Pure Polyimide Film (Non-Adhesive PI Film / Electrical Insulation Film) for

Product Specification

1. Product Overview

Nomay Pure Polyimide Film is a non-adhesive electrical insulation film for motor and transformer insulation, cable wrapping, flexible electronic assemblies, battery-module insulation and custom die-cut dielectric parts.

Also known as non-adhesive PI film, polyimide insulation film or polyimide film strip, this product contains no pressure-sensitive adhesive. It provides a separate dielectric layer and requires a suitable fixing or lamination method.

2. Product Construction

Construction: Single-layer polyimide film
Adhesive Coating: None
Adhesive Side: Not applicable
Release Liner: Not required for the standard non-adhesive construction
Surface: Smooth, non-adhesive film surface
Standard Color: Natural amber

Film thickness equals total thickness because the standard construction has no adhesive layer.

Black or colorless versions require separate film-grade and performance confirmation.

3. Base Material and Adhesive System

Base Material: Polyimide film
Adhesive System: None

The film provides a thin dielectric barrier between conductive components. It can be installed by inserting, wrapping with a suitable fixing method, mechanical retention, assembly pressure or lamination using a separately selected bonding system.

The standard film does not self-adhere or heat-seal to itself. When adhesive positioning or bonding is required, select a suitable single-sided or double-sided polyimide adhesive tape.

4. Available Specifications

Film Thickness: Reference nominal thicknesses include 12.5, 25, 50, 75 and 125 µm (0.0125, 0.025, 0.050, 0.075 and 0.125 mm). These are industry reference sizes; Nomay availability and thickness tolerance must be confirmed for the selected film grade.

Total Thickness: Equal to film thickness for the standard non-adhesive construction.

Width: Custom slit widths, subject to confirmation of film grade, thickness, slit tolerance and converting requirements.

Roll Length: Confirmed according to film thickness, width, winding requirements and order quantity. Please specify the required finished-roll or master-roll length.

Color: Natural amber. Black or colorless options require separate specification confirmation.

Available Formats:

• Slit rolls

• Film sheets

• Narrow film strips

• Insulation spacers

• Custom die-cut insulation parts

Thickness, width, roll length and dimensional tolerances must be confirmed as a compatible specification combination before ordering.

5. Key Features and Buyer Benefits

• Non-adhesive construction for independent electrical insulation

• Thin dielectric film for assemblies with limited installation space

• Flexible material for wrapping, inserting and shaped insulation components

• Thickness selection according to electrical and mechanical requirements

• Suitable for slitting, sheeting and die cutting

• No pressure-sensitive adhesive layer to transfer adhesive residue

• Formats suitable for electrical insulation converters and component manufacturers

Final thermal, electrical, mechanical and dimensional performance depends on the selected film grade, thickness and application conditions.

6. Application Procedure

Step 1: Identify the insulation function, component geometry, materials in contact with the film and operating environment.

Step 2: Specify film thickness, width, roll length, sheet dimensions or die-cut geometry, including tolerances.

Step 3: Confirm working voltage, required insulation performance, process temperature, exposure time and mechanical requirements.

Step 4: Slit, sheet or die-cut the film to the required dimensions, controlling edge quality and handling damage.

Step 5: Install using a suitable fixing method. For lamination, confirm compatibility with the separately selected adhesive or bonding system.

Step 6: Evaluate the selected film in the actual assembly before mass production, including retention, electrical insulation and performance after processing.

7. Application Industries

• Electrical and electronic equipment

• Motors and transformers

• Wire and cable manufacturing

• Flexible electronics

• Battery and energy-storage assemblies

• Automotive electrical and electronic assemblies

• Industrial electrical equipment

• Electrical insulation converting

• Precision die-cut component manufacturing

Film-grade suitability must be confirmed for the application and the complete assembly.

8. Application Scenarios

FPC and Flexible Electronics
For converted dielectric spacers and insulation components in flexible electronic assemblies. Use as a circuit substrate or laminated insulation layer requires confirmation of dimensional stability, surface condition and compatibility with the bonding and processing system. Bare PI film is not a ready-to-bond adhesive coverlay.

