Which document governs the standards of a protective case manufacturer?

A: Three: transport regulation for drop and sealing, test method for stacking, customer drawing for dimensions. Where they conflict, apply the stricter one.

Is checking resin at incoming enough?

A: No. Latches, pins and gaskets cause half of field failures, so salt spray and hardness are mandatory.

Why is pressure decay used more than immersion?

A: It reads whole-case leakage in minutes and reaches weld lines immersion misses; immersion stays a per-lot confirmation.

How is the outgoing sampling rate set?

A: Five percent for a stable lot, twenty after two lots with defects, back down after three clean lots.

How long are retained samples kept?

A: Twelve months, or to warranty end on export orders, same batch and cavity. ---

Protective Case Manufacturer Standards: Incoming to Outgoing

Quick answer: Standards at a protective case manufacturer split into three gates: incoming resin and hardware, in-process temperature and pressure, outgoing sealing and stacking. Each gate must leave a number, a sample and a record, or the buyer is paying for a verbal grade.

Why a protective case manufacturer splits quality into three gates
Incoming: resin, hardware and gaskets
Process: what injection and rotomolding must hold
Outgoing: sampling, pressure decay and stacking
Records and traceability: batch, retention, re-check
FAQ

1. Why a protective case manufacturer splits quality into three gates

Three gates answer three ways of losing control. Incoming failure is a resin switch: colour mottles, latches stop biting. Process failure is drift, wall thickness sliding from 3.4 to 3.0 mm, and the corner radius cracks at the first drop. Outgoing failure is a skipped item, and an inverted gasket ships anyway.

A protective case manufacturer moves criteria upstream because shell defects rarely rework: a thin wall cannot be thickened, a short-shot boss is scrap.

Gate	What is judged	Evidence
Incoming	Resin grade, salt spray, hardness	Batch sample
Process	Melt and mould temperature, wall	First-off report
Outgoing	Decay, immersion, stacking	Sampling sheet

2. Incoming: resin, hardware and gaskets

Resin is checked for melt flow, moisture and regrind. A melt index ten percent off nominal makes the same mould temperature short-shoot or flash. Hygroscopic resin above 0.2 percent moisture leaves silver streaks; regrind is capped at twenty percent.

Hardware decides seal life: latch springs and hinge pins must survive forty-eight hours of salt spray without white rust, and gaskets are gauged at 55 ± 5 Shore A.

Item	Criterion	If it fails
Resin	Index ±10%, moisture ≤0.2%	Return or downgrade
Hardware	48 h salt spray, no rust	Change supplier lot
Gasket	55 ± 5 Shore A	Full inspection

Protective Case Manufacturer inspection bench: black case open, pre-cut foam split into square cavities, four tiers of identical black cases on a pallet behind

3. Process: what injection and rotomolding must hold

Injection has four numbers: melt and mould temperature, packing, cooling. Melt runs 210 to 230 °C for PP, 280 to 300 °C for PC. Mould temperature governs shrinkage: five degrees colder bows a flat face by 0.2 mm.

Rotomolding trades those for biaxial ratio and peak internal air. PIAT must reach 205 °C so powder fuses and bubbles escape; below 190 °C the inner skin traps powder.

Process	Key parameters	Failure mode
Injection	Melt 210–230 °C, mould 40–60 °C	Sink, flash, drift
Rotomolding	PIAT 205 °C, 4:1 ratio	Uneven wall, bubbles

Protective Case Manufacturer shop floor: blue case open on a bench, harnesses and a circuit board set in foam, roller conveyor running behind

4. Outgoing: sampling, pressure decay and stacking

Outgoing samples by lot: appearance at inspection level II, AQL 2.5, tightened to 1.0 for functional items. Pressure decay is mandatory: 20 kPa for sixty seconds, no more than 1 kPa drop. Immersion follows IP67, one metre for thirty minutes. Stacking runs three tiers for twenty-four hours, failing above 2 mm of deflection.

Item	Sampling	Criterion
Appearance	AQL 2.5	No colour shift or flash
Pressure decay	5% per lot	20 kPa / 60 s, ≤1 kPa
Stacking	3 pcs per lot	3 tiers, 24 h, ≤2 mm
Drop	3 pcs per lot	1.2 m, six faces

Protective Case Manufacturer finished case standing on its side, box handle on the crown joined to a full-length reinforcing spine, four rounded corners

5. Records and traceability: batch, retention, re-check

A batch code decodes into date, machine and cavity, so a complaint leads back to one cavity in half an hour. Retain three pieces per batch for twelve months: a sample dropped under the same conditions separates design from use. Re-checks trigger on a resin change, a mould change, a stoppage beyond four hours or a batch complaint; a failure quarantines the lot.

Protective Case Manufacturer warehouse: blue tote boxes three high in a pinwheel on a timber pallet, vertical ribs aligned, racking behind

Conclusion

Three gates are worth a number and a sample facing each other at each stage. Incoming samples, process parameters and decay curves let an auditor re-run the judgement. What a protective case manufacturer sells is a set of criteria anyone can reproduce.

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