"After months of frustration, we had grown used to seeing blobs of resin caked on the mold..."
Nathaniel Wyeth
The humble plastic bottle is now one of the most commonly recycled household objects. But it was the product's cheapness and durability that led to its popularity over glass bottles. Nathaniel Wyeth (1911- 1990), a U.S. engineer, worked on the invention for almost a decade. When he asked a colleague if plastic could be used to store carbonated beverages such as Coca Cola, he was told that they would explode. A series of early experiments proved that carbonated beverages caused the plastic to expand. Obviously, the plastic was too weak, but the plastic could be strengthened if the long strands of molecules that form plastic were woven together. Wyeth knew that nylon gets stronger when its molecules are stretched and aligned, and developed a pre-formed mold that forced the nylon threads to interweave when plastic is extruded into it.
Molten plastic was lowered into the bottle-shaped mold and air shot through the plastic to spatter it all over the mold and create a form through layers of weaving. Initial results were far from successful, and Wyeth took nearly 10,000 attempts to solve what he termed the "pop bottle problem." He finally replaced the nylon and polypropylene material he had been using with polyethylene-terphathalate (PET), whose superior elastic properties guaranteed a transparent, resilient, wholly recyclable plastic bottle.
The bottle was quickly taken up by the booming soft drink industry and it was estimated that by 1999 ten billion bottles per year were being produced. Almost half of the polyester carpet made in America today comes from recycled plastic bottles.
