3M 235
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
- 1,500 cP Mixed Viscosity
- 1:2 Mixing by Weight
- 12,800 V/mm Dielectric Strength
Product Description
3M Scotchcast Electrical Resin 235 is a two-part electrical encapsulating epoxy mixed at 1:2 Part A to Part B by weight, or 31:69 by volume. Typical mixed viscosity is 1,500 cP. Cure schedules include 6 to 8 hours at 95 deg C or 2 to 3 hours at 120 deg C; the typical 18-minute gel time at 120 deg C is separate from these cure schedules. The cured resin has typical Shore D hardness 55 and 75% elongation. Typical dielectric strength is 12,800 V/mm on a 3.175 mm specimen under MIL-I-16923E.
Key features
- 1:2 component ratio by weight: Part A and Part B are mixed at 1:2 by weight; the corresponding volumetric ratio is 31:69.
- 1,500 cP mixed viscosity: This typical value applies after Part A and Part B are combined into the encapsulating resin.
- 12,800 V/mm dielectric strength: The typical cured-material result uses a 3.175 mm specimen under MIL-I-16923E.
Applications
Impregnation of small coils; electrical insulation of large castings, motors, transformers, and coils.
Technical Specifications
General Properties
Mechanical Properties
Electrical Properties
Other Properties
Additional Information
As-supplied / before-processing properties
Values are typical, not specifications, and reflect 2004 product data.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Mix ratio (A:B) | 1:2 | - | By weight |
| Mix ratio (A:B) | 31:69 | - | By volume |
| Part A viscosity | 13,000 | cP | Before mixing |
| Part B viscosity | 1,000 | cP | Before mixing |
| Mixed viscosity | 1,500 | cP | Combined resin |
| Gel time | 18 | min | 120 deg C |
| Cure schedule | 15 to 20; 6 to 8; 2 to 3 | h | At 75, 95, and 120 deg C, respectively |
After-processing / final-state properties
Values are typical, not specifications, and reflect 2004 product data.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Hardness | 55 | Shore D | Cured resin |
| Specific gravity | 1.10 | - | Cured resin |
| Compressive strength | 1,300 | psi | 10% compression; Fed. Std. No. 406, Method 1021 |
| Tensile strength | 1,300 | psi | 1/8 x 1/2 in specimen; Fed. Std. No. 406, Method 1011 |
| Elongation at break | 75 | % | Fed. Std. No. 406, Method 1011 |
| Flexural strength | 3,200 | psi | 1/2 x 1/2 in specimen; Fed. Std. No. 406, Method 1031 |
| Electric strength | 12,800 | V/mm | 3.175 mm specimen; MIL-I-16923E |
| Volume resistivity | 2.9 x 10^14 | ohm cm | 23 deg C; Fed. Std. No. 406, Method 4041 |
