Why is surface resistance a band rather than one value?

A: Antistatic modification is part volume conduction and part surface migration, so one compound shifts half a decade with mould temperature. The band 10^6–10^9 Ω drains charge without approaching a conductor.

Is four units enough out of 200?

A: At one per 50 it is. Twenty readings across lid, base and side wall cover three moulding positions, and any failure doubles the sample.

Is decay under 2 s the same as surface resistance?

A: No. Resistance measures capacity to drain, decay measures speed: a migrated surface passes resistance yet fails decay.

If lids will not close after eight-high stacking, is the case or the packing at fault?

A: Usually the packing. Stacking adds about 0.22 kPa average, so damage comes from edge shear and offset; corrugated sheets and corner boards bring the spread under 2 mm.

Can the 45-day tooling be shortened?

A: Not for a new tool. ESD compound needs three trial rounds; the only shortcut is re-cutting a similar cavity in 20 days.

ESD anti-static plastic instrument case wholesale

Quick answer: ESD anti-static plastic instrument case wholesale turns on batch spread: 200 units, 3.2 mm wall, all inside 10^6–10^9 Ω and decay under 2 s.

Three break points in an ESD anti-static plastic instrument case wholesale order
How 200 units all land inside 10^6–10^9 Ω
Colour difference and two marking positions
Squareness after eight-high stacking
Forty-five days of tooling and a 3.2 mm wall
FAQ

1. Three break points in an ESD anti-static plastic instrument case wholesale order

A single unit is bought on a sample; a batch is bought on the gap between unit 1 and 200. An ESD anti-static plastic instrument case wholesale order fixes 440 x 330 x 170 mm outside, 390 x 280 x 135 mm inside, a 3.2 mm wall and 3.1 kg empty once, and those numbers stop moving. What drifts is surface resistance, colour and marking position. Resistance follows how the conductive masterbatch disperses in the barrel, and morning and afternoon shots from one tool can sit half a decade apart. Colour drifts because pigment and antistatic agent are both small additions that fight each other. Marking position drifts on whether the jig moved with the tool.

Only the first is electrical; the other two are appearance and traceability, so an ESD anti-static plastic instrument case wholesale sheet needs a limit for each.

Wholesale stage	Consistency risk	Control value
Compounding	uneven masterbatch, half a decade in one batch	2 kg head sample per batch
Moulding	mould temperature shifts crystallinity	mould held to ±3 ℃
Printing	jig drift gives two mark positions	jig numbered with the tool
Packing	edge crush changes squareness	diagonal spread 2 mm or less

2. How 200 units all land inside 10^6–10^9 Ω

Surface resistance is a range, not a point. The target for an ESD anti-static plastic instrument case wholesale run is 10^6–10^9 Ω, three decades wide; keeping all 200 units inside it is the hard part. Split the range: 10^6–10^7 Ω is conductive enough that excess additive makes the shell brittle, 10^7–10^8 Ω is where most batches settle, and 10^8–10^9 Ω sits near the ceiling.

ESD anti-static plastic instrument case wholesale shell in black open, multi-cell foam base, twin latches, red-ring valve, IP67 embossed

Sampling takes one unit per 50, so 200 units give four, each read at five points: two on the lid interior, two on the base, one on a side wall. All five must sit inside the range; one point outside doubles the sample, a second failure returns the batch.

Decay under 2 s is a separate criterion. Batches exist that pass resistance and fail decay: the additive migrates to the surface, forms a conductive film, and that film dies in dry air. An ESD anti-static plastic instrument case wholesale test reads decay at 23 ℃ and 12% RH first, then resistance.

Friction voltage under 100 V is the third check, read after the shell rubs against its film; above 100 V the unpacking discharge can damage parts.

3. Colour difference and two marking positions

Beige is the common colour at this grade and the hardest to hold. An ESD anti-static plastic instrument case wholesale batch is judged on colour inside the batch only: ten units at random, measured at D65 and 45°/0°, with the mean ΔE held to 1.0 and no single unit past 1.5.

The two antistatic marks sit on the drawing: one at the top right of the lid, one on a short side, both from the same jig. Position tolerance is ±1.5 mm, and two positions in one batch are not accepted.

Consistency risk	Method	Limit
batch colour spread	10 random units, D65, 45°/0°	mean ΔE 1.0 or less
single unit colour	same	ΔE 1.5 or less
mark offset	calliper from edge to type	±1.5 mm
mark count	visual, every unit	2, one missing rejects

4. Squareness after eight-high stacking

The first thing an inspector sees is not resistance but squareness. On an ESD anti-static plastic instrument case wholesale pallet at eight high the bottom lid carries seven units, 32.2 kg at 4.6 kg packed, over a 440 x 330 mm face at 0.22 kPa. Damage happens at the corners, where a half-position offset turns compression into shear and the 3.2 mm wall bulges first.

ESD anti-static plastic instrument case wholesale line with injection molding machines, yellow overhead crane, cartons and pallets, workers nearby

Packing does two jobs: a 2 mm corrugated sheet between units, and four wraps of film plus 120 mm corner boards. With both, an eight-high stack holds a 2 mm diagonal spread; without them the spread reaches 5 mm. Past 2 mm at the mouth or the base, lid and mouth offset by 0.5 mm and IP65 no longer holds.

IP65 means dust-tight and splash-proof, not immersion. Drop is 1.0 m on six faces; the working range is −10 ℃ to 55 ℃.

5. Forty-five days of tooling and a 3.2 mm wall

Lead time starts at tool sign-off, not at the purchase order. One tool set runs 45 days from cavity machining to acceptance and does not compress: ESD compound shrinks differently, so three trial rounds are the floor.

Stage	Days	Content
Cavity machining	25 days	electrodes, polish, first check
Trials and rework	12 days	3 rounds, shrink corrected
Etch and acceptance	8 days	texture, marking jig, first article
Total	45 days	1 tool set

The 3.2 mm wall is the production baseline for an ESD anti-static plastic instrument case wholesale run. At 2.8 mm the cycle shortens about 12% but the corners collapse under eight high; at 3.6 mm the shell goes from 3.1 kg to 3.5 kg and daily output drops a tenth. The 200-unit minimum spreads changeover, because below 200 the setting scrap passes 8%.

Conclusion

An ESD anti-static plastic instrument case wholesale acceptance comes down to four points: 200 units inside 10^6–10^9 Ω with decay under 2 s and friction under 100 V, two marks in the same place, a 2 mm diagonal spread after eight-high stacking, and 45 days of tooling. Put those on the sheet; otherwise nothing is agreed.