Wholesale Polyesterimide Coated Round Wire Supplier & Suppliers

Premium Winding Materials Engineering: High-Performance Class 180 & Class 200 Enameled Magnet Wires Designed for Extreme Thermal Environments and Industrial Efficiency.

Primary Winding Products & CTC Series

Explore our foundational range of Continuously Transposed Conductors and high-temperature enameled wires manufactured under strict international quality guidelines.

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Chemical & Physical Profile of Polyesterimide (PEI) Magnet Wire

Understand the science behind high-temperature insulation coatings that secure critical energy pathways.

Polyesterimide (PEI) coating represents a major leap forward in polymer insulation chemistry. Characterized by high thermal stability, this material combines the excellent mechanical toughness of ester linkages with the exceptional thermal degradation resistance of imide rings. As a primary insulation system for round copper and aluminum magnet wires, PEI coatings exhibit thermal performance classifications ranging from Class 180 (H) to Class 200 (K).

Under high-voltage and high-current stress conditions, conventional enamel coatings deteriorate due to localized thermal spikes. The presence of the imide groups inside the polymer backbone of Polyesterimide prevents chains from sliding, significantly enhancing the wire’s resistance to thermoplastic flow up to temperatures exceeding 300°C. Additionally, it offers exceptional resistance to common industrial solvents, synthetic refrigerants, and cooling oils, making it the preferred choice for hermetic motor designs and heavy-duty transformers.

  • Excellent mechanical flexibility under high mechanical tension and fast winding operations.
  • Superior resistance to thermoplastic flow (cut-through temperatures ≥ 320°C).
  • Inherent chemical resistance against aggressive solvent vapors, varnishes, and transformer oils.
  • High breakdown voltage retention even under dynamic moisture exposure.

Insulation Performance Profile

Polyesterimide-coated magnet wires are rigorously tested for consistency across thermal, chemical, and electrical parameters:

Thermal Index: 180°C - 200°C (IEC 60317-0-1 / NEMA MW 35-C)
Heat Shock: ≥ 200°C / 220°C (without cracking)
Dielectric Breakdown Voltage: Up to 15kV (depending on build class)
Elongation Rate: ≥ 30% (for wire diameters > 0.1mm)

About Suzhou Daiming Electrical Materials Co., Ltd.

A global leader in developing, extruding, and coating high-integrity electrical conductor systems.

Daiming Manufacturing Plant in Suzhou

Operating from a sprawling 258,333.33 ft² manufacturing base in Suzhou, China, Suzhou Daiming Electrical Materials Co., Ltd. has established itself as an elite supplier of enameled aluminum wires, enameled copper wires, copper clad aluminum (CCA) enameled wires, and complex transposed conductors (CTC).

Our state-of-the-art facility integrates 30 advanced production lines, designed to achieve maximum extrusion and drawing consistency. By coupling high-speed vertical and horizontal enameling equipment with inline laser dimensional controls, we ensure that every micron of the polyesterimide coating complies with rigorous global tolerances. Our engineers leverage more than a decade of industry expertise to deliver customization across wire diameters, temperature configurations, and spool sizes.

30+
Advanced Production Lines
258k+
Facility Sq. Footage
10+
Cooperating Countries

China Sourcing Advantages for Polyesterimide Coated Wires

Unlocking value through vertical integration, rigorous testing standards, and geographic logistics superiority.

1. Material Sourcing & Cost Control

By establishing deep relationships with local electrolytic copper cathode and high-purity aluminum rod refiners in China, we insulate our global clients from volatile raw material fluctuations. Our integrated purchasing model optimizes cost configurations while ensuring raw chemical purity.

2. Sophisticated Enamel Layer Controls

Our facility utilizes closed-loop coating dies and computerized curing ovens. This ensures a concentric, defect-free lacquer layer of polyesterimide, which is continuously monitored for pinholes, concentricity, and mechanical flexibility.

3. Rigorous Testing Infrastructure

From raw rod chemical analysis using emission spectrometers to springback testing, peel tests, and breakdown voltage assays, every shipment is verified in our ISO accredited quality testing lab before shipping worldwide.

Targeted Industry Applications & Macro Winding Solutions

How specialized polyesterimide coated round wire drives efficiency across high-demand electrification sectors.

1. Advanced Powertrains & Automotive Motors

In modern automotive engineering, traction motors require magnet wires that withstand intense heat and high-frequency voltage spikes generated by modern inverters. Polyesterimide coated wires provide the requisite thermal threshold (up to 200°C) and partial discharge resistance. This translates to increased torque density, less heat output, and space-saving motor designs.

2. Heavy-Duty Transformers & Industrial Solenoids

Power grid and distribution transformers must manage persistent overload conditions without insulation breakdown. Enameled wire with PEI insulation maintains high mechanical integrity and insulation resistance even under intense vibration and constant operating temperatures, preventing turn-to-turn short circuits.

3. High-Speed Generators & Wind Turbines

Wind power and marine installations expose generating components to cyclical thermal shifts, salt mist, and mechanical stress. Our Class 180 and Class 200 enameled wires prevent moisture ingress and mechanical fatigue, enhancing turbine lifetime and slashing maintenance expenses.

