Technical paper, engineered for converters
Battery separator paper, filter media, release liners, electrical insulation papers and barrier papers — built to converter specifications with per-roll basis weight, thickness and lab data.
Request a QuoteTechnical paper is engineering, not stationery
"Technical paper" is the umbrella term for cellulose, glass-fiber and synthetic-fiber webs engineered for an industrial purpose. The largest sub-categories are battery separator paper (lead-acid, alkaline, lithium auxiliary), liquid and air filtration media, electrical insulation papers (transformer board, presspaper, NMN laminates), release liners for adhesives, abrasive backing paper, and specialty barrier papers for packaging.
The performance metrics are tightly defined and have nothing to do with print quality: basis weight, caliper, air permeability, electrical breakdown, oil absorption, dielectric strength, dimensional stability, surface roughness. Two reels that look identical on a pallet can perform differently on a converting line and lethally differently inside a transformer or a battery.
Sourcing Captain works with Chinese paper mills that already supply downstream into European and US converters. We specify by the converter's spec sheet — not by mill catalogue — and we issue per-reel lab data with every order so the buyer can release lots into production without re-testing.
Technical paper sourcing — six steps
Converter spec
Translate the converter's spec into a mill-side data sheet — basis weight, caliper, permeability, finish.
Mill shortlist
Two or three Chinese mills with the right web width and downstream export track record.
Trial reel
A sample reel for converter trials — we support the trial run on the buyer's line.
Production PO
Locked-price PO with per-reel lab data and an inspection clause.
PSI
Pre-shipment inspection of widths, edge condition and packaging on every reel.
Logistics
Freight booked under our contracts with humidity-controlled storage where required.
Per-reel documentation
Reel data sheet
Per-reel basis weight, caliper, air permeability and the application-specific test that matters.
Standards reference
TAPPI, ISO or DIN method reference for every test value.
Reel labels
Bilingual label with mill, lot, basis weight, width and length.
PSI report
Photo and video record of widths, edges and packaging.
Sample retain
A small cut held in our warehouse for downstream technical question support.
Sourcing dossier
Mill audit, supplier and per-reel traceability bundled as a single PDF.
Why a converter cannot afford an "almost" paper
Technical paper is sold to converters who run their lines at high speed, often unattended, with tight QA gates downstream. A roll that drifts on basis weight or caliper does not just produce off-spec output — it shuts the line down. A separator paper whose air resistance is wrong can leak the wrong way inside a battery cell and trigger thermal runaway. None of these failures are visible on the pallet.
Working with a sourcing partner who specifies the spec sheet, audits the mill, and issues per-roll lab data turns those failure modes into a paperwork formality. For global converters running high-speed lines on Chinese-sourced webs, the rejected-roll reduction is the case for the engagement.
Technical paper FAQs
Which technical paper categories do you cover?
Battery separator paper, filter media (liquid and gas), electrical insulation papers (kraft, presspaper, transformer board, NMN), release liners, abrasive backing, specialty barrier papers and converter-grade specialty papers. We will scope very specialised grades on a case-by-case basis.
Do you supply glass-fiber and synthetic webs as well as cellulose?
Yes — wet-laid glass mats, microfiber glass for AGM batteries, synthetic-fiber wet-laid webs and meltblown structures sit alongside cellulose papers in our supplier base.
Can you slit and rewind to converter widths?
Yes — we work with mills that slit to converter widths and we audit the slitting line as part of the supplier qualification. Edge condition is verified at PSI on every reel.
How do you ship reels?
Reels go on cradles or stretch-wrapped pallets inside lined containers. For humidity-sensitive grades we ship with desiccant and humidity indicator cards. The packaging plan is signed off before sealing.
What are typical lead times?
4–8 weeks from PO for standard grades, 8–12 weeks for build-to-order specialty webs. Trial reels are usually faster — 2–4 weeks. We confirm a binding lead time at PO time.
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Tell us what you need to source
Send specs, target volumes, and timelines. Our sourcing team replies within one business day with a sourcing plan and price guidance.