Description
Detailed Product Introduction
What is DDP Diamond Dotted Paper?
DDP Diamond Dotted Paper represents a breakthrough in transformer insulation technology. Unlike conventional insulation materials, DDP combines high-quality electrical insulation paper with a precisely engineered modified epoxy resin coating applied in a diamond-shaped dot pattern. This innovative design delivers exceptional electrical insulation properties while maintaining superior mechanical strength and thermal stability.
How DDP Works
The operational principle of DDP is based on thermosetting adhesive technology:
- Initial Application: DDP is wound between transformer coil layers during manufacturing
- Thermal Activation: During the coil drying process, when temperature reaches the resin’s melting point, the epoxy coating begins to soften and melt
- Adhesion Phase: The melted resin creates strong adhesive bonds between adjacent winding layers
- Curing Process: As temperature continues to rise, the epoxy undergoes cross-linking and solidifies permanently
- Final State: Adjacent layers become reliably bonded into a rigid, integrated winding unit
Key Features and Benefits
Superior Mechanical Stability
- High adhesive strength prevents winding displacement during short-circuit conditions
- Maintains structural integrity under extreme electromagnetic forces
- Ensures long-term mechanical reliability of insulation structures
Optimized Oil Impregnation
- Diamond dot pattern allows complete oil penetration between paper layers
- Minimal resin penetration into paper fibers preserves insulation properties
- Facilitates efficient gas discharge during operation
Excellent Electrical Performance
- Outstanding dielectric strength across various thicknesses
- Minimizes corona and partial discharge risks
- Maintains stable electrical properties under thermal stress
Enhanced Thermal Properties
- Modified epoxy resin provides superior heat resistance
- Suitable for high-temperature transformer operating conditions
- Maintains adhesive properties through multiple thermal cycles
Process Efficiency
- Single-sided coating simplifies manufacturing processes
- Predictable melting and curing behavior enables precise process control
- Compatible with standard transformer manufacturing equipment
Manufacturing Technology
SIDA’s DDP is produced using advanced coating technology that ensures:
- Uniform diamond pattern distribution
- Precise coating weight control (4.0-8.0 g/m²)
- Consistent single-sided adhesive thickness (6-12 μm)
- Stringent quality control at every production stage
Technical Specifications
Performance Data Sheet
| Test Report | ||||||||
| Product name: DDP Thickness:0.08mm Test time :2026.1 | ||||||||
| No | Test Item | Unit | Standard | Result | Test method | |||
| 1 | Thickness Tolerance | mm | 0.08±0.005 | 0.079 | JB/T10442.3 -2017/ IEC60554-3-5 |
|||
| 2 | Density | g/cm3 | 0.85-1.10 | 1.04 | ||||
| 3 | Single-sided adhesive thickness | μm | 5-15 | 11.5 | ||||
