Plastic has been user in firearms for decades - the Remington Nylon 66 was introduced in 1959 - but only recently in components other than stocks. Perhaps the best know weapon with a plastic stock is the M-16 of the Vietnam era. Now plastic frames, magazines, triggers and guards, and other components are routinely found in all types of firearms.
More on topic with the automotive direction of the blog, does anyone remember the Polymotor® from the mid to late 90's? As I recall most of the components, inluding the block and head, were made of plastic with metal inserts in high wear/high stress/high temperature areas. I believe the entire engine - it was a 2.0 liter 4 cylinder racing engine - weighed ~ 200 pounds.
naperlou, thanks for that input: plastic in firearms is a new one to me. That must be a very demanding application: heat, force/impact, etc. In automotive lightweighting, much of the materials design effort is to combine lighter weight composites and plastics with additional safety features.
@Ann: Well, I'm not sure which metals SABIC is thinking of which crack or fade from exposure to high temperatures or ultraviolet light! (Certainly not if "high temperatures" are defined as temperatures which would be high for plastics).
As far as fiberglass is concerned, I don't doubt that PC and PC/ABS have better weatherability than a fiberglass-epoxy composite. But I think they are trading one problem for a potentially worse one. Fiberglass has excellent chemical resistance. With PC and PC/ABS, you now have to worry about splashing gas or oil on the hood of your tractor. (Not to mention pesticides and other chemicals).
An injection molded hood will be cheaper and lighter than a compression molded composite hood or a formed metal hood. But I'm very skeptical of SABIC's claim that the performance will be better.
PC and PC/ABS might look attractive compared to other injection molding resins because of their impact strength, but their chemical resistance is not very good. Better choices might be BASF's Terblend, or Ineos' Triax, both of which are nylon-ABS blends. (They used to be competing products, but since BASF and Ineos combined their styrenics divisions into one company called Styrolution, they're now both under the same roof).
Thanks for that input, Dave. As the (correct) caption states, "The new formulation was developed to help overcome performance issues of fiberglass and metal, such as cracking or fading from exposure to high temperatures and ultraviolet light. SABIC's Lexan SLX resin is co-extruded over its Cycoloy resin and vacuum formed..." When talking to SABIC, they made it clear that they had worked closely with Apache to develop this material and overcome previous difficulties. The same goes for the white Volvo truck cab roof fairing made entirely from SABIC's Cycoloy polycarbonate/ABS resin, which they worked closely on with Volvo.
@Nadine- I have a keen interest in motorcycle and bike helmets as a rider of both and as an engineer. As others mentioned the best-performing motorcycle helmets use fiberglass, or lately Kevlar or carbon fiber for very high-end products. Polycarbonate is used for "budget" motorcycle helmets. They are heavier and there have been a few cases of splitting along mold lines in an impact.
You're correct that some of the new materials and processes in this article may shift the advantage back to plastics in helmets. (BTW, bicycle helmets are almost always a thin plastic shell with a thick polystyrene liner).
An aside- one big area for improvement is a truly "quiet" motorcycle helmet. The best helmets available still deliver 100+ db of wind noise at highway speeds, making earplugs a necessity. Most riders don't use earplugs...probably a source of regret in 10 years. (Mild tinnitus is my personal toll for not using them earlier)
I worked in the motorcycle business for many years. Helmets have always been the trickiest thing to make. Plastic helmets have been manufactured, but the best, lightest helmets have always been fiberglass. The reason is that the plastic shells were actually too durable! Thin fiberglass can be talored to crush and abrade at specific rates. The shell actually is designed to crumple like the front and rear zones of modern cars. The newest plastics will probably be able to take over soon, but so far the best helmets are fiberglass construction.
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