Description
Product Composition & Manufacturing
PSP 3050 Pressboard is engineered from high-purity, unbleached sulfate wood pulp combined with ultra-pure water, completely free of bonding agents or synthetic additives.
Unlike conventional hot-pressed boards, PSP 3050 achieves its final properties through an advanced hot-air drying process followed by precision calendering, resulting in superior dimensional stability and uniform density distribution.
This manufacturing method ensures consistent quality across all thicknesses while maintaining exceptional purity levels required for high-voltage applications.
Key Performance Characteristics
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Outstanding Dielectric Performance: Achieves ≥12 kV/mm dielectric strength in air and ≥40 kV/mm in transformer oil for thicknesses up to 1.5mm
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Superior Mechanical Strength: Minimum tensile strength of 90 MPa (machine direction) and 60 MPa (cross-machine direction)
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Excellent Oil Compatibility: Oil absorption rate of ≥6% ensures complete impregnation in oil-filled transformers
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High Chemical Purity: Low ash content (≤0.7%) and conductivity of aqueous extract (≤8-10 mS/m) prevent contamination
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Thermal Stability: Rated for continuous operation at 105°C (Class A insulation)
Quality Assurance
Every batch of PSP 3050 undergoes rigorous testing per IEC 60641-2 standards, ensuring compliance with international electrical insulation material requirements.
The product meets IEC 60641-3-1 B.2.1 B classification and is also compatible with JIS C 2305 and DIN 7733 standards.
Technical Data Tables
| Product name:Insulating press board (1-35kv) Thickness:0.8mm Test time :2024.4 | ||||||
| No. | Item | Unit | Requirements | Test Result | Test Method | |
| 1 | Thickness Tolerance | % | ±7.5 | 2.5 | IEC 60641-2:2004 | |
| 2 | Density | g/cm3 | 0.95-1.15 | 1.03 | ||
| 3 | Tensile strength | Lengthwise | N/mm2 | ≥55 | 57.9 | |
| 4 | Crosswise | ≥35 | 36.8 | |||
| 5 | Elongation | Lengthwise | % | ≥3.0 | 6.1 | |
| 6 | Crosswise | % | ≥4.0 | 5.2 | ||
| 7 | Shrinkage rate | Lengthwise | % | ≤0.7 | 0.56 | |
| 8 | Crosswise | ≤1.0 | 0.85 | |||
| 9 | Thickness | ≤5.0 | 4.4 | |||
| 10 | Ash content | % | ≤1.0 | 0.82 | ||
| 11 | Oil absorption rate | % | ≥15 | 19.4 | ||
| 12 | Water extraction PH | / | 6.0-9.0 | 7.45 | ||
| 13 | Water extraction Conductivity | mS/m | ≤8 | 7.8 | ||
| 14 | Electric strength (in oil) | KV/mm | ≥35 | 35.2 | ||
| 15 | Electric strength (in the air) | KV/mm | ≥10 | 10.3 | ||
| 16 | Water content | % | ≤8.0 | 7.7 | ||
| Test result: pass | ||||||
| Description of Products: Electrical Insulating Pressboard Thickness:1 mm Produces time:2026.01 | ||||||
| No. | Property | Unit | Normal Value | Test Result | Test Method | |
| 1 | Tolerance of Thickness | % | ≤7.5 | +3 | IEC60641-3-1: 2008 | |
