A method for identifying capsule defects in a tobacco filter includes measuring values for density and/or moisture content of the filter using a microwave measurement device. The measured values are compared with a threshold value and a presence of a capsule defect in the filter is determined if the measured valued undershoots the threshold value. A value for a degree of fluctuation of the measured values is determined at a region in front of a measurement location and/or behind the measurement location in which at least one measured value is below the threshold value. The value for the degree of fluctuation is compared with a predetermined capsule threshold value. The capsule defect comprises a broken capsule when the value for the degree of fluctuation exceeds the capsule threshold value, and the capsule defect comprises a missing capsule when the value for the degree of fluctuation undershoots the capsule threshold value.

A method for producing a rod containing herbaceous material comprises the steps of: providing a sheet material containing herbaceous material; shaping the sheet material into a rod-shape by conveying the sheet material along a conveying direction through a funnel-shaped converging device; and dispensing an additive onto the sheet material within the converging device.

A manufacturing method and a manufacturing device for manufacturing an aerosol generating substrate are provided. The manufacturing method for manufacturing the aerosol generating substrate includes: room temperature extrusion molding of a mixed material is performed to allow the mixed material to form an extrusion substrate; and the extruded substrate is cooled and hardened.

An aerosol generating material for use in an aerosol delivery device is provided, the aerosol generating material including a fibrous plant material, an aerosol former, and an active agent including at least a substituted 3-(1-methylpyrrolidin-2-yl)pyridine, a 3-(azetidin-2-yl)pyridine, or a 3-(azetidin-2-ylmethoxy)pyridine. The active agent is absorbed or adsorbed in or on the fibrous plant material. The disclosure further provides devices and aerosol provision systems incorporating such aerosol generating material.