Design And Properties Of Cellulose Diacetate Fiber Elements For Rapid Cooling Of Smoke

Recently,heat-not-burn cigarettes have appeared on the market as one of the less harmful alternatives to traditional cigarettes,and the mainsteam smoke of which can be inhaled after being cooled or else heat damage to oral and tracheal mucosa will occur.Therefore,the cigarette filter,also call aerosol-cooling element,which can achieve the rapid cooling of mainsteam smoke,is one of the keys to the research and development of heat-not-burn cigarette.Cellulose diacetate,the most common material of cigarette filter,was used as basis material in the paper,and the spiral long smoke channel structure was prepared by fused deposition modeling technology,a high thermal conductivity phase change spiral channel coating material was developed at the same time to build a combined rapid cooling element for smoke.The cooling structure and principle can not only be used for rapid cooling of the mainstream smoke of heat-not-burn cigarettes,but also provide reference for the smoke in other fields.Cellulose diacetate was plasticized in order to be used for fused deposition modeling.The influence of the content of plasticizer--glycerol triacetate on the thermal properties of cellulose diacetate was studied by dynamic mechanical thermal analysis,differential scanning calorimetry and thermogravimetry analysis.It was found that the glass transition temperature,melting temperature and the epitaxial initial decomposition temperature of the plasticizer system were decreased with the increase of plasticizer content.The plasticizer system owned a larger thermal processing temperature window,when the plasticizer content was 30 wt%.The fused deposition modeling process of cellulose diacetate/glycerol triacetate blend system with the above plasticizer content was discussed.The results shown that the plasticized cellulose diacetate profiles prepared in the temperature range of 205?215 ? have good forming performance,and the mechanical properties increased with the increase of temperature.The cellulose diacetate spiral structure was printed in optimized fused deposition modeling process.The effects of the distance between the threads on the draw resistance,mainstream smoke temperature and filtration efficiency of cigarettes were studied,and the data were compared with foreign control cigarettes,which used polylactic acid sheets with pleated surface as aerosol-cooling elements.It was found that the draw resistance decreased and the mainstream smoke temperature of cigarettes increased with the increase of the distance between threads,both them were lower than that of the control when the distance between threads was 1.5 mm,and the highest mainstream smoke temperature was not more than 55 ?.The filtration efficiency of cigarette increased with the decrease of the distance between the threads.Although the comprehensive filtration efficiency was lower than that of the foreign control cigarette with direct interception,it still belonged to medium tar cigarette the same as the control.Meanwhile,taking advantage of the centrifugal effect of spiral structure on smoke,cellulose diacetate/n-eicosane/single-walled carbon nanotubes spiral structure coating material was prepared to improve the heat storage and thermal conductivity of the coating material,and give full play to the synergistic cooling effect of structure and material.It was found that the phase transition temperature of the coated film was not different from that of n-eicosane,and the enthalpy of phase transition increased with the increase of n-eicosane content by differential scanning calorimetry.The enthalpy efficiency of the film can reach 84.1%,when the addition of n-eicosane was 30 wt%.The thermal conductivity and thermal conductivity velocity of the film were measured.It was found that the thermal conductivity of the film was increased by 18.4% and the instantaneous thermal conductivity was increased by about 3 times when the addition amount of single-walled carbon nanotubes was 1 wt%.In order to study the comprehensive performance of the combined cooling element,the aerosol rapid cooling components prepared were connected to the heating non-combustion cigarette for suction experiment and performance test and analysis,and the influence of the combined flue gas rapid cooling components on the temperature filtration efficiency and suction resistance of the mainstream cigarette smoke was discussed.It was found that the smoke cooling effect of the combined cooling element was further improved compared with that of the spiral structure element without high thermal conductivity phase change film and the foreign control cigarette,and the highest mainstream smoke temperature was as low as 53.64 ?.The combined cooling element obtained a better comprehensive filtration effect,because of the centrifugal action of spiral structure,which made the smoke be fully captured by the outer film.The draw resistance of cigarettes was 0.048 k Pa higher than that of foreign control cigarettes,and the deviation was within the tolerance range of national standard(±0.245 k Pa).