Materials & packaging

Electrical Insulation Materials

Insulation for motors, transformers, switchgear and high-voltage cable, coated, laminated, impregnated and converted on our own web lines.

Made at Ningbo · Bac Ninh · Johor

Development and manufacture

Winding shops buy on thermal class and breakdown voltage, so those are the two numbers our development work is aimed at. When a customer moves a motor from class F to class H, the change is rarely just a different film — the adhesive system, the cure schedule and the slot geometry all move with it. Our applications engineers validate the whole build-up on the customer’s own winding rather than on a coupon, because a laminate that passes flat and fails when cuffed has told you nothing useful.

Coating, nip lamination, calendering, slitting and rotary die-cutting run here, with a continuous beta gauge holding thickness across the web. We can supply by the roll, but we would rather supply the finished slot liner cut and formed to the lamination drawing — it removes a converting step and the scrap that comes with it. Breakdown voltage, tensile strength and thickness are measured per lot from samples pulled across the full web width.

Product scope

Polyimide films

PI film from 12.5 to 125 µm, plain, FEP-coated and adhesive backed, for class H and class C applications and flexible circuits.

PET insulation films

Polyester film and DMD, DM, NMN and NHN flexible laminates in classes B, F and H, from 0.15 to 0.50 mm total thickness.

Mica tapes and plates

Calcined and muscovite mica tape for high-voltage bars, plus rigid mica plate and machined mica parts for heating elements.

Insulating varnishes and impregnating resins

Solvent-free and solvent-based varnish for dip-and-bake and trickle impregnation, with validated cure schedules.

Fibreglass insulating sleeving

Silicone, acrylic and PU coated glass sleeving and braided sleeving in classes B to H, plain and self-extinguishing.

Epoxy and phenolic laminates

Grade 3240 epoxy glass, G10 and FR4 sheet, rod and tube, plus phenolic paper and cotton laminate, machined to drawing on request.

Heat-shrinkable tubing

Single and dual-wall tubing at 2:1 and 3:1 shrink ratio, including medium and high-voltage cable accessories and busbar sleeving.

Held in production

What the line holds, and how we know.

These are figures sustained across a production run rather than a best-case first article, each with the instrument or test that produces it.

CharacteristicHeld in productionVerified by
Thermal classB 130 / F 155 / H 180 °CThermal endurance to IEC 60216
Breakdown voltage, laminate≥ 12 kV/mmAC dielectric test set, per lot
Dielectric strength, PI film≥ 200 kV/mm at 25 µmPer IEC 60243
Tensile strength≥ 70 N/10 mmTensile tester to IEC 60626-2
Thickness tolerance±5% of nominalContinuous beta gauge across the web
Slit width tolerance±0.3 mmOptical width measurement
FlammabilityUL 94 V-0Certified test house, annually

Built and released against

  • IEC 60626 for combined flexible insulating materials
  • IEC 60893 and NEMA LI-1 for industrial rigid laminates
  • UL 1446 recognised insulation systems and UL 94 flammability
  • IEC 60684 for flexible insulating sleeving
  • IEC 60216 relative thermal index determination

Who buys it

  • Traction and industrial motor winding
  • Distribution and power transformers
  • Medium and high-voltage switchgear
  • Generator bar insulation
  • Cable accessories and terminations
  • Flexible circuits and battery packs

Related work

Neighbouring industries.

Programmes often cross these lines. Where a part touches more than one of them, a single engineer owns the whole thing rather than handing it between departments.

All industries

Send a drawing or a specification.

An engineer from the electrical insulation materials team replies within one business day with feasibility, the line it would run on, the tooling route and an indicative delivered cost.