Weaving Formulas

Count

A number indicating the Mass per unit Length OR

The length per unit mass of Yarn.

Expression of the fineness of Yarn.

There are three Systems to Calculate Count

1. Indirect System
2. Direct System
3. Universal System

1. Indirect system

Total No. of hanks per one pound is the count of that yarn (Ne) i.e. if 10 hanks (10 x 840 yds. or 7680 meters) weighs one Pound or 0.454 Kg, then the Count of Yarn in indirect system 10s or 10Ne.

This System widely used for staple fiber spun yarns like 100% Cotton, Viscose, Polyester fibers and their blends.

Higher the yarn Count i.e Ne the yarn is finer

Count = Length in hanks(840 yards)/Weight in Pounds

2. Direct System

Count = Weight in grams per 9000 meters of yarn

In this system the yarn numbering is called as Denier (D)

Higher the yarn number i.e Denier the yarn is coarser.

3. Universal System

Count = No of grams per 1000 meters or per km of yarn.

In this system count is called as Tex

Weight in Pounds

Length in hanks (840 yards)

Count = Commonly used other numbering systems

1. Nf – French count: – It is the No of 1000 meters length in ½ kg of yarn
2. Nm – Metric system: – Count is the No of 1000 meters length per kg. of yarn.
3. Worsted system: – Count is the No. of 560 yards in one lbs.
4. Linen system: – It is the No. of leas of 300 yards per pound
5. Hemp, Jute, Flax: – Count is the No of 14,400 yards length per pound of yarn

Conversion System

English (Ne) to Denier (D) – Denier = 5315 / Ne

English (Ne) to Tex – Tex = 590.5 / Ne

French (Nf) to English (Ne) – English (Ne) = Nf x 1.181

Twist per Inch or meter (TPI or TPM)

• To give strength to the yarn, certain twist is given in the yarn.
• TPI vary according to end use of yarn. More twist for warp yarns, medium twist for weft yarns and less twist for hosiery yarns.
• We calculate the twist as TPI or TPM.
• Twist is given in ‘Z’ direction or ‘S’ direction.
• If twist is given in CW direction it is ‘Z’ twist.
• If it is given in CCW direction it is ‘S’ twist.
• Single yarns are given ‘Z’ twist and double yarns are given ‘S’ twist.
• Twist relation for double yarn TPI = 0.7 x Single yarn TPI

Multi-filament Yarns

Multi-filament yarn are identified as 80/34/250, 80/34/0, 155/16/120

Here the first number denotes the Denier, second shows No. of filaments in the yarn & the last indicate No. of Twist per meter.