What is High Pressure Laminate?
High pressure laminate (HPL) is commonly used as the decorative surface for residential and commercial countertops and cabinets, work surfaces, laboratory surfaces, backsplashes, partitions, retail fixtures, panel applications, furniture. HPL is a paper-based product created by bonding melamine-impregnated decorative papers to layers of resin-treated kraft paper under high heat and pressure. In the press, decorative papers are permanently bonded to the kraft paper to form a sheet of laminate. Laminate is made up of several components and key ingredients:
The Overlay (or Wear Layer) is made from alpha-cellulose wood fibres. These lightweight papers are very absorbent and carry melamine resin and aluminum oxide from the impregnation process.
Decorative paper use alpha cellulose because it does not discolour when exposed to heat and light.
Kraft paper layers comprise soft/hard wood fibres, Kraft paper provides the strength and impact resistance to the laminate and gives it the primary performance characteristics.
Melamine resin saturates the top layer of paper for hardness and scratch resistance. Thermoset melamine resin produces a hard chemically resistant surface that is transparent and visually stable upon exposure to light. Melamine is a synthetic resin derived from the natural gas and petroleum industries.
Phenolic resin saturates the Kraft paper layers for strength and flexibility. It provides strength and impact resistance to the paper layers.
The manufacture of laminate actually consists of two processes — one for the decorative surface of the product and one for the core material. These two processes come together at the press as melamine treated decorative papers are permanently bonded to the resin-treated kraft paper to form a sheet of laminate.