4. Household Appliances & Industrial Pumps

Compressors in refrigerators, air conditioning units, and high-performance industrial pumps operate in harsh hermetic environments containing oils and refrigerants. Polyesterimide is chemically inert to chemical solvents and freon, preventing degradation over decades of service.

Technical Specification Matrix

Reference guide for choosing the correct thermal class, base metal, and dimensional parameters.

Property Copper Base Winding Wire Aluminum Base Winding Wire Testing Standard Reference
Wire Diameter Range 0.08 mm – 5.00 mm 0.20 mm – 6.00 mm IEC 60317 / NEMA MW 1000
Thermal Class Options Class 180 (H) / Class 200 (K) Class 180 (H) / Class 200 (K) ASTM D2307
Insulation Type Polyesterimide (PEI) / Overcoated PEI+PAI Polyesterimide (PEI) / Overcoated PEI+PAI Polymer Chemistry Assay
Elongation Rate ≥ 30% to 40% (Diameter Dependent) ≥ 15% to 30% (Diameter Dependent) IEC 60851-3
Springback Angle ≤ 5 Degrees (For thick dimensions) ≤ 6 Degrees IEC 60851-3
Cut-Through Temp ≥ 320°C ≥ 340°C IEC 60851-6

Global Procurement Requirements & Compliance Standards

Simplifying the supply chain process for global procurement teams and engineering specifiers.

As a global magnet wire supplier, we know that standard compliance is non-negotiable for Tier 1 automotive and industrial OEMs. Our manufacturing processes conform strictly to IATF 16949, ISO 9001, and ISO 14001 standards. Every batch of enameled wire is accompanied by material test reports (MTRs) certifying dimensional precision, electrical breakdown resistance, and chemical consistency.

Our products strictly adhere to environmental regulations such as RoHS (Restriction of Hazardous Substances) and REACH. In terms of shipping and handling, we supply custom packaging solutions including tapered plastic spools (PT-4, PT-10, PT-25, PT-90, PT-200) and cylindrical spools, enclosed in heavy-duty cardboard boxes and secured on export-grade wooden pallets to prevent damage during transit.

Compliance Highlights

  • UL Recognized Insulation System: UL certification guarantees safe application.
  • Environmental Standards: 100% compliant with REACH and RoHS protocols.
  • Packaging Customization: Dynamic sizing from mini spools up to bulk carriers.
  • Secure Logistics: Shock-absorbent packaging designed for ocean freight.

Comprehensive Product Selection Catalog

Browse our complete list of specialty enameled wires designed to meet varying electrical, thermal, and weight specifications.

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Polyesterimide Winding Wire FAQ

Get answers to common technical, commercial, and engineering questions regarding polyesterimide coated magnet wire.

What is the difference between Class 180 and Class 200 Polyesterimide Coated Round Wire? +
The main difference lies in the maximum continuous operating temperature the insulation can withstand over a 20,000-hour lifetime. Class 180 wire is certified for continuous operation up to 180°C, whereas Class 200 wire utilizes modified formulation resins to safely operate up to 200°C. Choosing Class 200 provides a higher safety margin for applications prone to rapid overload or thermal spikes.
Why should I choose Polyesterimide (PEI) over Polyurethane (UEW) enamel? +
Polyurethane (UEW) wire is solderable without stripping, which speeds up terminating connections, but its thermal rating is generally limited to Class 130 or 155. Polyesterimide (PEI) cannot be direct-soldered and must be mechanically or chemically stripped, but it offers vastly superior thermal index properties (Class 180/200), far better resistance to solvents and moisture, and much higher cut-through resistance.
Does Daiming manufacture customized wire diameters for enameled wire? +
Yes. We produce a wide range of custom dimensions. For copper wire, our diameter range spans 0.08 mm up to 5.00 mm. For aluminum wire, the range is 0.20 mm up to 6.00 mm. We also accommodate custom enamel thicknesses (Grade 1, Grade 2, and Grade 3 insulation layers) based on customer requirements.
How do you guarantee the quality and thickness of the polyesterimide enamel coat? +
Our 30 high-speed drawing and enameling production lines feature inline laser diameter gauges that scan 100% of the wire length for thickness and ovality. Additionally, every finished production spool undergoes rigorous QC lab testing, including breakdown voltage testing, thermal index validation, springback checks, and flexibility wrap tests.
Are your enameled winding wires compliant with RoHS and REACH regulations? +
Yes, our entire production line of enameled aluminum, enameled copper, and copper clad aluminum wire meets RoHS and REACH standards. We verify all chemical raw materials and enamel varnishes through independent testing facilities like SGS to ensure compliance.
What is the standard packaging and shipping configuration for bulk orders? +
Standard packing utilizes tapered plastic spools (such as PT-15, PT-25, and PT-90) wrapped in moisture-resistant plastic wrap, housed in thick cardboard boxes, and securely palletized. We can customize the packaging type according to our customers' automated winding setups.