In the realm of electrical insulation, the choice of materials directly determines the reliability and lifespan of transformers and other high-voltage equipment. The Electrical Insulation Kraft Paper from Hanyao is a fundamental component in transformer insulation systems, offering a proven combination of mechanical strength, dielectric integrity, and thermal stability. Manufactured from 100% high-purity wood pulp, this paper provides superior performance even under demanding conditions. With thickness options ranging from 80μm to 170μm and compliance with A-class insulation standards (105°C), it plays a vital role in coil insulation, cable wrapping, and other critical electrical applications. This article examines the product's specifications, key features, and the manufacturing quality that makes it a reliable choice for transformer and motor manufacturers worldwide.
Transformers are the workhorses of electrical power systems, and their reliability depends on the integrity of their insulation systems. Among the various insulating materials used, electrical insulation kraft paper remains a fundamental component, particularly in oil-filled transformers. Its role is to provide electrical insulation between winding layers, support mechanical stability, and withstand the thermal and electrical stresses of continuous operation. The Electrical Insulation Kraft Paper from Hanyao is specifically manufactured to meet these rigorous demands.
The paper is produced from 100% wood pulp with the highest purity standards, ensuring low ionic contamination and consistent dielectric properties. Its high mechanical strength, combined with excellent elongation and tear resistance, allows it to maintain structural integrity during transformer assembly and operation. When impregnated with transformer oil, the paper's dielectric strength is further enhanced, providing reliable insulation over the transformer's service life. With a breakdown voltage of 8 kV/mm and conductivity of aqueous extract below 8 mS/m, this paper meets the strict quality requirements of the electrical industry.
The following table summarizes the key specifications for the Electrical Insulation Kraft Paper from Hanyao.
| Property | Unit | 80 μm | 130 μm | 170 μm |
| Thickness | μm | 80 ±5.0 | 130 ±7.0 | 170 ±10.0 |
| Density | g/cm³ | 0.85–0.95 | ||
| Tensile Strength (MD) | N/mm | 6 | 11 | 14 |
| Tensile Strength (TD) | N/mm | 3.2 | 5.2 | 7 |
| Elongation (MD) | % | ≥2.0 | ||
| Elongation (TD) | % | ≥5.4 | ||
| Tearability (Cross Machine) | mN | ≥540 | ≥1080 | ≥1390 |
| Folding Endurance (Cross Machine) | times | ≥1800 | ≥2200 | ≥2500 |
| Breakdown Voltage | kV/mm | 8 | ||
| Conductivity of Aqueous Extract | mS/m | ≤8 | ||
| pH of Water Extract | — | 6.5–8.0 | ||
| Air Permeability | μm/(Pa·s) | ≤0.510 | ||
| Ash Content | % | ≤0.7 | ||
| Moisture Content | % | 6–8 | ||
These specifications demonstrate the paper's consistent quality and suitability for demanding insulation applications. The material is classified as A-class insulation, capable of withstanding operating temperatures up to 105°C.
The Electrical Insulation Kraft Paper offers several performance advantages that make it a reliable choice for transformer and motor manufacturers.
The paper is manufactured from 100% wood pulp with the highest levels of purity. The low impurity content minimizes ionic contamination, which can degrade dielectric properties over time. This ensures that the paper maintains its insulation performance throughout the transformer's service life, even under harsh operating conditions.
With high tensile strength (up to 14 N/mm in the machine direction) and excellent tear resistance, the paper provides the mechanical stability required during transformer winding and assembly. The high folding endurance (up to 2500 cycles) ensures that the paper can withstand repeated bending and handling without damage.
The paper delivers a breakdown voltage of 8 kV/mm, providing reliable electrical insulation between winding layers. The low conductivity of aqueous extract (≤8 mS/m) and neutral pH (6.5–8.0) ensure compatibility with transformer oil and other insulating fluids.
In addition to serving as interlayer insulation in power transformers, the paper is also used in power cable insulation, edge strips, and as a base material for other insulation products such as diamond dotted paper (DDP). Hanyao processes this paper into various forms to meet specific customer requirements.
The Electrical Insulation Kraft Paper is used in a variety of applications across the electrical industry:
• Power transformers – Provides insulation between winding layers, ensuring electrical integrity and mechanical stability.
• Distribution transformers – Used as interlayer insulation in smaller transformers, offering reliable performance at an economical cost.
• Instrument transformers – Ensures accurate and reliable operation in measurement and protection equipment.
• Power cables – Provides insulation for high-voltage cables, withstanding electrical and thermal stresses.
• Electrical motors and generators – Used in stator and rotor insulation systems, contributing to overall machine reliability.
• Insulation components – Processed into edge strips, crepe paper tubes, and other formed parts for custom insulation solutions.
The paper's versatility and reliability make it a staple material in electrical equipment manufacturing and maintenance.
Hanyao has specialized in electrical insulating materials since 2012, with a focus on consistent quality and customer satisfaction. The company is located in Suzhou City, close to Shanghai Port, facilitating efficient global logistics. Hanyao works with reliable local manufacturers equipped with state-of-the-art production lines and modern laboratories to ensure product quality.
The product has been tested by the third-party laboratory CEMT at customer request, confirming its compliance with international standards. Hanyao's production capabilities include slitting and winding machines to process standard materials into custom sizes, offering flexibility for different customer requirements. The company maintains stock availability for quick delivery, reducing lead times for urgent orders.
A: The paper is classified as A-class insulation, with a maximum operating temperature of 105°C.
A: The paper has a breakdown voltage of 8 kV/mm, ensuring reliable electrical insulation in high-voltage applications.
A: Yes, the paper is specifically designed for oil-filled transformers and is compatible with transformer oil. Its low conductivity and neutral pH ensure good oil compatibility.
A: Yes, Hanyao can process the paper into custom sizes using slitting and winding equipment. Please contact the sales team for specific requirements.
A: Hanyao maintains stock of standard sizes for quick dispatch. For custom orders, lead time depends on the quantity and specifications. Contact the sales team for detailed information.
A: Yes, free samples are available for evaluation. Third-party testing can also be arranged upon request.
The Electrical Insulation Kraft Paper from Hanyao provides a reliable, high-performance insulation solution for transformers, motors, and power cables. With its high purity, excellent mechanical strength, and consistent dielectric properties, it meets the demanding requirements of the electrical industry. Backed by third-party testing, flexible customization options, and a commitment to quality, Hanyao has earned the trust of customers in the Middle East, Europe, and Asia. For inquiries, technical specifications, or to request samples and quotations, the Hanyao team is available to provide detailed product information and responsive support.
