Phenolic Cotton Cloth Sheet/Tube/Rod

SIDA Phenolic Cotton Cloth Laminate is a high-performance composite insulation material manufactured by impregnating layers of premium cotton fabric with thermosetting phenolic resin, then cured under heat and pressure. Available in sheets, tubes, and rods, this Class E (120°C) insulation material delivers exceptional mechanical strength, superior electrical insulation properties, and excellent dimensional stability for demanding industrial applications.

Description

Manufacturing Excellence

SIDA Phenolic Cotton Cloth Laminated Products are engineered through a precision manufacturing process where multiple layers of high-quality cotton cloth are saturated with phenolic resin, baked into prepreg form, and then consolidated through hot-press molding. This process creates dense, uniform structures with outstanding mechanical integrity and electrical insulation performance. Our products conform to international standards including GB/T 1303-2009, IEC 60893-3-4, and NEMA LI-1 grades C and CE

Key Features & Advantages

  • Superior Mechanical Properties: High flexural strength (≥100 MPa) and compressive strength (≥147 MPa) ensure reliable performance under mechanical stress

  • Excellent Electrical Insulation: Volume resistivity of 10⁷-10⁸ Ω·cm and breakdown voltage ≥10 kV in transformer oil

  • Thermal Stability: Class E insulation rating (120°C continuous operation) with short-term capability up to 300°C

  • Easy Machinability: Can be drilled, milled, turned, and threaded without delamination
  • Dimensional Stability: Maintains structural integrity and tight tolerances even in humid conditions
  • Chemical Resistance: Resistant to most oils, greases, and weak chemicals (note: not suitable for strong acids/alkalis)
  • Certified Quality: UL approved (E310670), REACH and RoHS compliant

  • Versatile Forms: Available as sheets, rods, and tubes with customizable dimensions

Technical Data Tables

 Property requirements; Norm 60893-3-4©IEC:2003 (German version: EN 60893-3-4:2004)

Property

IEC 60893-2

Subclause

Unit

Min. oder Max.

Thickness of sheet to which test is applicable

mm

Type

PF CC 201

PF CC 202

PF CC 203

PF CC 204

PF CC 305

PF GC 201

Flexural strength

5.1

Mpa

Min.

≥ 1,6

100

90

110

100

125

140

Charpy impact strength ║to lamination (note 3)

5.4.2

kJ/m²

Min.

≥ 5

8,8

7,8

7

6

6

25

Izod impact strength ║to lamination (note 3)

5.4.3

kJ/m²

Min.

≥ 5

5,4

5,9

5,9

4,9

4,9

29

Electrical strength at 90 °C in oil ┴ to lamination

6.1.1

kV/mm

Min.

≤ 3

table 6

table 6

table 6

table 6

table 6

table 6

Breakdown voltage at 90 °C in oil ║to lamination

6.1.1

kV

Min.

> 3

1

20

1

20

1

20

Insulation resistance after immersion

in water

6.3

M Ω

Min.

All

1

5×101

1

5×101

1

1×10²

Water absorption

8.2

mg

Max.

All

table 7

table 7

table 7

table 7

table 7

table 7

Note:The product specifications provided are for reference purposes only. Please refer to the actual product for final specifications. We also offer various sizes and thicknesses to meet your specific needs. For further customization, please contact us.


Application Scenarios

Electrical & Power Industry

  • Transformer Insulation: Structural components, spacers, and insulating supports in oil-immersed transformers
  • Motor & Generator Parts: Insulating sleeves, end plates, and slot wedges
  • Switchgear Components: Base plates, terminal supports, and arc barriers
  • Circuit Breakers: Insulating links and operating rods

Mechanical & Industrial Equipment

  • Gear Wheels: Lightweight, wear-resistant gear components
  • Friction Surfaces: Brake linings and clutch plates
  • Bushings & Bearings: Self-lubricating bearing materials
  • Structural Supports: Machine bases and equipment frames

Automotive & Transportation

  • Electrical System Insulation: Battery trays, fuse holders
  • Engine Components: Thermal shields and insulating spacers
  • Transmission Parts: Wear pads and thrust washers

Aerospace & Defense

  • Aircraft Electrical Systems: Lightweight insulating components
  • Communication Equipment: RF insulating supports

Special Considerations

⚠️ Environmental Limitations: Not recommended for continuous exposure to strong acids, strong alkalis, or organic solvents like acetone

In high-humidity coastal environments, additional moisture-proofing treatments are advised to maintain long-term insulation resistance

⚠️ Voltage Limitations: Not suitable for ultra-high voltage applications above 220kV without additional insulation enhancements


Frequently Asked Questions (FAQs)

Q: What is the difference between phenolic cotton cloth and phenolic paper laminate?
A: Phenolic cotton cloth laminates offer higher mechanical strength and better machinability than paper-based phenolics, making them ideal for structural applications. However, paper phenolics have slightly better dielectric properties for pure electrical applications.
Q: Can phenolic cotton cloth rods be threaded?
A: Yes, our rods machine excellently and can be threaded for use as insulating bolts, nuts, and threaded rods. Standard thread sizes M12, M16, and M20 are readily available
Q: What is the moisture absorption rate, and how does it affect performance?
A: Water absorption is typically ≤2.2% after 24 hours
While moisture resistance is good, prolonged exposure to high humidity can gradually reduce insulation resistance. We recommend protective coatings for outdoor or humid environments
Q: Are these materials suitable for food contact applications?
A: No, phenolic cotton cloth laminates are not certified for food contact. They are designed for industrial electrical and mechanical applications only.
Q: What machining operations can be performed?
A: Our phenolic laminates can be sawed, drilled, milled, turned, ground, and tapped with standard carbide tools. They exhibit minimal delamination and maintain tight tolerances.
Q: What is the minimum order quantity for custom sizes?
A: Standard products have no MOQ. Custom machined parts require a minimum order of 50 pieces or 100kg, depending on complexity.
Q: How do I choose between 3025 and 3723 grades?
A: 3025 is the standard grade for general-purpose sheets. 3723 is the rod-specific grade with optimized mechanical properties for cylindrical applications. Both offer similar electrical performance.
Q: What certifications are available?
A: All products are UL 94 HB rated, with UL certification (E310670), REACH, and RoHS compliance available upon request


Testing Standards & Quality Assurance

SIDA Phenolic Cotton Cloth Laminates are manufactured and tested in accordance with:
  • IEC 60893-3-4: Insulating materials – Industrial rigid laminated sheets based on thermosetting resins
  • GB/T 1303-2009: Industrial rigid laminated sheets and rods based on thermosetting resins for electrical purposes

  • GB-T 5132.1-2009 / IEC 61212-1:2006: Insulating materials – Industrial rigid round laminated tubes and rods

  • NEMA LI-1: Standards for industrial laminates (grades C, CE)
  • UL 94: Flammability testing
  • ISO 527, ISO 179, ISO 75: Mechanical and thermal property testing

Quality Control: Each batch undergoes testing for density, water absorption, flexural strength, and dielectric strength. Certificates of Conformance (CoC) and test reports are provided with every shipment.

Do you have any questions? Contact us

Thank you for your interest in our insulation materials products! We look forward to providing you with quality service and excellent products. If you are ready to choose us, please leave your name, phone number and email address, and our team will contact you immediately to provide you with detailed product information and quotation.

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Phone

+86 15958243831

Email

jessie.feng@sidanm.com

Address

YiTian Building. 850 ChengXin Road,Yinzhou,Ningbo,China,315100

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