Return to The Products > Decorative Surfaces

Thermally Fused Papers

This overlay category is referred to by many names including thermally fused melamine (TFM), low pressure, direct pressure or simply as melamine overlays. Sub categories include the names Polyester and Decorative Phenolics. Thermally fused papers generally weigh between 60 and 130 g/m², and the paper formation is similar to the decorative sheet used for HPL. Thermally fused papers are saturated with reactive resins and partially cured at the point of manufacture to allow for storage and handling of the paper. Final curing is done at the time of hot press lamination when the resins form a hard, permanent thermoset bond between the paper and the substrate. No additional adhesives are required. Common end-use applications of thermally fused papers include laminate flooring, kitchen cabinets and countertops, shelving, store fixtures and home office furniture.

The three most common thermoset resin systems used in the production of saturated papers are melamine, polyester and phenolic resins. When double-stage impregnation equipment is available, saturating resins may be used to extend the melamine resin in the core of the melamine saturated sheet.

Melamine - The resin is introduced into the paper during an impregnating operation. After the paper is impregnated it is partially cured (“B” stage) using curing ovens. The melamine resin is fully cured at 300-400 psi and 300-400ºF during hot press lamination. The “B” staged paper has a definite shelf life that varies with temperature and humidity. Melamine resins are noted for their hardness, scratch resistance and color stability and are the most commonly used resin in saturated paper overlays.

Polyester - The resin is introduced into the paper during an impregnating operation. After the paper is impregnated it is partially cured (“B” stage) using curing ovens. Polyester resin is fully cured at 175-200 psi and 275-350ºF during hot press lamination. The “B” staged paper has a definite shelf life that varies with temperature and humidity. Polyester resins are noted for their chemical, stain, water and impact resistance, color clarity and machinability.