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. Today, 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 made of plastic instead of steel, there are several 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, which in turn reduces 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 were the one being hit, would you like the bumper to be metal or plastic? In addition,

we have to 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.