Functional filter plug wrap paper for control of the thermal energy of the aerosol from heated tobacco products (HTPs)
Next generation products, which include all kinds of e-vapour items as well as heated tobacco products (HTPs or “heat sticks”), have successfully entered the tobacco market in addition to conventionally combustible cigarettes. From the basic geometrical concept, HTPs resemble traditional filter cigarettes with various formats, and therefore, heat sticks require filter wrapping materials. Filter wrapping materials are thin and flexible sheets made of paper or other web substrates in order to enable specific quality and technical properties. In general, filter wrapping materials can be separated into tipping paper and filter plug wrap paper. The purpose of the present study is to focus on filter plug wrap paper and to describe individual technical functionalities of the paper. The application of a physically active substance on the plug wrap paper will hereby be demonstrated to lower the temperature of the aerosol generated by HTPs. As some heat stick versions are geometrically distinctively shorter than combustibles, the cooling rate of the aerosol is comparably low yielding high remaining temperature of the inhaled evaporation and distillation result. Selective surface treatment of the plug wrap paper through coating generates enhanced thermal absorptivity, and its efficiency will be quantitatively investigated under pilot plant test conditions as well as evaluated with heat absorption calculations and phase transition aspects. Moreover, mechanical embossing of the plug wrap paper is carried out to increase the effective area of the coated surface thus providing a stronger contribution to the temperature reduction.