3.Machining and processing HPL
Condensation resin adhesives are in the group of adhesives which have to be processed with a minimum of 2 to 5 bar bonding pressure in order to allow multi-layer and composite layer bonding. This allows the joining of different types of materials. The adhesive batches require corresponding additives (e.g. flours) for elastification of the glue line. They also produce a visually more uniform surface. Different types of hardeners allow a larger variation of bonding and pressing parameters. Impurities on the surface caused by adhesives and hardeners have to be removed before bonding, otherwise they can no longer be removed later without damaging the surface. Release agents applied to affected areas prevent adhesive residue on the surface of the HPL and bonding plates. Phenol and resorcinol resin adhesives are also used for manufacturing composite boards with increased resistance to flames.
Condensation adhesives are e. g.:
Hot presses: Single and multi-opening presses, short cycle presses, double belt presses.
Please note that low and uniform application of the adhesive as well as observing the pressing temperatures, pressures and times is required.
