How to choose a wallpaper glue powder supplier in China

Shortlist on evidence you can check before terms are discussed: a named model with published data, a fixed packing format, documents that match that model, and a sample you can test on your own wallpaper. The seven checks below cover the rest. Commercial terms belong after the model passes the trial, not before it.

Request the model TDSRead the sample protocol

Start with the model, not the company profile

  • A wallpaper glue supplier can only be compared on a named product. “Wallpaper adhesive powder” covers ordinary grades, universal grades, anti-mold grades and base powders sold for repacking, and those four behave differently in the bucket. Ask for the model name, the starch base and the published viscosity with its test conditions in the first reply.
  • If the reply is a catalogue of a hundred codes without a single test condition, you are comparing brochures rather than powder. The shortlist should get shorter at that point, not longer.
  • Model identity: a name, a grade and a starch base you can repeat in a purchase order. KARN lists K6 (ordinary grade, tapioca modified starch), 999 (universal grade, potato modified starch), 999+ (anti-mold grade) and KN-999 (a base powder for repacking).
  • Published data with test conditions: a viscosity figure means nothing without the solution concentration, instrument, rotor and speed. The finished KARN grades are quoted at a 5% solution, NDJ-8, No. 4 rotor, 6 rpm, ±10%; K6 is published at 38,000 ±10% mPa·s, and 999 and 999+ carry their current figure in the model TDS.
  • Packing you can plan around: 20kg net in a kraft paper bag with a PE liner, with pallets, loading, marks and labels confirmed per order rather than assumed from a photo.
  • A document set that matches the model: TDS and the pre-shipment QC standard by model, MSDS applicability by model and market, and a batch COA only when one was actually issued for that batch.
  • A sample protocol: how much powder, at which ratio, on which wallpaper, who runs the test and who keeps the record.
  • A repacking answer, if you sell under your own brand: 200g to 1kg packs, artwork, barcode and label language confirmed before production.
  • A clear answer on what the supplier does not do: no warehouse in your market, no local importer, and no third-party approval attached to a model unless a current document exists for it.

What the paperwork proves, and what it does not

  • A TDS describes a model. A COA describes one batch. An MSDS describes handling, storage and transport. None of the three replaces another, and none of them describes your wall. A supplier who sends a COA as a product datasheet, or a datasheet as a safety sheet, is showing you how documents are filed in that office.
  • Read the viscosity line first. A number without the concentration, instrument, rotor and speed cannot be compared with anything, including the supplier’s own second model.
  • Then ask which document applies to the batch you will actually receive, and keep the answer with the purchase order. A reference COA from an earlier batch explains the inspection fields; it is not a promise about the container in front of you.
  • TDS · Which model this is, its starch base, its published viscosity and test conditions, mixing guidance and packing · Whether the powder suits your wallpaper, your water or your wall
  • Pre-shipment QC standard · Which checks the factory runs on a model before loading · The result of a specific batch
  • MSDS · Handling, storage and transport safety information for the model and market · Product performance or approvals
  • Batch COA · What was measured on one identified batch · Consistency across future batches
  • Ask for the document that matches the model and the batch, not the thickest folder.

The sample is the only test that settles the model

  • Two models at a time is enough. Four samples produce four half-remembered opinions and no comparable record. Mix both at the ratio you intend to print on the pack, hang the wallpaper you actually sell, and write the result down while the paste is still wet.
  • The record matters more than the verdict. A trial that cannot be repeated on the bulk batch is an anecdote, and it will not help you when a seam opens three months later.
  • Model and batch on the bag · Lets the bulk delivery be compared against the sample that passed
  • Powder weight and water weight · Makes the ratio reproducible instead of “about right”
  • Water temperature, mixing time, rest time · All three change how thick the paste is before it reaches the wall
  • Wallpaper type and roll weight · The facing decides how much water it takes and how heavy the strip is
  • Wall condition and primer · A painted or sealed wall behaves differently from bare plaster
  • Open time, slide, seam tightness, dry result · The four observations that show whether the paste fits the way your installers work

How KARN fits this checklist

  • The table below answers the same seven checks with what this site publishes, so you can hold the page against the checklist instead of against a claim.
  • Model identity · K6, 999, 999+ and KN-999 with grade, starch base and intended use · The model code printed on the bag and the packing list
  • Published data · K6 at 38,000 ±10% mPa·s with its test conditions; 999 and 999+ viscosity in the model TDS · The TDS revision that applies to the order
  • Packing · 20kg net, kraft paper bag with a PE liner · Pallets, loading pattern, marks and label content
  • Documents · TDS and pre-shipment QC standard by model; MSDS applicability by model and market · Batch COA, when one is issued for the confirmed batch
  • Sample · Powder from the shortlisted model with the model TDS · Quantity, pack format and route
  • Repacking · 200g, 300g, 500g, 1kg and custom formats · Artwork, barcode and label language
  • Service scope · Manufacturing in China, with export shipments handled through independent forwarders · The forwarder, the documents handover and the delivery schedule
  • KARN does not claim a warehouse, an office or a registered importer in your market, and does not attach a third-party approval to a model unless a current document exists for that model.

What to decide before you send the inquiry

  • With those six answers a supplier can reply with a model, a document set and a sample plan in one round instead of five. That is also the point where a shortlist becomes a decision.
  • Which channel carries the first year: distributor, building-material store, private label or contractor supply.
  • Which wallpaper types you sell, with the roll weight if you know it.
  • Whether you buy 20kg bags, small packs from 200g to 1kg, or both.
  • Which mixing ratio you intend to print on the pack, because the trial should use that one.
  • Which language and which fields the label needs in your market.
  • Who runs the trial and who signs off on the result.

Frequently asked questions

How many wallpaper glue suppliers should we compare?

Two or three, and compare them on the same wallpaper at the same ratio. Beyond that the trial record stops being comparable, and the differences you see come from the test rather than from the powder.

Which document should we request first?

The TDS for the named model, including the viscosity test conditions. It is the only document that lets you compare two suppliers on the same basis before a sample is sent.

Is a factory audit needed before the first order?

An audit answers questions a document cannot, such as how batches are segregated and how the line is cleaned between models. It does not replace the sample, and the sample does not replace the audit. Decide which risk you are actually covering.

How do we compare two viscosity numbers?

Only inside the same method: same solution concentration, same instrument, same rotor, same speed. A figure quoted without those four details cannot be ranked against anything, including the same supplier’s other model.

Can a supplier send a COA with the sample?

Only if one was issued for that sample or batch. A COA that describes an earlier batch explains the inspection fields, but it does not tell you what is in the bag you are testing.

What should the first bulk order verify?

That the delivered batch behaves like the sample that passed: same mixing ratio, same water temperature, same wallpaper, and a seam check after full drying. Keep the sample record next to the delivery documents so the comparison is possible.