A set of panels includes first and second panels, and a mechanical locking device for locking by vertical relative displacement of the panels. A locking strip extends from a first edge of the first panel in a direction parallel to first and second panel surfaces of the first panel. The locking strip includes a locking element configured to cooperate with a locking groove at a second edge of the second panel for locking in a direction parallel to the first panel surface. Opposite edges respectively include cooperating tongue and tongue groove for vertical locking. The locking strip includes a flexing groove extending from the second locking strip surface into the locking strip, to increase a flexibility of the locking strip during the assembly.

A thermoplastic-based building panel, such as a floor panel. The building panel includes an upper layer arrangement, a lower layer arrangement, and a balancing layer provided between the lower and the upper layer arrangement. The building panel further includes a groove arrangement including grooves. A thermoplastic-based building panel including an upper layer arrangement and a balancing layer which is a bottom layer of the building panel. The building panel includes a groove arrangement, wherein a major portion of the grooves therein is provided in the balancing layer only. A thermoplastic-based building panel including a mechanical locking system for horizontally and/or vertically locking the building panel to an adjacent building panel. The mechanical locking system includes a cooperating surface which is situated in a balancing layer and is configured to cooperate with a cooperating surface of an adjacent building panel.

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.

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.

A thermoplastic-based building panel, such as a floor panel. The building panel includes an upper layer arrangement, a lower layer arrangement, and a balancing layer provided between the lower and the upper layer arrangement. The building panel further includes a groove arrangement including grooves. A thermoplastic-based building panel including an upper layer arrangement and a balancing layer which is a bottom layer of the building panel. The building panel includes a groove arrangement, wherein a major portion of the grooves therein is provided in the balancing layer only. A thermoplastic-based building panel including a mechanical locking system for horizontally and/or vertically locking the building panel to an adjacent building panel. The mechanical locking system includes a cooperating surface which is situated in a balancing layer and is configured to cooperate with a cooperating surface of an adjacent 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.

Floorboards provided with a mechanical locking system including a locking strip protruding from a first edge of a first floorboard. The locking strip is provided with a locking element configured to cooperate with a locking groove at a lower side of a second edge of a second floorboard for locking the first edge and the second edge in a horizontal direction. The first edge and the second edge are configured to be assembled by a vertical downward motion of the second edge towards the first edge. The second edge is provided with a calibrating groove adjacent the locking groove. Also, a method for producing a mechanical locking system.

A mineral-based floor panel including a mineral-based core, wherein the panel includes at least one groove. The at least one groove may be provided in a rear side of the panel. There is also disclosed other such mineral-based panels, such as a building panel, a wall panel, a ceiling panel or a furniture panel. There is also disclosed a method for forming such grooves in a mineral-based panel. Furthermore, there is disclosed a mineral-based panel including a mineral-based core and polymer-based lower layer(s) attached to the core. A locking system of the panel includes a strip extending horizontally beyond an upper portion of the panel, wherein at least a horizontal portion of the strip is entirely formed in the polymer-based lower layer(s).

A mineral-based panel including a mineral-based core and at least one groove. The at least one groove may be provided in a rear side of the panel. The mineral-based panels may be floor panel, a building panel, a wall panel, a ceiling panel or a furniture panel. A method for forming such grooves in a mineral-based panel. Furthermore, a mineral-based panel including a mineral-based core and polymer-based lower layer(s) attached to the core. A locking system of the panel includes a strip extending horizontally beyond an upper portion of the panel, and a horizontal portion of the strip is entirely formed in the polymer-based lower layer(s).