Radiators Hatchery Chicks Filo Pastry Cross
Today on "how it's made"... Car radiators... Hatchery chicks... Phyllo dough... And cross-country skis. When the gasoline in a car engine burns, up to 70% of the energy generated converts into heat. A lot of this heat goes out the exhaust system, but much of it stays heating up the engine. The car's cooling system prevents overheating. The system's key component is the radiator. A water-and-antifreeze mix absorbs the heat generated by the engine. The fluid then flows through the radiator tubes to cool down. The tubes are made from paper-thin brass. The 1.5-inch-wide strip is bent by rollers into the shape of a flat tube. The tubing then runs through a vat of bubbling-hot molten lead. As the 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 radiator. These are about 30 inches long. Meanwhile, another machine shapes a narrow strip of copper just 6/100 of an inch thick into what are called "cooling fins". As we'll see in slow motion, the machine folds the copper strip like a fan, 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 cooled fluid can then go back for another round of absorbing engine heat. The cooling fins come out of the machine cut to size. Then workers manually stack the tubes and fins one on top of the other. They straighten them out and apply a brass tag indicating the model number and date of production. Then they compress and strap the components together. Elsewhere, a computer-guided machine punches out a pattern on brass sheets. These will become what are called "headers". There's one on each side of a radiator. The punching tool then changes to a knife, which now cuts along the perforation lines. Using a press, they bend each header. Then punch slots for the radiator's tubes. Now, using a mallet, they hammer the headers onto the ends of the tubes. The banging inadvertently closes a few tubes, so they use a special roller to reopen them. After cleaning the surface, it's into an oven at 600 degrees fahrenheit. In just two minutes, the lead melts, fusing the tubes and cooling fins. After straightening out any crooked tubes, workers dip the headers in a tank of hot-liquid lead for 30 seconds. This solders them to the sides of the radiator. They apply a few drops of lead on the corners for reinforcement. The headers and tube openings are now encased in lead. Workers now feed a sheet of brass into a press to form the tanks that go onto the headers. One contains a brass tube. Hot transmission oil enters one end of it and exits the other, cooling along the way. Once workers finish soldering the tanks to the headers, they solder on what's called the filler net, a spout for pouring antifreeze into the tank. On the opposite tank, they solder on a water-intake pipe. This will be the entry point for the fluid heated by the engine. Finally, they coat the finished radiator in an asphalt-based black paint. The asphalt content makes the paint heat resistant and protects the radiator's cooling fins. Which came first, the chicken or the egg? It's an age-old question, and we can't give you the definitive answer. But we can take you to a hatchery to see how baby chicks are bred. It's the first step in commercial chicken farming, or the second step if you think the egg came first. Chicks come from eggs fertilized by mating, but a hen can lay eggs without mating. Those unfertilized eggs are the ones we eat. The fertilized ones go to the hatchery three or four days after being laid. Hatchery workers transfer the eggs onto special trolleys, then roll them into the incubator, where the temperature and humidity level mimic natural conditions. The egg yolk, egg white, and shell all nourish the embryo. Every hour, the trays shift 45 degrees to the opposite side and back, simulating the way hens turn their eggs while waiting for them to hatch. After 18 1/2 days, the eggs come out of incubation and go onto a conveyer belt. They pass under an infrared sensor that checks for eggs that are too transparent. These are unfertilized eggs that slipped through. The sensor triggers a suction device to remove them. They go to a rendering plant to become animal feed. The fertilized eggs continue along to the next station to be vaccinated against marek, a poultry disease. Automated needles pierce a hole in each shell and inject a vaccine into the amniotic fluid surrounding the chick. Now a suction device transfers the eggs to hatching trays, 168 eggs per tray. About 150 of them can be expected to hatch. The rest die in incubation or have physical defects. Day 19--  the chicks use their beaks to crack a hole through the shell, then a horizontal line all around. After six to eight hours, the chicks finally emerge from the shell. They're covered in short feathers called "down," and they're able to walk and see. After about four hours, their down has dried. Now workers roll the chicks to what's called the separator, a machine that separates the birds from the shell halves. The shells are larger than the chicks, so they stay on top while the chicks fall down to a conveyer belt below. The shells, which are high in calcium, go to a rendering plant. The chicks move on to be classified according to gender. Workers put the females down one chute, the males down another. They determine the sex by checking two rows of feathers. If one row's shorter than the other, the chick's a female. If the rows are the same height, it's a male. Each chute feeds a separate conveyer belt. An optical counter tracks the number of males and females. The chicks now fall into specially designed transportation boxes, 102 chicks per box. Some clients request that their order of chicks be vaccinated against bronchitis. Those boxes pass under an aerosol sprayer that sprinkles them with a mild dose of vaccine. Poultry farmers raise chicks for their meat or eggs. Females used for egg production begin laying eggs at about 20 weeks of age. For meat production, females reach slaughter weight at about 38 days. Males, depending on market size, take from 40 to 65 days. If you like greek food, then you've probably tasted baklava. It's made with a paper-thin, flaky dough called "phyllo," the greek word for "leaf". Phyllo dough itself is low-fat and cholesterol-free. Unfortunately, the stuff they usually fill it with isn't. Phyllo dough can be made by hand or by machine. Either way, it starts with the same dough recipe. The proportions are