QUICK AND EASY GUIDE TO THE BEST PLASTICS FOR ELECTRONIC ENCLOSURES

ENHANCE ENCLOSURE PERFORMANCE AND LONGEVITY

Specifying the right plastic(s) for your electronic enclosure is crucial. Different polymers can significantly impact the durability, functionality and overall performance of your device.

Most OKW plastic enclosures are molded from either ABS, ASA or ASA+PC as standard. All three are tough and dependable – though UV-stable ASA and ASA+PC are increasingly superseding ABS as the preferred plastics for new models.

Discover the benefits and pitfalls associated with the following plastics…

ABS – ROBUST AND POPULAR

ABS (Acrylonitrile Butadiene Styrene) is widely specified for electronic enclosures because of its good mechanical properties, impact resistance and ease of fabrication. ABS is a great choice for light-duty applications and is commonly used in consumer electronics. However, its UV stability is limited. It also has a relatively low melting point, which can limit its use in high-temperature environments.

ASA – THE UV-STABLE ALTERNATIVE TO ABS

ASA (Acrylonitrile Styrene Acrylate) improves on ABS by offering enhanced weather resistance and UV stability. ASA replaces the polybutadiene rubber found in ABS with acrylic rubber. This makes it suitable for outdoor applications  and – given that more than 50% of UVA rays can pass through standard window glass – it is also worth specifying for indoor applications too. ASA maintains many of the positive attributes of ABS, such as high strength and ease of processing. The downside is that ASA can be more expensive than ABS. Furthermore, ASA may still suffer from some degree of environmental stress cracking if exposed to chemicals such as benzene, toluene and xylene.

Read more about UV-resistant enclosures >>

PC – TOUGH AND HEAT RESISTANT (135 °C)

PC (Polycarbonate) is known for its strength and clarity, which is why it is specified for applications such as bulletproof glass. Polycarbonate also withstands temperatures up to 135 °C, making it more suitable for applications involving heat. However, it is prone to scratching and can be susceptible to chemical degradation by certain solvents and cleaners. Isopropyl alcohol (IPA) can be used in low concentrations for cleaning polycarbonate but higher concentrations or prolonged exposure should be avoided as they can lead to stress cracking.

ASA+PC – TOUGH AND UV-STABLE

ASA+PC blends combine the advantages of both ASA and PC, providing superior weatherability, UV stability and heat resistance. This material is excellent for outdoor enclosures that need to be tough in varying environmental conditions. The main limitation is cost, as the blend can be more expensive than using either material alone. That said, ASA+PC is an excellent blend – which is why it has now become the go-to standard plastic for many of our latest enclosure models.

PC+ABS – FOR HIGH STRENGTH AND GOOD HEAT RESISTANCE

PC+ABS is a blend that offers the excellent properties of both polycarbonate and ABS, such as high strength, good heat resistance and ease of processing. This material is particularly useful for creating sturdy, yet lightweight enclosures that can handle thermal stress and hard knocks. This is why we specified it for our SOLID-BOX (IK08, IP 66, IP 67) enclosures for industrial electronics. But, like other blends, the cost can be higher – and the material might still face limitations such as chemical sensitivity, depending on the application.

View the SOLID-BOX range >>

PMMA – INFRARED-PERMEABLE FOR REMOTE CONTROLS

PMMA (Polymethyl Methacrylate) – or acrylic – offers excellent UV resistance. It is also infrared-permeable which makes it perfect for wireless remote control devices. For this reason, handheld enclosures such as STYLE-CASE, SMART-CASE, SOFT-CASE, DATEC-POCKET-BOX and award-winning MINITEC can all be specified in PMMA as standard. However, PMMA is more brittle than other plastics listed here and can crack under impact.

View our wide range of handheld enclosures >>

SEBS (TPE) – FOR SOFT-TOUCH COMFORT

SEBS (Styrene-Ethylene/Butylene-Styrene) feels pleasant to touch. It is a thermoplastic elastomer (TPE) that combines rubber-like properties with the processing ease of thermoplastics. TPEs like SEBS are known for their flexibility, stretchability and return to their original shape after deformation. They can also provide ingress protection when specified as an intermediate ring between two sections moulded from a harder plastic such as ABS. SEBS is also known for its good UV stability. We specify SEBS for intermediate rings, seals, enclosure feet, case protectors and cable strain relief accessories.

TPV – THE SUPERIOR ALTERNATIVE TO TPEs

TPVs (thermoplastic vulcanizates) are made through dynamic vulcanisation, a process in which a rubber phase – typically EPDM (ethylene propylene diene monomer) is finely dispersed within a thermoplastic matrix such as polypropylene. This process essentially ‘cures’ the rubber within the thermoplastic; the process is irreversible. TPVs offer enhanced properties over many TPEs, especially in terms of durability and resistance to chemicals and environmental conditions. TPVs are typically chosen for demanding applications  in harsh conditions, while TPEs are specified when cost, flexibility and aesthetic qualities are more important.

PA – STRONG, WITH GOOD SLIDING PROPERTIES

PA (Polyamide) is known for its high strength, chemical resistance and good sliding properties. It is used in high-performance parts that need to withstand wear and tear, such as gears and bearings. We specify PA for cable glands and also for some potting boxes. However, one drawback of PA is its moisture absorption; it can absorb up to 7% of its weight in water. This can affect dimensional and mechanical stability.

View our thermoplastic potting boxes (PA and ABS) >>

View cable glands, counternuts and strain relief clamps >>

View our full range of plastic enclosures here >>

SPECIAL MATERIALS: SPECIFY A NON-STANDARD PLASTIC

Specifying a non-standard plastic for your preferred enclosure offers three main benefits:

UV stability – consider ASA or an ASA-PC blend if your ABS standard enclosure will need greater resistance to the Sun’s rays.

Custom colors – specify a bespoke colour at the moulding stage, rather than by lacquering (though this offers different textures, and matt, satin, glossy and metallic finishes /en/Customising/Lacquering.htm  /en/Customizing/Lacquering.htm).

Flammability resistance – a non-standard plastic may offer a high level of protection, such as V-0 (compared with UL 94 HB).
Learn more about UL 94 flammability testing.

Talk to our sales team to discuss what optional materials are available for your chosen OKW product.

View examples of enclosures in special materials >>

GET EXPERT ADVICE ON ENCLOSURES

Contact OKW for expert technical advice on which plastic(s) would be best for your electronic enclosures. Discover how easy it is to specify the ideal standard or customized housing for your device.

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Download a 3D model (X_T, STP, SAT) of your preferred model – see how your PCBs will look in your finished enclosure.

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