Abstract: A retaining device including a base having an upper face and a lower face, the base extending along a primary direction, having a width defined along a secondary direction perpendicular to the primary direction, and a thickness measured along a direction perpendicular to the primary direction and to the secondary direction, a plurality of retaining elements extending on the upper face of the base, each retaining element including a rod, the retaining elements being integrally formed with the base, the retaining elements being arranged in rows and in columns extending respectively along the secondary direction and the primary direction, wherein at least X rows and/or X columns of the retaining device have distinct numbers of retaining elements, where X is equal to 2.

Abstract: A molding device including a molding strip formed of a first material and extending along a machine direction, having a width defined along a transverse direction perpendicular to the machine direction, and a thickness measured along a direction perpendicular to the machine direction and to the transverse direction, and an inner face and an outer face, the molding strip including a plurality of cavities, characterized in that part of the cavities are at least partially obturated by a plugging material, so as to define molding cavities for forming retaining elements and/or preforms of retaining elements, and non-functional cavities.