Phenolic sheet is a hard, dense material made by applying heat and pressure to layers of paper or glass cloth impregnated with synthetic resin. Cellulose paper, cotton fabrics, synthetic yarn fabrics, glass fabrics and unwoven fabrics are all possible materials used in lamination. When heat and pressure are applied, polymerization transforms the layers into thermosetting industrial laminated plastic.
Bakelite phenolic sheet is produced in many commercial grades and with various additives to meet diverse mechanical, electrical and thermal requirements. Some common types include:
Paper reinforced NEMA XX per MIL-I-24768 PBG. Normal electrical applications, moderate mechanical strength, continuous operating temperature of 250 °F (121 °C).
Canvas reinforced NEMA C per MIL-I-24768 TYPE FBM NEMA CE per MIL-I-24768 TYPE FBG. Good mechanical and impact strength with continuous operating temperature of 250 °F (120 °C).
Linen reinforced NEMA L per MIL-I-24768 TYPE FBI NEMA LE per MIL-I-24768 TYPE FEI. Good mechanical and electrical strength. Recommended for intricate high strength parts. Continuous operating temperature 250 °F (120 °C).
Nylon reinforced NEMA N-1 per MIL-I-24768 TYPE NPG. Superior electrical properties under humid conditions, fungus resistant, continuous operating temperature of 160 °F (70 °C).