Insulating presspaper specification
Every figure below is a measured value held in our own records, not a nominal or catalogue value, and every electrical or mechanical figure carries the thickness it was measured at. A number without its test condition cannot be compared with a competitor's number, which is the main reason buyers get surprised after delivery.
Base material and measured properties
The board is made to our specification by our upstream paper mill on a tolling basis; we do not run a paper machine, and the mill is not named on this site — we confirm it during document checks or at the plant. All figures below are measured on that board after it reaches our works.
| Property | Value | Condition | Note |
|---|---|---|---|
| Material | 100% sulfate softwood pulp | — | Long fibre, higher tear resistance than hardwood-pulp board |
| Thickness range | 0.1 – 0.5 mm | Full range | Tolerance ±0.01 mm across the range |
| Breakdown voltage | 900 V to 4500 V | by thickness, 0.1 to 0.5 mm | Stated per thickness in the table below: 0.1 mm is our own measurement, 0.15–0.5 mm are guaranteed values |
| Temperature range | −40 °C to +105 °C | non-adhesive and adhesive-backed | +105 °C is the upper limit for both versions. The adhesive works best between 13 °C and 33 °C — that is an application and storage window, not a temperature rating |
| Tensile strength, machine direction | 55.8 N/cm | at 0.2 mm | Tested to ISO 1924-2 |
| Tensile strength, cross direction | 23.4 N/cm | at 0.2 mm | The MD/CD gap is normal for a rolled paper — design with it, do not average it |
| Oil absorption | 19.2 % | at 0.2 mm | Relevant to oil-impregnated designs |
| Standards declared | IEC 60641 · JB/T 8150 · ISO 1924-2 | — | See parts and grades before you rely on “IEC 60641” alone |
Breakdown voltage by thickness
| Thickness / mm | Breakdown voltage / V | Equivalent field strength | Status of the figure |
|---|---|---|---|
| 0.10 | ≥ 900 | 9.0 kV/mm | Measured by us |
| 0.15 | 1350 | 9.0 kV/mm | Guaranteed by us |
| 0.20 | 1800 | 9.0 kV/mm | Guaranteed by us |
| 0.25 | 2250 | 9.0 kV/mm | Guaranteed by us |
| 0.30 | 2700 | 9.0 kV/mm | Guaranteed by us |
| 0.40 | 3600 | 9.0 kV/mm | Guaranteed by us |
| 0.50 | 4500 | 9.0 kV/mm | Guaranteed by us |
The table has two tiers and we label them: the 0.1 mm figure is our own measurement; 0.15–0.5 mm are guaranteed values — we will write them into a technical agreement and reject a batch that falls below them, but they are not yet third-party tested at each thickness. We can arrange that per project. Breakdown voltage depends on electrode shape, the medium (air or oil) and the rate of rise, so compare suppliers only on a common test method, not on the number alone.
Forms we supply
| Form | Size | How it is produced |
|---|---|---|
| Roll | Width 1,005 mm. Length up to 200 m (0.1–0.3 mm) or 100 m (0.4–0.5 mm) | Direct from the paper line |
| Slit roll | Customer width, 10 mm minimum | Slit from the 1,005 mm roll; allow about 20 mm of edge waste across both sides when you calculate yield |
| Cut sheet | Customer length | Cut to length from a roll. A sheet size is a cutting specification, not a stocked item |
| Die-cut gasket / ring | Per drawing, ±0.02 mm die-cut tolerance | Stamped from roll material. Tooling for 18650, 21700, 26650 and 32650 cells is already made |
Options
- Adhesive: standard self-adhesive, non-adhesive, or film-laminated. Adhesive type can be changed per project.
- Colours: natural, red and cyan are covered by our own test reports, and green is also available. Cyan (青) is a real, current colour — it is the sample named on our own SDS (Cyan Insulating Cardboard) and on our own RoHS report. Other colours can be arranged per order. Colour is an identification aid, not a specification.
- Custom thickness: anywhere within 0.1–0.5 mm.
- Adhesive version: rated to +105 °C, the same upper limit as the plain board. Keep and apply it between 13 °C and 33 °C, out of direct sun and never below freezing — below 13 °C the adhesive stiffens and initial tack drops, above 33 °C it can bleed and the liner releases unevenly.
Documents we can send
| Document | Reference |
|---|---|
| Technical data sheet | By model, issued by us |
| MSDS / SDS | KA2605270025A |
| RoHS test report | LCSA05276122R (Chinese) / LCSA05276120R (English), Shenzhen LCS Testing Lab, issued 4 Jun 2026, applicant: Dongguan Chengfa Packaging Products Co., Ltd. |
| SGS test report | The material carries SGS reports: RoHS for natural, red and cyan, REACH SVHC screening (250 listed + 6 potential substances, at or below 0.1%, pass) and halogen. Issued by SGS-CSTC Guangzhou; available on request. |
| Photography | White-background product shots, application shots, packing photos, factory video |
Ordering terms
- MOQ: rolls from 100 m². Die-cut parts are confirmed after drawing and tooling review.
- Samples: free, shipped within 3–5 days, freight collected.
- Lead time: 15–20 days for a 40HQ including production and ocean leg; 7–10 days if capacity allows a rush slot.
- Capacity: about 8 × 40HQ per month depending on specification. Mixed containers accepted with at least 10 cartons per SKU.
- Terms: EXW Dongguan or FOB Shenzhen Yantian. See who handles customs.
Ask for a datasheet against your drawing
Send thickness, application and quantity. +86 178 7517 6368