Several Points of History of Auto Bumpers
Bumpers are an important and sometimes overlooked part of a car's design. When buying new cars, people tend to focus on the interiors, the design, powertrain and so on, but the small things also have their place and count too.
Bumpers are typically used on the front and the back of the car for handling an impact situation. A bumper is actually rather important if not glamorous. In case of an impact, the design, shape and position of the bumper determines the kind of impact the vehicle in question as well the impacted vehicle sustain. The Federal Motor Vehicle Safety Standards (FMVSS) has had a clause since 1971 to address the design of bumpers on vehicles.
Some of the trends have been (in chronological order):
1-Steel bumpers in classic vehicles. Observe how the Ford Model T (shown below) had no bumper. It was the first mass produced passenger vehicle ever, and the furthest point in the front of the car is the front end of the wheels. Steel bumpers were the first safety innovation.
2-The earliest bumpers didn't have a standard form and generally conformed to the designer's view of what was functionally and stylistically okay. The trouble with this was, of course, standardization and the inability of cars to have predictable performance in crash situations.
3- Bumpers were sometimes combined with tail lamps, and with other lamps. This trend continues till this day, but the main lamps of vehicles are seldom mounted on the bumper in modern cars. Here's a picture of the rear bumper of a Chrysler Dart, with a bumper-mounted tail light. This is a 1971 model.
You can guess what would happen in case of an accident or a fender bender. The lights would be unusable or badly damaged, making it difficult or impossible to safely drive the car even in case of a minor accident. The FMVSS No. 215 standard "Exterior protection" was amended in 1972, and called for greater safety in bumpers on street legal cars.
Bumpers were expected to be able to sustain 5mph impacts and be distinct in functionality.
Here's a 1976 AMC Matador, which has a clearly defined bumper with no lights mounted on it. Note the considerable size of the bumper and its bulk.
4- It isn't always that bumper norms/regulations were made more stringent. Under the Reagan administration, bumper specifications were relaxed to allow the manufacturers to save weight. In the 1980s, bumpers were almost always made from steel and its alloys, and this relaxed rule made it easier for manufacturers.
5-The next big improvement in bumper technology came with the advent of new materials. In the late 1980s, manufacturers became more capable at using polymers in the place of metals for body panels and interior components. The use of thermoplastic polymers made possible lighter bumpers which could also be moulded to suit the design of the vehicle. Here is a 1990s Audi cabriolet sports model which has an integrated bumper, made of a polycarbonate material. (The projections from the bumper are the spray cleaners for the head lamps)
A popular material used for making bumpers is Acrylonitrile butadiene styrene or ABS (which is also used to make diverse things like lego blocks, musical instruments to golf club heads).
6- The advent of composite materials has increased the chances that any car you will buy will have a fibreglass or carbon fibre based bumper too. For now though ABS has the advantage, since it is extensively used in 3D printing applications and therefore has the advantage of being adapted as and when companies move to such advanced manufacturing technologies.
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