Process sequence of weaving


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Process sequence of weaving

  1. 1. Process sequence of weaving
  2. 2. Flow chart of weaving: Yarn from spinning department Cone winding warping sizing Tying-in Pinning Drawing-in Reaching-in Denting Weaving loom Grey inspection Folding Pirn winding
  3. 3. Yarn from spinning department
  4. 4. Doubling & Twisting
  5. 5. Cone Winding  Winding is a process of transferring yarns from ring bobbins, hanks, cones etc into a convenient form of packages containing considerably long length of yarn.  The main purpose of winding or packaging is to form a single yarn package suitable for the next operation.
  6. 6. Creeling
  7. 7. Creel
  8. 8. Creeling
  9. 9. Warping Warping is aimed at preparing the weaver’s beam to be set up on the weaving machine. Warping carries out following operations :  Creation, out of a limited number of warp threads (creel load), of a warp composed of any number of threads with the desired length.  Arrangement of above-mentioned threads according to the desired sequence. The industrial warping process can be carried out according to two different technologies:  Sectional warping (conical drum or indirect warping).  Beam warping or direct warping (preparatory beam warping).
  10. 10. Sectional warping • Sectional warping is used for short runs, especially for fancy patterned fabrics.
  11. 11. Sectional warping • In this case, sections of the warp which may contain up to 1,000 ends are first wound onto a drum tapered with a given cone angle. •So cross wound sections are combined on the drum, and thus each layer of warp contains the same number of ends on the drum.
  12. 12. Sectional warping Then the warp threads altogether are transferred onto a weaver’s beam by unwinding the drum.
  13. 13. Direct/ High speed/ Beam warping  Beam warping is used for long runs of grey fabrics.  As an intermediate stage warper’s beams which may contain up to 1,000 ends are produced. • Then the threads of 6-12 warper’s beam are combined at the slashing (sizing) stage and wound onto a weaver’s beam (loom beam).
  14. 14. Direct warping
  15. 15. Sizing  Sizing is the application of adhesive coating in the warp threads before weaving.  The warp yarns can withstand the complex stresses to which they are subjected in the weaving machine.
  16. 16. Sizing  The size is usually a starch paste containing softening and other ingredients. • Starch sizes are usually not satisfactory for synthetic fiber threads and have to be replaced by special sizes (often containing synthetic polymers) which will adhere better to the threads.
  17. 17. Loom preparation
  18. 18. Before the weaver’s beam is mounted on the loom, each end is threaded through a heald eye and the reed; it also supports a drop wire.  To pass the warp threads through the hole of the drop wire is known as pinning.  If a single warp breaks drop wire will drop. As a result Machine will stop instantly to avoid end missing.
  19. 19. Pinning and drawing
  20. 20. Drafting  Drafting is known as the selection of heald frames or harnesses for individual warp threads according to the design.  Drawing in: To pull the warp threads through the heald eye of the heald wire.
  21. 21. Healds and frame
  22. 22. Threading of heddles
  23. 23. Denting Drawing threads through dent with hook  What is Reed? The reed is a comb-like structure consisting of regularly spaced wires. The word dent is commonly used to describe the space between two reed wires.  Denting: Denting means drawing the warp thread through the dent as required by reed plan and this determines more accurately the width of the fabric and the ends per cm.
  24. 24. Tying-in • Tying-in is used when a fabric is being mass produced. • The tail end of the warp from the exhausted weaver’s beam is tied to the beginning of the new warp. • Therefore, if every end on the new beam is tied to its corresponding end on the old beam, the drawing-in process can be omitted. • Following the tying-in process, all knots are pulled through the drop wires, heddles and the reed. The loom is now ready for operation.
  25. 25. Weaving
  26. 26. Fabric inspection
  27. 27. Folding
  28. 28. Baling
  29. 29. Delivery
  30. 30. Reference books of weaving  Weaving By M.K Talukdar  Weaving conversion of yarn to fabric. By     Lord & Mahmood. Hand book of cotton weaving. By Mir Publisher Weaving mechanism. By Banerjee Principle of Weaving. By Robinson Weaving calculation by R Sen Gupta
  31. 31. Basic motions and essential parts of a loom
  32. 32. Basic motions and essential parts of a loom  The warp unwound from the weaver’s beam passes round the back rest (back bearer) and comes to the heald frames (harnesses) , which are responsible for separating the warp sheet for the purpose of shed formation.  A drop wire signals the loom to stop immediately after a warp end breaks off.  It then passes through the reed (swinging frame in front of the heddles), which holds the threads at uniform spacing and is also responsible for beating-up the last inserted pick.  The cloth then passes over the front rest (breast beam), round the take-up roller, and is wound onto the cloth roller (cloth beam or merchandise beam).  In conclusion, the warp from the beam is fed to the weaving zone where it is converted into fabric and this fabric is then taken - up on a cloth roll.
  33. 33. Major reference points on a weaving machine  The front of the machine, where the fabric beam is      mounted is also called “weaver’s side. The back of the machine, where the warp beam is placed is called “warp side ". Facing the machine from front, the right of the observer indicates the right side of the weaving machine. This is the side where the pick is received (receiving side). The left side, where the pick is inserted from, is called the picking side. The warp yarns are numbered starting from the left side of the weaving machine. The harness frame numbering starts from the front side of the loom.
  34. 34. Essential Motions of a weaving loom Primary motions of weaving: In order to interlace warp and weft threads to produce a fabric on any type of loom, three operations are necessary: 1. Shedding 2. Picking or filling or weft insertion 3. Beating up Secondary motions of weaving: 4. Warp let-off 5. Take-up
  35. 35. Tertiary motions  Warp protector motion  Weft Change motion  Warp stop motion
  36. 36. Primary motions of weaving 1. Shedding: separating the warp threads into two layers to form a tunnel known as the shedding. Shed/ Tunnel Sley Race
  37. 37. Picking: passing the weft thread through the shed. The filling yarn emerges through a hole in the shuttle as it moves across the loom. A single crossing of the shuttle from one side of the loom to the other is known as a pick.
  38. 38. Shuttle with quill or pirn  The filling yarn is inserted through the shed by a small carrier device called a shuttle. The shuttle is normally pointed at each end to allow passage through the shed. In a traditional shuttle loom, the filling yarn is wound onto a quill or pirn
  39. 39. Beating – up/Battening Pushing the newly inserted length of weft, known as the pick, into the already woven fabric at a point known as the fell. Battening: The pressing of filling yarn by the reed against the portion of the fabric that has already been formed. Conventional shuttle looms can operate at speeds of about 150 to 160 picks per minute
  40. 40. Two additional operations are essential if weaving is to be continuous: 4. Warp control (or let - off): this motion delivers warp to the weaving area at the required rate and at a suitable constant tension by unwinding it from a weaver’s beam.
  41. 41. 5. Cloth control (or take - up): this motion withdraws fabric from the weaving area at the constant rate that will give the required pick spacing and then winds it onto a roller.
  42. 42. Weft insertion mechanism  This motion follows the shedding motion.  On conventional looms the filling yarn is inserted by means of a shuttle on which a pirn is mounted.  As the shuttle travels a length of weft yarn is laid down along the path of the shuttle.
  43. 43. Cone under picking mechanism
  44. 44. Tappet shedding mechanism
  45. 45. Jacquard weaving machine
  46. 46. Warp let-off mechanism
  47. 47. Drop wire & Reed
  48. 48. Twin loom beams
  49. 49. Take-up Motion
  50. 50. Classification of loom