Ring doubling and two for one twister, quality required by yarn to get best doubled yarn. Formula for double yarn count.

In this page

  1. Objectives of doubling
  2. Types of Doubling
  3. Qualities of Single yarn to get best Doubled yarn
  4. Formula for Double Yarn Count

Objectives of doubling

  • To increase strength of yarn
  • To increase smoothness, evenness, lusture, uniformity and compactness of yarn.
  • To obtain better deposition of twist.

Doubling Uses

  • Jeans sewing thread
  • type cord
  • cable yarn
  • tufting yarn

Types of Doubling

  1. Ring Doubling

    The difference of ring doubling from ring is:

    • No drafting
    • Creel in system is different & creel contains yarn(No rove)
    • Roller combination is different
    • Doubling yarn is designated as follows:

      Ends up of 40 Count 2/40
      Ends up of 10 Count 3/10

  3. Two For One twister (TFO)

    Here yarn is transferred to cone, then two ends yarns are combined (Doubled) and wound on a cone without twisting. Then the yarn is supplied to twister m/c where twist is applied in such a way that one revolution of rotating disc inserts two round of twist. The twisted yarn is then wound on a cone.

Qualities of Single yarn to get best Doubled yarn

  • The elongation of the yarn under lea strength tension should be uniform of the same count.
  • The twist should be uniform throughout
  • The breaking strength of yarn should not vary too much
  • 4% tolerance on either side should be allowed.

Formula for Double Yarn Count

  • Single yarn of same count
  • Final count = Single yarn count
    No. of doubling

  • Resultant count of component thread
    • Count: 1/N = 1/N1+1/N2 (N = Resultant counts, N1, N2= of same count yarn)
    • TPI of doubled yarn = TPI of single yarn (60-70%)