Maximization of the fill value of tobacco by applying factorial design of experiment

Abstract

Tobacco, thollgh in the conlonl or homan health is nol at all a dcsircJ product, plays a siglliJicun\ role in business amI acts as a major source ofcontrihution in the govcmlllcni cXc!Jc(jucr in the form oflilX. The lllatlUfacturing proce~s, especially in a reputed industry like British American Tobacco (BAT), is eqUIpped with the modem and sophisticated machines and equipment. However, there is still room for opiimiling the levels of the processing parameters. Two dryers slich as integrated labocco manufacturing (lTM) and steam trealing of slem (SIS) are two slich devices. Experiments wert COlHJuctcd by the design of experiment (DOE) approach to oplimi7.c some sclecled parameters with the aim of making greukr numhcr of clgarc([c slicks consuming a definite amounl of tobacco, The fill value (FY), a term commonly expressed as cubic cenlimeter per ten gram (ee!l0gm) of tobacco is adopted as it measure. The FV is, lhcrcrore, considered as the response - a lCrminolugy llscd in DOE to mdicate the large! parameter and the higher the value of FY, lile beller ~h()llld be lhe situation for lhe mdustry. But increasing the fill vulue lllust mcd ~ertaill precomlitl\lIls, one of which n, the quality ratio (QR) Thls ratio is acl\lall y 01)indlcalion of material utililaLion. Both lhe lTM and STS equipment are operated within a range of set eomI1IH)l1>. These comllliolls arc v;lrlcd by the operator depending on hi8 pcr,onal experience, taking into consideration of demand and lhe capacity of macillne" The most frequenlly u~cd conditions of the eqUIpment arc considered as control. The c.'periments de"gned to cany out the investlg<ltion were performed by slightly changing lhe parameters frum thc conlrol set conditions. To lakc into accolilltihe llatlll"alvanatlOn in the responses of the output, several experiments were eOllduclcd at the ",mc set conditions of the paramcters. The avcrage was taken as the estimate of the Lrueoutputs, Qualily !alio wal>\,orilled ill each case. lTM Dryer is uscJ to dry the lamina (tobacco leaf) and e.'perirncnts were eonduetcd 1o lind the most deSlred combination or the levels of infecd !low rale and damper position. In reed !low rate and damper position indicate respeclively (be alllount 01' input tobacco per hour and the mixmg ratio of the hot and the cold (nornal) air. These two factors were varied into three levelR i.e, infeed flo\~ rate of 4(1ilO,4200 amI 4500 kg/hr amI damper positIon to 0, 3 and 6. Both the infeed flow rate and the damper position were found to have' main effects on the fill value. Within the experimental limits of the factors, the maximum fill value was observed for an infeed flow rate of 4500 kg1hr and the damper position of '3', The condition IS de,irable for thc company as it has two-fold advantages - productIvity is increased duc lOhigher infeed flow rate and on the other hand, there is a reduction in tobacco consumption per stick as a result of higher fill value. However, a higher infeed flow rate results in grealer variability in the filling of tobacco. A ,ignificancc test W<lSalso eondueted by analysis of variance, 11was found that there was a signilieant interaetivc effect of the infced flow rate and damper position 011fill vnlue. Except in one marginal case of the nine set conditions, the quality ratio was male t\Jan 82% (the 11linimum limit). Maximum quality ratio was ob,etve(! to ()~cur at the flow ratc of 4200 kg/hI' an(! at the damper position of '3'. StC,llll trcating is perfonl1cd in thc STS dryer to expand the tobacco stem WIth the help of steam, \valer and hent. The parametcrs regulated in this c~se are the cutting moisturc, thc stcam pressure and the sleam flow rate. These three factors were varicd mto two levels anti their influence were dclel'llJined, Thc two levels of the factors were 38% and 40% for the euttillg moi~ture, 4 antl5 bar for stc~m pre,sure and 500 and (,00 kg/hr for steam now rute, All the three factors were found to have llldlVl(lual cffect on the fill value. Small mteraetive effect of the parameters on fill value waS <llwobserved. A steam flow rate ofr;oO kg/hr, steam pressure of S bar and a cutting nioistllle of 40'){,were found to have the inerense(! the fill value. A signi [jcanec test was also cmldllcted by the analysis of variance. It was found that the cutting 1l10i,turc, stenm pr£s~ure lUlU slcam flow rale - all these lhree pmameters had slglllr.cant effcd" on the fill value. T1lCinteraction between the culling lllol,ture and the steam flow rate, and thHt between the steam pressurc and steam now rate have sigtlificant effects on lill value. In all the cases quality ralio was verified amI found to comply with [he set limi1s.