Electrical insulating presspaper, slit and die-cut in our own plant

Chengfa has produced electrical insulating presspaper for lithium-cell and energy-storage insulation — sold in the Chinese market as Qingke Paper (青稞纸) — since 2008 in Qiaotou, Dongguan. The base board is 100% sulfate softwood pulp. Slitting, length cutting, adhesive coating, film lamination and die cutting are done in the same building, so a tolerance claim on our datasheet is something the people who cut your order can actually control. The board itself is made to our specification by our upstream paper mill on a tolling basis — we do not operate a paper machine, and the mill is a long-term partner we do not name on this site; we confirm it directly during document checks or a plant visit.

0.1–0.5 mmthickness range, tolerance ±0.01 mm

1,005 mmstandard roll width

13 linesproduction lines, 2,000 m² works

2008 sincefocused on battery and motor insulation

What we actually supply

Presspaper rolls

100% sulfate softwood pulp, 0.1–0.5 mm, width 1,005 mm. Roll length up to 200 m for 0.1–0.3 mm and 100 m for 0.4–0.5 mm.

Slit rolls and cut sheets

Slit from the 1,005 mm parent roll. Allow about 20 mm of edge waste across the two sides when you calculate yield.

Die-cut gaskets and rings

Cut from your CAD or DXF drawing. Tooling for 18650, 21700, 26650 and 32650 cells is already made.

Adhesive-backed and laminated

Standard self-adhesive version, non-adhesive version, or film-laminated. Adhesive type can be changed per project.

Three things we will not tell you

These are the sentences that cause claims later, so they are stated up front.

Common supplier claims in this category, and our position
Claim you may receive	Our position
Breakdown voltage for every thickness	We state it per thickness: ≥ 900 V at 0.1 mm (measured by us) and 1350 / 1800 / 2250 / 2700 / 3600 / 4500 V at 0.15 / 0.2 / 0.25 / 0.3 / 0.4 / 0.5 mm as guaranteed values. Third-party testing at each thickness can be arranged per project.
A flame-retardancy class, or a management-system certificate	Neither is held. The paper is not rated for flame retardancy and we hold no system certification. If your design needs a rated material, an epoxy board such as our 3240 grade is the realistic route.
Door-to-door delivered pricing with duties prepaid	We quote EXW Dongguan or FOB Shenzhen Yantian. We are not a delivered-terms supplier, and we would rather say it before the order than after.

Why the naming matters International technical literature specifies this material as presspaper under the IEC 60641 series, with part numbers and grade designations. The Chinese market name 青稞纸 / 青壳纸 does not appear in that literature. We publish both names on every page so that a buyer moving between a Chinese quotation and a Western datasheet can see they are the same material.

Where to go next

Full presspaper specification — measured parameters with test conditions, forms, colours, tooling.
IEC 60641 parts and grades — why “complies with IEC 60641” is not a specification, and what to ask for instead.
How to vet a presspaper supplier — the eight checks that catch most problems before an order.
Trade terms, MOQ and lead time — who pays duties, how long a container takes, what a sample costs.

Request samples or a quotation

Samples are free; they ship within 3–5 days. Send thickness, application and monthly quantity for a quotation. Call, WhatsApp or WeChat: +86 178 7517 6368