Study On The Reduction Of Leaf Consumption Per Box Of Slim Cigarettes Based On Six Sigma DMAIC Method

The per-box leaf consumption rate of cigarettes is one of the 15 primary benchmark indicators and 13 key lean indicators established by the State Tobacco Monopoly Administration.It serves as a comprehensive reflection of an enterprise’s technological and management capabilities.In the case of HN Fine Cigarettes,specifically the HJY(AS)brand,the per-box leaf consumption rate is relatively high and unstable.Reducing the per-box leaf consumption rate of HJY(AS)cigarettes is the main focus of this research project.This study investigates and improves the issue of high per-box leaf consumption rate in fine cigarettes by applying the Six Sigma methodology and tools,in combination with production practices and cigarette manufacturing requirements.The DMAIC process is primarily used for the investigation.In the Define phase(D),the research scope,timeline,and risk assessment are outlined.In the Measure phase(M),the effectiveness of the measurement system is validated.Through the use of process mapping,identification of key processes,cause and effect matrix(C&E),and FMEA analysis,nine potential key input factors are identified,including X3(cutting width measurement system)and X6(finished tobacco moisture content measurement system)that are further analyzed.In the Analyze phase(A),analysis is performed using single-factor variance,two-factor variance analysis,paired-sample t-test,and DOE experiments on the nine potential key factors.Five key input factors significantly associated with the per-box leaf consumption rate(Y)are selected.In the Improve phase(I),the cutting width(X3)is analyzed and improved using a single-factor three-level three-replication DOE experiment.The hot air temperature(X5)and HT steam flow rate(X6)are analyzed and improved using a two-factor two-level experiment with three central points.The conveyor pressure(X7)and recirculation coefficient(X8)are analyzed and improved using a two-factor two-level experiment with three central points.Optimal values for the relevant parameters are determined through experimentation and subsequently validated.In the Control phase(C),the improved processes and optimal parameters are incorporated into standards and control methods.The complete Six Sigma process effectively and systematically addresses the problem,ensures the solidification and control of the achievements,and achieves the long-term stability of key factors within the defined range,thereby playing a positive role in practical production.Reducing the per-box leaf consumption rate is a comprehensive task that requires the application of the Six Sigma methodology to analyze and explore system issues.The key feature of this project is the efficient determination of the optimal response value for the per-box leaf consumption within the process parameter range through analysis and improvement of key factors using DOE experimental design,while minimizing the number of trials and costs.The average per-box leaf consumption rate of HJY(AS)cigarettes was successfully reduced from 22.5 kg/box to 21.94 kg/box,resulting in a significant decrease and creating substantial economic benefits for the company.The Sigma level also improved from 1.78 to 3.59,indicating a significant enhancement in the stability of the per-box leaf consumption rate,thereby achieving the research objective.The study conducted rigorous statistical analyses,including single-factor and two-factor variance analyses using Minitab software,to investigate the selected potential factors.The findings revealed significant correlations between the specific fuel consumption of HJY(AS)fine-cut tobacco per single box and five factors: sliver width,hot air temperature in the drying process,HT steam flow rate,pressure of the tobacco conveyor,and the reconstituted tobacco percentage coefficient.To determine optimal parameter values,a scientifically designed Design of Experiments(DOE)trial was performed,aiming to minimize experimental trials and costs.The optimal values obtained were as follows: sliver width of 0.85 mm,hot air temperature of 117°C,HT steam flow rate of 348kg/h,pressure of the tobacco conveyor at 110 h Pa,and reconstituted tobacco percentage coefficient of 120%.Within the drying process analysis,both hot air temperature and HT steam flow rate were identified as significant factors.By employing a DOE trial with a reduced number of experiments(13 groups),and analyzing the response surface model constructed from these trials,a distinct curved response curve was generated.This approach allowed for the determination of the optimal response value within the parameter range,effectively reducing costs and enhancing efficiency.It is worth noting that although the study achieved the desired specific fuel consumption per single box,a gap was observed when compared to optimal values of other domestic companies,potentially due to variations in cigarette blends,production processes,and equipment configurations.Future research should expand the investigation to include additional processes such as leaf drying and re-roasting,while considering upgrades and modifications to critical process components.In practical production,while the implementation of optimized equipment parameters led to a reduction in specific fuel consumption,it also introduced fluctuations in sensory quality,thereby affecting product quality stability.Consequently,it is recommended to integrate a sensory quality evaluation system with equipment parameter adjustments to enhance the stability of product quality.