Lecture 19

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					Lecture 20
Sewing Thread
 Yarn:
  – Collection of fibers used to weave or
    knit textile fabrics

 Thread:
  – Thread is used to sew different things

       Yarn                  Thread
• Used for the     •Used for sewing
manufacturing of   purpose
• Made by fibers   •   Made by yarns
• Weaker           •   Stronger
• Less uniform     •   More uniform
• Big package      •   Small package
• Single ply       •   More than one plies
                Question ?
    Sewing thread is selected before

 Needle     is selected before sewing
         Sewing Thread…
 It is made by reverse twisting
 single yarns or plied yarns.
 Reverse twist is given for balancing

 Yarn plies will be separated when
 passing through needle and tension
 disks if not balanced properly
              Sewing thread…
   Twist:
    – The number of turns per inch or centimeter

    – A thread with too little twist may fray or break
    – A thread with too much twist can cause
      snarling, looping or knotting

    So balance is the key and a good sewing
    thread has it
            Twist direction…
   There are two types of threads
    – S twist
    – Z twist

   Which is better for sewing and why?
             Thread Types…
   Basically there are two types
    – Natural
       Animal
            Silk thread is used for silk and wool
       Plant
            Cotton thread is used for Linen, cotton
       and rayon

    – Synthetic
           Nylon and Polyester threads are used for
          Synthetics and stretch knits
           Thread Finishing…
Thread is finished to enhance its suitability
  for different sewing purposes
 Soft:
    – Just Dyed and lubricated
   Mercerized
    – Thread is mercerized. Thread gets some luster
      and strength. Also good affinity for dying.
   Glazed
    – Thread is treated with starches and then
     polished for a high luster. It gets hard,
     providing good abrasion resistance and ply
          Thread Finishing…
   Bonded
    – Synthetic threads are treated with
      resins. Tough smooth coating results in
      a good abrasion resistance and ply
   Gassed
    – Passing thread from a flame at high
     speed. It reduces the hairiness on
        Thread Properties…
   Elongation
   Uniformity
   Ply security
   Lubricity
   Strength
   Breaking strength
   Loop strength
         Thread breakage…
   Wrong thread
   Incorrect or damaged needle
   Machine adjustment is improper
   Operator handling
   Wrong threading
   Worn machine parts
   Weaker sewing thread
   Less elongation
         Thread breakage…
   Color fastness
   Wash fastness
   Crock fastness
   Light fastness
   Cold water migration
   Sublimation

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