Engineering plastic housings for explosion-proof handheld scanners
Boyang Hardware machines industrial safety / hazardous area instrumentation parts to customer drawings in Zhongshan, China. The photographs below are from production archives; the route, material and finish listed are typical for this part family and are confirmed at quotation.
What the part does
Housings and shells for explosion-proof scanners, gas detectors and other portable instrumentation used in oil, gas, chemical and mining environments. The housing must protect electronics from impact, dust and, in some designs, explosive atmospheres.
Why this geometry is demanding
- Engineering plastics such as glass-filled nylon and POM absorb impact without cracking and are far lighter than metal equivalents.
- The flanged base and mounting holes must be flat and accurately positioned so the device seals against a gasket.
- Depending on volume, the same geometry can be CNC machined for prototypes or injection moulded for production.
Typical material and finish
Glass-filled nylon (PA66+GF), POM, ABS or PC+ABS, typically in black. Material choice depends on impact, temperature and chemical resistance requirements.
Process route
- CNC machining from engineering plastic stock (prototypes / low volume) or injection moulding (production)
- Drilling and tapping of mounting holes
- Finishing of sealing faces and gasket lands
- Deburring and surface cleaning
- Assembly of inserts, gaskets or electronics if required
Inspection and quality control
Mounting hole patterns and sealing surfaces are dimensionally checked. Visual inspection is strict: sink marks, voids and cracks are not acceptable on safety-device housings. First-article inspection records are kept for new moulds.
Quality approach for this part family
Mounting hole patterns and sealing surfaces are dimensionally checked. Visual inspection is strict: sink marks, voids and cracks are not acceptable on safety-device housings. First-article inspection records are kept for new moulds.
Common questions about industrial safety / hazardous area instrumentation machining at Boyang
Should a plastic housing be CNC machined or injection moulded?
CNC machining is faster for tens or hundreds of units and avoids tooling cost. Injection moulding becomes economical above roughly 5,000 pieces and gives tighter repeatability. Boyang can quote both routes for the same design.
What plastic is best for a rugged handheld scanner?
Glass-filled nylon (PA66+GF) is the most common choice: high impact strength, good chemical resistance and easy to mould. POM is used when low friction and stiffness matter; PC+ABS is used when a high-gloss cosmetic finish is required.
Can threaded inserts be moulded or machined in?
Yes. Brass or stainless threaded inserts can be over-moulded, pressed in after machining, or installed with heat staking. The method depends on torque and pull-out requirements.