3.Machining and processing HPL
The “worktop” HPL composite element allows the use of common wood machining tools. Many complex solutions can be implemented, resulting from the installation shapes of hobs, sinks, etc. but also from the ideas of modern kitchen design. This combination of simple mechanical sturdiness on site and the adaptation to local conditions cannot be rated highly enough. Many other materials – especially those based on inorganic raw materials – do not have these additional benefits. Visually appealing results can be achieved with the combination of worktop elements with other materials (e.g. edge banding, end strips, metal feet).
Routing, drilling, sawing
For all routing, drilling and sawing work on the worktop, a sufficiently rigid supporting surface has to be ensured, so that no breaks or tears occur in narrow board sections.
Cutouts and inner openings are required in the worktop for installing hobs or sinks and for pipe openings. The corners always have to be rounded. The inner radius should be as large as possible: For cutouts up to 250 mm side length the corners need to have a minimum radius of 6 mm.
A hand-held router is generally recommended for cutouts. When using a jig saw, the corners have to be drilled first. Cuts with a jig saw have to be made with the board turned upside-down to minimise scratches in and tearing of the cover layer. The material is not suitable for sharp edges as these can result in cracks. This particularly applies to the hob area where the frequent heat influence causes increased shrinkage tension. All cut edges have to be free from tears as torn edges can also result in cracks.
If the edges cannot be reworked with a router, sanding paper, files or small hand-held plans can be used to break the edges. Metal plans with TCT blades have proven particularly suitable for this.
Holes and cutouts
Holes and cutouts have to have a size which allows sufficient expansion capacity for any installed components (e.g. pipes, cables, fasteners). Cutouts in the element, e. g. for access points, switches or fan grids, need to have rounded inner edges with an internal radius of at least 6 mm. The edges of the cutout should also be smooth and free from grooves, dents and cracks. All cutouts, holes and access openings which expose the chipboard substrate have to be carefully sealed with sealants.
Due to the expected movement in the worktop itself or from installed pipes, these have to be centred so that a minimum spacing of 2 – 3 mm is ensured in all locations. This is to prevent condensation from reaching the substrate. The cut edges on the access openings have to be sealed.
