Acrylic: Still Performing 75 Years On

ACRYLIC DURING WARTIME 

Watching the emotional footage of the RAF Spitfire and Hurricane flypast Captain Tom Moore’s home in Marston last week, we thought it only right (and timely with VE Day 75 today) that we celebrate one of the fabulous materials discovered and used on aircraft in the early days of WWII … acrylic!

PREFERABLE EQUIVALENT TO GLASS

As a lighter, impact resistant and rigid equivalent to glass, acrylic has always offered product designers, engineers and innovators plenty of advantages.  That’s why they used it during World War II (on both sides!) on air and underwater based frontline machinery; submarine periscopes, turrets, airplane windows and airplane canopies.

Half the weight of glass, acrylic canopies were introduced shortly before WWII on the Supermarine Spitfire and Westland Whirlwind and are still used on fighter aircraft today, giving pilots better visibility, even when consistently exposed to adverse weather conditions, higher impact strength (acrylic withstands much more energy before breaking), greater peripheral vision and a lot safer than glass when shattered.

More well-known by its trademark terms Plexiglas® and Perspex, acrylic – or PMMA (polymethyl methacrylate) as our product design geeks refer to it – offers product innovation and development teams fabulous properties when it comes to material selection for plastic injection moulding projects.

ACRYLIC IN UK MANUFACTURING

PMMA is often used in UK manufacturing and suggested in the design for manufacturing process because of its’ increased transparency, UV and scratch resistance.  Commonly found moulded over cars’ rear lights, instrument clusters in vehicles, lenses, medical devices and as enclosures for exhibits.

We’ve recommended the use of it in many projects, including for UK developer and manufacturer of advanced yachting instrumentation systems B&G The BEC team have worked closely with their product innovation team for over 30 years, manufacturing a wide range of plastic injection moulded products including injection moulded components.

As engineers we find acrylic easier to machine, drill and with a little heat can be easily moulded and shaped.   But decades in this game have taught us that it is always worth checking external factors which can affect the end product in its final environment.  Whilst acrylic is great, some chemicals can be detrimental to its performance and can affect it badly, but our product design and development team have loads of experience and can help with that:

Pros

· Excellent transparency
· Good optical qualities
· Weather resistance very good (retains optical clarity for many years)
· Flexibility and dimensional stability
· Good resistance to scratching/abrasion (coatings available to improve it!)
· UV resistant
· BPA-Free alternative to Polycarbonate
· Food contact grades available

Cons

· Can be brittle compared to other resins
· Not the best chemical resistance

Did you know?
The deep-sea submarine Trieste had conical windows made from acrylic – 17cm thick!  In the Mariana Trench (the deepest oceanic trench on Earth!) at a depth of 30,000 feet the pressure was more than 6 tons per square inch!  That’s pretty strong!

If a lighter, flexible alternative to glass is what you’re after, then perhaps acrylic is the right material for your NPI? Call our team of plastic injection moulding experts to discuss further, we’d love to help (and we love a challenge!).  Give us a call on: 01425 613131 or email us.