Particle parameters of microwave-expanded cut stems and their influences on slim cigarette quality

Gray correlation and regression analyses were used to study the influences of microwave-expanded cut stem with different particle sizes on the physical properties and mixing homogeneity of cut tobacco blends. The effects on the levels of smoke components, such as the seven harmful components in smoke, and sensory quality of the mainstream cigarette smoke were also evaluated when the blends were made into slim cigarettes. The experimental results were as follows. 1) The contribution index of sliced width (X₁) and shredded width (X₂) was approximately the same for filling capacity; this was true for the proportion of long strands, small strands, the blending uniformity and smoke hazard index (H). However, for the amount of mainstream smoke released, the contribution index of X₁ was slightly larger than X₂. 2) When the sum of sliced and shredded width was ≤0.6 mm, the dust contents of the cigarettes and tobacco, as well as the loss from the cigarette end, were high and did not meet the product quality requirements. 3) Cigarette draw resistance initially increased then decreased and the RSDs increased with the changes in the cut parameters. 4) When the sum of sliced and shredded width exceeded 0.9 mm, the degree of mixed uniformity of microwave-expanded cut stems significantly decreased. 5) The amount of tar, nicotine, and CO released initially increased and then decreased with the increased cut-stem width, peaked at 0.9 mm. 6) With increasing cut-stem width, cigarette's sensory quality decreased and the smoke hazard index initially increased then decreased. Generally, the total cut stem width should preferably range from 0.7 mm to 0.8 mm and X₁ equals or slightly bigger than X₂.