Polycarbonate Enclosures Vs. Fiberglass Enclosures

Overlooking the advantages of polycarbonate could be a costly mistake for outdoor and industrial applications. The benefits of purchasing a polycarbonate enclosure instead of fiberglass can be found in the strength of the enclosure, its durability, and its modification possibilities.


Polycarbonate enclosures can withstand over 900 pounds of impact, which is more than four times the impact resistance of fiberglass enclosures, which is calculated at about 200 pounds. This also makes it more durable during the shipping process.

UV Light Resistance

When fiberglass enclosures are exposed to UV light, their outer coating fades and the fibers are then exposed to direct UV rays which cause the material to “bloom” and deteriorate. In contrast, Integra mixes a UV inhibitor into the material before the enclosure is molded, making it present throughout and unable to wear away. Integra’s polycarbonate enclosures are injected molded which means they are single piece construction.

Polycarbonate is a strong, durable material that withstands the harsh conditions of the outdoors and ultimately lasts longer than fiberglass enclosures. It is also used in car windshields and headlights, because unlike fiberglass, this highly durable plastic maintains its shape, color, and strength even when exposed to direct light. The benefits of polycarbonate in solar applications are unmatched.


One of the major differences between polycarbonate and fiberglass enclosures is their modifiability, which includes machining during production or adjusting in the field. When modified, fiberglass enclosures give off a very fine dust that is irritant to the skin, can be dangerous to inhale, and is so fine it is hard to clean up. Polycarbonate enclosures produce small curls of material that can be easily swept away and are not dangerous to touch or inhale.

Because fiberglass is made up of interwoven fibers, the material is also more likely to splinter while modifying, which causes waste. Polycarbonate enclosures can be easily modified in the field using standard tools without being damaged or causing health concerns. It’s also a fully recyclable material at the beginning or end of the product’s life cycle.

NEMA Rating

All Integra polycarbonate enclosures are NEMA 4X rated, which means that these enclosures are watertight and can withstand direct water spray.

Integra also has a special NEMA 6P rated series that can be submersed in up to 6 feet of water for up to 24 hours. These are particularly useful in Marine applications as polycarbonate is resilient against saltwater corrosion.

Appearance Features

Polycarbonate enclosures also have a cleaner look than fiberglass, especially when exposed to time and the elements. Integra offers custom color and design options for polycarbonate enclosures to match your application and company branding. These enclosures are molded using colored plastic, so the pigment shows all the way through and won’t scratch off or fade like painted fiberglass enclosures. Integra also offers clear and smoked covers to finish the look.

Check out our Battle of the Boxes article for more detailed  information on how polycarbonate stands up to fiberglass.

For more information contact us online or call 440-269-4966 to speak with an expert.

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