| abstract |
A method of making a strip (2020) having a predetermined value of cross-sectional porosity and cross-sectional porosity distribution value for use as an aerosol-forming substrate in a heated aerosol-generating article (2000, 2001, 2002), comprising the steps of : providing a continuous sheet (2) of aerosol-forming material having a specified width and a specified thickness, the continuous sheet of aerosol-forming material being aggregated transversely with respect to its longitudinal axis, the aggregated aerosol being formed around the aggregated aerosol with a packaging material a continuous sheet of material to form a continuous strip, cutting the continuous strip into a plurality of discrete strips, determining values for cross-sectional porosity and cross-sectional porosity distribution for at least one of the discrete strips, and controlling one or more manufacturing parameters to ensure that the cross-sectional porosity and cross-sectional porosity distribution values of subsequent strips are within the predetermined values. The predetermined value of the cross-sectional porosity is preferably in the range of 0.15 and 0.45 and the predetermined value of the cross-sectional porosity distribution is preferably in the range of 0.04 and 0.22. The predetermined value may be selected to optimize aerosol deliverables for different types of heated aerosol-generating articles. In preferred embodiments, the continuous sheet may be crimped prior to gathering. |