Quality you can document, not just claim.
Every bottle is backed by an audited quality system and real, repeatable testing — from resin drying to leak, drop and print-adhesion checks.
Quick answer: Shijin runs an ISO 9001:2015 quality management system across three plants in Shenzhen, Huizhou and Guangzhou. Every order passes three independent inspection gates — incoming material (IQC), in-process (IPQC) and pre-shipment (OQC) — with leak, drop, capacity and print-adhesion checks run on the actual bottle rather than on a sample of resin. Each carton can be traced back to its resin batch, molding machine and shift. The ISO 9001:2015 certificate and the material and compliance test reports held on file for each order are available in English on request.
This page explains exactly how that works — so you can audit us before you place a purchase order, not after.
Audited & export-ready
Our certifications give overseas brands the paperwork they need — and the confidence that our processes are independently verified.
ISO 9001:2015
Quality management system certified — documented processes from incoming resin to final shipment.
EU Documentation
Material and food-contact test documentation supplied for European Economic Area orders.
Factory Audit
Third-party factory audit and supplier verification reports available on request.
PCR Documentation
Recycled-content supply-chain documentation for PCR PET and PE programmes.
Shijin Engineering & Quality Team
This page’s compliance and testing content is reviewed and verified by our in-house engineering and quality-control specialists. Original certificates and English translations of the documents held on file (ISO 9001:2015 certificate, material test reports, factory audit records) are available on request for factory audits, EU orders and customs clearance. Request certificate copies →
Proven on your bottle
We don’t promise a finish or a seal we haven’t verified. Here’s what every design goes through before it ships.
Leak / vacuum test
Bottles are held at 0.6–0.8 MPa air pressure, inverted, with zero leakage.
Drop test
1–1.2 m vertical free-fall, three times, without cracking (on request).
Flame & water-hanging
PE bottles are flame- and water-tested before printing to prevent ink peeling.
Capacity verification
Net + brim capacity checked against spec (e.g. +15–45 ml headroom by size).
Consistency is engineered in
Controlled drying
PET/PE resin dried at 170–180°C for 3–4 h; masterbatch at 100–120°C for 2 h — the foundation of clear, strong walls.
Color accuracy
Masterbatch ratios are standardized by finish (transparent, pearl, high-gloss, frosted) for batch-to-batch consistency.
Dedicated QC dept.
A standalone quality department inspects at incoming, in-process and pre-shipment stages before goods leave the warehouse.
What gets checked, and when
Quality is not one final check at the end of the line. It is three separate gates, each with its own checklist and its own sign-off — so a problem is caught at the stage where it is still cheap to fix.
IQC — incoming material
Before anything is melted. We verify the material we were actually shipped, not the material the paperwork claims.
- • Resin grade and supplier batch number logged against the purchase record
- • Moisture content checked before drying (critical for PET clarity)
- • Masterbatch colour matched against the approved standard chip
- • Recycled (PCR) content confirmed against the recycled-material supply-chain documents
- • Incoming cartons inspected for contamination and mixed grades
IPQC — in process
During molding and decoration. The first shot off every mold is the reference for the whole run.
- • First-article inspection signed off before mass production starts
- • Hourly patrol checks on weight, wall thickness and neck dimensions
- • Bottle weight and capacity spot-checked against the approved spec
- • Neck finish and thread fit tested against your cap, pump or sprayer
- • Print position, colour density and adhesion verified during silk-screen / hot-stamp runs
OQC — pre-shipment
On finished, packed goods. This is the last gate before a container is sealed, and the one your own QC will repeat.
- • AQL sampling inspection on the finished batch
- • Leak / vacuum test on the assembled bottle (bottle + closure, not bottle alone)
- • Drop test on packed units where the route justifies it
- • Carton count, labelling and shipping marks checked against the packing list
- • Retained samples kept from the batch for later reference
Inspection methods reference
The table below is the working list our QC department runs against. Exact tolerances are agreed per project, because a 30 ml dropper bottle and a 1,000 ml detergent bottle cannot share a single specification.
| Check | Method | Typical acceptance | Stage | Record |
|---|---|---|---|---|
| Resin moisture | Drying log + moisture check before feed | Dried per material schedule (e.g. PET 170–180 °C / 3–4 h) | IQC | Drying record |
| Colour match | Visual comparison vs approved chip, under standard light | Within the agreed finish band (transparent / pearl / frosted / gloss) | IQC + IPQC | Approved sample |
| Bottle weight | Digital scale, sampled units | Within mutually agreed ± tolerance of the mold spec | IPQC | Patrol sheet |
| Wall thickness | Sectioned sample / thickness gauge | No thin spot that fails the drop test | IPQC | Section report |
| Capacity | Gravimetric fill to marked level | Net + brim capacity within spec; headroom agreed by size (e.g. +15–45 ml) | IPQC + OQC | Capacity sheet |
| Neck & thread fit | Assembly with your closure, torque / leak check | Seals without cross-threading or weeping | IPQC | Assembly check |
| Seal integrity | Air pressure 0.6–0.8 MPa, inverted, held | Zero leakage on the assembled unit | OQC | Leak test log |
| Drop resistance | 1–1.2 m vertical free-fall, three drops | No cracking or seam failure (on request) | OQC | Drop test log |
| Print adhesion | Flame / water-hanging pre-treatment, then tape-peel and rub test | Ink does not peel, flake or smear | IPQC | Decoration sign-off |
| Accessory assembly | Fit test on pump, sprayer, cap or dropper | Smooth actuation, no leakage at the collar | IPQC | Assembly record |
| Packing & marks | Count per carton, label and shipping-mark check | Matches the packing list exactly | OQC | Packing list |
If your product needs a check that is not on this list — a specific pull force, a chemical resistance soak, a stakeholder-specific protocol — tell us at the quotation stage. It is far easier to build a test into the plan than to retrofit it after production.
