Polyethylene terephthalate (PET) has become exceptionally popular as a packaging material thanks to its transparency, light weight and mechanical resistance. A linear thermoplastic comprising repeated ethylene glycol and terephthalic acid chains, PET is easily and widely recyclable, making it a smart choice for responsible packaging manufacturers. PET packaging is easily identifiable thanks to the #1 recycling code symbol on its base. First introduced in 1941, PET was initially utilized in the production of photographic films, video tapes and plates for X-ray images. Since the early 1970s when a double-axis orientation and blowing method of bottle making was found, PET’s use expanded from general packaging to beverage applications. PET bottle production sees ethylene glycol and terephthalic acid combine to produce small pellets of PET resin. These pellets are melted at temperatures of between 250 – 300ºC, creating a liquid which is then injected into molds to produce preforms. The required features of the preforms are created as the preform cools and crystallizes. The preform is then made flexible by heating it to 80º, with the final bottle shape created by placing the preform into a suitable mold and inflating it with a high-pressure stream of air. Today, PET is widely used for beverage, food, edible and non-edible liquids and powders, with PET largely replacing glass in the food industry and, increasingly, in the alcoholic and non-alcoholic beverage sectors.
