3M 281
Harmonization Code : 3506.91.90.99 | Prepared glues and other prepared adhesives, not elsewhere specified or included; products suitable for use as glues or adhesives, put up for retail sale as glues or adhesives, not exceeding a net weight of 1 kg ; Adhesives based on polymers of headings 3901 to 3913 or on rubber; Other ; Other
Main features
- Class F (155 deg C) Temperature Rating
- Thermally Conductive Encapsulation
- Upgraded Structural Characteristics
Product Description
3M™ Scotchcast™ Electrical Resin 281 is a two-part, semi-flexible, filled epoxy liquid resin engineered for the impregnation and encapsulation of electrical and electronic components. It is characterized by high temperature and electrical stability, maintaining its flexibility even after prolonged heat aging. This resin is designed for applications requiring greater mechanical strength, higher tensile strength, better thermal shock resistance, and higher thermal conductivity than standard encapsulants like Resin 241.
Key features
- High temperature rating: Rated for Class F (155°C) continuous service, ensuring reliable performance in high-heat environments.
- High thermal conductivity: Effectively dissipates heat to protect internal components from thermal stress and failure.
- Flexible curing profile: Can be cured at low temperatures, though higher temperature cure schedules optimize mechanical properties.
Applications / Suitable for
- Impregnation and encapsulation of coils and transformers
- Potting of motors
- Protection of electrical and electronic components
Technical Specifications
General Properties
Physical Properties
Mechanical Properties
Thermal Properties
Additional Information
As-supplied / before-processing properties
Typical properties; these values are not intended for use in preparing specifications.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Mix Ratio (Weight) | 2:3 | - | A:B |
| Mix Ratio (Volume) | 37:63 | % | A:B |
| Initial Viscosity | 320,000 | cps | Part A at 23°C (73°F) |
| Initial Viscosity | 38,000 | cps | Part B at 23°C (73°F) |
| Mixed Viscosity | 75,000 | cps | at 23°C (73°F) |
| Flash Point | 202 | °C | Part A (395°F) |
| Flash Point | 188 | °C | Part B (370°F) |
| Gel Time | 21 | minutes | at 121°C |
After-processing / final-state properties
Typical properties; these values are not intended for use in preparing specifications. Properties measured at 23°C (73°F) unless otherwise stated.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Color | Cream | - | - |
| Specific Gravity | 1.43 | - | Cured |
| Hardness | 65 | Shore D | Instantaneous |
| Compressive Strength | 3500 | psi | 10% Compression |
| Tensile Strength | 2100 | psi | 1/8" x 1/2" Sample |
| Elongation | 45 | % | at break |
| Flexural Strength | 1250 | psi | 1/2" x 1/2" Sample |
| Electric Strength | 350 | V/mil | 1/8" (3.175 mm) sample |
