Studies on travellers: Part-I
Prof. S.S. Lavate, Sandip Rathod, Ashish Hulle, and Sonal Ukey Department of Textiles D.K.T.E. Society's Textile and Engineering Institute, “Rajwada”, Ichalkaranji- 416 115 Maharashtra, India
There are various parameters during yarn production, which can influence the quality and production of yarn. One of them is the traveller characteristics of a ring spinning machine. The traveller imparts twist to the yarn and enables winding of the yarn on the cop. Traveller has a great impact on yarn quality parameters. In this research work an attempt has been made to study the effect of different traveller types on the yarn quality. Five different types of travellers were used to spin 34S and 38S Ne cotton carded yarn on ring frame. Yarn properties such as tenacity, elongation, lea strength, IPI i.e. imperfection index and hairiness index, end breakage rate per 100 spindle-hr. as well as winding cuts were determined. An implication of this study has been reported in this paper.
Keywords: Ring yarn, traveller finish, traveller weight, uniformity, end breaks, winding cuts.
RING SPINNING stands alone as the primary choice for spinning high quality yarn from almost any type of textile staple fibre. Ring frame technology is simple and old, but the quality and production requirements of the present scenario puts a lot of pressure on the technologist to bring advancement in the machine to improve the production, efficiency and quality, so that a good quality yarn can be produced at a lower manufacturing cost . Rings and travellers are the dominant elements in the ring spinning process and play an important role in the twisting process. The correct selection of rings and travellers influence the productivity as well as the quality of the process. Traveller pronounced effect on yarn strength, hairiness and end breakage rate. It is very important for the technologist to understand this and act on them to optimise the yarn production and quality . The traveller speed in a ring frame is the main limitation in achieving higher spindle speed because of the frictional resistance of traveller over the ring flange. For minimizing friction so as to attain higher traveller speed, different traveller designs, metallurgy, many surface finishes have been suggested by the ring and traveller manufactures.
The present study was, therefore aimed to investigate the influence of travellers of different makes, profiles and surface finishes on yarn quality and productivity of a ring spinning frame. This study will help in choosing correct traveller for effective ring spinning as we as getting quality product.
Materials and methods
In this study, five different types of travellers having different finishes were used and labeled them as A, B, C, D, and E. The traveller company has developed a new process in which certain RS and CS finishing components were diffused onto the traveller's surface and are fixed in their place. Traveller A is coated with sapphire, B & D with silver, and C & E with nickel coated travellers. The traveller finish reduces temperature rise and increases the wear resistance.
From initial trials in spinning mills, 5/O traveller was found to be suitable to spin 34S Ne and 7/O was found to be suitable to spin 38S Ne 100% cotton carded yarn on ring fame. Each type of traveller was run for 4 days. All travelers are 'C' shaped and each traveller is having U1 UM UDR profile. Traveller type and their respective weight are exhibited in table 1. Yarns with different counts having TPM of 1000 were manufactured on ring fame using 0.9S Ne roving hank. Spindle speed was set to 18000 rpm. Single ring having diameter of 38 mm with only one flange (3.2 mm in width) was used. The entire study was carried out for four months. The sufficient samples were collected and various yarn properties were tested. On daily basis full doff end breakage study was also conducted. Table I exhibits the details regarding different traveller type and their weight.
Table No. 2
Table No. 3
Results and discussion
The results of this effect of travellers on various yarn qualities are shown in Tables 2 and 3. These results are tabulated and graphs are plotted using which conclusions can be made.
In this study the comparison of performance of traveller 'A' which is well established in the market with the performance of other travellers in terms of yarn properties and end breakage rate was done.
Average Count and Count CV%:
Fig. 1 (a) and 1 (b) shows the effect of traveller type and number of days on count variation of 34S and 38S Ne yarn respectively. There is no significant effect of traveller type with the days on count CV% of both yarns.
