Aerosol-forming article with tight segment

Abstract

An aerosol-forming article includes: a tight segment; an aerosol-forming substrate segment; an airway segment; and a filter segment. The airway segment is located between the aerosol-forming substrate segment and the filter segment. The tight segment is located at an end of the aerosol-forming substrate segment away from the filter segment. The airway segment has an airflow channel axially penetrating the airway segment. An axial air permeability of the tight segment is less than an axial air permeability of the aerosol-forming substrate segment.

What is claimed is: 
     
         1 . An aerosol-forming article, comprising:
 a tight segment;   an aerosol-forming substrate segment;   an airway segment; and   a filter segment,   wherein the airway segment is located between the aerosol-forming substrate segment and the filter segment,   wherein the tight segment is located at an end of the aerosol-forming substrate segment away from the filter segment,   wherein the airway segment has an airflow channel axially penetrating the airway segment, and   wherein an axial air permeability of the tight segment is less than an axial air permeability of the aerosol-forming substrate segment.   
     
     
         2 . The aerosol-forming article of  claim 1 , wherein the axial air permeability of the tight segment is 0. 
     
     
         3 . The aerosol-forming article of  claim 1 , wherein the tight segment comprises a non-aerosol-forming material comprising at least one of a carbon fiber material, a metal membrane, a ceramic, and a high molecular material. 
     
     
         4 . The aerosol-forming article of  claim 1 , wherein a material of the tight segment is a same material as a material of the aerosol-forming substrate segment,
 wherein the same material comprises an aerosol-forming material, and   wherein a bulk density of the tight segment is higher than a bulk density of the aerosol-forming substrate segment.   
     
     
         5 . The aerosol-forming article of  claim 1 , wherein the airway segment is hollow and is provided with a side wall and a hollow cavity, and
 wherein the hollow cavity is the airflow channel axially penetrating the airway segment.   
     
     
         6 . The aerosol-forming article of  claim 5 , wherein a side flow hole penetrating the side wall is formed in the side wall of the airway segment. 
     
     
         7 . The aerosol-forming article of  claim 6 , wherein an axial position of the side flow hole is close to one end of the aerosol-forming substrate segment and is away from one end of the filter segment. 
     
     
         8 . The aerosol-forming article of  claim 1 , wherein the airway segment comprises a first airway segment close to the aerosol-forming substrate segment and a second airway segment close to the filter segment. 
     
     
         9 . The aerosol-forming article of  claim 8 , wherein a cross sectional area of the airflow channel of the first airway segment is smaller than or equal to or greater than a cross sectional area of the airflow channel of the second airway segment. 
     
     
         10 . The aerosol-forming article of  claim 1 , wherein the airway segment is cylindrical.