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FREQUENTLY ASKED QUESTIONS (faq)

For easy of use, our FAQs are separated into categories:

PLASTIC MATERIALS:

PLASTIC MATERIALS:

WHAT IS THE BEST PLASTIC MATERIAL FOR ELECTRONIC ENCLOSURES?

‘Best’ depends on many factors including the intended application and the harshness of the operational environment. But as a rule we favour a blend of acrylonitrile styrene acrylate and polycarbonate (ASA+PC) for strength and UV stability. ASA+PC is the standard plastic on many OKW enclosures (though other plastics can be specified on request).

From an engineering perspective, the value of ASA+PC lies in its stability over time. Many enclosure failures are not caused by immediate overload but by slow degradation after years of exposure and thermal cycling. ABS – once a ‘go to’ plastic for enclosures – can discolour and become brittle under UV light, even when used indoors. ASA+PC resists this ageing far better because it replaces the butadiene rubber found in ABS with an acrylic rubber that is resistant to UV light and weathering – dramatically improving durability in outdoor and light industrial environments.

PC+ABS is also an excellent plastic. It is the standard material on our rugged SOLID-BOX (IP 66, IP 67, IK 08) enclosures for industrial electronics. PC+ABS delivers a carefully balanced combination of properties that align closely with the wider demands of enclosure design, rather than excelling in just one area.

By blending polycarbonate with ABS, the material captures much of PC’s high impact strength, thermal resistance and dimensional stability, while retaining the excellent processability, surface finish and cost efficiency of ABS. The result is a material that performs reliably across mechanical, thermal, aesthetic and manufacturing requirements. PC+ABS offers strong resistance to impact, cracking and fatigue. Its toughness remains more consistent across a wider temperature range than ABS alone, reducing the risk of brittleness in cooler environments or softening near internal heat sources.

Despite its UV vulnerability, ABS remains popular in electronic enclosures because it offers a very attractive balance of performance, appearance and cost. For these reasons, it was the plastic of choice for many years (and was the standard material on many early OKW enclosures). ABS provides good stiffness and impact resistance for its cost. It supports thin-wall designs and delivers an excellent surface finish.

View this OKW guide for more information about plastics for electronic enclosures >>

ABS VS POLYCARBONATE: WHICH PLASTIC IS BETTER FOR MY ENCLOSURES?

ABS offers excellent electrical insulation. It is typically the better choice where the environment is benign, where internal temperatures are low and when cost, appearance and ease of manufacture are the dominant concerns. ABS moulds easily, has an excellent finish and offers good stiffness and impact resistance for general indoor use. This makes it well suited to office equipment, consumer products and low-power electronics where long-term exposure to heat or sunlight is limited. A number of popular OKW enclosures are still offered in ABS as standard, though other plastics (such as an ASA+PC blend) can be specified on request .

Polycarbonate becomes the better option as soon as mechanical toughness, thermal margin or safety robustness start to dominate the design brief. It retains impact strength across a wider temperature range, resists cracking and maintains mechanical integrity at higher continuous temperatures – which is particularly important for enclosures that contain power electronics or are subject to thermal cycling. Polycarbonate is also widely available in high-performance flame-retardant grades with strong compliance credentials, although it is more expensive and can be more sensitive to certain chemicals and to residual moulding stress than ABS. Polycarbonate can also be specified as transparent, an option for lids on industrial electronic enclosures such as IN-BOX (IP 66, IP 67, IK 08).  

In practice, ABS is often better for simple, cost-driven indoor housings (though they can still be vulnerable to discolouration and degradation caused by UV light). Polycarbonate is better for demanding or safety-critical enclosures. Many designers ultimately choose a PC+ABS blend precisely because it occupies the middle ground, retaining much of ABS’s manufacturability while gaining much of polycarbonate’s toughness and thermal performance.

WHICH PLASTICS ARE SUITABLE FOR OUTDOOR ELECTRONIC ENCLOSURES?

Plastics intended for the outdoors must maintain their mechanical properties, dimensional stability and appearance despite prolonged exposure to UV radiation, temperature cycling, moisture and atmospheric pollutants. This immediately narrows the field compared with indoor housings because many otherwise common enclosure plastics (such as ABS) can degrade under long-term weathering.

