PI Film Voice Coil

Description

Harnawa Insulations Private Limited is a manufacturer of polyimide film for voice coil applications in India, supplying high dimensional stability kapton-type PI film to loudspeaker manufacturers, audio equipment OEMs and transducer producers across India and internationally. Voice coil polyimide film is a speciality grade of kapton-type polyimide film engineered for the extreme demands of loudspeaker voice coil former manufacture — where dimensional stability under heat, low mass, and resistance to adhesives and lacquers are all critical.

Whether you are manufacturing high-power loudspeaker voice coils, tweeter voice coil formers, compression driver formers or any audio transducer that needs a thermally stable, lightweight, non-resonant film former, Harnawa supplies voice coil polyimide film in 25–125 μm thicknesses with custom slit widths available from our Bhiwandi facility.

What is Polyimide Film for Voice Coil?

Voice coil polyimide film is a speciality kapton-type PI film selected and processed for the specific requirements of loudspeaker voice coil former manufacture. A voice coil former is a thin cylindrical tube around which the voice coil wire is wound — the former must be extremely lightweight (to minimise moving mass), dimensionally stable at the elevated temperatures generated during high-power operation, and chemically resistant to the adhesives and lacquers used in voice coil assembly.

Kapton-type polyimide film is the preferred material for premium voice coil formers because it outperforms paper, aluminium and Kapton in the combination of low mass, thermal stability to 400°C, chemical resistance and acoustic neutrality (no self-resonance). Voice coil PI film is supplied in precision-slit rolls that can be directly wound onto mandrels in the voice coil manufacturing process.

Base Material	Kapton-type polyimide film — high dimensional stability grade
Key Property	High dimensional stability — critical for precise voice coil winding
Temperature Range	-269°C to +400°C — handles high-power voice coil heat
Chemical Resistance	Resistant to adhesives, lacquers, solvents and coil impregnation compounds
Flame Retardancy	UL 94 V-0, halogen-free, RoHS/REACH compliant

Polyimide Film Types & Grades — Full Range

Harnawa manufactures the complete range of kapton-type polyimide film grades. Voice Coil Film (highlighted below) is a high dimensional stability grade for loudspeaker and transducer former manufacture:

Grade / Series	Type Code	Description & Key Use
HN Series	Standard	Standard kapton-type polyimide film, 0.5–10 mil.
FEP Coated Film	FH / FHF	FEP coated polyimide film — heat sealable.
Black PI Film	BX / BY / BL	Opaque black polyimide film, 13–125 μm.
ESD PI Film	Functional	Anti-static polyimide film for PCB protection.
Aluminized PI Film	Functional	Sputtered aluminium polyimide film for EMI shielding.
CR Film	CR / FCR / FCRF	Corona resistant polyimide film, ≥80 hr. For VFD motors.
Thermal-Conductive	MT Series	Polyimide film with thermal conductivity >0.36 W/m·K.
NHN Composite	Laminate	Non-woven/polyimide film/non-woven. Breakdown: 8–10 kV.
Colourful PI Film	Specialty	Red, Green and Transparent polyimide film.
Voice Coil Film — This Product	Specialty	High dimensional stability kapton-type polyimide film for loudspeaker voice coil formers. 25–125 μm. Precision-slit rolls for direct mandrel winding.

Typical Applications of Polyimide Film Voice Coil

Loudspeakers

Woofer voice coil formers
Midrange driver formers
Tweeter voice coil formers
Subwoofer formers
Full-range driver formers

Professional Audio

PA speaker coil formers
Studio monitor drivers
Line array driver formers
High-power stage speakers
Compression driver formers

Transducers

Automotive speaker formers
Headphone driver formers
Earphone voice coils
Ultrasonic transducers
Sonar transducer formers

Industrial

Linear actuator formers
Vibration test speakers
Acoustic measurement drivers
Hearing aid receivers
Medical transducers

Polyimide film voice coil applications — loudspeaker and audio transducer formers

Kapton type PI film for voice coil former manufacture India

Key Features & Benefits

High Dimensional Stability: Low shrinkage at operating temperatures — critical for precise voice coil geometry and consistent acoustic performance
Lightweight: Low mass density minimises voice coil moving mass — directly improves speaker sensitivity and transient response
High Temperature Resistance: Withstands -269°C to +400°C — handles extreme heat generated in high-power voice coil operation
Chemical Resistance: Resistant to voice coil adhesives, lacquers, impregnation varnishes and solvents used in speaker manufacturing
Precision Slit Rolls: Supplied in precision-slit widths for direct mandrel winding in production
No Self-Resonance: Acoustically neutral — does not introduce unwanted resonances into the audio signal
RoHS / REACH Compliant: Safe for export to EU, USA and global markets

