Most LDPE complaints are not about the wrong product. They are about a product that measured differently from what was promised. So this page is the list of what we measure, the tolerance we hold, and the paper you get with the delivery.
These are the numbers we work to. If a lot falls outside them, it does not ship.
What we measure
Tolerance
Why it matters to you
Average thickness
Plus or minus 5 percent of nominal
This is what you paid for. Under-gauge film is a hidden price rise.
Thickness variation across web
Within 10 percent of average
Uneven film telescopes on the roll and burns seals in patches.
Bag width and length
Plus or minus 3 mm
Bags that do not fit jam automated packing and annoy hand packers.
Seal strength
Tested to failure on samples per lot
A seal that fails in transit turns a cheap bag into an expensive claim.
Roll width
Plus or minus 2 mm
A few millimetres wrong and a former jams. Nothing else on the roll matters if it will not run.
Colour and opacity
Matched to approved sample per lot
Brand colours drifting between lots is the complaint retail buyers escalate.
The checks, in the order they happen
Quality on a blown-film line is not one inspection at the end. It is five checkpoints, and each one catches a different failure.
01
Incoming resin check
Every granule batch is logged against its supplier and grade. Melt flow index and moisture matter: wet resin gives you bubbles and weak spots, and no downstream check fully recovers from it.
02
Line setup against the job card
Die, air ring, haul-off speed and treater set to the recorded spec for your product, not to whatever the last job used. Food-grade work gets a purge before the run.
03
In-run gauge scanning
Thickness measured at multiple points across the web during the run and logged. Drift gets corrected while the bubble is still running, which is the only time correcting it is cheap.
04
Converting checks
On cutting and sealing lines we pull samples at intervals: width, length, seal integrity, gusset, perforation position and print register.
05
Lab and lot tests
Seal strength to failure, dart impact for puncture resistance, and for food-grade orders a migration test to IS 9845. Results go on the lot report.
06
Pack, label, document
Every bale or carton labelled with product, size, micron, lot number and date. The test report references the same lot number, so the paperwork and the plastic agree.
Food-grade and pharma: what the paperwork has to say
For direct food contact, the standard that matters in India is IS 9845, which governs migration of constituents from plastics in contact with food, read alongside IS 10146 for polyethylene specifically. A credible food-grade supply has four parts:
Virgin resin, no recycled content. Recycled film cannot be certified for food contact because the input history is unknown.
Migration testing on material from your lot, not from an archive.
Food-safe inks on the non-contact surface only.
A report that carries your lot number, which is the version that survives an FSSAI or customer audit.
For pharma and cleanroom work we also run double-bagged packing, and we can supply antistatic film where powders are involved. See food-grade bags and pharma packaging.
What we do not claim
We are a blown-film converter, not a laboratory, and we say so. Migration and heavy-metal testing is done at an accredited lab and the report is theirs, not ours. We also do not claim LDPE is biodegradable, because it is not. It is resin code 4: recyclable and reusable. Anyone telling you otherwise is selling you something. See LDPE recycling.
If something does go wrong
No factory has a zero-defect year. What matters is what happens on the phone call afterwards.
Send the lot number
It is on the bale label. With it we can pull the job card, the gauge log and the resin batch for that exact run, usually within a day.
We replace or credit
If the material is outside the tolerances on this page, it is our problem, not a negotiation. Replacement lot or credit note, your choice.
We tell you the cause
You get the actual reason: die build-up, a resin batch, a sealing temperature. A supplier who cannot explain a defect will produce it again.
The fastest way to judge a supplier is to hold the film. Tell us the spec and we will send a sample with the same report format that ships with a production lot.
