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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

CONVERSION TABLE FOR YARN COUNTS:

  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  

 

CALCULATIONS:

  • 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

 


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