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Know Your Plastics Series: High-Density Polyethylene (HDPE)

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Identifying Synbol for HDPE/PEHD resin. Sometime in the 1930s, during the Second World War, the first HDPE was created, in the United Kingdom. Its first application? High-frequency radar cables. Fast forward 20plus years, the United States took on the commercial production of HDPE and, the polymer plastic has garnered popularity ever since. What is HDPE? A petroleum-based thermoplastic  (click for more on thermoplastics) , High-Density Polyethylene (HDPE) AKA Polyethylene High Density (PEHD) is widely renowned for its excellent strength levels –an outstanding strength-to-density ratio, tensile strength and specific strength. This strength is possible because HDPE polymers have little or no branching. The "little or no branching" characteristic results in significantly stronger intermolecular forces that make HDPE harder and more resistant to temperatures of up to 120  0 C (248  0 F) for short periods. This property also makes HDPE resistant to a lot of acids, caustics

Know Your Plastics: Polyethylene Terephthalate (PET or PETE)

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Different PET products For every container used for soft drink and water, shampoo and liquid soap, cooking oil, food dressing and spread and; For every oven food tray, roasting bag, curtain, upholstery, thread, tyre cord filament, industrial fibre, and industrial filtration fabric, you are more than likely looking at a plastic product made of Polyethylene terephthalate. Still in doubt? Look for the inscription “bubble” or the recycling code “1” encased in a triangle of chasing arrows on the container or the item itself and, there you have it! You have identified a polyethylene terephthalate AKA PETE AKA PET! Polyethylene Terephthalate recycling code and acronyms Background The very first preparation of PET was made during a 1940 study of phthalic acid by Rex J. Whinfield and James T. Dickson of the Calico Printers Association, England. However, the war at the time delayed the publication of its patent specification. This stalled the production of the Terylene fibre by Imperial C

Know your Plastics Series: Polymers

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Plastic is everywhere! Plastic is in everything! Plastic has pervaded every aspect of human existence and is as commonplace as the sand on the seashore. Its benefits are numerous and have been discussed in some detail in the preceding article in the Know Your Plastics Series ( Click here to read ). However, its major disadvantage is improper disposal and recycling of plastics when discarded. To recycle plastic material more effectively and efficiently, one must understand the components and constituents of each plastic-type, known as polymers What is a Polymer? Hermann Staudinger, an organic chemistry professor at the University of Applied Sciences in Zurich in the 1920s is the “Father of Modern Polymer development”. His discoveries in macromolecular chemistry earned him the 1953 Nobel Prize in Chemistry. Monomers in a Polymer A polymer is any natural or synthetic substance made of multiple, identical, repetitive units of smaller molecules, AKA monomers, which are bonded tog