Plastics. There’s a great future in plastics. Think about it. let’s look more closely at some of the most common plastic resins that we use daily and how they were first developed or discovered. We hope that you will not only find this interesting but that it will also help to clarify the resin that best suits your needs. And please note that we’ll be considering only the most generic resin types. There are many formulations from different manufacturers, so before you choose any resin make sure you read and understand the material datasheet. Click Here to find some great online resources for important material characteristics.
#1 Polycarbonate or PC
First discovered by accident way back in 1898 in Germany, PC wasn’t synthesized or commercialized until 1958 by Bayer, under the trade name Makrolon. GE came out with their version, Lexan, in 1960. PC is similar to another clear plastic, acrylic, but it’s stronger and more temperature-resistant and thus more expensive. PC can be made as transparent as glass, and along with its high impact resistance. it’s great for hockey rink windows, safety helmets, lenses, and compact discs. With the application of low heat, it can easily be bent or folded like sheet metal, thus its popular use in Polycarbonate CNC Machining. PC is not great, however, for resisting solvents and oils and most varieties are not food-safe because they contain BPA. It also scratches easily and so the surface needs a scratch-resistant coating.
#2 Polyamide (PA) or Nylon
PA was invented in 1938 by Dr. Wallace Caruther’s team at DuPont, nylon was originally intended as a substitute for rayon or silk in the making of women’s hosiery, which had become ever more fashionable, and even necessary as hemlines got higher. Silk at that time came mainly from Japan but this supply became endangered because of World War II. Hugely successful, nylon was the first example of a truly engineered synthetic compound, designed as the result of pure research rather than being accidentally discovered through experimentation. With the advent of World War II, nylon was used to make ropes, parachutes, nets, and gas tanks because of its durability and resistance to hydrocarbons. Nylon is strong, lightweight, and heat-resistant and can be strengthened with the addition of glass fibers to make mechanical components that have good durability and low surface friction. And, of course, nylon fabric is still very common in outerwear. However, nylon does absorb water over time and it’s not resistant to strong acids or bases.
#3 ABS(Acrylonitrile Butadiene Styrene).
This very useful plastic was introduced by Borg-Warner in 1954. It’s stronger than nylon, easy to mold, and more impact-resistant, so it’s considered an engineering-grade plastic. You’ll find ABS in CNC machining, gears, shafts, and other light-duty mechanical components. It’s also a good insulator for electrical connectors. ABS is used to make sporting goods, toolboxes, typewriter keys, and, famously, Lego bricks. Additionally, ABS is sometimes combined with PC to make PC-ABS, which improves overall strength and enhances moldability while maintaining tight molding tolerances and CNC machining. One potential drawback is low UV resistance, which caused one of the biggest automotive recalls in history in the 1990s due to faulty seat belt actuators.
#4 Polyethylene or PE
Another accidental discovery, PE was first identified in 1898. but it wasn’t until the early 1950s that chemists in Germany and the Netherlands tried to synthesize it on an industrial scale. Philips Corporation had a process that wasn’t stable and they ended up making tons of non-conforming plastic that nearly bankrupted the company. That is until all that scrap material was bought up by the American toy company Wham-O who, in 1958, needed a huge supply of cheap and available plastic to keep up with a sudden worldwide craze for Hula Hoops. Now PE in various formulations is the single most common plastic in the world. It’s found in numerous food containers and packaging, plastic bags and shrink wrap, and even gears and bearings. PE is flexible, versatile, tough, and chemical-resistant. But because there are so many varieties with different melt temperatures it can be hard to sort for recycling.