Arcwire IR 155 Dip and Bake Impregnating Varnish
Solvent-borne class 155 F impregnating varnish for shops working with a dip tank and a curing oven. It penetrates a tight winding at ambient temperature and builds full slot fill over two or three dip and bake cycles.
Grade Arcwire IR 155 | Range Electrical Insulation and Wire Enamels | Technology Solvent-borne heat-curing insulating resin varnish
Technical Data Sheet
Arcwire IR 155
Issue 2026.09
1. Product description
A solvent-borne class 155 F impregnating varnish for shops working with a dip tank and a curing oven, which is the lowest plant requirement in the impregnation range and the most tolerant of interruptions and mixed batch sizes. Because the solvent leaves during bake, the film shrinks as it goes and draws back from the slot, so full fill is built over two or three dip and bake cycles rather than one. It penetrates a tight winding readily at ambient temperature and is the practical choice for rewind and repair work, where the geometry varies from unit to unit.
2. Features
- Needs only a dip tank and a curing oven
- Penetrates a tight winding at ambient temperature
- Tolerant of interruptions and mixed batch sizes
- Full slot fill over two or three dip and bake cycles
- Suited to rewind and repair work where geometry varies from unit to unit
3. Recommended uses
Impregnation of stators, rotors, armatures, field coils and transformer coils, in production and in rewind and repair shops.
Substrates. Wound stators, rotors, armatures, field coils and transformer coils, over enamelled wire, slot liners, tapes and sleeving.
4. Typical properties
| Property | Typical value | Method |
|---|---|---|
| Technology | Solvent-borne heat-curing insulating resin varnish | Formulation |
| Appearance | Clear liquid, amber to brown | Visual inspection |
| Carrier | Organic solvent, released during the drain period and bake | Formulation |
| Non-volatile matter | 40 to 60 per cent by weight | ISO 3251 |
| Density | 0.95 to 1.05 g/cm³ at 23 °C | ISO 2811-1 |
| Supply viscosity | Set for dip penetration at ambient temperature; flow time confirmed on the Certificate of Analysis | ISO 2431 |
| Thermal class of the material | 155 F | IEC 60085 for the designation; thermal endurance to IEC 60216-1 |
| Bond strength, helical coil | 80 to 300 N at 23 °C, falling to 15 to 80 N at 155 °C | IEC 61033 |
Typical values, not a specification. Values for each batch are given on its Certificate of Analysis.
5. Application
| Parameter | Guidance |
|---|---|
| Method | Dip, flood or roll dip at ambient temperature |
| Winding preparation | Winding clean and dry; preheat to drive off moisture, then allow to cool before dipping |
| Tank viscosity | Top up with the thinner specified for the grade to hold the tank at the flow time on the Certificate of Analysis, checked at a fixed temperature |
| Drain and solvent release | Drain until dripping stops, then allow the solvent to evaporate before the oven |
| Cure | Oven cure on the schedule stated for the grade, timed from when the winding reaches temperature and set against unit mass |
| Cycles | Two or three dip and bake cycles where full slot fill is required |
| Next step | Optional surface seal with Arcwire VA 180 finishing varnish |
Process. Dip, flood or roll dip at ambient temperature, drain, solvent flash-off, then oven cure. Two or three cycles where full slot fill is required. Thermal class 155 F.
6. Storage and handling
Store in closed containers in a cool, dry place away from direct heat, and keep the dip tank covered between runs to limit solvent loss. 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.