**Different Formulas of Weaving Calculation**

**Raju Tex**

Production Executive,

B.J.Group, Mawna, Gazipur

Chittagong Textile Engineering College

**Facebook:**https://www.facebook.com/ERZRAZU

**Weaving Calculations:**

The process of producing a fabric by interlacing warp and weft threads is known as weaving. The machine used for weaving is known as weaving machine or

**loom**. Weaving calculation is very important to produce fabric. It is also very critical task for weaving master. Different formulas and calculation of weaving are given in this article.

Weaving process |

**Different Formulas of Weaving Calculation:****Reed Count**

It is calculated in stock port system.No. of dents in 2 inches is called Reed

**Count**.

EPI

**Reed count**=

**……………………..**

1 + Weft crimp percentage

**Reed Width**

100 + Weft crimp percentage

**Reed Width**= Cloth width X

**………………….....................…**

100

**Cloth Cover Factor**

EPI

**1. Warp cover factor**=

**…………………….**

√Warp Count

PPI

**2. Weft cover factor**=

**……………………..**

√Weft Count

Wp.C.F. X Wt.C.F.

**3. Cloth cover factor**= Wp.C. - F Wt.C.F +

**…………………………**

28

**Crimp % :**

Crimp Percentage is defined as the mean difference between the straightened thread length and the distance between the ends of the thread while in cloth, expressed as a percentage.

Warp length - Cloth length

**Warp crimp%**=

**……………………………..**X 100

Cloth length

Weft length - Cloth length

**Weft crimp%**=

**……………………………..**X 100

Cloth length

**Loom:**

Motor pully diameter

**Loom Speed**= Motor RPM X

**…………...…………..**

Loom pully diameter

Actual Production

**Loom Efficiency (%)**=

**…………………………..**X 100

Calculated Production

**Fabric Specification:**

EPI X PPI

**Fabric specification**=

**………………………….**X Fabric width

Warp count X weft count

Or

Warp count X weft count

**Fabric specification**=

**………………………….**X Fabric width

EPI X PPI

**Weight of yarn in a cloth:**

The weight of cloth manufactured on looms depends upon the weight of yarns in the warp and weft: ends/inch, picks/inch and the weight of size on the warp.

Therefore, Cloth weight = Weight of warp + Weight of weft + Weight of size (All in lbs.)

Total No. of Ends X Tape Length in Yds.

**Where as Weight of warp in lbs**. =

**……………………………………………………..**

840 X Warp Yarn Count

Length of Cloth (Yds) X Picks / inch in Cloth X Reed Width (inch)

**Also Weight of weft in lbs**.=

**……………………………………………………………………….**

840 X Weft Yarn Count

**Weving Calculations:**

Calculating linear yards of fabric produced on a weaving machine per hour of operation can be done using the following formula:

**Linear Yards/Hour**= (picks per min. / picks per in.) x (60 min. per hr. / 36 in. per yd) x loom efficiency (%)

**Linear Meters/Hour**= (picks per min / picks per centimeter) x (60 min. per hr. / 100 cm per meter) x loom efficiency (%)

**Square Yards/Hour**= Linear Yards Per Hour x Fabric Width (Yds.)

**Square Meters/Hour**= Linear Meters Per Hour x Fabric Width (Meters)

**Rate of Filling Insertion (Yards/Min)**= Loom Speed (Picks/Min) x Loom Width (Yds.) x Loom Efficiency (%)

**Rate of Filling Insertion (Meters/Min)**= Loom Speed (Picks/Min) x Loom Width (Meters) x Loom Efficiency (%)

**Exmple of Weving Calculations:**

**Example-1:**What are the linear yards of fabric produced on a machine running 650 picks per minute, inserting 58 picks per inch, and operating at a 92% efficiency?

**Linear Yards/Hour**= (picks per min. / picks per in.) x (60 min. per hr. / 36 in. per yd) x loom efficiency (%)

**Linear Yards/Hour**= (650picks per min. / 58picks per in.) x (60 min. per hr. / 36 in. per yd) x .92 loom efficiency

**Answer:**17.2

**Example-2:**What is the rate of filling insertion in a loom running 720 picks per minute with a width of 2.5 meters at 93% efficiency?

**Rate of Filling Insertion (Meters/Min)**= Loom Speed (Picks/Min) x Loom Width (Meters) x Loom Efficiency (%)

**Rate of Filling Insertion (Meters/Min)**= 720(Picks/Min) x 2.5 (Meters) x .93 Loom Efficiency

**Answer:**1674 meters of filling inserted per minute