SpecialFocus

Elevating safety: Plastics for a secure aerospace

aerospace
by Andy Baumler, Spartech
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hen it comes to our modern world, we understand that every facet of our lives needs plastics. In aerospace, plastics transform a flying metal tube into a safe, durable and lighter-weight high-functioning environment that is aesthetically pleasing and comfortable. Plastics are an integral part of an aircraft’s ability to function and many parts using plastics are not there solely for the sake of a lightweight solution. Plastics used in aircrafts are engineered and designed to provide additional benefits, such as fire resistance, chemical resistance, visibility and strength.

interior aircraft cabins and seat components
Royalite® RoyalAero™ thermoplastic sheet provides a fire-rated, rigid acrylic/PVC solution that combines very high impact strength, tensile strength, stiffness and hardness with excellent formability, outstanding chemical resistance and deep-draw formability, making it the perfect application choice for interior aircraft cabins and seat components. Photo courtesy of Spartech.
Safety considerations in aircrafts

While flame-ratings are usually top of mind when considering which plastic works best for various parts in an airplane, it’s more than simple fire resistance. Plastics need to meet specific fire rating characteristics; but what does that mean?

The Federal Aviation Regulations (FAR) outline the following standards:

  • FAR 25.853 paragraph (a): How fast materials will burn (measured in vertical or horizontal burn test) – Flash fires cannot occur.
  • FAR 25.853 paragraph (a): How much melting may occur (observation of dripping/flaming material in burn test) – Material cannot spread the fire to other areas.
  • FAR 25.853 paragraph (d) Part IV & Part V: How much heat and smoke come off the materials if combustion occurs (OSU 65/65 test and smoke density test) – There cannot be smoke so thick so you cannot see an exit or too much heat to prevent you from getting to the exit.

All these requirements are carefully considered so that passengers have time to exit an aircraft in case of an emergency, but it is also important to consider some of the less obvious safety needs of various components.

Planes are subjected to many harsh conditions, both climate and chemical, on a day-to-day basis. Some plastics can withstand wide temperature swings and corrosive chemicals. Designers and engineers look for interior components that can withstand the constant use of cleaning chemicals that keep passengers protected from illness but are tough on the parts.

Those are considerations for the aircraft itself, but what about passengers, pilots and ground crews? Instrumentation panels which provide critical data to the pilots require plastics that protect them while also enhancing the visibility of the information displayed, whether it’s during the bright light of day or the dark of night.

While instrumentation plays a very important part in a pilot’s ability to get passengers into the air and back on the ground, visibility in the air and on the ground is also essential. The plastic materials of cockpit windows are highly engineered transparency systems that are designed to withstand high impact and resist scratching while providing the utmost clarity.

“In aerospace, plastics transform a flying metal tube into a safe, durable and lighter-weight high-functioning environment that is aesthetically pleasing and comfortable.”
edge-lit instrumentation panels
Polycast® Acrylic sheet options both unshrunk and preshrunk materials such as POLY II that is used in edge-lit instrumentation panels. Polycast® UV-SC is a custom cell cast acrylic sheet that blocks out significant near-infrared radiation while maintaining high visible light transmission. Photo courtesy of Spartech
Another consideration for pilot safety is the many hours spent in the upper atmosphere exposed to strong sunlight. Cell cast acrylic sheet that blocks out significant amounts of near-infrared and UV radiation, while maintaining high visible light transmission, helps lower temperatures and blocks harmful UV rays, protecting pilots.
We hope you enjoyed your flight!
For passengers on a flight, getting to the destination is the top concern. However, airlines looking to differentiate themselves, are also searching for ways to make passengers feel more comfortable and the interior aesthetics and feel of the aircraft aren’t to be overlooked. There are few limitations to the ways plastic sheet can be manufactured and finished to create a comforting and welcoming environment. Decorative and embossed films laminated to thermoformed plastic sheet can be a beautiful but cost-effective method for plane interiors.
Which plastic to use?
  • Seating and structural components such as bulkheads and galley areas use acrylonitrile-butadiene-styrene (ABS), polyvinyl chloride (PVC)/acrylic, PVC/ABS and thermoplastic polyolefin (TPO), possibly with laminated decorative films and/or embossing.
  • Flame-rated sheets are used in shims in batteries.
  • Cell cast and stretched acrylic are used in military, commercial and general aviation glazing applications for fixed and rotary wing aircrafts, including:
    • Aircraft transparencies
    • Helicopter bubbles
    • Cabin windows
    • Edge-lit illuminated panels
    • Wing tip lenses

Andy Baumler is the market development manager, aerospace & transportation for Spartech. For or more information, contact Spartech at 11650 Lakeside Crossing Court, Maryland Heights, MO 63146-8606 USA; by phone at (314) 569-7400; or online at www.spartech.com.