Arcwire SB 155 Self-bonding Overcoat Enamel
Bondcoat applied as the outermost passes over a cured base enamel, so the finished coil can be fused into a self-supporting body by hot air, solvent or resistance heating. The bondcoat is rated class 155 F and sets the working temperature of the bonded coil.
Grade Arcwire SB 155 | Range Electrical Insulation and Wire Enamels | Technology Heat or solvent activated bondcoat resin in organic solvent
Technical Data Sheet
Arcwire SB 155
Issue 2026.09
1. Product description
A bondcoat applied as the outermost passes over a cured base enamel, so that the finished coil can be fused into a self-supporting body by hot air, by solvent applied to the wound coil or by injecting current through the winding, with no former, tape or impregnation step. It is used for air-cored and voice coils, deflection and sensor coils, small ignition coils and any assembly where the wound shape has to hold itself. The bondcoat softens well below the thermal class of the base enamel, so it is the bond and not the base film that sets the working temperature of a self-bonded coil, and the activation route has to be agreed before the grade is fixed.
2. Features
- Coil fused into a self-supporting body without former, tape or impregnation
- Activation by hot air, by solvent or by current through the winding
- Cured on the line without activating the bond
- Bondcoat class 155 F sets the limit over base enamels of 155 F to 180 H; over a lower class base, the base sets the limit
3. Recommended uses
Air-cored and voice coils, deflection and sensor coils, small ignition coils and other assemblies where the wound shape has to hold itself.
Substrates. Cured polyvinyl acetal, polyester or polyesterimide base enamel on fine round copper conductor, typically 0.05 mm to 1.00 mm.
4. Typical properties
| Property | Typical value | Method |
|---|---|---|
| Technology | Heat or solvent activated bondcoat resin in organic solvent | Formulation |
| Appearance | Clear liquid, colourless to amber | Visual inspection |
| Non-volatile matter | 25 to 30 per cent by weight | ISO 3251 |
| Thermal class of the material | Bondcoat 155 F over a base enamel up to 180 H; the bonded assembly is limited to 155 F, or to the class of the base enamel where that is lower, for example 120 E over Arcwire PV 120 | IEC 60085 for the designation; thermal endurance to IEC 60216-1 |
| Bond strength after activation | 10 to 60 N at 23 °C on 0.20 to 1.00 mm conductor, depending on diameter and activation route | IEC 60851-3 |
| Bond strength at elevated temperature | Measured at the agreed service temperature of the coil; the bond softens well below the class of the base enamel | IEC 60851-3 |
| Flexibility and adherence after elongation | No cracking after 15 to 32 per cent elongation followed by winding on a mandrel of 1 to 3 times the conductor diameter | IEC 60851-3 |
| Continuity of coating, pinhole faults | 0 to 5 faults over a 5 m sample at the specified test voltage | IEC 60851-5 |
Typical values, not a specification. Values for each batch are given on its Certificate of Analysis.
5. Application
| Parameter | Guidance |
|---|---|
| Method | Last two to four passes on the enamelling line, die or felt application |
| Substrate | Cured polyvinyl acetal, polyester or polyesterimide base enamel on fine round copper conductor, typically 0.05 to 1.00 mm |
| Line cure | Cured in the oven sequence without activating the bond |
| Activation route | Hot air, solvent applied to the wound coil, or resistance heating by current through the winding; the route is agreed before the grade is fixed |
| Activation conditions | Temperature, solvent or current set for the coil geometry and confirmed on trial coils |
| Next step | Bonded coil used without former, tape or impregnation, within the class 155 F limit of the bondcoat or the class of the base enamel where that is lower |
Process. Applied as the last two to four passes on the enamelling line and cured without activating the bond. Bond developed later at the coil winder by hot air, by solvent or by resistance heating. Base enamel up to class 180 H, with the bondcoat rated class 155 F, which is what limits the bonded assembly in service.
6. Storage and handling
Store in the original closed containers indoors, in a dry place away from direct heat and frost, and stir before charging the applicator. 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.