After-Sales Support FAQ

Separate soft caking from hard caking first. If the lumps break under light hand pressure and leave no hard residue on a 40-mesh sieve, it is soft caking — usually caused by transport vibration plus surface moisture pickup. It normally does not affect performance, but measure moisture and dispersibility before feeding it into production.

If the lumps need knocking to break and the interior is dense, it is hard caking. Either the powder absorbed moisture and set, or stacking pressure bound the particles together. Feeding it directly will cause poor dispersion and film specks, and crushing it in-house is not recommended.

Document and sample at the same time: photograph the outer carton, the breach, the batch label and a cut section of the cake; retain 500 g and send us the batch number. We pull the retention sample from the same batch for parallel comparison and issue a written conclusion, which shows whether this is a transport issue or a batch issue.

Rule out sample preparation first: a finer particle size reads whiter and brighter, and pressing pressure and substrate shift the numbers considerably. Only ΔE measured under identical preparation — same pressure, same substrate, same instrument, D65 — is comparable.

A common acceptance convention: ΔE ≤ 1.5 is treated as the same colour, 1.5–3 depends on the hiding power and dosage in the formula, and ΔE > 3 is a reject. That threshold is best written into the quality agreement rather than negotiated case by case.

If it is out of tolerance, segregate by batch number. Do not blend two batches to "average" the colour — the blend is neither traceable nor acceptable at incoming inspection.

Four checks, in order — most issues are found before the fourth.

1. Same specification: grade, surface treatment type and coating level, particle size band. One difference changes the hand feel. 2. Formula changes: new lot of base oil, adjusted thickener system, substituted dispersant. 3. Process parameters: dispersion tip speed, time, temperature. After scale-up, shear energy is often lower than in the lab. 4. Dosage: lab trials are often dosed "a few drops per 100 g"; at scale the weighing error scales with it.

Send the bulk retention sample together with the original lab sample. We run a parallel comparison on particle size, whiteness, oil absorption and dispersibility, and the index that diverges identifies the cause.

Compare test conditions before comparing numbers.

D50 depends on dispersion medium, dispersant type and dose, ultrasonic power and duration — a 10–20% spread between condition sets is common. Whiteness depends on instrument calibration, the standard plate and how tightly the sample is pressed. Oil absorption depends on how the endpoint is judged.

Align three things: the same method standard, the same dispersion conditions, the same endpoint. If a gap remains after alignment, retest through the arbitration route agreed in the contract — each side retains a sample and both go to the same third party, or samples are consolidated at one site and run on one instrument.

We keep retention samples for 24 months, so the same batch can be pulled and retested in parallel to establish whether the difference is in the batch or in the test conditions.

Establish whether the finding holds before deciding on disposition.

Three things to confirm: whether sampling was representative (multi-point, avoiding the surface layer), whether the test method matches the standard behind the limit, and whether the limit was taken for the correct application (EU 1223/2009 or the Chinese Safety and Technical Standards for Cosmetics).

The first action is quarantine, not disposal: store the batch separately, do not feed it, do not blend it, and run a retest plus extended testing on the retention sample. If the exceedance is confirmed, it goes through the quality complaint process and we trace all downstream shipments of that batch by batch number.

One hard rule: do not "dilute" an abnormal batch with a conforming one. Afterwards neither batch is traceable, and neither will pass acceptance.

An isolation test settles it: disperse this powder alone in the same medium, with no other powders and no other additives. If specks remain, the cause is the powder itself (hard agglomeration or moisture). If they disappear, the cause is the formula or the process.

Three common formula causes: adding powder into the oil phase instead of oil into powder; a dispersant mismatched to the surface treatment (silicone-treated powders run more freely in non-polar systems); and skipping the wetting stage by heating too early.

Two common process causes: insufficient dispersion tip speed (same time at half the tip speed gives a very different result), and incomplete vacuum deaeration, which traps particles inside bubbles.

Send us the isolation test result plus the formula composition (redacted is fine) and we can identify which side the problem sits on.

Unopened, sealed and stored cool and dry (≤30 °C, RH ≤60% recommended), standard grades carry a 24-month shelf life; the COA marking governs.

Past shelf life does not automatically mean unusable, but it must be retested: moisture, microbiology, dispersibility and hue. If it passes, it can continue in use. If it fails, it cannot be "downgraded" — cosmetic raw materials have no downgrade route, only disposition as non-conforming material.

Opening the package is often the bigger risk: repeated moisture pickup and contamination from sampling both happen after opening. Use within three months of opening, and label the remainder with batch number and opening date.

Usually it is not the coating coming off — it is a change in compatibility.

Surface treatment (silicone, fluorine, amino acid) sets the hydrophilic-lipophilic balance of the powder. Changing the base oil changes the solvent environment, so the system's ability to solvate the treatment layer changes with it, showing up as floating, streaking in the bulk, or viscosity drift.

Test it directly: run the same powder in both base oils in parallel. Floating only in the new oil points to compatibility; floating in both points to the treatment layer.

Two routes out: switch to a treatment type matched to the polarity of the target oil (more thorough), or keep the powder and adjust the polar component ratio in the system (smaller change).

Three things on site: do not open the bag, do not decant, do not sieve. Quarantine the whole package and take four photographs — outer carton, breach, batch label, powder condition.

Send us three things: batch number, photographs, carrier waybill number, and file it as a quality complaint. Contaminated powder cannot be sieved back into use — sieving removes neither foreign matter nor microorganisms.

For prevention, match packaging to the transport route: for long haul and export, an inner PE liner plus fibre or steel drum, with stretch wrap on the pallet; for small trial quantities the original packaging is fine with an outer carton added.

Both are possible, and anything that can be resolved remotely does not need a visit.

Samples: 500 g each of the same-batch retention sample and the problem sample, with system composition (redacted is fine — oil phase, powder phase, additive types and ratio ranges) and a description of the symptom. We run a parallel comparison on particle size, whiteness, oil absorption and dispersibility, and issue a written conclusion.

Site visit: arranged when a production line shows a batch-wide abnormality that cannot be localised remotely. Prepare the line parameter records, the list of affected batches and defective samples beforehand.

Response times and cost allocation follow the contract or service agreement; where a written commitment is needed, technical service terms can be signed separately.

Three bases: the quality agreement or purchase contract signed by both parties, the specifications and test methods stated on the COA, and the agreed arbitration testing route. Where none of the three exists, putting one in place costs far less than arguing batch by batch later.

Five steps: issue identified → quarantine, retain samples, document with photographs → complaint filed (batch number, quantity, symptom, test data) → joint retest or third-party arbitration → decision and disposition (replacement, return, technical support).

Judgement deadlines, cost allocation and return arrangements follow the contract. A standard Quality Complaint Form template is available from us on request.

Through batch traceability. Our records cover three things: raw material lot, production batch, and retention sample plus shipment routing. Given a batch number, we can tell which customers received that batch and whether the retention sample is still in place.

Two things to do on your side: segregate stock by batch number and avoid cross-batch blending; record the affected product batches and dosages for later assessment.

Once it is confirmed as a single-batch issue, the scope stays with that batch and does not need to be extended to others.