ASA is one of the most widely used materials for outdoor enclosures because it offers excellent inherent UV resistance and weatherability while retaining good stiffness, impact strength and mouldability. Unlike ABS, it does not rely on UV-sensitive butadiene rubber so it resists embrittlement, colour fade and surface cracking during prolonged exposure to UV rays. For outdoor products where appearance and dimensional stability must be maintained for many years, ASA is often the baseline material.

Polycarbonate is commonly used outdoors – particularly where impact resistance and thermal performance are critical. When properly stabilised, polycarbonate provides outstanding toughness and good high-temperature performance, making it suitable for enclosures likely to encounter impacts, wide temperature swings or internal heat dissipation. Blends such as ASA+PC are especially effective outdoors, combining polycarbonate’s mechanical robustness with ASA’s superior resistance to UV and weathering.

Read this blog post for more information >>

WHICH PLASTIC SHOULD I CHOOSE FOR HIGH-TEMPERATURE ELECTRONICS?

Specifying a plastic for high-temperature electronics is fundamentally about maintaining mechanical integrity, dimensional stability and safety margins during both continuous operating temperatures and short-term thermal spikes. In these applications, commodity enclosure plastics such as ABS are usually unsuitable because they soften, creep or lose strength too close to the temperatures commonly encountered around power conversion, motor control or densely packed electronics.

For many high-temperature electronic enclosures, polycarbonate or flame-retardant PC+ABS is the practical starting point. Polycarbonate offers a significantly higher heat deflection temperature and better creep resistance than ABS, allowing it to retain stiffness and fastener integrity when internal hotspots develop. Flame-retardant PC+ABS extends this capability while improving processability and compliance confidence. PC and PC+ABS are widely used in power supplies, control equipment and safety-critical housings where temperatures are elevated but not extreme.

When temperatures move beyond the comfortable range of PC-based materials, higher-performance engineering plastics become necessary. Polyesters such as PBT (polybutylene terephthalate) can offer improved thermal stability and chemical resistance, particularly in industrial environments, while maintaining reasonable mouldability. For still higher temperatures, materials such as PPS (polyphenylene sulfide), PEI/Ultem™ (polyetherimide) or high-temperature polyamides provide excellent dimensional stability, low creep and strong electrical performance at sustained elevated temperatures, albeit at substantially higher material and tooling costs.

The correct choice is therefore governed not just by the headline temperature rating but by long-term behaviour under load, by the enclosure’s role in safety compliance and by realistic worst-case thermal conditions including abnormal operation. In high-temperature electronics, it is usually better to select a material with a comfortable thermal margin rather than to operate close to a polymer’s limits because enclosure deformation, fastener relaxation or loss of flame performance over time can undermine both reliability and compliance.

CAN PLASTIC ENCLOSURES PROVIDE SUFFICIENT IMPACT RESISTANCE?

Plastic enclosures can provide more than sufficient impact resistance for a wide range of electronic products – provided the material selection and mechanical design are aligned with the expected operational conditions. Modern engineering plastics such as polycarbonate, PC+ABS and ASA+PC offer high energy absorption and toughness, allowing enclosures to survive drops, knocks and vibration that would permanently dent or deform thin metal housings. In many applications, plastics are preferred because they dissipate impact energy through controlled deformation rather than by transmitting it directly to internal components.

However, impact resistance is not solely a material property; it is strongly influenced by enclosure geometry and design detail. Generous radii and uniform wall thickness play a decisive role in preventing cracks. A well-designed PC+ABS enclosure can outperform a poorly designed polycarbonate one, while even very tough plastics can fail if sharp corners, thin unsupported sections or high residual moulding stresses are present.

Environmental conditions must be considered. Some plastics lose impact strength at low temperatures or after prolonged exposure to heat and UV light. For example, ABS can embrittle over time in sunlit environments, whereas polycarbonate and ASA-based blends retain toughness more reliably. For outdoor or cold-weather use, materials with stable impact performance across the full temperature range are essential, and stabilised grades should be selected accordingly.

In practice, plastic enclosures routinely meet demanding impact requirements in consumer, industrial and safety-critical equipment, including drop tests specified in product standards. Impact resistance of IK 07 and IK 08 are recommended for some industrial applications. Examples of IK-rated enclosures include OKW’s SOLID-BOX and IN-BOX.

DOWNLOAD TECHNICAL INFORMATION

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 You can also access these pdf files by:

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  • clicking on a product (the product number is the link)
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  • clicking on one or more links (ie ASA) in the Material section to download pdf files.

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