The trade calls it single usage plasticware but that is just industry speak for throw away plastic dishes, plastic plates, bowls, drink ware and cutlery. They come in many styles and colours so for your next party you can go for the recycled option even with champagne flutes. Factories make pottery by injecting plastic into moulds; however they make cups, plates and bowls using a different process called thermoforming.
Before the forming phase can begin, an automated system loads polystyrene pellets into a machine called an extruder. The extruder heats the pallets until they melt, then it forces the molten plastic through a die to shape a hard plastic sheet about two millimeters thick. The factory uses moulds to form this continuous sheet into plastic cups. First, the sheet passes through a three-metre long oven that heats the hard plastic until it becomes malleable. Then it enters the thermoforming machine which simultaneously pushes and vacuums the sheet into the mould cavities, forming row after row of cups.
The entire process takes just three seconds. The cops then travel to the trimmer, which uses a dye to cut them off the sheet and the machine grinds up the leftover plastic and melts it into new sheets so there’s no loss of material whatsoever.
The trimmer feeds the cups directly to a machine that stacks them, then feeds them to a conveyor belt in one long line. The conveyor transports them to a machine called the lip roller which reheats the cups just enough to make the plastic flexible. It folds the rim over forming a rounded lip.
Cutlery can also be made from melted polystyrene pellets as well as from polypropylene, a lighter more flexible and less expensive type of plastic. The cutlery moulds consist of two halves. In one half the utensil cavities are the right side up and in the other half the cavities are upside down. A plastic injection machine melts the pellets and injects the molten plastic into the mould. A built-in cooling system solidifies the form in about 10 seconds and the extracted cutlery drops to a conveyor belt that leads directly to the automated packaging equipment for certain customers such as fast food restaurants. A factory packages utensils individually; the automated wrapping machine cuts polythene film to size, heat sealing the ends.
A factory can also use polypropylene pellets to make straws. The black beads are pickles to colour the plastic. An extruder melts the pellets, then forces the molten plastic through a circle shaped dime. As the long continuous straw leaves the extruder, it cools and hardens in a tank of chilled water. The giant straw is then cut with a knife into individual straws, which fall onto a conveyer belt which transports them to the packaging line. Just like the forks, these straws will also be individually wrapped but in paper and not plastic film.
The wrapper machine feeds them one by one into a paper sleeve. Gears mesh the edges together, creating a crimped seal. The dyes on this machine turn ordinary straws into flexible ones by forming a corrugated section that allows for bending at the top of the straw. The machine compresses the corrugation to preserve the shape. A factory can print customised designs in up to six colours applied simultaneously. Ultraviolet lamps built into the printing press dry the ink instantly. And when you are using disposable party ware, remember to never overfill a plastic plate at a party as it could prove to be embarrassing!