Diamond Dotted Paper (DDP) is a specialized insulating material primarily used in electrical applications, particularly in transformers and motors. It is characterized by its unique coating of modified epoxy resin applied in a diamond pattern on electrical insulating paper. This design enhances its mechanical strength, electrical insulation properties, and thermal stability.
Characteristics of Diamond Dotted Paper
- Insulation Properties: DDP features excellent electrical characteristics due to its smooth, uniform surface, which minimizes the risk of electrical partial discharge. This is crucial for maintaining the integrity of high-voltage equipment
- Thermal and Moisture Resistance: The polyester film substrate provides high thermal stability and moisture resistance, allowing DDP to perform effectively in harsh environments
- Flexibility and Processing: DDP can be easily cut, laminated, and bonded, making it adaptable for various shapes and sizes required in engineering applications
Production Process
The production of DDP involves several key steps:
- Material Preparation: High-density pulp is shaped and coated with epoxy resin on one or both sides.
- Curing Process: The epoxy resin is partially polymerized at low temperatures before being fully cured at higher temperatures (typically above 100°C) to ensure proper adhesion and insulation performance
- Drying Conditions: The drying process is critical; for example, maintaining a temperature of 100°C for one hour or 130°C for 20 minutes is necessary to achieve optimal properties
Applications
DDP is widely used in:
- Transformers: As an interlayer insulation material that enhances the reliability and performance of winding layers.
- High-Voltage Equipment: Its properties make it suitable for preventing breakdowns and insulation failures in various electrical devices