Processing and working instructions HPL and HPL elements PR ...

PRODUCT INFORMATION
The application of the individual adhesives is explained below:
a) Dispersion adhesives
These include PVAc adhesives and 2-component PVAc dispersion adhesives. Apply the adhesive with a
toothed spreader or hand roller. This can also be done with adhesive application machines or four-roller
machines. Cold pressing is carried out using screw clamps, spindle presses or single-/multi-daylight presses,
and warm pressing with single- or multi-daylight presses, short cycle presses, roller presses or double-belt
presses. Take care to observe the pressing times/temperatures accurately with sparing and even adhesive
application.
b) Condensation resin adhesives
These include urea resin, melamine-urea resin, phenolic resin and resorcinol resin. Phenolic- and resorcinol
resin are used principally for DUROPAL HPL elements which require high resistance to exposure to flames.
Condensation resin adhesives require corresponding additives in order to make the adhesive joint elastic.
The guideline values can vary according to the hardener type. Impurities consisting of remains of adhesive
or hardener cannot be removed from the DUROPAL HPL surface after bonding without damaging the material.
Ensure therefore that these are completely removed before bonding. For cold and warm pressing, the
same tool specifications apply as for dispersion adhesives.
c) Contact adhesives
Without hardener: When applying with a toothed spreader, the application direction on the core material
and laminate should be at right-angles to one another. The adhesive can also be applied with a brush,
or by spraying and pouring systems. In all cases, great care and good ventilation must be ensured when
working. Contact adhesives require a short, powerful contact pressure. The open time can be reduced by
accelerated drying of the adhesive films, although over-drying should be avoided. Dried-on adhesive films
can be reactivated by heat, e.g. infrared radiation.
The pressing procedure is carried out as described.
With hardener: This adhesive enables higher stress and temperature resistance of the joint. For further
information, please consult the manufacturer.
d) Mixed adhesives
General working recommendations cannot be given here, since this category is divided into different types
and used only for special bonding.
e) Hot-melt adhesives
These are used principally for edge bonding.
099 PI Processing and working instructions Page 22 of 34