Floor board and method for manufacturing such floor boards

A floor board, comprising:

• a substrate having side edges and a decorative surface layer applied to said substrate;
• and
• at least one side edge together with a side edge opposite thereto forming a first pair of opposite side edges of said substrate,
• wherein said first pair of opposite side edges comprises mechanical first and second coupling parts, respectively, allowing said floor board to couple at the respective side edges with a similar floor board by means of an angling down motion such that, in a coupled condition, said floor board and a further floor board become locked both in a vertical direction perpendicular to a board plane defined by the intercoupled floor boards, as well as in a horizontal direction parallel to said board plane,
• wherein said first coupling part comprises a sideward tongue, wherein said sideward tongue comprises a front section, a rear section, and a middle section situated in between said front section and said rear section,
• wherein a bottom surface and/or a side surface of said front section of said sideward tongue is at least partially curved, wherein said bottom surface of said front section defines a front downward tongue contact portion,
• wherein a top surface of the front section of said sideward tongue is at least partially inclined downwardly in a direction away from the middle section and rear section, wherein said top surface of said front section defines a front upward tongue contact portion,
• wherein a bottom surface of said middle section of said sideward tongue defines a middle lower contact portion situated in between adjacent inactive portions of the middle section of the sideward tongue,
• wherein a bottom surface and/or a side surface of said rear section of said sideward tongue is at least partially upwardly inclined in a direction away from the middle section and front section, wherein said inclined part of said bottom surface and/or said side surface of said rear section defines a rear downward tongue contact portion,
• wherein said rear section is configured to accommodate an upwardly protruding locking element of a second coupling part of a further floor board,
• wherein said second coupling part comprises a recess for accommodating at least a part of the sideward tongue of a further floor board, said recess being defined by an upper lip and a lower lip, wherein the lower lip extends beyond the upper lip, wherein said lower lip comprises a front section, a rear section, and a middle section situated in between said front section and said rear section, wherein said upper lip is located above and connects to the front section of the lower lip, and wherein the lower lip being provided with a upwardly protruding locking element being located in the rear section of the lower lip,
• wherein a bottom surface and/or a side surface of said front section of said lower lip is at least partially curved, wherein said bottom surface of said front section of said lower lip defines a front upward lip contact portion,
• wherein a bottom surface of the upper lip is at least partially inclined downwardly in a direction away from the middle section and rear section of the lower lip, wherein said bottom surface of said front section defines a front downward lip contact portion,
• wherein a top surface of said middle section of said lower lip defines a middle upward lip contact portion situated in between adjacent inactive portions of the middle section of the lower lip, and
• wherein a top surface and/or a side surface of said rear section of said lower lip is at least partially upwardly inclined in a direction away from the middle section and front section of said lower lip, wherein said inclined part of said top surface and/or said side surface of said rear section defines a rear upward lip contact portion, and wherein said top surface and/or said side surface of said rear section of said lower lip partially defines said upwardly protruding locking element,
• wherein, in coupled condition of adjacent floor boards, the sideward tongue and lower lip define at least three mutually spaced lower contact zones, wherein:
• a front lower contact zone is defined by the co-action between the front downward tongue contact portion of said floor board and the front upward lip contact portion of another floor board,
• a middle lower contact zone is defined by the co-action between the middle downward tongue contact portion of said floor board and the middle upward lip contact portion of another floor board, and
• a rear lower contact zone is defined by the co-action between the rear downward tongue contact portion of said floor board and the rear upward lip contact portion of another floor board,
• and wherein, in coupled condition of adjacent floor boards, the sideward tongue and upper lip define at least two mutually spaced upper contact zones, wherein:
• a first upper contact zone is defined by the co-action between the front upward tongue contact portion of said floor board and the front downward lip contact portion of another floor board, and
• second upper contact zone is defined by the co-action of a top side surface of the first coupling part of said floor board, and a side surface of the upper lip, located above the front downward lip contact portion, of another floor board.