| 2 | Apparent Density | g/cm3 | 0.95-1.15 | 1.05 | ||
| 3 | Tensile strength | MD | MPa | ≥80 | 89 | |
| CMD | ≥45 | 65.1 | ||||
| 4 | Elongation | MD | % | ≥3 | 3.77 | |
| CMD | ≥4 | 5.72 | ||||
| 5 | Shrinkage | MD | % | ≤0.7 | 0.4 | |
| CMD | ≤1.0 | 0.62 | ||||
| Thick.D | ≤6.0 | 3.4 | ||||
| 6 | Compressibility C | % | ≤11 | 10.01 | ||
| 7 | Reversible part of Compressibility. Crev | % | ≥45 | 57.2 | ||
| 8 | Ash content | % | ≤0.7 | 0.46 | ||
| 9 | Oil absorption | % | ≥13.0 | 20.36 | ||
| 10 | PH of aqueous extract | / | 6.0-9.0 | 7.58 | ||
| 11 | Conductivity of aqueous extract | mS/m | ≤5 | 4.41 | ||
| 12 | Electrical strength | in air | KV/mm | ≥12 | 12.13 | |
| in oil | ≥40 | 40.25 | ||||
| 13 | Moisture content | % | ≤6.0 | 5.8 | ||
| Test result: Pass | ||||||
| Test Report | ||||||
| Description of Products: Electrical Insulating Pressboard Thickness:1.25 mm Produces time:2026.01 |
||||||
| No. | Property | Unit | Normal Value | Test Result | Test Method | |
| 1 | Tolerance of Thickness | % | ≤7.5 | +2 | IEC60641-3-1: 2008 | |
| 2 | Apparent Density | g/cm3 | 0.95-1.15 | 1.04 | ||
| 3 | Tensile strength | MD | MPa | ≥80 | 88.2 | |
| CMD | ≥45 | 63.9 | ||||
| 4 | Elongation | MD | % | ≥3 | 3.85 | |
| CMD | ≥4 | 5.46 | ||||
| 5 | Shrinkage | MD | % | ≤0.7 | 0.39 | |
| CMD | ≤1.0 | 0.6 | ||||
| Thick.D | ≤6.0 | 3.5 | ||||
| 6 | Compressibility C | % | ≤11 | 10.21 | ||
| 7 | Reversible part of Compressibility. Crev | % | ≥45 | 57.6 | ||
| 8 | Ash content | % | ≤0.7 | 0.46 | ||
| 9 | Oil absorption | % | ≥13.0 | 20.58 | ||
| 10 | PH of aqueous extract | / | 6.0-9.0 | 7.6 | ||
| 11 | Conductivity of aqueous extract | mS/m | ≤5 | 4.46 | ||
| 12 | Electrical strength | in air | KV/mm | ≥12 | 12.6 | |
| in oil | ≥40 | 42.11 | ||||
| 13 | Moisture content | % | ≤6.0 | 5.7 | ||
| Test result: Pass | ||||||
| Test Report | ||||||
| Description of Products: Electrical Insulating Pressboard Thickness:1.5 mm Produces time:2026.01 |
||||||
| No. | Property | Unit | Normal Value | Test Result | Test Method | |
| 1 | Tolerance of Thickness | % | ≤7.5 | +1.5 | IEC60641-3-1: 2008 | |
| 2 | Apparent Density | g/cm3 | 0.95-1.15 | 1.14 | ||
| 3 | Tensile strength | MD | MPa | ≥80 | 96.8 | |
| CMD | ≥45 | 66 | ||||
| 4 | Elongation | MD | % | ≥3 | 3.85 | |
| CMD | ≥4 | 5.23 | ||||
| 5 | Shrinkage | MD | % | ≤0.7 | 0.28 | |
| CMD | ≤1.0 | 0.4 | ||||
| Thick.D | ≤6.0 | 3.12 | ||||
| 6 | Compressibility C | % | ≤11 | 8.15 | ||
| 7 | Reversible part of Compressibility. Crev | % | ≥45 | 57 | ||
| 8 | Ash content | % | ≤0.7 | 0.46 | ||
| 9 | Oil absorption | % | ≥13.0 | 19.25 | ||
| 10 | PH of aqueous extract | / | 6.0-9.0 | 7.48 | ||
| 11 | Conductivity of aqueous extract | mS/m | ≤5 | 3.58 | ||
| 12 | Electrical strength | in air | KV/mm | ≥12 | 13.02 | |
| in oil | ≥40 | 42.62 | ||||
| 13 | Moisture content | % | ≤6.0 | 5.7 | ||
| 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.We have more sizes available. For details, please contact jessie.feng@sidanm.com.