| 4 | Oil absorption | % | ≥20 | 23 | ||||
| 5 | Moisture | % | 4.0-8.0 | 6.72 | ||||
| 6 | Bonding strength | kpa | ≥650 | 830 | ||||
| 7 | Tensile strength | MD | N/10mm | ≥60 | 63 | |||
| CMD | ≥30 | 32 | ||||||
| 8 | Tearing strength | MD | mN | ≥450 | 486 | |||
| CMD | ≥500 | 562 | ||||||
| 9 | Elongation at break | MD | % | ≥1.5 | 1.7 | |||
| CMD | ≥2.7 | 4.9 | ||||||
| 10 | Breakdown voltage | in air | kV | ≥0.88 | 1.7 | |||
| Test result: Pass | ||||||||
| Test Report | ||||||||
| Product name: DDP Thickness:0.13mm Test time :2026.1 | ||||||||
| No | Test Item | Unit | Standard | Result | Test method | |||
| 1 | Thickness Tolerance | mm | 0.13±0.007 | 0.131 | JB/T10442.3 -2017/ IEC60554-3-5 |
|||
| 2 | Density | g/cm3 | 0.85-1.10 | 0.97 | ||||
| 3 | Single-sided adhesive thickness | μm | 5-15 | 13 | ||||
| 4 | Oil absorption | % | ≥20 | 24 | ||||
| 5 | Moisture | % | 4.0-8.0 | 7.2 | ||||
| 6 | Bonding strength | kpa | ≥650 | 839 | ||||
| 7 | Tensile strength | MD | N/10mm | ≥110 | 115 | |||
| CMD | ≥35 | 42 | ||||||
| 8 | Tearing strength | MD | mN | ≥900 | 1011 | |||
| CMD | ≥1000 | 1163 | ||||||
| 9 | Elongation at break | MD | % | ≥1.5 | 1.88 | |||
| CMD | ≥2.7 | 4.5 | ||||||
| 10 | Breakdown voltage | in air | kV | ≥1.37 | 2.88 | |||
| Test result: Pass | ||||||||
| Product name: DDP Thickness:0.18mm Test time :2026.1 | ||||||||
| No | Test Item | Unit | Standard | Result | Test method | |||
| 1 | Thickness Tolerance | mm | 0.18±0.01 | 0.182 | JB/T10442.3 -2017/ IEC60554-3-5 |
|||
| 2 | Density | g/cm3 | 0.85-1.10 | 0.95 | ||||
| 3 | Single-sided adhesive thickness | μm | 5-15 | 13 | ||||
| 4 | Oil absorption | % | ≥20 | 24 | ||||
| 5 | Moisture | % | 4.0-8.0 | 7.3 | ||||
| 6 | Bonding strength | kpa | ≥650 | 735 | ||||
| 7 | Tensile strength | MD | N/10mm | ≥160 | 163 | |||
| CMD | ≥55 | 78 | ||||||
| 8 | Tearing strength | MD | mN | ≥1350 | 1475 | |||
| CMD | ≥1500 | 1622 | ||||||
| 9 | Elongation at break | MD | % | ≥1.5 | 2.01 | |||
| CMD | ≥2.7 | 5.69 | ||||||
| 10 | Breakdown voltage | in air | kV | ≥2.0 | 3.52 | |||
| Test result: Pass | ||||||||
| Test Report | ||||||||
| Product name: DDP Thickness:0.25mm Test time :2026.1 | ||||||||
| No | Test Item | Unit | Standard | Result | Test method | |||
| 1 | Thickness Tolerance | mm | 0.25±0.01 | 0.241 | JB/T10442.3 -2017/ IEC60554-3-5 |
|||
| 2 | Density | g/cm3 | 0.85-1.10 | 0.97 | ||||
| 3 | Single-sided adhesive thickness | μm | 5-15 | 13 | ||||
| 4 | Oil absorption | % | ≥20 | 23 | ||||
| 5 | Moisture | % | 4.0-8.0 | 7.2 | ||||
| 6 | Bonding strength | kpa | ≥650 | 1019 | ||||
| 7 | Tensile strength | MD | N/10mm | ≥230 | 248 | |||
| CMD | ≥70 | 166 | ||||||
| 8 | Tearing strength | MD | mN | ≥2000 | 2245 | |||
| CMD | ≥2300 | 2453 | ||||||
| 9 | Elongation at break | MD | % | ≥1.5 | 2.53 | |||
| CMD | ≥2.7 | 5.96 | ||||||
| 10 | Breakdown voltage | in air | kV | ≥2.25 | 5.1 | |||
| Test result: Pass | ||||||||
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.
