I.Phenolic Cotton Cloth Sheet Introduction

Phenolic Cotton Cloth Sheet, commonly designated as PFCC201, is a rigid laminated insulation material manufactured by impregnating electrical-grade cotton cloth with thermosetting phenolic resin, followed by drying and hot pressing under high temperature and pressure.

Key Features

• Excellent electrical insulation performance
• High mechanical strength and dimensional stability
• Good wear resistance and machinability
• Continuous operating temperature up to 120°C
• Class B electrical insulation (130°C insulation system)
• Suitable for long-term service in transformer oil and other oil-immersed electrical equipment

Standard Specifications

II. Typical Applications

Electrical Insulation

Widely used as structural insulating components in electrical equipment, including:

• Electric motors
• Power transformers
• Switchgear
• Insulating barriers
• Terminal boards
• Contact support components

Its excellent oil resistance makes it particularly suitable for oil-immersed electrical equipment.

Mechanical Engineering

Due to its high mechanical strength, wear resistance, and low friction coefficient, Phenolic Cotton Cloth Sheet is widely machined into:

• Gears
• Bushings
• Guide rollers
• Wear pads
• Spacers and washers

These components help reduce equipment weight, operating noise, and maintenance costs.

Industrial Applications

• Acid- and alkali-resistant sealing components for chemical processing equipment
• Insulating liners for railway electrical cabinets
• Structural insulation supports for wind power and photovoltaic (PV) equipment

III. Manufacturing Process

1. Resin Preparation

Prepare the phenolic resin with the required solid content and viscosity to ensure optimum impregnation performance.

2. Cotton Cloth Impregnation

Electrical-grade cotton cloth is uniformly impregnated with phenolic resin, allowing complete penetration into the fabric structure.

3. Drying

The impregnated cotton cloth is dried to remove volatile solvents while carefully controlling the pre-curing stage.

4. Lamination & Hot Pressing

The dried prepreg layers are stacked according to the required thickness and cured under controlled temperature and pressure to produce the finished laminated sheet.

IV. Machining Recommendations

Dimensional Tolerance

Engineering drawings should clearly specify machining tolerances.

• Thickness tolerance: ±0.20 mm
• Hole diameter tolerance: ±0.10 mm

Recommended Machining Equipment

For optimum machining quality, the following equipment is recommended:

• CNC machining centers
• CNC milling machines
• CNC routers
• Oscillating knife cutting machines

Conventional cutting tools should be avoided to minimize edge chipping and delamination.

Environmental Conditions

Maintain stable temperature and humidity during machining. To minimize moisture absorption and dimensional variation, the interval between machining operations should preferably be less than 30 minutes.

Finishing

• Remove all burrs.
• Apply a standard 5 × 45° chamfer where required.
• Package finished parts using anti-static protective packagingto prevent damage during storage and transportation.