Epoxies are recommended for applications requiring resistance to chemicals and humid environments. They have low moisture absorption and good dimensional stability, mechanical strength, bond strength, and fungus resistance. Laminates based on silicones have low moisture absorption, and they maintain their electrical properties over a wide range of service conditions. Polyimide binders extend the use-temperature range of glass laminates upward. These resins can also withstand lengthy solder-bath exposure without blistering.
Papers are the lowest-cost reinforcing materials used in making laminates.
Types include kraft, alpha, cotton linter, and combinations of these. Papers provide excellent electrical properties, good dimensional stability, moderate strength, and uniform appearance. Cotton cloth is used for applications requiring good mechanical strength. The lighter-weight fabrics are not as strong but have excellent machinability. Asbestos, in the form of paper, mat, or woven fabric, provides excellent resistance to heat, flame, chemicals, and wear.