The term “plastic enclosure” refers to a container that is designed to house, protect or accommodate objects in any other way. Not confined to the angles of rectangles or squares, plastic enclosures may be molded into virtually any shape. The high level of flexibility achievable by plastic enclosures stands in stark contrast with metal enclosures, which are not nearly so customizable. Another advantage they have over metal enclosures is their lightweightness, which lends them particularly to applications in portable electronics. They are also better insulators and less electrically conductive than their metal counterparts. Most often, plastic enclosures are used to enclose electronics of some sort to hold them together, keep them away from dust and dirt and shield them from impact damage. They may encase consumer, commercial or industrial products. Examples of everyday objects that are housed in plastic enclosures include calculators, coolers, desktop computers, laptop computers, remote controls, televisions, video game controllers and wireless internet controllers.
Plastic enclosures may be fabricated from a variety of different plastic materials, the choice of which depends on the needs of an application. Enclosures designed for heavier duty or more intensive applications, for example, are typically made out of high-density polyethylene (HDPE). HDPE is a strong thermoplastic made from petroleum; it is known for extreme heat and cold resistance, longevity, liquid and corrosion resistance and low production costs. Other common plastic materials used for plastic enclosure fabrication include polyvinyl chloride (PVC), acrylonitrile butadiene styrene (ABS), acrylic and polypropylene. PVC, which is good for insulation applications, is a very common and popular thermoplastic. It is lightweight and exhibits qualities of toughness, flexibility, acid resistance, base resistance and water resistance. ABS, valued for its mechanical toughness and impact resistance, is a terpolymer synthesized from styrene and acrylonitrile in the presence of polybutadiene. It is lightweight and does not pose a threat to human health, provided it is handled properly. Acrylic, known more precisely as poly(methyl methacrylate) or PMMA, is known for being incredibly strong and sturdy, capable of withstanding incredible amounts of pressure. In addition to plastic enclosures, it is used to make bone cement, aircraft windows, aquarium windows, submarine viewing ports and motorcycle helmet visors. Polypropylene, abbreviated to PP, is both very strong and uncommonly resistant to bases, acids and chemical solvents. Polypropylene enclosures may be welded.
Regardless of the exact material chosen, most plastic enclosures, if they are being made from a thermoplastic, are fabricated via molding. All molding methods begin with the collection raw plastic material, which manufacturers subsequently heat until liquified, or molten. How manufacturers proceed after this depends on whether they are following the steps of the blow molding process or the injection molding process. If they proceed with blow molding, the manufacturers will carry on by either injecting or squeezing the molten plastic into a preform or mold cavity. After this, manufacturers will blow compressed air into the cavity, rendering the plastic shape hollow. Once the shaping process has finished, the plastic will be allowed to cool and harden. Following this step, the newly created plastic enclosure will be ejected from the mold. Similarly, if manufacturers choose injection molding, they will proceed by injecting the molten plastic into a mold cavity, the shape of which it will adapt. Manufacturers will then end the injection molding process in the same way that they end the blow molding process: by allowing the plastic to cool and hardening and then ejecting it. Both methods create strong, long-lasting plastic enclosures.
Plastic enclosures are practical, customizable, easy to make and durable. Better insulators and less likely to undesirably conduct electricity than similar metal enclosures, they are a great investment. They protect what is important to you and your application and make sure it always runs smoothly. They do, however, vary in levels of thermal stability, chemical resistance, heat resistance, impact resistance and general strength. In addition, they are, of course, available in different shapes, sizes and colors. What’s more, they are built to fit any number of regional and/or industry standard regulations, including NEMA (National Electrical Manufacturing Association) standards, EPA (Environmental Protection Agency) standards and ISO (International Standards Organization) standards. Variety is the spice of life, but sometimes, this variety can make confusion and uncertainty. The best way to combat these byproducts of shopping is to consult with one or more of the many excellent enclosure manufacturers listed on our website. They will be able to provide you with advice and exact information on material choices, color options, configurations, prices and industry standard adherences.
Types of Plastic Used in Manufacturing Electronic Enclosures
There are a variety of plastic materials that are used for manufacturing electronic enclosures. Each type of plastic has unique attributes and performs differently in different situations. Some materials offer a more pleasing aesthetic finish while some ensure proper heat insulation, making them appropriate for electrical and electronic components. Following find a discussion of the various types of popular plastics including their qualities and uses in manufacturing.
Acrylonitrile Butadiene Styrene (ABS)
Most commonly, ABS is used for manufacturing electronic enclosures, as it performs well within most performance parameters. If impact and chemical shielding are required, ABS is considered as a suitable building material. Given its poor UV resistance, ABS is considered suitable for indoors enclosures but performs poorly in outdoor environments.
Acrylonitrile Styrene Acrylester (ASA)
When an electrical enclosure is installed at a healthcare, wellness, food manufacturing, pharmaceutical or laboratory facility, Acrylonitrile Styrene Acrylester is deemed appropriate, as it can be endowed with anti-microbial properties. ASA provides protection even against fungi and viruses, which makes it a major material for electronic enclosures fitted at bacteria-prone areas.
Combination of Acrylonitrile Styrene Acrylester and Polycarbonate
ASA is blended with polycarbonates when electrical enclosures need to withstand high temperatures and perform well in impact-ridden environments, such as in warehouses. Moreover, blending ensures that enclosures are resistant to weather, chemicals, and outdoor environments. The combination of polycarbonate and ASA results also in flame resistance. Products made via blending have the highest level of flame resistance and can be extinguished within five seconds on average.
Carbon Neutral Bioplastic
These are new types of plastics and are biodegradable. In different environments, they perform just like ABS but have significantly lower environmental implications. The raw materials used for manufacturing these types of plastics are naturally occurring and are certified biodegradable. This is a food grade plastic that also has application in special soft-case enclosures.
This type of plastic is preferred when wear-resistant, electrical insulation, and sliding properties are required. However, PA plastics often perform below manufacturing specifications as they absorb moisture and are affected by acids and alcohols.
Polycarbonate, a part of the polyester family and the most extensively used thermoplastic, is used for making enclosures when durability, thermal stability and transparency are important factors. Polycarbonate enclosures are installed both outdoors and indoors, as they offer suitable ultraviolet and temperature resistance. However, PC is typically not used independently but in combination with ASA.
Blend of Polycarbonate and Acrylonitrile Butadiene Styrene (ABS)
When enclosures are used at sub-zero temperatures, PC is blended with ABS for ensuring temperature resistance and high-impact strength. Enclosures made with PC and ABS are fitted indoors, as these product are also flame resistant up to UL 94 V-0.
Styrene Ethylene Butadiene Styrene (SEBS)
SEBS is used to manufacture weather-resistant and chemical resistant enclosures. It is used for hand-held devices as the plastic is pleasing to human touch.