Pulp at a high consistency of about 4 to 20% is fed from a slice (5) onto a formation support (2) that is permeable to water, for the manufacture of a fibre-based product. Before the slice (5), the pulp is led in the flow direction into a flow channel (4) tapering on at least part of its length and limited by a surface moving at a velocity different from the pulp flow velocity to fluidize the pulp. The pulp is fed by force into this flow channel (4) by means of a feeding device that supplies kinetic energy to the pulp and is separate from the moving surface, for example a high-consistency pump (P).