Why are car bumpers rarely made of metal?
We all know that vehicles have front and rear bumpers, which are basically made of plastic, so how do plastic bumpers ensure insurance? Why use plastic bumpers?
Let's take a look at some car test data first. In the case that most vehicles have plastic bumpers, the crash test score can still reach 5 stars. Why is the crash test result so good? In fact, the bumper is an exterior cover for the front part of the car. The original bumper material was indeed metal, but after a lot of tests and accumulation of experience, it was found that plastic was used instead of metal. Material is a more appropriate choice.
Let's look at a simple example, which is one of the main reasons why vehicle bumpers change from metal to plastic. We assume that a pedestrian suddenly appeared in front of the car owner while driving, and a collision occurred without rushing to avoid it. At this time, the owner of the car must be willing to have a plastic bumper, so that it will cause less damage to pedestrians. Minimize the damage to pedestrians as much as possible. The front bumper can feel a certain amount of shrinkage when you press it with your hand. This design is to give pedestrians a certain amount of buffering when the vehicle collides with pedestrians, so as to reduce the damage to pedestrians.
In the crash test video of IIHS in the United States, when the vehicle at a speed of about 64km/h hits the front 25% of the obstacle and hits the obstacle, the bumper of the car is shattered. We can imagine that even if we replace the bumper with a metal material, that is, a relatively thin layer of metal, it will not have any effect at all. Even if it reaches a thickness of 1cm, it will not have much effect on the result. Influence, take a look at the door after a side collision accident, even the A-pillar, B-pillar, the deformation will be very serious.
Of course, reducing production costs and later maintenance costs is also a reason for using plastic materials. After using plastic as the main material, the manufacturing cost and maintenance cost can be greatly reduced. I believe everyone knows the price of plastic and the price of metal. Plastic is relatively cheap and easy to shape. Moreover, there are many kinds of plastics. The material used in the bumper of the car is relatively elastic. If the collision is not very serious, the bumper will spring back to its original shape, just like if we squeezed a mineral water bottle, it can be restored.
If the whole material is made of metal, there is no way to do it. You can only remove it and make a new sheet metal. After finishing the sheet metal, you can repaint it. In this way, after the sheet metal treatment, the structure of the metal material itself will have some changes, which will affect the appearance. . The strength will also be deviated, which will affect the safety performance. Anyone who has done sheet metal knows that the maintenance cost of this sheet metal is also very high. With a small bump down, the repair is done and it costs about as much to replace a brand new plastic bumper.
Another reason is related to long-term use considerations. Metal materials will rust or corrode if they are exposed to the air for a long time without painting. The cost of making a bumper is too high, but using plastic instead, not only the cost is lower, but also the plasticity is higher, and there is no need to worry about rusting if scratched, even if there is no time to touch up the paint and repair, the problem It will not be big, and the car can be driven normally.
In fact, the main purpose of replacing the bumper of a car with a plastic material is to protect the safety of pedestrians more. For part of the reason, it is indeed to reduce the weight of the vehicle in exchange for better fuel economy. Most of the cars now use plastic bumpers. Maybe with the development of technology, there will be better materials to replace them. No matter what the material is, driving safely can better ensure safety.
Post time:Feb-11-2022