure, this kind of body structure is mainly used in electric cars, which also conforms to the development trend of new energy vehicles. As an example, the ECOmove QBEAK of Denmark, an energy-efficient electric vehicle, had a body size of 3,000×1,750×1,630mm and a fitting mass of only 425Kg. While traditional cars of the same size weigh more than 1,000 kg, even the smaller Smart, with a body size of 2,695×1,663×1,555mm, has a spare mass of 920-963 kg.


In theory, the single-form body uses a simple structure and lightweight plastic, saving more than 60% of the weight of a metal body of similar specifications.

2. Rotational molding process: new car development faster
We know the benefits of this molding process, so what is the integral roto-molding process? Is simply adding plastic raw materials to specific in a mould, then make the mold along two vertical axis rotation and heating unceasingly, the mould of plastic will be under the action of gravity and thermal energy, evenly coated, melt adhesive on the entire surface of the cavity, forming the shape of the required, again through the cooling setting, stripping process after a integrated products, etc. Below is the simplified process schematic diagram.

One of the characteristics of the integral rotational molding process is that large or super large hollow plastic products with complex curved surfaces can be prepared at one time. This just meets the car body volume, appearance lines streamline, curved surface smooth requirements.
Some people may confuse plastic molding process as a whole and one-piece stamping molding process, in fact, the latter is due to simplify welding technology, improve the structure strength, enhance the purpose of the beautiful sex, see more at the door in the stamping, but it is not out of the body of traditional manufacturing method, and the former is a method of subversive to car body manufacturing one-time finish.

Although the technology is still in its infancy, it still has many advantages. Such as:

Traditional vehicle development costs about 13 million USD, which greatly restricts the development of cars. This new process simplifies the body structure, reduces the difficulty and cost of parts manufacturing, and shortens the manufacturing cycle of products.

Compared with traditional steel body, the weight of all-plastic body is reduced by more than twice, which helps to achieve lightweight body and reduce fuel consumption.

One-shot molding technology has a variety of module kits, which enables customized production and improves the degree of individuality of car body.

Due to the use of environmentally friendly plastics, the car body will not pollute the environment, and the car body will not be corroded during daily use.

The car body can be made on class A surface by color mixing of materials, which saves A lot of investment in phosphating and electrophoresis process compared with traditional painting process, making the production process more environmentally friendly and less energy consumption.
3. plastic body can be safe as well
We know that the body of the safety requirements are very high, this kind of molding body really can meet the strength requirements, it can protect our safety? What are its advantages and disadvantages?

Due to the natural strength of plastics, and easy to produce shrinkage deformation, simple plastic structure is not enough to meet the strength requirements. In order to solve this problem, many integrated body will use built-in steel mesh structure or add strengthening materials such as glass fiber, to enhance the structural strength of the body.

In the case of an internal steel structure, the mesh is embedded in the mold and coated with material during the rotational process, just as in a reinforced concrete structure, the mesh counteracts the shrinkage of the plastic and increases the strength of the body. In addition, in order to further strengthen the body, some manufacturers will add aluminum frame inside the body, although the weight increases part of the body, but can effectively ensure the safety of the power system mounted on the frame.

Of course, due to a molding all plastic body of mould machining accuracy, speed, combining a model unity products have higher requirements, process is difficult, if simply using fiber reinforced, either in advance or after mix can make fiber mixed with raw material evenly, this led directly to products mechanical properties of car body is not very stable.

In conclusion, one – piece molding greatly reduces the weight of the body from the point of view of material and structure. Although this kind of body still has many shortcomings at the present stage, it is still in its infancy, but there are plans to enhance the strength.

The technology is currently limited to the low-speed electric vehicle market, but is expected to be widely used in the future. Improved safety will be key to a wider rollout.

If you see an electric car on the street in the future, people might just say, “Look, it’s plastic.” You can say, “Honey, that’s a molded plastic body.”

Post time: May-13-2022