The invention relates to a panel, such as a floor panel, a wall panel or a ceiling panel, in particular a decorative panel and to a method for producing such panel. The panel according to the present invention comprises a core layer comprising a first composite material and a second composite material which have different material characteristics. The panel is further provided with a plurality of cavities.

Building panels, especially laminated floor panels are shown, which are provided with a locking system and several core grooves at the rear side in order to save material and decrease weight. Building panels, each having a surface layer on a front side, a backing layer on a rear side and an intermediate core, wherein the intermediate core and the surface and the backing layer all comprise wood fibres and thermosetting resins, the building panels are provided with a locking system for vertical and horizontal locking of a first edge of a first building panel to an adjacent second edge of a second building panel.

A method for forming grooves in a board element. An exemplary method includes arranging the board element in contact with a support member, and forming at least one groove in a rear side of the board element by removing material, such as chips, from the board element by rotating one or more cutting devices including a plurality of tooth elements configured to rotate around a rotational axis. A method further includes counteracting, such as preventing, a displacement of the board element away from the support member during forming of the at least one groove, wherein the counteracting, such as preventing, includes arranging at least a portion of the board element between an obstruction element and the support member.

Building panels provided with a locking system for vertical and horizontal locking of a first edge and a second edge of adjacent panels. The locking system includes a displaceable tongue at least partly arranged in a displacement groove, a tongue groove, a cavity provided in a strip at the first edge, and a protrusion extending downwards at the second edge. The displaceable tongue is arranged to be displaced at least partly into the tongue groove during locking, and wherein the protrusion is arranged to be located in least a portion of the cavity when the panels are locked vertically and horizontally.

Building panels, especially laminated floor panels are shown, which are provided with a locking system and several core grooves at the rear side in order to save material and decrease weight. Building panels, each having a surface layer on a front side, a backing layer on a rear side and an intermediate core, wherein the intermediate core and the surface and the backing layer all comprise wood fibers and thermosetting resins, the building panels are provided with a locking system for vertical and horizontal locking of a first edge of a first building panel to an adjacent second edge of a second building panel.

A flanged duct blank has a male part defined by lead notches formed at each side of a leading end and has a female part defined by trail notches formed at each side of a trailing end. The male part includes a lock tab. The female part includes a leg part and a Z-bend. The Z-bend includes a leg part and a gap. The duct blank is repeatedly clamped and bent by a pivoting wiper to form a duct portion. The pivoting wiper includes a clench tool that has a retractable rib and a retractable roller. With the lock tab inserted into the Z-bend and the retractable rib engaged with the Z-bend, the retractable roller clenches the leg part over the lock tab to lock the male and female parts together in a duct seam.

Building panels provided with a locking system for vertical and horizontal locking of a first edge and a second edge of adjacent panels. The locking system includes a displaceable tongue at least partly arranged in a displacement groove, a tongue groove, a cavity provided in a strip at the first edge, and a protrusion extending downwards at the second edge. The displaceable tongue is arranged to be displaced at least partly into the tongue groove during locking, and wherein the protrusion is arranged to be located in least a portion of the cavity when the panels are locked vertically and horizontally.

Building panels provided with a locking system for vertical and horizontal locking of a first edge and a second edge of adjacent panels. The locking system includes a displaceable tongue at least partly arranged in a displacement groove, a tongue groove, a cavity provided in a strip at the first edge, and a protrusion extending downwards at the second edge. The displaceable tongue is arranged to be displaced at least partly into the tongue groove during locking, and wherein the protrusion is arranged to be located in least a portion of the cavity when the panels are locked vertically and horizontally.

A flanged duct blank has a male part defined by lead notches formed at each side of a leading end and has a female part defined by trail notches formed at each side of a trailing end. The male part includes a lock tab. The female part includes a leg part and a Z-bend. The Z-bend includes a leg part and a gap. The duct blank is repeatedly clamped and bent by a pivoting wiper to form a duct portion. The pivoting wiper includes a clench tool that has a retractable rib and a retractable roller. With the lock tab inserted into the Z-bend and the retractable rib engaged with the Z-bend, the retractable roller clenches the leg part over the lock tab to lock the male and female parts together in a duct seam.

Building panels provided with a locking system for vertical and horizontal locking of a first edge and a second edge of adjacent panels. The locking system includes a displaceable tongue at least partly arranged in a displacement groove, a tongue groove, a cavity provided in a strip at the first edge, and a protrusion extending downwards at the second edge. The displaceable tongue is arranged to be displaced at least partly into the tongue groove during locking, and wherein the protrusion is arranged to be located in least a portion of the cavity when the panels are locked vertically and horizontally.