Radiator manufacturing
When gasoline burns in a car engine, up to 70% of the energy generated converts into heat. A lot of this heat goes out through the exhaust system, but much of it stays in the engine, heating it up. The car’s cooling system prevents the engine from overheating. This system has a key component known as the radiator. In the radiator, a water and antifreeze mix absorbs the heat generated by the engine. This fluid flows through the radiator’s tubes to cool down. These tubes are made from paper-thin brass. Rollers bend the four-centimeter-wide strip into the shape of a flat tube. This tubing system runs through a vat of bubbling hot molten lead.
When this tubing exits the vat, it runs through cold water that hardens the lead coating. A cutter then chops the tubing into pieces, the length of which varies according to the model of the radiator, usually about 76 centimeters long. Meanwhile, another machine makes a narrow strip of copper, just one and a half millimeters thick, into what are called cooling fins. This machine folds the copper strip fan-like and then perforates it, creating mini air vents. When the hot fluid runs through the tubes, these fins will transfer the heat to the air flowing through the radiator.
The cooling fluid can then go back for another round of absorbing engine heat. The cooling fins come out of the machine cut to size. Workers manually stack the tubes and fins one on top of the other, straighten them out, and then apply a brass tag indicating the model number and date of production. The radiator is then compressed and the components are strapped together. Elsewhere, a computer-guided machine punches out a pattern on brass sheets to create headers, one on each side of the radiator. The punching tool then changes to a knife, which cuts along the perforation lines using a press. The press bends each header and punches slots for the radiator’s tubes. Workers use a mallet to hammer the headers onto the ends of the tubes, but this can inadvertently close a few tubes, so a special roller is used to reopen them.
After cleaning the surfaces, the assembled radiator goes into an oven at 315 degrees Celsius. In just two minutes, the lead melts, fusing the tubes and cooling fins. Workers straighten out any crooked tubes and then dip the headers in a tank of hot liquid lead for 30 seconds to solder them to the sides of the radiator. To reinforce the assembly, they apply a few drops of lead on the corners.
Next, workers feed a sheet of brass into a press to form the tanks that go onto the headers. One tank contains a brass tube where hot transmission oil enters one end and exits the other, cooling along the way. After finishing this work, the tanks are welded to the headers, and a filler neck, a spout for pouring antifreeze into the tank, is soldered on. On the opposite tank, they weld on a water intake pipe, which will be the entry point for the fluid heated by the engine. Finally, the finished radiator is coated with an asphalt-based black paint. The asphalt content makes the paint heat-resistant and protects the radiator’s cooling fins.
