Does an IP6X dustproof case let nothing in?

A: The criterion is no visible deposit, not zero. Talc at 2 kg/m³ runs for 8 hours with 2 kPa of vacuum inside.

Can it double as a waterproof case?

A: Not by default: one is tested with powder, the other with water, and a case can pass IP6X while failing IPX4.

Should the gasket be greased?

A: A thin film helps, a thick one attracts dust. Grease lets the cord slide; it does not add sealing.

Can a vent membrane pass dust?

A: Its pores arrest over 99% of particles above 0.3 μm. The real risk is clogging, so replace it on schedule.

How often does it need attention?

A: By opening count. Wipe the face monthly for daily use, and renew the gasket every two to three years. ---

Dustproof Case Explained: Particle Size, Seals, Filtration

Quick answer: A dustproof case is judged not by how hard the lid shuts but against a particle spectrum: coarse grains are stopped by geometry, fine ones ride the air and need a compressed seal or a filter. Settle size, pressure and frequency first; the IP number means little without them.

What a dustproof case is: three gates
Particle size: which band is hardest to stop
Sealing faces: the joint is the main door
Filtration and breathing: where pressure escapes
Ranking the three gates, and upkeep
FAQ

1. What a dustproof case is: three gates

The goal is not zero ingress but holding the dust mass entering the cavity below a threshold. IEC 60529 sets the criteria: IP5X allows a little dust without affecting operation, IP6X requires no visible deposit. The same shell, tested with or without vacuum, sits one grade apart.

Three gates do the work: gap geometry, seal compression and air exchange. The order cannot be reversed: an open gap makes a tight face pointless.

A dustproof case is often confused with a waterproof one: liquid against talc. A 0.2 mm gap stops water by surface tension yet passes 20 μm dust.

Dustproof case: black body opened, plain lid interior, base foam cut with round and long pockets holding circular discs

2. Particle size: which band is hardest to stop

Dust is a spectrum: cement 5–50 μm, flour 10–100 μm, sand 50–500 μm, sawdust 100–1000 μm, fume 0.01–1 μm.

Movement decides ingress more than size. Above 50 μm gravity settles the grain on the seal; between 1 and 50 μm it follows the air through any gap; below 1 μm it stays suspended and only a filter stops it.

The opponent is the band that stays airborne. Ask what powder is on site, then discuss a rating.

Dust	Size	Motion	Demand on the seal
Cement, lime	5–50 μm	Rides the air	Above 25% compression
Sand	50–500 μm	Settles, abrades	Hard face
Carbon black	0.01–1 μm	Brownian	Filter required

3. Sealing faces: the joint is the main door

The lid joint has the longest perimeter; latch holes, hinge bores, handle mounts and the valve port add the rest.

Four seal types cover this: a flat gasket at 15–25% compression, an O-ring at 20–30%, a lip seal that tightens with pressure, a double lip that scrapes dust.

The groove matters more than the rubber: 10–15% wider than the cord, deep enough for 25% compression, with a rounded floor. A parting-line burr over 0.1 mm presses a channel into the gasket, and that channel leaks.

A soft lid is the hidden leak: 0.3 mm of lift at mid-span is enough, and a 0.05 mm feeler finds it.

Dustproof case: light grey unit open on a wooden bench, moulded lid pockets with zip bags and coiled cable, foam tray under a multimeter

4. Filtration and breathing: where pressure escapes

A 40 K swing at 101 kPa creates about 13 kPa, enough to push air through the weakest gap and carry dust.

A one-way valve opens outward but its seat fails once powder sticks. A vent membrane of expanded PTFE, with 0.1–1 μm pores, passes 100–1000 millilitres per minute per square centimetre and arrests 99% of 0.3 μm particles.

Keep them apart: valve on the top face, membrane on the side. A clogged membrane shifts the load back to the seal, so it is a service part.

Dustproof case: black case open by a window, egg-crate foam across the lid gripping a clear bag, empty base, round valve in the front panel

5. Ranking the three gates, and upkeep

Close the gap, compress the face, then manage airflow. Gaps are cheapest: move a parting line, add a baffle, blind a latch hole. More compression needs a deeper groove.

Upkeep is wipe and replace: wipe the face before every close, since one grain of sand cuts a groove; grease thin, or it collects dust. Where dust lands tells you why.

Symptom	Cause	Fix
Dust along the lower wall	Low compression	Deeper groove
Dust around latches	Open holes	Blind caps
Even film everywhere	Breathing	Add a membrane

Dustproof case: grey body standing upright, arched one-piece handle on top, two latches clamped, small valve port at the upper corner

Conclusion

A dustproof case is three gates working together: geometry for coarse grains, compression for the suspended band, relief for airflow. Ask about all three, and the dustproof case earns its price.

This article covers container-side specifications and design implications only, not the handling, loading or use of the contents.