Eleven months after a shipment, a customer sent back photographs of a gel that would not thicken, along with four bags carrying their own brand and no lot code. The repacker had printed the artwork beautifully and left the production date off, because the customer’s template did not have a field for it. Nobody could say which reactor batch those bags came from, so nobody could test a retained sample, and the claim was settled at the full invoice value plus freight.
Private-label powder looks like a simple transaction: buy a tonne, print your name on the bag, sell it. The traceability chain is what you are actually buying, and it is easy to break in the twenty minutes between the hopper and the sewing head.
Repacking cuts the chain in three places
The first cut is at the lot code. Original bags carry the manufacturer’s lot, which links to a reactor batch, a drying run and a retained sample. When powder goes into a repack hopper and comes out in a different bag, that link is only preserved if somebody prints the original lot on the new bag or records the mapping in a packing log. If neither happens, the link is gone.
The second cut is the retained sample. Most manufacturers keep 500 g per lot for twelve to twenty-four months. A repacker who does not keep a matching sample has nothing to send to a lab when a customer complains, and the manufacturer’s sample may be from a different part of the same batch.
The third cut is the weight. A 25 kg bag filled to 24.6 kg is within most tolerances and invisible on a pallet, but over a 20 tonne order it is 320 kg of missing product, and it shows up as a yield loss the customer cannot explain.
What belongs in the co-packing agreement
Six lines, and they are not negotiable. Who prints the lot code and in what format. Who keeps the retained sample, for how long, and where. Who owns the safety data sheet and which company name appears in section 1. What the deviation notice period is when a batch falls outside the agreed range. What the bag weight tolerance is and how it is checked. And who is liable when a claim cannot be traced because a code is missing.
| Item | Weak answer | Workable answer |
|---|---|---|
| Lot code | customer’s own sequence | manufacturer lot plus repack date |
| Retained sample | none | 500 g per repack run, 24 months |
| SDS owner | repacker | named legal entity, reviewed yearly |
| Weight check | gross only | net, 3 bags per pallet, logged |
The contamination nobody plans for
A repacker running two brands through one hopper is running two grades through one hopper. Powder sticks to the cone, the butterfly valve seat and the screw flight, and a 100/200 mesh order packed after a 30/60 order will carry coarse granules into a fine product for the first forty bags. The customer’s line notices before anyone else does: a metering screw that normally delivers 4.2 g per cycle starts delivering 4.6, and the pads come out heavy.
In one case the mix went the other way. Fines from a 100/200 run stayed in the hopper and contaminated a coarse order bound for a cable compounder, where the fines bridged the filling nozzle and stopped the line twice in a shift. The repacker’s response was to add a purge step, which is the right fix, but only after the customer had already paid for the downtime.
Before signing, ask to see the changeover procedure and the last three months of packing logs. If the repacker cannot produce a log that ties a finished bag to an incoming lot, the brand on the bag is the only thing you own. The polyacrylate powder range page lists the grades that are commonly repacked, with the mesh cuts that should never share a hopper without a full wash-down.
Da maohua
Zhengzhou Flor New Materials Co., Ltd. specializes in SAP super‑absorbent polymer products. Serving personal hygiene, agriculture & horticulture, pet supplies and other industries, we leverage supply‑chain resources to provide particle‑size selection, performance matching and customized solutions based on clients’ practical requirements.