Application Scenarios
Primary Applications
1. Oil-Filled Power Transformers
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Core Insulation: Used as inter-lamination insulation between core sheets
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Layer Insulation: Separates winding layers in distribution and power transformers
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Cylinders & Tubes: Fabricated into insulating cylinders for lead exits and winding supports
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Spacers & Wedges: Maintains precise spacing between windings and core structures
2. Distribution Transformers
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Barrier insulation between high and low voltage windings
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End insulation and pressure rings
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Lead insulation and support structures
3. Instrument Transformers
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Precision insulation for current and voltage transformers
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High dielectric strength ensures reliable performance in compact designs
Secondary Applications
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Reactors: Shunt and series reactor insulation
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Electric Motors: Slot insulation and wedges (at reduced thermal loads)
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Bushings: Insulating components for high-voltage bushings
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Molded Parts: Pressed and machined into custom insulation components
Environmental Considerations
PSP 3050 is specifically designed for oil-immersed environments, demonstrating excellent compatibility with:
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Mineral transformer oils
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Synthetic ester liquids
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Natural ester liquids (subject to compatibility testing)
Not recommended for dry-type transformers or applications requiring Class B (130°C) or higher temperature ratings.
Frequently Asked Questions (FAQs)
Q1: What is the main difference between PSP 3050 and PSP 3030? A: PSP 3050 is manufactured using hot-air drying and calendering without bonding agents, while PSP 3030 is a hot-pressed board. PSP 3050 offers higher purity and better oil absorption characteristics, making it superior for critical transformer applications.
Q2: Can PSP 3050 be supplied in custom thicknesses and dimensions? A: Yes, while standard thicknesses range from 0.8mm to 4.0mm for sheets, custom thicknesses and formats are available upon request. Maximum sheet sizes can reach 2200 x 4200mm depending on manufacturer capabilities.
Q3: How should PSP 3050 be stored before installation? A: Store in a clean, dry environment at 23°C and 50% relative humidity per IEC 60641-2 conditioning standards. Protect from moisture, dust, and direct sunlight. Storage life is typically 12 months; material remains effective if retested after this period.
Q4: Is PSP 3050 compatible with all transformer oils? A: PSP 3050 demonstrates excellent compatibility with standard mineral transformer oils and most synthetic esters. For natural ester fluids or specialty oils, compatibility testing is recommended. The material’s ≥6% oil absorption ensures complete impregnation.
Q5: What is the dielectric strength advantage of using PSP 3050 in oil vs. air? A: Dielectric strength increases significantly in transformer oil: from ≥12 kV/mm in air to ≥40 kV/mm in oil for thicknesses up to 1.5mm. This 3x improvement is due to oil’s higher dielectric constant and impregnation of the board’s microstructure.
Q6: Can PSP 3050 be punched or machined without delamination? A: Yes, the calendered manufacturing process and absence of bonding agents result in excellent internal cohesion. The material can be punched, cut, and machined into complex shapes for custom insulation components without delamination.
Q7: What quality certificates are available? A: Standard certification includes IEC 60641-3-1 B.2.1 B compliance. Additional certificates such as ISO 9001 quality management, REACH compliance, and batch-specific test reports are available upon request.
Testing Standards & Compliance
International Standards
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IEC 60641-3-1: Specification for pressboard – Part 3: Specifications for individual materials – Sheet 1: Requirements for pressboard, types B.2.1 B (PSP 3050)
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IEC 60641-2: Methods of test for pressboard and presspaper – governs all testing procedures
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IEC 60085: Thermal evaluation and classification of electrical insulation (Class A, 105°C)
Quality Control Tests Performed
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Mechanical Testing: Tensile strength (MD/CMD), elongation, shrinkage, compressive strength
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Electrical Testing: Dielectric strength in air and oil, insulation resistance, partial discharge
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Chemical Testing: Ash content, pH of aqueous extract, conductivity, moisture content
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Physical Testing: Density, thickness tolerance, oil absorption rate, dimensional stability
Certifications
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RoHS compliant
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REACH compliant
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Conflict-free materials sourcing
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ISO 9001 manufacturing quality