Method and device for forming product stacks of folded or unfolded product blanks made of paper, chemical pulp or the like

In a method for forming product stacks of folded or unfolded product blanks made of paper or chemical pulp, product blanks are supplied consecutively to a stacking surface and placed in an upright position. A separating element is inserted between two consecutive product blanks as the product blanks are moved against a channel wall of a discharge channel for temporary support of a rear side of the product blanks, to thereby form a first product stack with a predetermined number of product blanks between the separating element and the channel wall. The channel wall is opened to thereby allow the first product stack to be transferred to the discharge channel, and a sliding element is inserted between the product stack and a subsequent second product stack, as the first product stack is moved to the discharge channel.