Enclosures can house finished components of an IT or entertainment system. They can also house printed circuit boards and other electronic components of a system. An enclosure helps to organize components, secure connections, and provide protection from fingers, dust, and liquids.
For designs that are used by person sitting at a desk or a work bench, manufacturers offer a wide variety of stock desktop enclosures.
Desktop enclosures usually have distinguishing features such as rubber feet, light weight, and attractive style. Different materials are suitable for fabricating desktop enclosures, including steel, aluminum plastic, and fiberglass. But many people choose enclosures based on aesthetics, and a plastic molded enclosure usually provides the most opportunity for an attractive appearance. They are molded of polycarbonate or ABS plastic.
Typical desktop enclosures are not NEMA rated enclosures because they are used in a clean environment and have no need to be rated waterproof or dustproof. This doesn’t mean a plastic desktop enclosure won’t protect your design from a spilled cup of coffee. Rather it means the enclosure is not intended for outdoor locations and factory equipment washdowns.
6 Considerations for selecting a plastic enclosure for your desktop
1. Plastic desktop enclosures offer style
Because plastic is easily molded, manufacturers offer a pleasing variety of shapes and sizes ranging from small hand-held boxes to medium-size boxes. Unlike sheet metal and die-cast aluminum boxes, plastic excels at stylish rounded shapes and corners. Some enclosures fit together, providing easy stacking for an orderly, attractive look. There are enclosures that are made of transparent plastic, allow users to see the components inside and marvel at the technology.
2. Plastic enclosures provide functionality
Unlike metal enclosures that block radio signals, plastic enclosures are ideal for wi-fi and Bluetooth enabled devices.
Many desktop enclosures have a flat recessed area in the top cover to hold a printed label. The recess helps prevent the edges of the label from handling that could lead to the label peeling. Alternatively, color digital printing on this area is an option that’s growing in popularity.
Molding gives plastic a lot of flexibility. Some plastic enclosures have built-in compartments for batteries, hinged doors, and infrared windows. Inside, often they have molded-in mounting bosses for attaching components like printed circuit boards.
Of course, plastic desktop enclosures are inherently non-conductive, which is convenient for preventing ground loops and protecting users from the electricity inside.
3. Plastic enclosures are no substitute for cabinets
If you need a desktop enclosure to hold devices like servers, communications equipment, and instruments, you need a sturdy enclosure that allows for cooling. In such applications, you need a metal cabinet, not a plastic enclosure. Table-top cabinets with fans, removable sides and doors are readily available.
4. Plastic enclosures come in limited colors
Stock enclosures come in a limited palette, most often shades of gray, although there some colorful plastic desktop enclosures are available. Custom plastic colors are available, but they require a special order that is affordable only when you buy in very large quantities. The same is even more true for custom molding.
If a bright, colorful finish is important in your application, consider an anodized aluminum enclosure instead.
5. Plastic enclosures may trap heat
Unlike an aluminum enclosure that is great at removing heat from the design, a plastic enclosure may trap heat faster than it releases it. Heat buildup could be a damaging limitation of a plastic enclosure, so understand the wattage involved and your heat dissipation requirements before specifying.
6. Plastic enclosures need modifications
Your stock enclosure will not come ready to use, not exactly. Desktop enclosures require openings for switches, power cables, indicators, displays, and signal wires. The openings can be cut at the factory per your drawing, or you may choose to modify the box yourself. Be careful, as drilling plastic is trickier than drilling metal. You need to have the right bit and the right drill speed to avoid cracking your new enclosure.
Conclusion
Plastic makes a great material for a desktop enclosure, considering the factors we’ve discussed above. Plastic enclosures are flexible, lightweight, and relatively affordable. Most important, they offer more refined aesthetics.