### Introduction

• In calculations of cloth, important raw material calculations which are often required during raw material calculation are to estimate
• the amount of material in a piece of cloth of given dimensions and
• the amount of different types of yarns required to produce a cloth similar to given sample.
• In RAW MATERIAL CALCULATIONS, we need to add on the waste made in weaving as well as in the preparatory processes.
Various other factors need to be taken care during calculation:
- Contraction of Weft and Warp.
- No. of intersections

What is Felting wool ? | Shrinkage of Wool | Relaxation

### Quantity of Material

All the calculation are done using the following formulas

• Total Quantity of Material in a piece of cloth = Weight of Yarns + Sizing Materials
• Total weight of Yarns = Wt. of Warps + Wt. of Wefts
• Tape Length = Length of piece + Crimp/ Regain/ take-up
• Ends per inch = Reed Count * Reed Width
• Total No. of Warp Ends = Body Warps + Selvedge Warps
• Total Length of Warp = Total Warps * Tape Length
• Wt. of Warp Yarns = Total Length of Warps/ Warp Count
• Total No. of Weft Ends = Picks per inch * Length of Piece

• Total Length of Weft = Total Wefts * (Width of cloth + Crimp)
• Wt. of Weft Yarns = Total Length of Wefts/ Weft Count
• Number of Repeats = (Total warps – selvedge warps)

Repeat size

• No. of Yarn Package required = Total yarn weight/ Yarn Weight per Package

### Numerical based on raw material calculation

Example 1

Grey and Mono-coloured Plain Fabric –

A cloth 44.5 inches wide on a 72’s Stockport reed is woven with 32’s Warp and 40’s Weft and 64 picks per inch. Selvedges ¼” on each side, are drawn 4 ends per dent. The count of the selvedge yarn is same as that of the warp yarn. The length of piece is 40 Yards. If regain of the warp is 5%, calculate –

a.) Total No. of Ends in Warp.

b.) Total Length of Warp Yarn in Hanks.

c.) Total weight of warp yarn in the piece.

d.) Total weight of weft yarn in the piece.

e.) Total weight of yarn in the piece.

Sol:

(a) Total No. of Warps = 3168 + 72 = 3240

(b) Total Length of Warp Yarns = 3240*42/840 = 162 Hks

(c) Wt. of Warps = 162/ 32 = 5.06 lbs

(d) Wt. of Wefts = 40*64*44.5/(840*40) = 3.4 lbs

(e) Total wt. of yarns = 5.06 + 3.4 = 8.46 lbs

Example 2

 Given Particulars Fabric Design Stripe Plain Selvedge width ¼ inch each Reed Count 84’s Stockport Selvedge Denting 4:4 Cloth Width 40.5 inch Selvedge Yarn Count 2/42’s Bleached Cotton Weft Count 50’s Length of piece 30 Yards PPI 72 Warp Crimp/ Regain 4%

 Given Particulars Fabric Design Stripe Plain Selvedge width ¼ inch each Reed Count 84’s Stockport Selvedge Denting 4:4 Cloth Width 40.5 inch Selvedge Yarn Count 2/42’s Bleached Cotton Weft Count 50’s Length of piece 30 Yards PPI 72 Warp Crimp/ Regain 4%

Calculate –

(a) Total No. of Ends in Warp.

(b) Total Length of each coloured Yarn in Hanks.

(c) Total weight of each coloured yarn in the piece.

(d) Total weight of yarn in the piece.

Sol: (a) Total No. of Warps = 3360 + 84 = 3444

Number of Repeats = 3360/ 21 = 160

(b) Length of Warp Yarns

 Total length of 40’s Dark Brown Ends 3 Ends 3*160 = 480 480*31.2/840 = 17.9 Hks Total length of 36’s White Ends 6 Ends 6* 160 = 960 960*31.2/840 = 35.7 Hks Total length of 32’s Green Printed Ends 1 Ends 1*160 = 160 160*31.2/840 = 5.95 Hks Total length of 36’s Light Brown Ends 10 Ends 10*160 = 1600 1600*31.2/840 = 59.5 Hks Total length of 2/50’s Grandrelle (Dark Yellow & White) Ends 1 Ends 1*160 = 160 160*31.2/840 = 5.95 Hks Total length of 2/42’s Bleached Selvedge Ends 84 Ends 84*31.2/840 = 3.12 Hks

RAW MATERIAL CALCULATIONS Reviewed by Suraj Gupta on July 28, 2020 Rating: 5