3.Machining and processing HPL
After correct covering and bonding, the HPL can be machined further together
with the substrate.
The surface of HPL consists of high-quality melamine resins, which makes it relatively hard. Tool wear is greater than with most wood-based products. Tools with TCT blades have proven to be very suitable. Polycrystalline diamond blades are also suitable for standard machining processes.
Whenever a decorative surface has to be moved over the bearing surface for machining or vice versa, it is recommended to use a guide or base (e. g. chipboard) to move along with the HPL. For machine tools it is possible to use flat bearing surfaces with grooves instead, in order to keep the contact area with the HPL as small as possible. No base is required for tables with air cushion support.
Avoid any vibration and fluttering of the sheet. This is particularly important when processing unbonded sheets of HPL. It is recommended that processing be carried out on a flat, solid surface. Sharp blades and smoothly running tools are essential for flawless working. Breaking, splintering or bowing of the decorative side are the result of incorrect machining or unsuitable tools. The resulting grooves can lead to the formation of cracks on composite elements.
All corners of cutouts and inner openings on composite panels and HPL- Compact should be rounded. The inner radius should be as large as possible: For cutouts up to 250 mm side length, the corners have to have a minimum radius of 6 mm (see fig. 23).
