Electrical properties of selected Formlabs SLA resins
Electrical properties of selected Formlabs SLA resins
Chemical, optical, mechanical, thermal, or electrical characteristics reflect how a specific material behaves under certain conditions. These attributes can help you assess the benefits of one material versus another for a specific use case.
ASTM-tested properties appear in the datasheets for our resins. There are many other properties that Formlabs has not officially tested.
To the best of Formlabs knowledge, the information contained herein is accurate. Formlabs makes no warranty, expressed or implied, regarding the accuracy of these results to be obtained from the use thereof.
Resistivity and conductivity (ASTM D257)
Surface resistivity is the resistance to leakage current along the surface of an insulating material. Volume resistivity is the resistance to leakage current through the body of an insulating material. Higher surface or volume resistivity means lower leakage current and less conductivity.
Except for ESD Resin, Formlabs resins are good insulators and not conductive:
- Surface resistivity for all Formlabs resins (excluding ESD Resin) is greater than 2 x 10^14 Ω/sq.
- Volume resistivity for all Formlabs resins (excluding ESD Resin) falls within 1.7–1.8 x 10^14 Ω·cm.
Volume and surface resistivity (ASTM D257-14) test specifications:
- Temperature: 25 °C
- Voltage: 100 VDC
- Electrode type: Inner electrode 1.20 in, 0.525 in gap between inner and outer electrode
The average test results from five measurements done by Formlabs on various resins are:
| Material | Thickness (cm) | Volume Resistivity (Ω·cm) | Surface Resistivity (Ω/sq) |
|---|---|---|---|
| Durable Resin V2 | 0.835 | 1.70 x 10^14 | > 2 x 10^14 |
| High Temp Resin V1 | 0.790 | 1.80 x 10^14 | > 2 x 10^14 |
| Black Resin V4 | 0.798 | 1.78 x 10^14 | > 2 x 10^14 |
| Rigid 4000 Resin V1 | 0.802 | 1.77 x 10^14 | > 2 x 10^14 |
| Clear Resin V4 | 0.797 | 1.78 x 10^14 | > 2 x 10^14 |
| Tough Resin V5 | 0.802 | 1.77 x 10^14 | > 2 x 10^14 |
Dielectric strength (ASTM-D149)
Dielectric strength measures how long a material can effectively insulate over a period of time, More specifically, it measures what voltage a material can withstand before it fails to insulate. This helps determine the safety of a material and whether it should be used in electrical applications. The dielectric strength of a material is measured in two ways:
- Breakdown (V): the voltage at which the material breaks down or punctures
- Volts per mil (V/mil): how much voltage a material can withstand per unit of thickness
Dielectric strength (ASTM-D149-09) test specifications:
- Frequency: 60 Hz
- Electrode type: Cylindrical rods, 6.4 mm diameter, rounded edges
- Ramp-up time: 500 V/s
The average test results from five measurements done by Formlabs on various resins are:
| Material | Thickness (mil) | Breakdown (V) | Dielectric Strength (V/mil) | Dielectric Strength (kV/mm) |
|---|---|---|---|---|
| Durable Resin V2 | 24 | 18,200 | 791 | 31.1 |
| High Temp Resin V1 | 28 | 21,600 | 773 | 30.4 |
| Black Resin V4 | 30 | 24,400 | 820 | 32.3 |
| Rigid 4000 Resin V1 | 24 | 17,800 | 749 | 29.5 |
| Clear Resin V4 | 29 | 19,000 | 656 | 25.8 |
| Tough Resin V5 | 33 | 19,800 | 600 | 23.6 |
| ESD Resin V1 | 125 | < 0.5 | < 4.0 | N/A |
| Grey Resin V5 | 125 | 52,400 | 415 | 16.3 |
| Material | Thickness (mm) | Dielectric Constant | Dissipation Factor |
|---|---|---|---|
| Durable Resin V2 | 8.35 | 3.5 | 0.0184 |
| High Temp Resin V1 | 7.90 | 2.6 | 0.0114 |
| Black Resin V4 | 7.98 | 3.3 | 0.0135 |
| Rigid 4000 Resin V1 | 8.02 | 3.4 | 0.0092 |
| Clear Resin V4 | 7.97 | 3.4 | 0.0135 |
| Tough Resin V5 | 8.02 | 3.1 | 0.0159 |
Dielectric constant and dissipation factor (ASTM D150)
Dielectric constant, or relative permittivity, measures how well a material stores electrical energy in an electric field. The dissipation factor, or loss factor, indicates how much electrical energy is lost as heat within the material and measures the inefficiency of an insulating material. Both properties are critical in applications where materials are subjected to alternating electrical fields, such as in capacitors, insulators, or radio frequency (RF) components.
