Durostone Sheet is a high-performance fiber-reinforced composite material primarily used in electrical insulation. CAS761 is one of its specific models, belonging to the thermosetting glass fiber reinforced composite material category. It typically uses epoxy resin or unsaturated polyester resin as the matrix, reinforced with glass fibers (alkali-free glass fibers). This type of material combines the high strength of fibers with the insulating properties of resins, making it a critical insulating structural material in electrical equipment.
1. Core Features and Advantages
Durostone CAS761 is designed and optimized for electrical insulation applications. Its core features include:
High Electrical Insulation: High volume resistivity and excellent tracking resistance, suitable for insulation in high-voltage environments.
High Mechanical Strength: Tensile strength up to 300-500 MPa, flexural modulus approximately 20-25 GPa, good impact resistance, and ability to withstand mechanical stress during equipment operation.
Strong Dimensional Stability: Low coefficient of thermal expansion, minimal deformation in extremely high temperatures or humid environments, ensuring assembly accuracy.
Resistant to Chemical Corrosion: Resistant to oils, solvents, and most industrial chemicals, suitable for complex environments such as substations and industrial motors.
Good Processing Adaptability: Can be molded into complex shapes (such as partitions and supports) through molding, lamination, etc., with a smooth and easy-to-clean surface.
Summary of Advantages: Compared to ordinary plastic or metal insulation components, CAS761 balances lightweight, high insulation, and weather resistance, making it the preferred lightweight insulation option for high-voltage electrical equipment.
2. Main Application Areas
Due to the aforementioned characteristics, the CAS761 is widely used in the manufacture of medium and high voltage electrical equipment. Typical applications include:
Switchgear: such as insulating partitions and contact supports for circuit breakers and disconnectors, isolating high-voltage live parts from grounding structures.
Transformers/Reactors: winding supports and interlayer insulation plates, reducing eddy current losses and fixing winding positions.
Motors and Generators: slot wedges and phase-to-phase insulation blocks, protecting coils from mechanical damage and improving insulation reliability.
Industrial Power Distribution: insulating components for ring main units and gas-insulated switchgear, adapting to compact design requirements.
Durostone CAS761 is primarily used in the production of printed circuit boards (PCBs) as a high-precision auxiliary material or special insulating component. Its high dimensional stability (low coefficient of thermal expansion), excellent insulation, and heat resistance make it suitable for manufacturing PCB lamination molds (ensuring alignment accuracy and thickness uniformity of multilayer boards), drilling pads (reducing drill bit skew and protecting the board surface), or as an interlayer insulating layer in high-voltage/high-reliability PCBs, replacing some traditional materials to improve insulation strength and production yield. It plays a particularly important role in aerospace, industrial control, and other scenarios with stringent PCB performance requirements.
3. Usage Precautions
Processing Limitations: As a thermosetting material, it cannot be remelted and recycled after molding. Strict control of molding temperature, pressure, and curing time is necessary to avoid internal air bubbles or delamination.
Moisture Management: Although its moisture resistance is better than ordinary resins, prolonged exposure to high humidity environments (e.g., humidity > 85% RH) may lead to surface creepage risk. Surface coatings or sealing designs are required.
Chemical Compatibility: Avoid contact with strong acids or high-temperature solvents (e.g., concentrated sulfuric acid, dichloromethane), as these may corrode the resin matrix.
Brittleness Risk: Thermosetting materials have lower toughness than thermoplastics and may crack under strong impact. Stress-absorbing structures must be incorporated into the design.
4. Disadvantages Analysis
Non-recyclable: After curing, thermosetting resins cross-link into a three-dimensional network, making them difficult to degrade or regenerate after disposal, which contradicts the trend of a circular economy.
High cost: The investment in raw materials (high-performance glass fiber, specialty resins) and molding equipment is substantial, resulting in a higher unit price than ordinary engineering plastics (such as PA66).
Poor low-temperature toughness: In environments below -40℃, the material becomes increasingly brittle, potentially making it unsuitable for outdoor equipment in extremely cold regions.
5. Market Usage Frequency
Durostone CAS761 belongs to the mid-to-high-end insulation material category, and its market usage frequency is directly related to the demand from downstream electrical equipment:
It is frequently used in high-voltage/ultra-high-voltage switches, extra-high-voltage transformers, and other fields, as these scenarios have extremely high requirements for insulation reliability, and the performance of alternative materials (such as epoxy boards) is difficult to match.
In medium- and low-voltage power distribution (such as low-voltage switchgear), due to cost sensitivity, it may be partially replaced by more economical SMC (sheet molding compound) or phenolic resin boards.
Durostone CAS761 is a thermosetting composite material designed specifically for high-voltage electrical insulation. Its high reliability makes it irreplaceable in critical scenarios. Despite issues with non-recyclability and cost, its performance advantages make it still important in high-end electrical equipment and will continue to be upgraded and iterated in the future with the development of new energy.
Next time we'll talk about another model (Durostone CFR767) in the Durostone series.