What is the single most revealing thing to ask for in a case factory audit?

The mould maintenance log with shot counters. A tool is a wearing asset: it degrades with every shot, and a factory that runs one to failure will produce good parts until the day it does not. A maintained tool has recorded shot counts, cleaning intervals and a refurbishment history. Asking to see this for a mould currently in production tells you more about process discipline than any certificate on the wall.

How do I tell whether the factory actually made the sample I was shown?

Ask to see the mould for the part and watch a shot being produced. Then compare that fresh part to the sample. If they match on texture, gate mark and flash, the factory owns the process. If the sample is visibly finer than what the machine produces, or if the mould is off-site, the sample was likely sourced elsewhere and the quotation is a trading margin rather than a manufacturing capability.

How do I verify an IP67 or drop-test claim?

Ask for the test report, then read three things: which laboratory issued it, which specific part number and configuration it covers, and the date. A report for a similar case in the same family does not cover your configuration. Where the rating matters, specify that testing is performed on production parts from your order and that you receive the report with the shipment, rather than relying on a historical document.

What are the reliable red flags?

Incoming material stored outdoors or without lot identification; inspection records filled in for the whole day in advance; no gauge calibration dates; a testing area where the equipment is present but unpowered or covered in dust; and an inability to produce a non-conformance record - a factory that has never rejected anything is either new or not recording rejections.

Should I audit in person, or is a remote audit enough?

Remote audits by video can verify documents, storage conditions and, with a cooperative host, machine identity and shot counters. They cannot verify what you would notice in person: housekeeping, whether operators follow the documented process, the condition of tools in storage, and the general pace of the floor. For a first order or a new tool, an in-person visit is worth the cost. For a repeat order from a known supplier, a documented remote review is usually sufficient.

Protective Case Factory Audit: On-Site Checklist

The purpose of an audit is narrow and specific. You are not assessing whether a factory is impressive; you are establishing whether its process will repeat the sample you approved, at your volume, on your schedule, next year as well as this one.

Six areas that carry the signal

Area	What to ask for	What good looks like
Mould management	Maintenance log with shot counters for the mould running your part	Recorded shot counts, cleaning intervals, refurbishment history, tools stored with rust protection
Incoming material	Resin lot records and incoming inspection results	Lots identified and traceable, material stored dry and sealed, supplier certificates on file
In-process control	First-piece and patrol inspection records for the current run	Records completed at the time of inspection, with actual measured values rather than ticks
Measurement	Calibration status of the gauges in use	Calibration labels in date, gauges stored properly, a defined calibration interval
Testing capability	Evidence of the tests the quotation claims	Equipment powered and in use, test records tied to specific part numbers and dates
Non-conformance	Recent rejection records and corrective actions	Rejections are recorded, root causes are stated, and corrective actions are closed with dates

Walking the floor: what to look at

Injection-moulding line and injection machine view — Floor layout sets the cycle: raw material, mould, moulding, assembly, inspection.

Documents tell you what the system says. The floor tells you whether the system is used. Walk it in production order and let the process show you its own weak points.

Material store. Is resin sealed and identified? Is it dry? Nylon and some grades of ABS absorb moisture and must be dried before moulding; a store without drying capability will produce inconsistent parts and the cause will not appear in any document.
Moulding machines. Are process parameters displayed and consistent between identical machines running the same part? Wide parameter variation between machines producing the same item is a sign that settings are operator-dependent rather than controlled.
Tool storage. Are moulds stored clean, closed, and protected? A tool left open on the floor accumulates damage that appears later as flash or dimensional drift.
Secondary operations. Foam cutting, printing, assembly. Are these in-house or subcontracted? If subcontracted, ask how the subcontractor is controlled - that is where your schedule risk lives.
Packing line. Is there a defined packing method and a check that the right quantity and the right accessories are in the carton? Mix-ups at packing are a common and entirely preventable source of claims.
Reject area. Is there one, and is it segregated? A factory with no visible rejected material is either perfect or not sorting.

Ask an operator, not a manager, what happens when a part fails inspection. The answer you want is a specific action - tag it, put it in that bin, tell that person. The answer you do not want is a shrug, or "we don't really get that".

Capacity: the question behind the question

Stated capacity is nearly always optimistic because it assumes an empty schedule. What you need to know is available capacity for your order in your window, which is a different number.

How many machines, and what tonnage range - does your part fit the machines they actually have, or only their largest?
What is the current order book cover, in weeks, for machines of the size your part needs?
How many shifts, and what is the plan if the order slips?
Which operations are single-points of failure - one printing machine, one foam cutter, one technician who alone can set a particular tool?
What happens at peak season, and when does peak season start for them?

Red flags worth acting on

Records completed in advance, or all in the same pen at the same time.
A test report that covers a different part number or configuration than the one quoted.
Reluctance to show a mould or to run a shot during the visit.
No lot traceability on incoming material or on finished goods.
Key operations subcontracted without disclosure.
A sample noticeably better finished than anything on the production floor.

None of these is automatically disqualifying - every factory has gaps, and a good supplier will tell you where theirs are before you find them. What matters is the response when you raise one: a specific corrective action with a date, or a reason why it does not apply. For a JUNZHIJIA programme, audits are welcomed and the documents above are available for review; what is confirmed on a visit depends on which production line and which stage of your order are running that day, which is why visits are scheduled against a live run rather than a showroom.

How to Audit a Protective Case Factory: A Buyer's On-Site Checklist

Six areas that carry the signal

Walking the floor: what to look at

Capacity: the question behind the question

Red flags worth acting on

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