Motor and Transformer Insulation
For slot liners, coil separators and interlayer barriers, subject to the equipment's electrical, thermal and mechanical requirements. Suitability must be assessed within the complete insulation system.

Wire and Cable Wrapping
For mechanically retained or subsequently laminated insulation wraps. Standard bare PI film does not self-adhere or heat-seal to itself.

Battery-Module Insulation
For dielectric spacers and barriers between cells, busbars and surrounding components after verification of voltage, puncture resistance, edge protection and fixing requirements. This product is not an internal battery separator or a thermal-runaway barrier.

Custom Die-Cut Insulation
For sheets, strips, spacers and shaped dielectric parts manufactured to the customer's drawing, dimensions and tolerances.

9. Performance and Operating Conditions

Temperature Performance
Applicable continuous operating temperature and peak process temperature depend on the selected film grade, exposure time, mechanical load, environment and required service life. Confirm these conditions for the selected specification before ordering.

Electrical Performance
Dielectric strength and breakdown voltage depend on film grade, thickness, conditioning and test method. Specify working voltage and required test conditions. Film test values do not replace verification of the finished assembly's insulation design.

Peel Adhesion
Not applicable because the standard product contains no pressure-sensitive adhesive.

Mechanical and Converting Performance
Thinner film generally offers greater flexibility and lower assembly thickness. Thicker film generally offers greater handling strength. Selection must also consider puncture resistance, edge quality, dimensional tolerances and installation stresses.

Dimensional Stability
For precision lamination or heat processing, confirm shrinkage and dimensional stability under the intended temperature and exposure time.

10. Comparison and Selection Guide

Choose Pure Polyimide Film when:

• A separate electrical insulation layer without pressure-sensitive adhesive is required.

• The film will be inserted, mechanically retained, wrapped with a suitable fixing method or laminated using a separately selected bonding system.

• Rolls, sheets, strips or die-cut dielectric parts are required.

Choose Single-Sided Polyimide Tape when:

• One adhesive-coated side is required for positioning, insulation or masking.

• The adhesive matches the substrate, process temperature, exposure time and removal requirements.

• For PCB solder masking, the selected model is suitable for the soldering process.

Choose Double-Sided Polyimide Tape when:

• Two surfaces must be bonded using a PI film carrier with adhesive on both sides.

• Adhesive compatibility with each bonding surface has been confirmed.

Choose a Laminated or Heat-Sealable Film when:

• The assembly requires an integrated bonding layer or a heat-sealing function.

• Bare non-adhesive PI film alone cannot provide the required bond.

A release liner is a handling feature of a selected adhesive construction; it does not by itself determine whether single-sided or double-sided tape is needed.

11. Important Selection Notes

• This product is non-adhesive and requires a suitable installation or fixing method.

• Reference thicknesses are selection guidance, not confirmation of stock or availability.

• Standard amber film, black film and colorless film may have different properties and require separate grade selection.

• Temperature and electrical performance must be confirmed for the selected film grade and thickness.

• FPC substrate, lamination and cable applications require assessment of the complete material and processing system.

• Battery-module insulation applications require verification of mechanical protection and electrical separation.

• Complete application testing before mass production.

12. Send Your Application Requirements

For film selection, sample evaluation and quotation, please provide:

• Application, component and materials in contact with the film

• Installation or fixing method

• Continuous operating temperature, peak process temperature and exposure time

• Film thickness and tolerance

• Width and roll length, or sheet dimensions

• Finished-roll or master-roll requirements

• Die-cut drawing and dimensional tolerances, if applicable

• Working voltage and required dielectric or breakdown-voltage test conditions

• Mechanical, puncture-resistance or dimensional-stability requirements, if applicable

• Order quantity and destination country

• Any required testing or certification standard

Nomay will use these requirements to confirm the film grade, product specification, sample requirements, minimum order quantity and quotation. Required testing or certification can be arranged according to the agreed standard and product scope, with completion requirements confirmed before order acceptance.