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:

Where, Nm - metric count, Nec - cottoncount

CONVERSION TABLE FOR WEIGHTS:

CONVERSION  TABLE FOR LINEAR MEASURES:

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

visit our HOME PAGE for complete list of Textile articles