TECHNICAL REVIEW

Plastic Material

POLYCARBONATE (PC)Standard polycarbonate (PC) or Glassfibre reinforced (PC+GLAS)

Benefits: Very high impact resistance Also available in transparent form Easy machining with normal tools High lP rating Clean attractive finish Wide operating temperature range Self-extinguishing Good resistance to chemical attack Low weight Good UV resistance Excellent insulating properties Cost-effective material for harsh environments

Drawbacks: No EMC shielding

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ABS (Acrylnitrile-butadiene -styrene)

Benefits: Easy machining with normal tools Easy colouring through pigmentation Low weight Good resistance to chemical attack Excellent insulating properties

Drawbacks: Slightly lower impact resistance compared with PC Slightly lower operating temperature range compared with PC Slightly lower UV resistance compared with PC. Recommended for outdoor use if protected against weather influences Not available in transparent form No EMC shielding

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GRP -  GLASS FIBRE REINFORCED POLYESTER

Benefits: Excellent record of resistence to corrosion and chemical attack High impact resistance Rigid construction High weather resistance Wide operating temperature range Fire resistant Good insulating properties

Drawbacks: More expensive than PC Cannot be machined using standard tools No EMC shielding Heavier than other plastic enclosures

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Polycarbonate and ABS enclosure materials
The FIBOX thermoplastic enclosures are made of polycarbonate (PC) or acrylnitrile-butadiene-styrene (ABS) materials. High impact-resistant polystyrene (PS) enclosures are available to order.

Polycarbonate is an amorphous thermal plastic material whose high heat resistance and excellent physical properties make it an ideal material for enclosures. Polycarbonate can withstand a wide range of temperature fluctuations and its good electrical properties are unaffected by humidity. As a self-extinguishing material polycarbonate requires no protective coating.

ABS is another amorphous thermal plastic material with good physical properties and high resistance to chemical attack. It is an ideal cost effective material.

UV resistance of Fibox enclosures polycarbonate, transparent and greyVirtually all plastic materials are susceptible to degradation under the influence of U.V. radiation, but the quality polycarbonates used in FIBOX enclosures show high durability in this respect, too.

In European latitudes FIBOX enclosures can be used, without hesitation, in outdoor applications. Over the years a slight discoloration, especially of the transparent cover material, will occur. If this must be avoided, a sun roof is recommended.

In tropical latitudes the grey coloured material still performs with only some discoloration. This is due to the TiO used in the grey pigmentation in order to UV-stabilize the material. The transparent material, however, which absorbs the U.V. radiation throughout the material, will in due time (some years) not only turn yellowish, but the high impact resistance will decrease, see below. But more than lowering the impact resistance, the transparent materials allow the UV-radiation to detonate the components mounted inside the enclosure.

The polycarbonates used in FIBOX enclosures have been tested and approved by Underwriters Laboratories, Melville, N.Y. USA, in conformity with standard UL 508 par. 34; 16-22. This standard specifies testing 720 hours in ‘Weatherometer’ (intensified UV light combined with water spray). After testing the materials must retain 85% of the original values with respect to tensile and flexural strength, impact resistance, flammability, and glow wire ignition


UV resistance of Fibox enclosures ABS

ABS materials are less protective against UV rays if directly exposed, can be used if protected against weather influences.

Maintenance of polycarbonate and ABS enclosures
Polycarbonate and ABS enclosures require no actual maintenance. Any dusty units can be cleaned with soap and water. If a detergent is used, the enclosure should be thoroughly rinsed in clean water. Do not use any solvents.