Can an injection molded protective case ship as the only packaging?

Answer: Yes, once two points are confirmed: it passes a 1.2 m six-face drop, and the latches hold at 15 kg.

What separates a 3 mm wall from a 3.5 mm wall?

Answer: Stiffness against weight. At 1.2 m the thicker wall deflects about 30% less and costs 0.3 kg. Choose 3 mm when people carry it, 3.5 mm when stacked in a vehicle.

Is thicker foam always safer?

Answer: No. Foam must match the clear height; a 30 mm liner pressed into 25 mm is pre-compressed and has no travel left. Set the height first, then take 2 mm off.

How do I choose between IP65 and IP67?

Answer: Short immersion decides it. Rain and spray are covered by IP65; a case that may go overboard needs IP67 plus a vent.

Can one case body serve all four scenarios?

Answer: The shell can, the configuration cannot. One mould feeding four builds is normal, but foam, gasket and latches are chosen per scenario. Sharing them ends in over-protection.

Where an Injection Molded Protective Case Is Used

Quick answer: An injection molded protective case is used mainly for inspection instruments, medical response, electronics and vehicle-mounted kits. The shell is shared; wall thickness, foam, seal grade and latches change, and 0.7 mm of wall or 15 mm of foam decides the carried weight and the protection delivered.

Where an Injection Molded Protective Case Fits
Inspection Routes and Foam Density
Medical Transfer and Wipeable Walls
Electronics and Static Drain
Outdoor and Vehicle Mounting
FAQ

1. Where an Injection Molded Protective Case Fits

An injection molded protective case is shaped by one mould: lid curvature, body depth, hinge pockets and latch seats are fixed at tooling. Everything after that is configuration: load, opening frequency, seal grade and foam depth.

Scenario	Load	Wall	Foam	Seal	Latches
Inspection instruments	8 kg	2.8 mm	25 mm	IP65	2 cam latches
Medical response	6 kg	3.0 mm	20 mm	IP67	4 cam latches
Electronics	12 kg	3.2 mm	30 mm	IP67 vented	4 cam latches
Vehicle mounted	15 kg	3.5 mm	15 mm	IP66	2 latches, lock holes

Wall thickness is the parameter most often over-specified. Going from 2.8 mm to 3.5 mm adds about 0.45 kg and buys limited stiffness, yet a technician walking six kilometres a day feels that weight first. On a vehicle floor, vibration and stacked loads justify it.

2. Inspection Routes and Foam Density

An inspection case hangs from a hand most of the day, so the side walls carry the handle load. Handle bosses thicken to 4.5 mm and the handle is rated 15 kg static against an 8 kg working load.

Foam density matters more than thickness here. A 25 mm EVA layer at density 45 absorbs everyday knocks; at density 60 the compression stroke halves and a sharp instrument corner starts to punch through. The usual layout is asymmetric: 25 mm in the base, 10 mm in the lid.

3. Medical Transfer and Wipeable Walls

Medical work pushes an injection molded protective case toward cleanability. Ribs that trap fluid are out, internal corners go to R5 or larger, and the gasket groove is removable so a dual-lip EPDM seal can be replaced. The interior must survive a chlorine wipe daily for a year.

The better the seal, the sharper the pressure problem. A closed case moving from a 25 °C store into a −10 °C vehicle, or over a 2000 m pass, builds a 0.15 bar differential that pins the lid shut, so a membrane vent rated 50 ml/min equalises it while holding IP67. A gloved hand must also open the lid in three seconds, so cam latches sit one palm span apart.

4. Electronics and Static Drain

Once electronics go into an injection molded protective case, the problem shifts from impact to static. Plain PP sits near 10^16 ohms surface resistance, so a rubbed shell discharges into a board. Either compound the resin with conductive masterbatch down to 10^6–10^9 ohms, or keep the shell insulating and put the drain path in the foam.

Cushion depth is recalculated at 12 kg. A 30 mm liner holds peak acceleration under 40 g in a 1.2 m drop, but only with no air gap: past 5 mm it shifts before hitting the wall.

5. Outdoor and Vehicle Mounting

Outdoor use tests UV and temperature together. With 2% carbon black and a hindered amine stabiliser, a case runs 1000 hours of xenon arc exposure with colour shift under 3. Forty cycles between −20 °C and +60 °C must not embrittle a latch tongue. Latch life is counted in openings: four loadings a day is 7000 over five years, so the tongue is designed for 10,000.

Failure mode	Trigger	What the user sees	Configuration fix
Tongue fracture	Cold handling	Catch snaps in the seat	PA66 with glass fibre
Gasket hardening	Long sun exposure	Water beads inside	EPDM plus a shade rib
Foam collapse	Frequent opening	Instrument rattles	3 mm support plate
Hinge loosening	Loaded carrying	Lid sits crooked	Stainless pin with circlip

Conclusion

Across the four scenarios the pattern is configuration, not shell: load and opening frequency first, wall thickness second, foam and sealing last. Skip that order and the same mould gives a case heavy where it should be light. An injection molded protective case holds its place in all four settings only when each build is specified against the job it does.

This article discusses only the container (case body) side of specifications and design intent, and does not cover any handling, loading or use of the contents.