Weaving calculation

1. WEAVING
CALCULATION
BY
VIGNESH DHANABALAN
Vignesh Dhanabalan - vignesh dhanabalan@hotmail.com

2. Items Units
Weave, drawing-in and lifting plan -
Fabric width Cm
Warp density Ends/cm
Weft density Picks/cm
Warping (Colour pattern) -
Wefting (Colour pattern) -
Warp crimp %
Weft crimp %
Warp count & material Tex
Weft count & material Tex
Fabric weight Gm/sq. m
Points to be noted for calculation

3. Fabric Weight Calculation
• This is done by calculation of fabric size 1 m x 1 m.
• The formula for warp weight:
• Warp weight (gm/sq m.) = [ends/cm x 100 x tex x (1+warp crimp%)] ÷ 1000
• The formula for weft weight:
• Weft weight (gm/sq m.) = [picks/cm x 100 x tex x (1+weft crimp%)] ÷ 1000
• Fabric Weight (gm/sq. m) = warp weight + weft weight
Vignesh Dhanabalan - vignesh dhanabalan@hotmail.com

4. Fabric weight classification
Weight Range Typical examples
Sheer: 0-50 g/m2 (0-1/2 oz/yd2) Lingerie, women”s hosiery, sheer
cutrains
Light: 50-150 g/m2 (1-4 1/2
oz/yd2)
“Top weight”, shirts, blouses,
dresses, linings
Medium: 150-300 g/m2 (4 1/2 – 9
oz/yd2)
“Bottom weight”, shirts, suits,
sports denim, terry towels
Medium-Heavy: 300-600 g/m2
(9-18 oz/yd2)
“Bull denim”, workwear, best
terry towels, overcoats
Heavy : 600 g/m2 (18 oz/yd2) and
up
Winter coats, upholstery, mats,
carpets

5. Finding crimp% and yarn count
• Crimp%=
[(extended length) – (sample length) x100%] ÷ (sample length).
• For yarn count, it is determined through the weight of specific
length and then calculate the count.
• Yarn count (tex) = yarn weight (gm) per 1000 meter.
Vignesh Dhanabalan - vignesh dhanabalan@hotmail.com

6. Weft Consumption per pick
• In the shuttleless weaving machine the weft consumption
in meters per pick is:
Where,
b – is the reed width
K –is the co-efficient of the take-up in percent
x –is the length of the weft extending from the fabric.
Vignesh Dhanabalan - vignesh dhanabalan@hotmail.com

7. Weft Consumption per shift
• Number of supply packages consumed with in eight hours shift
at a 100% machine efficiency:
Where,
Nm –is the metric count of the weft thread
G –is the weight in kg of the weft yarn package on the bobbin
n –is the machine speed in rpm
Vignesh Dhanabalan - vignesh dhanabalan@hotmail.com

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9. Vignesh Dhanabalan - vignesh dhanabalan@hotmail.com
Weft carrier velocity

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13. Thank you
Vignesh Dhanabalan - vignesh dhanabalan@hotmail.com