Now the material of automobile bumper is mostly polypropylene plastic, which is mainly located in

the front (front bumper) and rear (rear bumper). In addition to maintaining the original protection function,

the front and rear bumpers of the car should also pursue the harmony and unity with the body shape and

pursue their own lightweight. The photo below shows the front and rear bumpers of the car.

In fact, early car bumpers were made of steel. Nowadays, some heavy vehicles, special vehicles, military

vehicles or steel bumpers have been developed, and as ordinary passenger cars, the current bumpers are

all made of plastic. As for why the bumper is plastic instead of steel material, mainly for the following reasons:

1. In terms of appearance, the plastic bumper is very easy to manufacture and has the best coordination with

the body, which makes the appearance of the car very beautiful. And polypropylene is a very light plastic, which

can reduce the weight of the car, thereby reducing fuel consumption.

2. The manufacturing cost is relatively low, which can reduce the cost of the whole vehicle. On a car, the front

and rear bumpers are the most vulnerable parts. If the bumper is made of iron, it is very troublesome to repair,

and the correction of sheet metal parts is more complicated than plastic parts.

3. Based on the need to protect pedestrians; imagine if the same car was driving ahead at the same low speed

and hit a pedestrian. If you're the one being hit, do you want the bumper to be metal or plastic? Also, let's distinguish

between bumpers and crash beams. Generally speaking, cars have front and rear crash beams, and some low-end

models may only have front crash beams. The crash beam is located behind the bumper and is usually made of

boron steel sheet. If pedestrians are protected with bumpers made of soft plastic, the water tank and engine are

protected with steel crash beams.

4. In addition, most plastic bumpers are injection-molded with pp material, which has a high melting point and

strong heat resistance density. It is the lightest type of general-purpose plastics and has high corrosion resistance.

5. Reduce maintenance costs. Most plastic bumpers are made of plastic, resin and other materials with good elasticity.

They have good impact resistance, strong plasticity, low maintenance costs, and corrosion resistance; some small bumps

The resulting deformation can be restored by pouring water in the pot or using a hair dryer.