Technical Specifications — Voice Coil Polyimide Film

Base Material	Kapton-type polyimide film — high dimensional stability grade
Thickness Range	25–125 μm (1–5 mil)
Tensile Strength (MD)	Up to 170 MPa
Elongation	40–50%
Dielectric Strength	Up to 6000 V/mil
Temperature Range	-269°C to +400°C
Standard Width	520 mm \| Precision slit widths to order
Roll Length	1500 m standard \| Custom lengths available
Flame Rating	UL 94 V-0, Halogen-Free
Certifications	CE, Mil-P-46123, RoHS/REACH, ISO 9001, ISO 14001

Certifications & Compliance

SAFETY

CE ListedEuropean Conformity — required for all EU market sales

MILITARY

Mil-P-46123Type 1, Item A — US Military performance specification

ENVIRONMENT

RoHS CompliantRestriction of Hazardous Substances — EU directive

CHEMICAL

REACH CompliantEU Chemical Safety regulation for export markets

FLAME

UL 94 V-0Highest flame retardancy rating — self-extinguishing

QUALITY

ISO 9001International quality management system certification

ENVIRONMENT

ISO 14001Environmental management system certification

SAFETY

Halogen-FreeNo chlorine, fluorine or bromine — safe for all markets

Why Buy Voice Coil Polyimide Film from Harnawa Insulations?

Manufacturer — Not a Trader

We manufacture voice coil polyimide film directly — better pricing, faster lead times and technical support for your voice coil application.

Precision Slit Widths

Precision-slit rolls in exact widths for your mandrel dimensions — 10 mm and up. Direct-to-production rolls.

Full Thickness Range

25–125 μm in stock. Choose the exact thickness for your voice coil mass and stiffness requirements.

Certified Quality

CE, Mil-P-46123, RoHS/REACH, ISO 9001, ISO 14001. Full certification documentation with every order.

Pan-India Supply

Fast dispatch from Bhiwandi to loudspeaker and audio manufacturers across India.

Export Ready

Exporting to USA, UK, UAE, Germany, Singapore, Malaysia and more.

Supply & Packaging

Standard Width: 520 mm | Precision slit widths to your specification
Roll Length: 1500 m standard | Custom lengths available
Packaging: Rolls on plastic/cardboard cores, wrapped in polyethylene film
Storage: 15°C–30°C, 40%–70% RH, away from sunlight
Shelf Life: 24 months from manufacture date
Lead Time: 2–5 working days (standard) | 7–14 days (custom slit orders)

Related Polyimide Film Products

HN Polyimide Film — Standard kapton-type PI film
FEP Polyimide Film — Heat sealable FEP coated polyimide film
Black Polyimide Film — Opaque black polyimide film
Colourful PI Film — Red, green and transparent polyimide film
Aluminized Polyimide Film — Metallized PI film for EMI shielding

Frequently Asked Questions — Polyimide Film Voice Coil

Why is polyimide film used for loudspeaker voice coil formers?

Polyimide (kapton-type) film is preferred for voice coil formers because it combines the lowest possible mass with high thermal stability (to 400°C), excellent dimensional stability, and chemical resistance to adhesives and lacquers. Low mass reduces the moving weight of the voice coil assembly, directly improving speaker sensitivity and transient response. High thermal stability protects the former from heat generated during high-power operation.

What thickness of polyimide film is used for voice coil formers?

The most common thicknesses for voice coil formers are 25 μm (1 mil) for high-frequency tweeters and earphones where minimum mass is critical, 50 μm (2 mil) for midrange and general purpose drivers, and 75–125 μm for high-power woofers and subwoofers where additional stiffness and thermal mass are beneficial. Harnawa supplies 25–125 μm in precision-slit widths to your exact former dimension.

Is voice coil polyimide film a kapton-type film?

Yes. Voice coil polyimide film uses the same PMDA-ODA kapton-type polyimide chemistry as standard HN film, selected and supplied in a high dimensional stability grade with precision slit edges for direct use in voice coil former winding. Same temperature range (-269°C to 400°C) and same electrical and mechanical properties.

Do you supply precision slit widths for voice coil winding?

Yes. We supply precision-slit rolls in exact widths matching your former height dimensions — from 10 mm and up. Tolerance on slit width is tight to ensure consistent voice coil geometry. Contact us with your former dimensions and we will confirm availability and lead time.

What is the price of polyimide film for voice coil in India?

Price depends on thickness, slit width and order quantity. Contact us at enquiry@harnawainc.com or WhatsApp +91 7276671876 for pricing on voice coil polyimide film in India.

About Harnawa Insulations Private Limited

Harnawa Insulations Private Limited is a manufacturer of polyimide films and polyimide products based in Bhiwandi, Maharashtra, India. We supply the complete range of kapton-type PI films — including voice coil film, HN, FEP, Black, ESD, CR, NHN, Aluminized, Thermal-Conductive and Colourful — to motor manufacturers, transformer OEMs, electronics companies, PCB fabricators and audio equipment manufacturers across India and internationally.

polyimidefilms.com is owned and maintained by Harnawa Insulations Private Limited. For bulk pricing, OEM supply and export enquiries contact enquiry@harnawainc.com or visit harnawainc.com.