roughly 40% water to 60% flour. They use two types of wheat flour-- high-protein flour to make the dough strong and flexible and low-protein flour to make its texture smooth. They also add sorbate, a preservative, to increase shelf life. After about 15 minutes of mixing, the dough is ready. They cut off a section and feed it into a machine called the divider, which transforms it into a cylindrical wad. They hand-roll the wad into a rough ball, then feed it two or three times through a machine that kneads the dough into a rounder, harder ball with no air bubbles trapped inside. They can tell when it's ready just by feeling it. Then a machine called the sheeter flattens the ball into what looks like pizza dough. Workers stack about 30 sheets with craft paper in between to absorb some of the moisture. Now the key step--  opening the dough. First, they lay a large cotton cloth over the work surface. It must be 100% cotton to absorb the moisture. Otherwise, the dough would stick together. They take the sheet of dough and begin stretching it by hand until it's approximately 27 square feet. Even though the dough is stretched thin, it doesn't tear. This is due partly to its protein content and partly to the skill of the worker. They repeat the process with all 30 sheets, stacking them one on top of the other. Then they take a plank of wood, called a "sanida" in greek, and roll the dough sheets onto it one by one, removing the cloths that were in between. They sprinkle corn starch on the dough, just enough to prevent sticking. Too much corn starch will burn the dough. Now they move the sanida to another table and cut along one side of the dough. They remove the wood and open the sheets flat. Then they cut rectangles measuring 13x17 inches, standard phyllo size. Each sheet of phyllo dough is about as thin as a sheet of tissue paper, but it's strong and flexible enough not to tear when a baker works with it. Machine-made phyllo dough is a much faster method, used primarily for mass-produced frozen-food items. An automated machine called the stretcher transforms a big wad of dough into a thin, flat sheet, applying just the right amount of corn starch. A continuous air current coming from underneath creates an air bubble. The height of the bubble tells them whether the dough is the right consistency. The dough dries under infrared lamps. This step is necessary because this method doesn't use craft paper and cotton cloths to absorb the excess moisture. The dried sheet of dough rolls onto a spool. They cut along the side to release the dough and lay it flat. Using a template, they cut the standard size rectangle, yielding about 800 sheets of phyllo dough. They roll about 20 sheets together at a time and wrap them in plastic. Then, they vacuum-pack and heat-seal the package. Phyllo dough stays fresh for six weeks in the refrigerator, six months in the freezer. Cross-country skis used to look pretty much all the same-- long, narrow, and wooden. Today's skis, however, come in many different styles, specifically designed for the many types of cross-country-- telemark, back-country, all-terrain, touring, and racing. Archeologists in scandinavia have uncovered ski artifacts 5,000 years old. These stone-age skis enabled people to hunt during the winter. Skiing became so vital a means of transportation that the vikings worshipped a god and goddess of skiing. 19th-century scandinavian soldiers wore skis in winter warfare. They held races in their spare time, turning cross-country skiing into a popular sport. From there, it just snowballed. One way to make cross-country skis is compression molding, a process that uses heat and pressure to bond the components together. First, a computer-guided blade cuts out what will become the ski's underside, called the gliding surface. It's made of pre-assembled fiberglass laminate and polyethylene thermoplastic, a friction-resistant material. They lay it into the bottom half of a mold, then glue on steel edges for grip. This spray makes the adhesive dry faster so that they can apply the principle adhesive-- epoxy. A rubber shock absorber goes on the back, followed by a durable plastic reinforcement called the heel-piece protector. The ski's wooden core is made of aspen and birch laminated together. Next comes a sheet of fiberglass impregnated with epoxy for extra reinforcement. The wood core is now sandwiched between two high-resistance layers. Then, for decoration, a plastic film with a silk-screen design. With everything now in the bottom half of the mold, they clamp on the top and tape it up to ensure nothing shifts out of place. Then it's into a press that compresses the mold and heats it to 185 degrees fahrenheit. This activates the epoxy, hardening it in 12 to 15 minutes, depending on the thickness of the ski. Now they do a rough cut to trim off the excess. Then they sand all the edges until they're smooth. They run the gliding surface across a grinding stone, that white object you see below. This extra step is only for the higher-end models. Another way to make cross-country skis is by a process called reaction-injection molding. First, they place the skis' top layer, a fiberglass-epoxy sheet, in the mold... Then the gliding surface, made of pre-assembled fiberglass laminate and polyethylene with a high-resistance backing. Instead of a wooden core in the middle, this press injects a super-resilient plastic. In just three seconds, the injection phase is over, and the reaction phase begins. This demonstration shows what happens. First, the polyurethane inflates... Then it hardens. After eight minutes, it's hardened enough to come out of the mold. They let the ski cure for up to eight hours, at which point it's strong enough to support the weight of a skier. Now, these three components-- the top layer, the polyurethane middle, and the gliding surface--  are one. Now comes the finishing. First they trim and bevel the edges. They sand the gliding surface. Then they carve a groove down its length. This gives the ski directional stability. All that's left to do now is decorate the skis. First the background color and a quick-drying, solvent-based lacquer. They apply the design manually, one color at a time, using the silk-screening process. A typical design consists of five to seven colors, including the background. To keep the skis looking vibrant, they protect the paint with a coat of transparent varnish.