In Ring Spinning, the lapping on rollers either on top or bottom rollers is one of the chronic issue especially in PV fiber dyed Spinning at higher and higher spindle speeds. The huge amount of physical effort is required in removing lapping and joining broken threads. If it is too high, it affects workload of operators also. There are two options now in hand to reduce lapping frequency on the rollers in ring frames. Either use of higher capacity suction motor to increase the suction pressure or reduce number of openings on suction ducts. The use of higher capacity motor consumes more power on continual basis, but reduction of number of opening on suction tube requires nominal one time investment in every 5 to 6 years. Then we started searching for alternative suction system which will have less number of openings on main suction duct i.e Common Tube Suction System.


The study was conducted and covered various aspects of the comparative features of both common tube and existing suction system. The effect on improvement in suction level, reduction in frequency of roller lapping and installed efficiency and little bit cost effectiveness is also seen. This paper highlights details of study and its results.


We installed first common tube suction system on one of our LR6 ring frame for trial and observed for few days to see the changes on suction level, frequency of lapping and efficiency of the ring frames. The machine on which common suction tubes are installed compared with the adjacent machine running with same material, count, and speed, but with earlier suction tubes for suction pressure. The following table shows the comparison of two machines running on 33Ne 65/35 PV blended yarns.


Comparison of Suction Levels of Common and Individual Suction Tube Systems

M/c Position

Suction with Common Tubes

Suction with Individual Tubes

Difference in suction

Increase in suction %

Fan End

23cm

15.63cm

7.37cm

47.15%

Middle

19cm

13.74cm

5.26cm

38.28%

Gear End

19cm

13.49cm

5.51cm

40.84%

Average Suction

20.33cm

14.28cm

6.10cm

42.71%


The improvement in suction is about 40% with common tubes compared with earlier tubes. This improvement in suction is because of reduction in the opening points on the main suction duct across the length of the machine by 1/8th that means instead of 8 suction tubes in one section of 8 spindles each, now we require only one opening on the duct for common suction tubes & rest of 7 opening points are closed in each section.


Hence lesser the opening of duct, higher is the suction with same capacity motor. There is no impact on increase in power consumption also as main suction motor speed is un- affected.

 

Comparison of Frequency of Lapping with Common Suction and Individual Suction System


Date/Machine

M/c with Common Tubes

M/c with individual Tubes

Shifts

6/5/2001

4

53

III

7/5/2011

2

54

I

7/5/2011

6

62

II

7/5/2011

3

40

III

8/5/2011

10

26

I

8/5/2011

6

31

III

Average lapping/machine/shift

4.5

44.16

Reduction in lapping = 88.36%


The above table shows reduction in number of lapping to the extent of 88% due to increase in suction by 40%.The operator is happy and feed back received from all ring frame operators of all three shifts is quite good. The other benefits are lapping tendency at top roller necks & bottom roller is also negligible. The web of broken end which was earlier forming lapping on roller surface instead it sucked by suction system due to poor suction with earlier tubes. Now with common tubes, instead of forming lapping, straight away sucked due to improved suction.


Comparison of Installed Efficiencies with Common Suction and Individual Suction System.

Installed Efficiency with Common Tube Suction (%)

Installed Efficiency with Individual Tube Suction (%)

Increase in Efficiency (%)

87.20%

85.00%

2.20%

88.10%

87.80%

0.30%

88.00%

86.50%

1.50%

86.30%

85.90%

0.40%

86.50%

85.00%

1.50%

Average = 87.22%

Average = 86.04%

Average = 1.18%


The above table shows that the efficiency is increased by 1%. These common tubes also help in improving efficiency of ring frame. It is hardly or nothing to do with breakage rate, but helps in reduction of lapping on the rollers once the end breaks. The repairing of broken end once the lapping is formed is very tedious, laborious and time consuming, but due to lesser lapping with common tubes, operator is joining ends faster and there is improvement in efficiency also. At the same time, workers physical effort is reduced to great extent as they were wasting huge energy in removing lapping and joining the threads earlier.


Comparison of Cost Effectiveness of both suction systems

Parameters

Common Suction Tube

Individual Suction Tube

Number of Suction Tubes

60

480

Cost /Tube

` 500

` 12

Cost /Machine of 480 Spindles

` 30000

` 5760

Life of Tubes

Much more

1 year

 

Even though the initial cost is high, but life is much better and free from lapping on rollers is the another biggest advantage to the spinner. There is improvement in the breakage rate, and due to less lapping, operator can piece broken end faster. Hence cost is not a big issue.


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