L3-4Cotton mixing techniques.pptx happens to

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1. PROCESS AND QUALITY CONTROL IN SPINNING Cotton Fibre Engineering Program

2. Cotton Fibre Engineering Program 4 Stages: Cotton Purchasing strategy Cotton testing Bale management Cotton fibre selection

3. Cotton Purchasing Strategy It should be based on an evaluation of the technological values of cotton. It means cotton fibres should primarily meet technological requirements. Other factors such as yarn count, twist and end-product specifications also determine what kind of cotton to use. Purchasing strategies should also optimize cotton blend components under inventory and quality constraints. Scientific procedures that use parametrical linear programming can be used for this task.

4. Cotton Testing Testing fibre characteristics will produce an accurate evaluation of the variability of the bale population. Generated data can be used for bale management and for implementing suitable fibre selection techniques.

5. Bale management Storage and retrieval of cotton bales. Two methods: By group or category By bale identification number Selection of method depends on the warehouse structure and the bale population size.

6. Cotton fibre Selection Implementation of suitable bale picking schemes: Provides the mill with uniform fibre characteristics on a mix-to-mix basis without violating inventory constraints. Fibre/yarn modelling: Controls the desired output characteristics.

7. Bale Management Systems

8. Objectives To get uniform yarn quality. To minimize shade variation of the finished fabric. To reduce or control fabric barre.

9. Bale Selection Systems BIAS (Bale Inventory Analysis System) EFS (Engineered Fibre Selection) Linear Programming Technique

10. Bale Inventory Analysis System (BIAS) Developed by M/S Zellweger Uster . Mix is formed in a way that bales taken from stock are having minimum variation in quality parameters from bale to bale and from day to day.

11. (BIAS) – Process Steps 100% testing of bales : All the bales received are tested in HVI. Tested results are exported to BIAS. Categorization of bales : All bales tested are numbered and divided into categories according to SCI and Mic. Mix formation : For example, mix for 20 bales: For SCI – Make 6 categories: <80, 80-90, 90-100, 100- 110, 110-120, >120 For Mic – Make 6 categories: <3.0, 3.0-3.3, 3.4-3.6, 3.7-3.9, 4.0-4.2, >4.2 So, all bales tested are stocked into 36 categories.

12. (BIAS) – Process Steps Print out of mix plan : Enter bale number of each bale issued. Average of all quality parameters will be printed. BIAS helps to reduce variation in quality parameters on day-to-day basis for particular mixing. Fibre information from HVI and yarn information from Tenso Rapid – to improve performance and profitability of the spinning process.

13. Lecture 4

14. Engineered Fibre Selection (EFS) Developed by Cotton Incorporated. Follows below steps: Determination of cotton specifications. Opening line configuration and availability. In-house inventory management. Mix profiles. Bale selection. Mix evaluation and performance verification.

15. Determination of Cotton Specifications Cotton specifications are a function of end-product performance expectations and the machinery complement. Specifications of the end-product should be determined and allocated into needed cotton attributes and intermediate product and machinery performance requirements. Various quality control reports and charts can be assembled. These can be used to assist the manager in determining which process/product variables are correlated to cotton HVI measured properties.

16. Opening line configuration and availability Blending efficiency. Cleaning efficiency. Higher opening line blending efficiency enables mill to process a wider range of critical fibre properties. This system assists mill management to determine the best CV% for various HVI-measured properties through control charts. This in turn facilitate correlating these trends to mill quality and efficiency.

17. In-house inventory management Mill-owned central warehouses. Mill warehouses at each plant. Just-in-time shipments from merchant warehouses.

18. In-house inventory management The software program include EDI translation program to pass the documents between cotton merchants and mills. It is used for verification of HVI properties of shipments before they are sent from the vendor. If there are any great differences between the current inventory HVI property and coming shipments, the managers can prepare in advance for changes in mixing selection.

19. Mix Profiles Cotton fibre mixing model gives the impact of software program solution on the cotton fibre mixing quality and cost. For the programming, visual basic language is used and for storing the database, SQL server is used.

20. Mix Profiles As software program give the mixing of satisfying mixing quality parameters and at lowest cost, you can save maximum amount of mixing cost if you are buying cotton fibre required for the mixing. Typical strategy of fibre selection: Establishing the mix profile. Population profile analysis. Bale picking system. Mix evaluation and verification.

21. Mix Profiles

22. Mix Profiles

23. Bale Selection A Bale selection program should involve these basic steps: Examine the population distributions of fibre properties of cotton bales. Implement reliable bale picking schemes based on the distributions of fibre properties of the blae population and bale management methodology. Control average output characteristics by developing reliable fibre -yarn relationships.

24. By-group Bale Selection

25. By-group & category Bale Selection

26. Bale Selection Methods Three Methods: Standard Distribution. Normal Distribution. Moving Point Distribution.

27. Standard Distribution Proportional Distribution. Proportional Weight Category approach (PWC)

28. Normal Distribution

29. Moving Point Distribution

30. Mix & Process Performance Evaluation Bale Management System program provides the average and distribution CV% of each mix plotted as control charts. By closely monitoring these charts and reports, cotton buyers can refine their purchasing practices to lower costs and improved mill operations and also lowers the inventory levels. In many cases, labour cost can also be reduced.

31. Engineered Fibre Selection (EFS)

32. Engineered Fibre Selection (EFS) https://cottonworks.com/fiber/fiber-science/engineered-fiber-selection-software

33. Linear Programming Technique (LPT)

34. Linear Programming Technique (LPT) Uses: Determine optimum blend for mixing. Determine optimum product mix in production planning. Reduction of inventory of dyes and chemicals. Determine optimum raw material purchases. Identify bottleneck areas in production. Minimize total cost and maximize quality. Formulation of LP model in cotton mixing.

35. Benefits U se of HVI data eliminates cotton bale sample cutting and classing at the mill. Reduction of inventory carried by the mill. Just-in-time delivery of cotton improves quality. Yarn quality is improved including yarn count variation, strength and Uster statistics. Fewer fabric defects. Elimination of cotton mix selection as a cause of barre.

36. Benefits Reduction of comber noils without loss of quality. Improved efficiencies lead to lower labour costs. Improved warehouse management. Short fibre control improved. Adjustment of mix averages and distribution CV% based on values of incoming but not yet received cotton. Better contract management, reporting and improved communications/ understanding between textile mills and their cotton suppliers.