Fig. 2 (a) and 2 (b) exhibits the effect of traveller type and number of days on tenacity of 34S and 38S Ne yarn respectively.
Fig. 1: Effect of traveller type and no. of days on count CV%
Fig. 2: Effect of traveller type and no. of days on tenacity
It can be clearly observed from above fig. 2 (a) and fig. 2 (b) that the breaking tenacity property of both yarns goes on decreasing with number of days. From the ANOVA results it was found that; there is a significant difference between the tenacity of yarn manufactured from traveller A and other travellers for 38S yarn but same is not true in case of 34S Ne yarn. Number of days of usage of traveller does have a significant effect on the yarn tenacity. However, yarn tenacity increases with the increase in traveller mass. This can be attributed to the fact that, an increase in traveller mass results in higher spinning tension. Hence, the fibers get straightened out as they emerge out from the front roller nip . Therefore, 34S and 38S Ne for both counts “B” type traveller shows better tensile strength compared to all other types of traveller with respect to an increment in number of days. Traveller A is giving higher yarn strength than other travellers.
Breaking Elongation (%)
Fig. 3 (a) and 3 (b) displays the effect of traveller type and number of days on breaking elongation of 34S and 38S Ne yarn respectively. It is observed that the breaking elongation of yarn is slightly increases with decrease in traveller weight.
There is a significant difference in breaking elongation of yarn manufactured with traveller A and other travellers, but overall trend increases as with days. However, it also exhibits the overall behaviour of reduction in elongation as the light weight travellers impart high number of turns per unit length; hence elongation is also higher in light weight yarn. Hence, 34S Ne “C” type traveller, 38S Ne “E” type traveller gives better breaking elongation percentage compared to all other types of travelers. Traveller A is giving the yarn with lower elongation than most of the travellers.
Fig. 3: Effect of traveller type and no. of days on elongation (%)
Fig. 4: Effect of traveller type and no. of days on lea strength CV%
Lea Strength and Lea Strength CV%
Effect of traveller type and number of days on lea strength variation of 34S and 38S Ne yarn is as shown in fig. 4 (a) and 4 (b) respectively.
As there is an increment in the days for usage of traveller there is an increase in Lea strength C.V.%. There is a significant difference between the lea strength variation of yarn manufactured with traveller A and other travellers (B, C, D, & E). For both counts in most of the cases the yarn manufactured with traveller A is having higher lea strength variation. In all trend of lea strength variation keeps increasing as with days. These above results infer that due to day wise traveller weight decrease there is an increase in lea strength CV%, this is due to the increase in balloon size more warp around thread guide and reduce in the twist flow. Also the product of bundle strength (lea strength) & count of yarns i.e. CSP continuously decreases with respect to increase in tension in yarn. The results correlates with the finding of Usta I. et al., stated that as the traveller weight is decreased the yarn lea strength CV% will increase. Hence, 34S and 38S Ne for both counts “B” type traveller performs better in strength CV% than all other types of traveller.
Yarn Uniformity (%)
Effect of traveller type and number of days on U% of 34 S and 38S Ne yarn is as shown in fig. 5 (a) and 5 (b) respectively. There is a significant effect of traveller type on yarn uniformity. For all types of travellers, it was observed that with increase in number of day's U% increases. With the number of days, there is a reduction in weight of traveller. It may result in reduction of traveller point of contact with the ring, thereby increasing the traveller burning rate . Due to different finishes, travellers have different wear characteristics. With the increase in traveller mass, the twist flow increases in the spinning zone that may lead to better binding of edge fibre in the yarn body and they do not eject out from the spinning triangle, resulting in better yarn evenness .
Fig. 5: Effect of traveller type and no. of days on yarn uniformity (%)
The overall traveller weight loss is found to be higher with traveller A as compare to that of traveller B, C, D, and E. U% rate for traveller B, C, D, and E is lower and better than traveller A. Therefore, 34S Ne “E” type traveller, 38S Ne “D” type traveller performs better U% when compared to that of all other types of travellers.
