Method for making a sub-unit of a smoking article

A method for making a sub-unit of an HNB smoking article, comprising the steps of:

• preparing a rod segment of the tobacco industry, wherein the rod segment comprises at least one chosen from a filtering material, suitable for making a filter of the smoking article, a heating element configured for allowing passage of a flow of air and/or another gas for heating, a tobacco-based element, and an aerosol generator;
• wrapping a connecting strip of wrapping material around the rod segment about a wrapping axis such that a first portion of the connecting strip is superposed on a first end of the rod segment and a second portion of the connecting strip is axially protruding from the first end of the rod segment to define a tubular wrapping enclosing a containment chamber;
• after the wrapping step, placing a filling material of the tobacco industry inside the containment chamber by partial filling the containment chamber to leave an end portion of the tubular wrapping end free to form a closing wall;
• making the closing wall, transverse to the wrapping axis, defining an at least partial closure of the containment chamber, specifically by folding an end portion of the second portion of the connecting strip.