Techno-Economic Feasibility of Running - In of Rings in PV Fiber Dyed Spinning

The ring and traveler decides the type of spinning technology and make the spinning successful of quality yarns. These parts are very crucial and important as faras yarn quality is concerned especially for the producers of premium quality yarns and fabrics. These are changeable depending upon the kind of fibers. The ring life depends on fibers spun, speeds, but these parameters are some times beyond control and not compromising by spinners. The one of the major factors affecting the life of rings is their quality and procedure of running-in and its techno-economic feasibility as far as investment is concerned. This paper highlights in detail why imported rings are affordable to spinners even though they are costly.

The advantages of imported rings not requiring formal running-in are : 1.No reduction in production speed, in spite of this, you may do running-in of the rings even at higher speed than regularly running speeds 2.No frequent traveler changes are required. Hence no extra stoppage of machines for changing travelers 3. Due to no additional traveler changes, over time is not required at all 4.You need not require additional quantity of travelers for running-in process. Hence saving in consumption of travelers 5. No burden of extra works like traveler change/over time/no confusion in managing traveler changes during running-in process.

Saving in Traveler Consumption During Running in of Imported Rings

The above table shows the consumption of traveler during running-in and total saving is ` 58060.8 for running-in of 6720 rings resulting into ` 8.64 per ring. This means `8.64 per ring is recovered from capital invested in rings at the beginning itself during running-in period. Some times, for reduction of traveler consumption cost during running-in, spinners forcefully use low grade low cost travelers for running-in and later on, start facing working problem throughout the life of rings. The use of regular travelers is advisable during running-in process even though there is little increase in traveler cost initially, but later on you will benefit in terms of working.

Saving in Production During Running in of Imported Rings

The above table shows the saving of production on account of running-in with imported rings which do not require running-in. The running-in can be done with only 4 changes (normal) without reduction of speed of ring frames. In spite , we can do running-in at maximum speed of spindle set in the steps in the program i.e above the regular speed by 1000rpm.In our running-in process, there is a gain of 3000rpm during running-in which we were reducing during running-in with local rings earlier. If the market price of yarn is ` 140 /Kg and cost of yarn produced during running-in will be ` 1364160 for 6720 rings. The recovery of investment in the rings at the beginning itself will be ` 203 per ring. This is an opportunity cost which might be incurred if we buy yarn from out side for loss of 9744Kg on account of running-in with local rings instead of going for imported rings.

Saving in Production during Running in due to frequent traveler change

The traveler change not only increases cost of traveler consumption, but also reduces production as machine is stopped for every traveler change for cleaning ring surface and change of traveler. The time for each change is about 30 minutes. If we calculate

production loss because of increased additional stoppage of machine for traveler changes, will be come around 1298.88Kgs if we go for local rings, but with imported rings, this is net saving of production. With the same market rate of yarn, this will be around ` 181843.2 for 6720 rings. The recovery due to this saving will be ` 27 per ring, if we could have been gone for local rings.

Saving in Over Time during Running-in of Imported Rings

The above table shows over time of workmen for cleaning rings and changing travelers during running-in of local rings and absolutely, there will not be any over time for this work during running-in of imported rings which do not require running-in also. The cost of over time is direct saving, if we go for imported one. This will be around ` 6.75 per ring saving on account of imported rings compared to local rings. For successful running-in of rings, it is necessary to ensure the following things before start of running-in process of rings, if you are going for local rings.

1.The one or two set of ring rail must be kept in spare depending on the spindle age of mill, to reduce down time of machine on account of running-in 2.If you are replacing rings with your regular maintenance team, then you have to compromise on some maintenance schedules of other machines, other wise either resource or do it on over time 3.The count for running-in must be closer to average count of the spinning 4.The required quantity of travelers must be procured for running-in well in advance 5.If there is strict control on over time, then you have to make aware concerned person for rise of over tine on account of running-in 6.There should not be single idle spindle during running-in. The idle spindles left behind without running-in and start giving trouble at later stage through out the life of rings.

The running in is treating rings while putting on the machine and good care of rings at the beginning will always pays you on later stage. Hence do take care of running-in.

The author is a Senior Manager & HOD Spinning PV, Raymond Ltd, Chhindwara (M.P).