CONSTANTS AND CALCULATIONS:
FIBRE FINENESS, YARN COUNTS AND CONVERSIONS:
Micronaire value(cotton) : The unit is micrograms per inch. The average weight of one inch length of fibre, expressed in micrograms(0.000001 gram).
Denier(man-made fibres): Weight in grams per 9000 meters of fibre.
Micron:(wool): Fineness is expressed as fibre diameter in microns(0.001mm)
Conversions:
Denier = 0.354 x Micronaire value
Micronaire value = 2.824 x Denier
YARN COUNTS:
It is broadly classified into 1. DIRECT and 2.INDIRECT system.
DIRECT SYSTEM:
English count (Ne)
French count(Nf)
Metric count(Nm)
Worsted count
Metric system: Metric count(Nm) indicates the number of 1 kilometer(1000 meter) lengths per Kg.
Nm = length in Km / weight in kg (or)
Nm = length meter / weight in grams
INDIRECT SYSTEM:
Tex count
Denier
| tex | Ne | den | Nm | grains/yd | |
| tex | den/9 | 1000/Nm | gr.yd x 70.86 | ||
| Ne | 590.54/tex | 5314.9/den | Nm x .5905 | 8.33 / gr/yd | |
| den | tex x 9 | 9000/Nm | gr/yd x 637.7 | ||
| Nm | 1000/tex | 9000/den | 14.1 / gr/yd | ||
| grains/yd | tex / 70.86 | den / 637.7 | 14.1/Nm |
Where, Nm - metric count, Nec - cottoncount
CONVERSION TABLE FOR WEIGHTS:
| ounce | grains | grams | kilograms | pounds | |
| ounce | 437.5 grains | 28.350 grams | |||
| grains | 0.03527 ounces | 0.0648 grams | |||
| grams | 0.03527 grains | 15.432 grains | 0.001 kgs | ||
| kilograms | 35.274 ounces | 15432 grains | 1000 grams | 2.2046 pounds | |
| pounds | 16.0 ounces | 7000 grains | 453.59 grams | 0.4536 kgs |
CONVERSION TABLE FOR LINEAR MEASURES:
| yard | feet | inches | centimeter | meter | |
| yard | 3 feet | 36 inches | 91.44 cms | 0.9144 meter | |
| feet | 0.3333 yards | 12 inches | 30.48 cms | 0.3048 meter | |
| inches | 0.0278 yards | 0.0833 feet | 2.54 cms | 0.254 meter | |
| centimeter | 0.0109 yards | 0.0328 feet | 0.3937 inches | 0.01meter | |
| meter | 1.0936 yards | 3.281 feet | 39.37 inches | 100 cms |
- grams per meter = 0.5905 / Ne
- grams per yard = 0.54 / Ne
- tex = den x .11 = 1000/Nm = Mic/25.4
- Ne = Nm/1.693
- DRAFT = (feed weight in g/m) / (delivery weight in g/m)
- DRAFT = Tex (feed) / Tex(delivery)
- DRAFT = delivery roll surface speed / feed roll surface speed
- No of hanks delivered by m/c = (Length delivered in m/min) / 1.605
CARDING:
(1). P =( L x 1.0936 x 60 x effy ) / (hank (Ne) x 36 x 840 x 2.2045)
P - production in kgs / hr
L - delivery speed in m/min
effy- efficiency
Ne - English count ( number of 840 yards in one pound)
840 - constant
2.2045- to convert from lbs to kilograms
(2).production in kgs / hr = (L x Ktex x 60 x effy) / ( 1000)
L - delivery speed in m/min
Ktex- sliver count in Ktex (kilotex)
effy - efficiency
1000- to convert to kilograms from grams
(3). production in kgs / 8 hrs = (0.2836 x L x effy) / (Ne)
L - delivery speed in m/min
effy - efficiency
Ne - English count
(4).prodn / 8 hrs = (Hank x Nd) /( Ne x 2.2045)
Hank = no of hank (840 yards)delivered by the machine
Nd = no of deliveries
Ne = hank of the material
(4).Total draft in card = (feed weight in g/m) / (sliver weight in g/m)
DRAWFRAME:
(1.)Break draft = surface speed of 2nd roller / surface speed of back roller
(2).Main draft = surface speed of 1st roller / surface speed of 2nd( middle) roller
(3).Total draft = surface speed of delivery roller / surface of feed roller
(4).production in kgs / 8 hrs = (0.2836 x L x effy x Nd) / (Ne)
L - delivery speed in m/min
effy - efficiency
Ne - english count
Nd - No of delvieries
(5.).prodn in kgs / hr = (FRD x FRrpm x 3.14 x 60 x effy x Nd) / (Ne x 840 x 36 x 2.2045)
FRD - front roller dia in inches
FRrpm - front roller rpm
effy - efficiency
Ne - Sliver hank
Nd - number of deliveries
SPEEDFRAME + RINGFRAME
(1).Twist / Inch (TPI) = Spindle speed / FRS
FRS - front roller surface speed in inches/min
(2).FRS = FRrpm x 3.14 x FRD
FRS - Front roller surface speed
FRD - front roller diameter
(3).T.P.I = T.M. x sqrt(count or hank)
T.M. - Twist multiplier
sqrt - square root
(4).prodn in kgs / 8 hrs = (7.2 x SS x effy) / (TPI x Ne x 1000)
SS - spindle speed
(5).Spindle speed = m/min x TPI x 39.37
(6).hank delivered = spindle speed / ( tpi x 62.89)
(7).Ring traveller speed in m/sec =( spindle speed x ring dia in mm x 3.14) / (60 x 1000)
WINDING:
(1). production in kgs / 8 hrs = (0.2836 x L x effy x Nd) / (Ne)
L - delivery speed in m/min
effy - efficiency
Ne - english count
Nd - No of delvieries
(2). P =( L x 1.0936 x 60 x effy ) / (hank (Ne) x 36 x 840 x 2.2045)
P - production in kgs / hr
L - delivery speed in m/min
effy- efficiency
Ne - English count ( number of 840 yards in one pound)
840 - constant
2.2045- to convert from lbs to kilograms
