Chemical Tank Pressure Vents Candy Wafers Food Trucks Traditional Ropes
Today, on "how it's made"... It's common for pressure to build up inside chemical tanker trucks during transport. Special vents regulate that pressure, preventing any unwanted gas build-up, which could lead to an explosion. Pressure relief vents are standard equipment on chemical tanker trucks. They ensure tanks can hold up to the pressures inherent to this industry. Production starts with a bin of wax pellets. They use pellets to make models of the vent's parts in a process called lost-wax casting. Pellets are fed into an injection machine. The wax melts into a mold of the vent's lower housing. Four wax models are fused to a single wax tree stand. The tree stand is left to cure for a couple of hours. Once cured, a worker dips the wax tree into a slurry of ceramic. He removes the stand of wax models, then twirls it to drain any excess ceramic. This is the first of several ceramic coatings. Between coatings, he applies silica sand to the wet ceramic. The sand rains down onto the ceramic, creating a stucco effect. The first layer of stucco is finally granulated. The next few layers will be coarse. By building up progressively coarser layers of stucco, he creates a ceramic shell with the desired thickness and strength. The final layer of sand is very coarse. Air pumps through the sand as the worker dumps the models. This process ensures uniform coverage of the heavier sand. They bake the forms next, melting out the wax and hardening the ceramic into shells. Next, a team pours blazing liquid steel into a ladle. The ceramic shells have been heated to around 3,000 degrees in an oven. Workers pour hot, liquid steel into the hollow tree. They add a chemical sealer, then top the molten metal with a piece of ceramic-fiber insulation. After about 3 hours in an oven, the steel castings are solid. A worker shatters the ceramic, revealing the vent-housing parts. A powerful circular saw slices the parts off the tree. Workers clean off any ceramic residue. Computer-guided tools calibrate the pressure-vent housing part to precise specifications. After cleaning and polishing, the part is complete. It's time for assembly. The worker starts with the top of the pressure vent. A large spring is inserted to aid pressure relief. A metal plate is added to seal the top of the vent to the lower part. The lower vent housing is then seated on the metal plate. He moves the assembly under a hydraulic ram. The ram presses the lower housing, the sealer plate, and the spring to a specific tension. He then screws the lower housing to the top of the vent. A metal ring inscribed with the vent's model and flow rate is attached at the top. This chemical tank pressure vent is now ready for testing. The technician screws it to the test stand. He activates a system that forces compressed air into the vent. This confirms whether the vent works at the desired setting. Once approved, he attaches a cover to shield the vent from rain and snow. The trackable serial number is etched into the top using a laser. This vent is now ready to prevent hazardous situations. The candy wafer is a classic american treat. Invented in 1847, it's a thin, lightweight disk of sugary candy. It's softer and dissolves faster than hard candy. You can bite into it right away or let it melt in your mouth. These candy wafers come in eight different flavors. The original roll has a random assortment of 38 pieces. Part of the fun is seeing how many of your favorite flavors you get. This factory makes one flavor at a time. The first step is to add food coloring and flavoring to pulverized sugar. This pink color and mint flavoring produces a wintergreen taste. Corn syrup comes next, along with a binding solution of vegetable gums and gelatin dissolved in water. After mixing for about 8 minutes, the candy dough's consistency is checked. If it isn't thick, elastic, or sticky enough, more binding solution is added until the dough is just right. Workers divide the dough into chunks, then feed them into a dough shooter. This is the first station on the wafer-forming line. The black dough is licorice flavor. A conveyor returns leftover dough from the end of the line to be reused for making new wafers. They're pushed through a slot, forming the dough sheet that's 20 inches wide by about an inch thick. This yellow dough is lemon flavored. A steady sprinkle of cornstarch prevents the sheet from sticking to the equipment. Rollers compress and stretch the dough forward, flattening the sheet to an inch thick. The next station stamps on the company logo, then cuts out the wafers. The cutter moves up and down 180 times per minute. The wafers fall through a gap to a moving conveyor belt below. The conveyor belt moves the wafers to a multilevel tunnel dryer. They pass through the dryer 13 times over the course of an hour. These green wafers are lime flavored. The dryer temperature is about 150 degrees fahrenheit, warm enough to remove half of the moisture without melting the sugar. These brown wafers are chocolate flavor. Once out of the dryer, the wafers pile up in trays without sticking. Workers stack the trays in a drying room. It's heated and humidified with steam. The candy wafers stay here until their moisture level drops to between 0.75% and 1%. The factory tests a few samples using a device called a penetrometer. It measures the force required to penetrate the candy wafer to the point of breaking it. This ensures the candies are the correct consistency. When the trays come out of the drying room, workers send the candies to the packaging line. The colors are mixed together, ensuring every roll of candy has a random assortment of flavors. The wafers flow into channels, which stand them on their sides. Workers grab about two rolls' worth, then fill two channels of a feeder that takes them to the wrapping station. Another worker fills in the gaps, ensuring each roll has 38 pieces. The wrapping machine cuts printed, translucent paper wrapping and applies a bead of glue to one edge. In a matter of seconds, the machine lifts the roll into the wrapper, seals the edges, and twists the ends closed. As the sealed rolls move on a conveyor belt, heated blocks iron the twisted ends flat. Each candy wafer roll weighs 2 ounces. Workers pack 24 rolls per retail box, then pack the boxes in shipping cases. In addition to a traditional roll with assorted flavors, the factory also produces