1.1 Introduction

End break rate tests are carried out in almost every spinning mills. The evaluation of these tests are done according to 1000 spindle hours and 25,000 spindle hours. As end break rate Per 1000 spindle hours (EBTSPHR) increases efficiency decreases and the problem in subsequent stages of processes warping, sizing and weaving also increases. End break is closely related to fibre quality and its variation at the ring frame no matter is the raw material having high quality matters . End break rate also closely related to mechanical conditions of the machine. Nowadays, end break rate increases with high machine speeds and yarn quality deteriorates with increasing machine speed. Therefore to reduce end break rate should start from raw material selection and control of that material at all stages of processing. Higher end break rate also causes quality loss of grey state fabric and increases the cost of weaving have to be faced and this makes EBTSPHR more important than it is actually expected. Today many systems are available to determine the number of end breaks Per spindle . However, this systems costs much and only the defective spindles could be identified . It is not the number but the reasons of end break rate is important . These systems also incapable of giving sufficient information about the causes of end break rate such raw material , spinning process etc. Secondly these on-line systems could only be used effectively with Knowledge based problem analyses and problem solving systems and PC-programs .

This information or knowledge age that we are moving into have made an enormous effect upon the existing systems . It is not collecting and filing the data but to make us of it with knowledge based become more important . As a natural result of that CIM systems should be set up in mills but it must be evaluated by knowledge based PC-programs other wise it won't do any good to mill performance level . Therefore, one could easily say that important steps are

GET DATA
MAKE USE DATA SOLVE PROBLEMS

Getting data could be carried out off line or on-line but the main attention should be paid upon the make use of data. Secondly, even with the on-line systems off-line tests should be carried out to find the actual causes of end break rates.

1.2 Effects of EBTSPHR

An increase in end break rate causes great losses in mills such as

Therefore ,by reducing number of end break rate eliminates many problems in spinning . The causes of end break differ from mill to mill and type of raw material used even fibre to fibre friction could be the main cause. These problems could only be analyzed and solved through Knowledge Based Quality Management systems and PC-programs .

1.3 PC-program application

ITC&M investigates the end break rate in 3 sections:

1) Normal test 2 hour
2) Total test from empty the full bobbin
3) Complete stroke diagram of single cop.

And these test results are resolved in problem analyses / problem solving techniques.

Stoppages and their causes analyses are examined via Knowledge Based Problem Analyses/Problem solving techniques and SPC techniques are used as well. ITC&M have carried out many quality improvement tests to increase production gram Per spindle hour. There exists a close mathematical relation between fibre properties coming out front rollers and yarn quality and end break rate. In other words fibre properties at ring frame is the main quality index of the spinning mill and it is a measure of machine maintenance ,quality ,process control and management conducted in the mill.

Raw material having so appropriate properties can turn into card waste in spinning hence fibre properties at different stages of processes are as important as fibre mix selection . Faulty mixing of blends will also deteriorate the fibre properties at different stage of processing . To overcome all these problems at actual mill running conditions we have developed fibre mix selection, bale management, process sum control PC-programs to solve this existing problems. Technical data/machine settings at blow room ,carding and combing preparation ,draft organization have great influence on the amount of total waste and yarn quality . It is very clear that all our systems have been carefully designed to solve mill problems and resulted from the actual mill work carried out on many spinning mills. Presley at 1/8 in readings ,comb sorter and micronaire readings all the other fibre parameters could be derived with 95% confidence range . Therefore,by make use of simple and non expensive instruments more real results could be obtained. Presley or stelometre are the only instruments which measure the fibre strength directly and correctly since fibre is weighed .By measuring fibre strength at 1/8 in and mean fibre length by number and with hand staple length plus micronaire readings neps , color, maturity, non-lint contents and all the other cotton fibre properties could be computed at 95 % correlation coefficient .

Mean fibre length and coefficient variation of fibre length distribution could also be computed from spectrograph . We have developed very extensive spectrograph curves such as power spectrums, frequency and time domain with different types of windowing functions which eliminates the problems that used in classical systems such as 54 channels such as not being able to detect the exact wave length and analyze harmonic faults .

The most important reason mmf spun yarn break less is low CV% of fibre length distribution and cohesive frictional forces fibre to fibre . Mean fibre length and CV% of fibre length together with CB(L) (variation of yarn in different cut lengths) determine the yarn strength and thin thick places . An increase in CBL results in with roughness in fabric appearance and this is generally caused by faulty setting of drafting systems such as roller setting ,pressures ,top roller shore hardness ,top roller elastic recovery % etc . Our PC-program draft zone setting is a very effective and scientific tool to determine all these above parameters as well as optimum ratch setting distances according to given fibre length values such as mean fibre length and staple length . Process sum PC-program together with CBL-strength analyses PC-program detects faulty running process in spinning line. It could be seen that simple stoppages and their causes tests could give very detailed information on the performance of complete mill.

Following points are determined from this PC-program:

  1. Stoppages and their causes and pareto analyses
  2. End breaks Per 1000 spindle hour by each machine, fixer, spinner ,lot
  3. Spinner cycle time
  4. Gram spindle hour
  5. Actual efficiency
  6. Production efficiency
  7. Spinner performance index
  8. Pneumofil % waste
  9. Doffing times and frequency
  10. Expected Production Per shift and day

Therefore ,it becomes possible :

RING PERFORMANCE TEST compares spinners' performances as well as providing information such as which machines have high end break rate and waste % and late interference of the spinners.

1.4 Summary and conclusions

ITRU GROUP LTD has explained that by this PC-program how important one simple test could become and how valuable information could be gathered to solve many sided problems.

We have also established similar quality/process control tests that are carried out many spinning mills together with KNOWLEDGE BASED QUALITY MANAGEMENT SYSTEMS and PC-programs. It is interesting to note that continuos improvement in quality levels have been achieved in ring and rotor systems spinning.

1.5- Ring Spinning Performance as a Part of R&D Project

We carry out this PC-program as a part of R&D project . If you are interested in this project please get in touch with us.

for further details please contact with us

1.6  Pc-program Outputs  How to use  the  PC-program  

a)Carry out Spinning  Performance  Test   as instructed at least two hours for each ring frame

b)Analyses

Find the  highest  end break rate and  ring  waste of given lot

Find the   % of  ring  waste  to optimize ring spindle speed

Find the causes  of end  breaks  of given lot  

Investigate and find the causes of stoppages and solve theproblem

Find the    potential  for  training  spinners  to increase  their performance

c) Optimization  of  ring spindle  speed

Carry  out  ITRU  test plans  of  increasing  ring spindle  speed  and optimize  and lower end break rate and improve yarn  quality as outlined in  R&D project. If you make use of this Pc-Program effectively you will also definitely achieve an increase in spindle speed rpm ,less waste and improved yarn quality and fabric properties.


 


 

Samples

Technical Data
Tecnical Analyses
Shift Efficiency Analyses indexed by Machine Number
Parete Chart of Causes of End Breaks
Parete Chart of Filtered Data
Pie Chart of End Breaks
File Manager
Averages of Spinner Cycles Time Chart
Single Values Chart of Filtered Data
Averages of Act EFF% indexed by Ne/Lot/Tpi/Summary


ITRU GROUP LTD -International Textile Research Unit
Serving to textile industry ,science and technology since 1992

© 1992-2015 by Itru Group Ltd-International Textile Research Unit