Available Specifications
- Thickness Options: 0.08mm, 0.13mm, 0.18mm, 0.25mm (custom thicknesses available)
- Width Range: 5mm to 1500mm
- Standard Roll Lengths: Customizable based on customer requirements
- Coating Type: Single-sided modified epoxy resin in diamond dot pattern
Testing Standards & Certifications
SIDA’s DDP products are manufactured and tested according to international standards:
- IEC 60554 – Specification for cellulosic papers for electrical purposes
- IEC 60641 – Pressboard and presspaper for electrical purposes
- GB/T 1094 – Power transformers (Chinese National Standard)
- ASTM D202 – Standard Test Methods for Sampling and Testing Untreated Paper Used for Electrical Insulation
- IEC 60243 – Electric strength of insulating materials – Test methods
All products undergo rigorous quality control including:
- Dielectric strength testing (air and oil)
- Tensile strength and elongation testing
- Adhesive strength verification
- Dimensional accuracy inspection
- Moisture content analysis
- Long-term thermal aging tests
Application Scenarios
Primary Applications
1. Oil-Immersed Power Transformers
- Inter-turn insulation for high-voltage windings
- Layer-to-layer insulation in complex winding configurations
- Critical for transformers rated 35kV and above
- Ensures mechanical stability during fault conditions
2. Distribution Transformers
- Inter-layer insulation in low and medium voltage coils
- Enhances structural integrity of compact winding designs
- Ideal for both pad-mounted and pole-mounted units
- Suitable for transformers up to 2500kVA
3. Rectifier Transformers
- Specialized insulation for high-current applications
- Withstands mechanical stress from DC rectification
- Maintains performance under harmonic loading conditions
4. Instrument Transformers
- Precision insulation for current and voltage transformers
- Ensures accuracy and reliability in metering applications
- Suitable for indoor and outdoor installations
5. Reactor Coils
- Insulation for shunt reactors and series reactors
- Provides mechanical support under continuous vibration
- Excellent performance in high-inductance applications
Industry Sectors
- Electric power generation and transmission
- Industrial power distribution systems
- Renewable energy installations (wind, solar farms)
- Railway electrification systems
- Mining and heavy industry
- Data center and critical infrastructure
Installation and Usage Guidelines
Storage Requirements
- Store in cool, dry environment (temperature: 15-25°C, humidity: <60%)
- Keep away from direct sunlight and heat sources
- Maintain original packaging until use
- Use within 12 months of manufacture date for optimal performance
- Protect from moisture, dust, and contamination
Application Process
Step 1: Preparation
- Ensure winding surfaces are clean and dry
- Cut DDP to required dimensions with precision tools
- Allow material to acclimate to workshop conditions
Step 2: Winding Application
- Apply DDP with coated side facing the desired bonding surface
- Maintain consistent tension during winding
- Ensure proper alignment and overlap where required
Step 3: Thermal Processing
- Follow transformer manufacturer’s drying schedule
- Typical activation temperature: 105-130°C
- Monitor temperature profile to ensure complete melting
- Allow sufficient time for curing phase (typically 135-150°C)
Step 4: Oil Impregnation
- Proceed with vacuum impregnation process
- Diamond dot pattern facilitates rapid oil penetration
- Verify complete impregnation through standard testing
Safety Precautions
- Handle with clean, dry gloves to prevent contamination
- Avoid sharp bends that may damage the coating
- Use appropriate cutting tools to prevent edge fraying
- Follow all electrical safety protocols during installation
- Dispose of waste material according to local environmental regulations
Frequently Asked Questions (FAQs)
Q1: What makes DDP different from regular insulation paper?
A: DDP features a modified epoxy resin coating applied in a diamond dot pattern, whereas regular insulation paper has no adhesive properties. The dotted coating allows DDP to bond winding layers together during thermal processing while maintaining excellent oil impregnation characteristics. This unique design provides both mechanical stability and superior electrical performance that conventional paper cannot achieve.
Q2: At what temperature does the DDP coating melt and cure?
A: The modified epoxy resin coating typically begins to melt at approximately 105-130°C during the coil drying process, creating adhesion between layers. As temperature increases to 135-150°C, the resin undergoes cross-linking and cures into a solid state. The exact temperature profile should be optimized based on your specific transformer manufacturing process and equipment.
Q3: Can DDP be used in dry-type transformers?
A: DDP is specifically designed for oil-immersed transformers. The diamond dot coating pattern is optimized for oil impregnation and may not provide optimal performance in dry-type transformer applications. For dry-type transformers, we recommend consulting with SIDA technical support to identify the most suitable insulation materials for your specific requirements.
Q4: How do I choose the right thickness of DDP for my application?
A: Thickness selection depends on several factors:
- Voltage rating of the transformer (higher voltage requires thicker insulation)
- Physical space constraints in the winding design
- Required dielectric strength and mechanical strength
- Manufacturing process considerations
Refer to the technical specifications table above for breakdown voltage values at different thicknesses. For detailed guidance, our technical team can assist with insulation coordination calculations based on your transformer design parameters.
Q5: What is the shelf life of DDP, and how should it be stored?
A: DDP has a storage period of 12 months when stored properly. Optimal storage conditions include:
- Temperature: 15-25°C (59-77°F)
- Relative humidity: <60%
- Protected from direct sunlight, heat sources, and moisture
- Keep in original sealed packaging until use
Proper storage ensures the adhesive properties and electrical characteristics remain stable throughout the shelf life.