chocolate-only rolls. Production has modernized over the years, but the recipe itself hasn't changed much since the first candy wafer rolled off the production line in 1847. Food trucks used to only sell sandwiches and other prepackaged food. Not anymore. The modern food truck is a mobile restaurant with a full kitchen inside. Food is cooked fresh and sold to customers through a service window. Most food trucks are standard panel trucks. Their cargo area is a fully equipped commercial kitchen with a service window on one side. They're usually customized by boutique companies, so there's no standard method. However, certain modifications to the panel trucks are common, like enhancing the truck's suspension system or reinforcing the flooring and walls to support the kitchen's weight. The lighten the load, this company builds the kitchen's structural components out of aluminum bars rather than heavy steel. Once the pieces are cut, a worker assembles, then welds them together. This structure will support a stainless-steel countertop. Workers cut the countertops and cabinets from thick sheets of stainless steel. They bend the sheets using a machine called a press break. For this countertop, they bend a 90-degree angle on the front end to form a 1.5-inch square edge. To construct walls and ceilings, they rivet thin sheets of stainless steel or aluminum to panels of wood. Fire-retardant plywood is used for the kitchens. The boards are installed over styrofoam insulation. They leave the truck's aluminum floor as is. Once the walls, ceiling, and flooring are complete, it's time to install the kitchen's cabinets and counters. Workers screw each counter support to the wooden structure of the wall, then fasten the countertop with rivets. They peel off the film that was protecting the stainless-steel surface. Next, they install the major appliances, which include a commercial refrigerator, freezer, and cooking equipment. Then the electrical box is installed. They connect wiring for the outlets, lighting, water heater, water pump, and air-conditioning system. The generator is installed underneath the nearest counter. It supplies the truck with electricity. Next to the electrical box is the power-transfer box. It contains a switch that enables the truck to use an outdoor power source. The switches for the interior and exterior lighting are underneath the electrical box. Workers install the light fixtures, cabinetry, sink, and serving window. They also install the gas lines that power the commercial cooking equipment. This truck has several gas appliances-- a six-burner gas range with large oven, a deep fryer, a charcoal grill, and a flattop cooking surface. The kitchen is equipped with a ventilation hood over the cooking area. Its powerful fan gathers smoke and sends it out a vent on top of the truck. It's time to outfit the exterior. Some food trucks are painted, but most use graphics that are digitally printed on adhesive vinyl. After positioning each panel of the design, they apply heat with a torch. This removes trapped air, stretching the vinyl over rivets and other protrusions. This mobile eatery is ready to roll with a kitchen that meets fire-code and food-service regulations. It may not provide the ambiance of a sit-down restaurant, but when a food truck pulls up, you never need a reservation. Rope has been made out of plant fibers for centuries. Stronger synthetic and steel cords are available, but there's still a market for traditional twine. They have their own unique strengths, and that's why we are still bound by their ties. Woven from manila, sisal, or flax fibers, traditional ropes are a binding element in our world. They're easier to grip and stretch less than synthetics. At this deep and narrow building, they've been twisting fibers into rope for more than two centuries. They're still producing rope the old-fashioned way. The process starts with racks of natural-fiber yarns. The yarns are funneled through separators, which configure them to twist evenly together. The fibers then travel through tubes that squeeze them into bundles. Workers tie the ends of the bundles onto a wheeled vehicle called the forming machine. They roll the machine back until there's no slack in the bundles. The machine is then sent to the opposite end of the factory, over 1,000 feet away. As the machine travels backwards, its gears turn hooks, twisting the yarns into a tight configuration. The formation of the twists ensure an even distribution of tension. This is what makes rope so strong. This long, indoor space is called a ropewalk. There aren't many of them left in the world. Halfway down, a worker places a trestle underneath the twisting yarns. This keeps them off the floor and prevents tangling. When the machine reaches the back wall, it stops, and workers cut both ends of the strands. They tie them to posts to maintain tension and prevent unraveling. The twisted fibers stretch from one end of the building to the other. On one side, they tie three of the strands to a machine that will transform them into a rope. Halfway down, they bring in a cart that holds a piece of grooved wood known as a top. They tuck the twisted strands into the grooves of the top. They then roll the cart down to face the rope-making machine. A worker ties rope around the strands in the top. This holds them in place as the rope-making machine twists the three strands into one. The cart rolls along rails propelled by twisting action. It leaves newly formed rope in its wake. The rope machine with twisting hooks remains in the same place. When the cart arrives at the opposite side of the building, the rope is formed. A worker removes the ties around the top. They now have a piece of rope that's over 700 feet long and almost 5 inches in diameter. They slice the rope at both ends. Then they wind it onto a big spool, packing it into a tight coil. This traditional rope is almost ready to be shipped. The customer requested looped ends for securing the rope with a shackle. So, the rope-maker unravels the ends and pierces the rope with a hollow tool called a fid. He makes a loop and slides the unraveled strands through the fid. He finishes the job by weaving the strands into the rope. They're ready to test a segment of the rope. Two hydraulic jaws pull it until it breaks. The rope must be able to handle 55 tons of force. Traditional ropes have the strength to carry on, as they have done for a very long time.