Fig. 6 (a) and 6 (b) indicates the effect of traveller type and number of days on total imperfections of 34S and 38S Ne yarn respectively. With the number of days there is an increase in total imperfections in all cases. It is observed that, for 34S Ne; traveller A is giving higher imperfection value as compared to that of other travellers. IPI value for traveller B, D, and E lower is showing independent in yarn properties 1st day to last day.
Fig. 6: Effect of traveller type and no. of days on total imperfection
There is a significant difference between traveller A and traveller B, C, D, and E for all types. It can be observed from the above graph that, the yarn imperfection level day wise increases with the decrease in traveller mass. However, it shows that the decreasing in yarn tension is very much dependent on centrifugal force applied on ring traveller during spinning of fibers into the yarn. They exhibit increase in imperfection (thin places, thick places & neps) . IPI for traveller B, C, D, and E is lower and better than traveller A. However, 34S Ne “E” type traveller, 38S Ne “D” type traveller perform better IPI when compared to all other types of traveller and no. of days.
Uster Hairiness Index
Fig. 7 (a) and 7 (b) shows the effect of traveller type and number of days on hairiness index of 34S and 38S Ne yarn respectively.
It can be inferred from below figure 7 that number of processing days have negative effect hairiness value. It was found that there is a significant difference in the hairiness index between yarn manufactured with traveller A and traveller B, C, D, and E. Traveller weight has an influence on the yarn hairiness especially lighter weight travellers producing more hairiness as comparable to the heavier weight travellers. It is because light weight travellers form large balloon size which comes in frictional contact with spindle separators. It shows that the yarn hairiness generally increased as the traveller weight was decreased, regardless of type or coating. It is generally accepted that yarn hairiness increased as the spindle speed is increased and also the yarn tension decreases as the weight of traveller decreases
Fig. 7: Effect of traveller type and no. of days on hairiness index
Traveller A is having higher hairiness index than that of other travellers. However, 34S Ne “E” type traveller, 38S Ne “D” type traveller produces yarn with less hairiness value compared all other types of traveller.
End Breaks/100 Spindles Hour
Fig. 8 (a) and 8 (b) shows the influence of traveller type and number of days on end breakage rate. It was found that there was a significant effect of traveller type and number of days on end breakage rate. It is observed that breaks goes on increasing gradually with number of days.
It is concluded that with the decrease of traveller mass over a period the value of yarn end breakage increases. The evidence comes from Jhatial A. K. et. al., that an excessive lighter weight traveller would cause a rise in the end-breakage. End breakage rate for B, C, D, and E traveller is lower and better than A traveller. However, 34S and 38S Ne for both counts “B” type traveller gives lower end-breakage rates.
Fig. 8: Effect of traveller type and no. of days on end breaks/100 spindles hrs. (%)
Fig. 9: Effect of traveller type and no. of days on winding cuts
It can be clearly observed from fig. 9 (a) and fig. 9 (b) that the winding cuts levels of both yarns goes on increasing with number of days.
There is a significant difference between the winding cuts/100 Km variation of yarn manufactured with traveller A and other travellers (B, C, D, and E). These above results infer that day to day deterioration in the yarn qualities with number of days, there is reduction in weight of traveller there is an increase in winding cuts. Hence, 34S Ne “E” type traveller, 38S Ne “D” type traveller produces yarn with less winding cuts value compared all other types of traveller.
Type of finish on traveller has significant effect of its performance in terms of yarn properties and breakage rates on ring frame. Decrease in traveller weight due to prolonged traveller usage cause is the main factor which influences the yarn properties. Traveller number 5/0 for “B” type traveller is suitable for 34S Ne and traveller number 7/0 for “B” type traveller is suitable for 38S Ne carded yarn. In many aspects the performance of travelers with specific finish (B, C, D, and E) was found to be better than that of already well established traveller (A) in market.
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