- For applications requiring insulation, use resins with a lower dielectric constant.
- For electrical applications requiring high capacitance, use resins with a higher dielectric constant.
| Material | Dielectric constant | Dissipation factor |
|---|---|---|
| Rigid 4000 Resin V1 | 3.22 at 6.78 MHz 3.17 at 13.56 MHz 3.07 at 27.12 MHz | 0.021 at 6.78 MHz 0.021 at 13.56 MHz 0 at 27.12 MHz |
| Rigid 10K Resin V1 | 2.72 at 6.78 MHz 2.69 at 13.56 MHz 2.65 at 27.12 MHz | 0.007 at 6.78 MHz 0.002 at 13.56 MHz 0 at 27.12 MHz |
| Flexible 80A Resin V1 | 3.71 at 6.78 MHz 3.60 at 13.56 MHz 3.48 at 27.12 MHz | 0.051 at 6.78 MHz 0.046 at 13.56 MHz 0.018 at 27.12 MHz |
| High Temp Resin V2 | 3.39 at 6.78 MHz 3.33 at 13.56 MHz 3.26 at 27.12 MHz | 0.021 at 6.78 MHz 0.019 at 13.56 MHz 0 at 27.12 MHz |
| Tough 1500 Resin V1 | 3.13 at 6.78 MHz 3.07 at 13.56 MHz 3.00 at 27.12 MHz | 0.028 at 6.78 MHz 0.026 at 13.56 MHz 0.003 at 27.12 MHz |
| White Resin V4 | 3.22 at 6.78 MHz 3.14 at 13.56 MHz 3.07 at 27.12 MHz | 0.034 at 6.78 MHz 0.029 at 13.56 MHz 0.004 at 27.12 MHz |
| PU Rigid 650 Resin V1 | 4.03 at 6.78 MHz 3.89 at 13.56 MHz 3.75 at 27.12 MHz | 0.077 at 6.78 MHz 0.076 at 13.56 MHz 0.081 at 27.12 MHz |
| PU Rigid 1000 Resin V1 | 3.93 at 6.78 MHz 3.82 at 13.56 MHz 3.69 at 27.12 MHz | 0.065 at 6.78 MHz 0.064 at 13.56 MHz 0.068 at 27.12 MHz |
| Clear Resin V2 | 3.72 at 60 Hz 3.33 at 1 kHz 3.16 at 1 MHz | 0.015 at 60 Hz 0.011 at 1 kHz 0.047 at 1 MHz |
| ESD Resin V1 | 26.95 at 1 MHz | 0.371 at 1 MHz |
| Grey Resin V5 | 4.28 at 1 MHz | 0.036 at 1 MHz |
Comparative Tracking Index (ASTM D3638)
Comparative Tracking Index (CTI) measures a material's resistance to electrical breakdown when exposed to a wet or contaminated surface. Specifically, it quantifies the maximum voltage at which a material can withstand electrical tracking between two electrodes on its surface. Tracking refers to the formation of a conductive path along the surface of the material, often caused by moisture, dust, or contaminants.
Comparative Tracking Index test specifications:
- Lab maximum: 600 V
| Material | CTI (V) |
|---|---|
| Tough 1500 Resin | 600 |
| ESD Resin V1 | 600 |
| Clear Resin V5 | 600 |