Arcwire CP 155 Epoxy Casting and Potting Compound
Two-component, mineral-filled class 155 F epoxy system for encapsulating coils, sensors, ignition components, small dry transformers and low voltage control assemblies. It is supplied for metered mixing and for casting under vacuum where voids cannot be tolerated.
Grade Arcwire CP 155 | Range Electrical Insulation and Wire Enamels | Technology Two-component mineral-filled epoxy, solvent-free
Technical Data Sheet
Arcwire CP 155
Issue 2026.09
1. Product description
A two-component class 155 F epoxy system for encapsulating coils, current and position sensors, ignition components, small dry transformers and low voltage control assemblies, supplied for metered mixing and for casting under vacuum where voids cannot be tolerated. Mineral filler loading is set to raise thermal conductivity and to bring the expansion of the cured body closer to that of the conductor and the housing, since the difference in expansion is what cracks an encapsulation under thermal cycling rather than the peak temperature itself. Viscosity and gel profile are specified against the cavity, because the resin has to reach the bottom of the part and release its air before it gels.
2. Features
- Mineral filler raises thermal conductivity
- Filler brings expansion closer to the conductor and housing, to resist cracking under thermal cycling
- Viscosity and gel profile specified against the cavity
- Suited to metered mixing and vacuum casting
- Class 155 F
3. Recommended uses
Encapsulation of coils, current and position sensors, ignition components, small dry transformers and low voltage control assemblies.
Substrates. Coil assemblies, magnet wire, ferrite and laminated cores, printed boards, sensor bodies, and thermoplastic, thermoset or metal housings and moulds.
4. Typical properties
| Property | Typical value | Method |
|---|---|---|
| Technology | Two-component mineral-filled epoxy, solvent-free | Formulation |
| Appearance | Filled resin component and liquid hardener component | Visual inspection |
| Mix ratio | Fixed for the grade and stated on the label and Certificate of Analysis | Formulation |
| Mixed viscosity | Set against the cavity and the smallest gap the resin has to reach | IEC 60455-2 |
| Gel profile | Set so that the resin reaches the bottom of the part and releases its air before it gels | IEC 60455-2 |
| Density, cured | 1.5 to 1.9 g/cm³ at 23 °C, rising with filler loading | ISO 1183-1 |
| Electric strength, cured | 15 to 25 kV/mm at 23 °C on a 1 mm specimen | IEC 60243-1 |
| Thermal class of the material | 155 F | IEC 60085 for the designation; thermal endurance to IEC 60216-1 |
| Coefficient of linear thermal expansion, cured | Reduced by filler loading toward that of the conductor and housing; value stated for the grade supplied | ISO 11359-2 |
| Thermal conductivity, cured | Raised by mineral filler loading; value stated for the grade supplied | ISO 22007-2 |
Typical values, not a specification. Values for each batch are given on its Certificate of Analysis.
5. Application
| Parameter | Guidance |
|---|---|
| Method | Two-component metered mixing, then gravity or pressure fill; casting under vacuum where voids cannot be tolerated |
| Part preparation | Parts, moulds and housings clean and dry; mould release and housing pretreatment as agreed, since these set the adhesion |
| Mixing | Stir the filled component until uniform, meter both components at the stated ratio and degas the mix |
| Dilution | Not diluted |
| Filling | Fill within the pot life stated for the grade, so the resin reaches the bottom of the cavity and releases its air before it gels |
| Cure | Oven cure and post cure on the schedule stated for the grade |
Process. Two-component metered mixing, degassing or casting under vacuum, gravity or pressure fill, then oven cure and post cure. Mould release and housing pretreatment set the adhesion. Thermal class 155 F.
6. Storage and handling
Store both components in their original closed containers in a dry place at the temperature stated on the label, keeping the hardener sealed against moisture, and stir the filled component before use as the filler can settle. Shelf life is stated on the label and Certificate of Analysis. Handle and use the product in line with its Safety Data Sheet.
7. Safety and regulatory information
Read the Safety Data Sheet before use. Safety Data Sheets and regulatory declarations are issued by our technical centre against the product and batch supplied, so they are sent on request rather than published. Request a Safety Data Sheet or declaration.
This Technical Data Sheet is published for on-screen reference. The information is given in good faith from laboratory and application experience and describes typical values; it is not a specification and does not replace a trial on your own substrate and line. Arctic Materials may revise this sheet without notice. Issue 2026.09.
Technical Data Sheets on this site are for on-screen viewing. For a controlled copy, write to tech@arcticmaterials.com.
Other grades in this range
Need a Safety Data Sheet, a regulatory declaration or a grade specified to your line? Contact our technical centre.