Phenolic Resins
Phenolics are a class of resins commonly based on phenol (carbolic acid). Phenolics are thermosetting resins that cure through a condensation reaction producing water that is removed processing. Phenolic resins are typically combined with glass fibres or mineral fillers.
Phenolic resins are used in a wide range of applications including electronics, ballistics, mine ventilation, offshore water pipe systems, aerospace, rail and mass transit. They offer good thermal and electrical insulation, low density, excellent durability, and easy of forming complex contours.
They are ideal for high temperature applications where parts must meet fire safety, smoke emission, combustion and toxicity requirements. They are flame retardant and heat and chemical resistant. Self-extinguishing fillers can also be added. Phenolics are applied as adhesives or matrix binders in engineered woods (plywood), and are found in brake linings, clutch plates, circuit boards, and subway car panels.
Advantages
- High temperature resistance
- Creep resistance
- Excellent thermal-insulation and sound-damping properties
- Corrosion resistant
- Excellent resistance to fire, smoke, and smoke toxicity
Limitations
- Surfaces produced are dull, not glossy
- Colours are limited to red, brown, or black due to the resin’s natural brown colour. For this reason parts need aesthetic finishing after moulding, such as surface prep and priming or painting.
Processing technologies
The best processes for producing parts with this material are:
- Open Moulding
- Resin Transfer Moulding (RTM)
BFG International’s experienced designers and engineers select the optimal process in each case based on variables such as the client’s tooling budget, dimensional tolerance and physical properties of the parts, and production volume.
| Techinical details | |
|---|---|
| Maximum use temperature | 149 – 204 °C |
| Flexural strength | 7 – 14 ksi |
| Flexural modulus | 1.0 – 1.2 Msi |
| Tensile strength | 5 – 9 ksi |
| Tensile modulus | 0.8 – 1.7 Msi |
| Density | 1.3 – 1.4 grams/cc |
| Moisture absorption | — |
| Elongation | 0.5 – 0.8 |
| Coefficient of thermal expansion (x10-5) | 3 – 5 |