Honest, documented recycled options
For brands with sustainability targets, we offer PCR (post-consumer recycled) PET and PE supplied with recycled-material supply-chain documentation — with clear guidance on what recycled content can realistically achieve for clarity and strength.
We’d rather set the right expectation than over-claim — that’s what “honest sustainability” means to us.
Paperwork your market will accept
Buying direct from a factory saves money only if the import paperwork holds up. These are the document types we routinely arrange with accredited laboratories for export orders — issued to the standard that applies to your destination market.
Food-contact compliance
Migration and material-safety testing against EU 10/2011 and equivalent regimes for bottles and closures used with cosmetics, personal care and food-adjacent products.
Heavy metals & migration
Third-party analysis for heavy-metal content and migration limits, so your own regulatory filing has a test report behind it rather than a supplier statement.
Recycled content (PCR)
Supply-chain documentation for PCR PET and PE, covering the recycled percentage claimed on-pack.
Physical performance
Leak, drop and closure-torque test reports on the finished assembled unit — the numbers your own QA team and your retail customer will ask to see.
Print & decoration
Adhesion and abrasion results for silk screen, hot stamp and labelling, relevant when packaging travels through humidity or is handled heavily on shelf.
Supplier audit
Third-party supplier verification records and the ISO 9001:2015 certificate, plus the factory audit pack (process flow, equipment list, QC records) for buyers running their own vendor approval.
Certificates are issued by third-party bodies and testing laboratories — they are not self-declared statements. Because testing is project-specific, tell us your destination market and product use case, and we will tell you which documents apply and what they cost before you commit.
Non-conformance, handled openly
A supplier is judged less by whether a defect ever happens than by what happens next. Every non-conforming batch follows the same documented route, and you are told at each step.
Identify & segregate
Suspect goods are physically separated and tagged at the moment they are found — they cannot re-enter the flow.
Grade & record
The batch is graded against the agreed specification and raised as a recorded non-conformance, with photos where relevant.
Root cause
We trace back through the batch record to the machine, shift and material lot, and identify whether the cause is material, tooling, machine or process.
Corrective action
A fix is applied to the cause — not to the symptom — and the corrected batch is re-inspected before it ships.
Commercial resolution
Rework, replacement or credit is agreed with you in writing, based on what the defect actually is and what your deadline allows.
Close & prevent
The record is closed with the action that prevents recurrence, and the lesson feeds back into the inspection checklist for future orders.
Traceability: batch code to carton
Every production run carries a batch code that ties the finished bottle back to the conditions that made it. If a question arrives months after delivery, we can answer it from the record.
- Resin lot — supplier and batch number from the IQC log
- Date & shift — when the run was molded and by which team
- Machine — which molding machine and mold produced the batch
- Process parameters — drying record and key settings used
- Inspection results — first-article, patrol and OQC sheets for that run
- Retained sample — a physical reference piece kept from the batch
In practice this is what makes a claim answerable. Instead of “we will look into it”, we can reopen the exact record for the units in your warehouse.
Visiting the factory
Buyers are welcome to audit us in person or send a third-party inspector. Our plants are in Huizhou and Guangzhou, roughly two hours from Shenzhen — we can arrange pickup, an interpreter and a full walk-through of molding, decoration and QC.
Prefer a remote check first? We will run a live video walkthrough of the line producing your order, with the QC sheets on camera.
Questions buyers ask about our QC
Yes. We send the ISO 9001:2015 certificate, third-party supplier verification records and any product-specific test reports in English as soon as you ask — before any payment. If your compliance team needs the documents verified at source, we will give you the issuing body and certificate numbers so you can check them independently.
Yes, and we would rather do so early. Seal failure is almost always a bottle-and-closure interaction issue, not a bottle-only problem. Send us a sample closure (or specify the neck standard) and we will test fit, torque and leak behaviour on the assembled unit, then report the result.
Send photos and the batch code from the carton. We reopen the production record for that batch, inspect the retained sample, and come back with a root cause and a proposed resolution — replacement, rework or credit — in writing. We do not ask you to accept a defect that falls outside the agreed specification.
We will not quote a headline percentage that we cannot substantiate. What we can do is agree an acceptance sampling plan (AQL) with you up front, inspect every batch against it, and share the actual inspection results for your order. That gives you a verifiable number for your own vendor scorecard rather than a marketing claim.
Yes. Notify us of the inspection date and we will make the line, the QC records and the warehouse available. If you use a service such as SGS, Intertek or Bureau Veritas, we are used to their checklists and will work to their schedule. For remote buyers we also offer a live video walkthrough at the pre-shipment stage.
It depends on the grade and the percentage. High-quality PCR PET can reach appearance close to virgin at moderate recycled ratios, while high recycled fractions usually mean a slightly warmer, less water-clear tone — which many brands now treat as a feature. We will show you samples at the percentage you are considering so you decide with the bottle in hand, not from a brochure.
Batch records, inspection sheets and retained samples are archived so that a shipment can still be traced well after delivery — which matters when a retail customer raises a question months into the season. If your contract requires a specific retention period, we will confirm it in the order terms.
Shijin operates an ISO 9001:2015 quality management system. Compliance documentation - material test reports, food-contact migration testing and recycled-content supply-chain records - is provided per order against current documents on file, appropriate to the product and market. We hold ourselves to a simple rule: we only present a certificate or test report that exists and can be verified by the issuing body.
Have a bottle in mind? Let’s make it.
Send us your capacity, material and quantity — our engineering team replies within one business day with a quote and 3D-ready options.