Textile Calculations [PDF]

Zitiervorschau

10/27/13

TEXTILE CALCULATIONS

TEXTILE 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 SYSTEM

2.

INDIRECT SYSTEM

INDIRECT 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

DIRECT SYSTEM ·

Tex count

·

Denier

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CONVERSION TABLE FOR YARN COUNTS Tex Tex Ne

590.54/tex

Den

Nm

Grains/yd

den/9

1000/Nm

gr.yd x 70.86

5314.9/den

Nm x .5905

8.33 / gr/yd

9000/Nm

gr/yd x 637.7

Den

tex x 9

Nm

1000/tex

9000/den

tex / 70.86

den / 637.7

Grains/yd

14.1 / gr/yd 14.1/Nm

Where, Nm – metric count, Nec – cotton count

CONVERSION TABLE FOR WEIGHTS Ounce Ounce Grains

Grains

Grams

437.5 grains

28.350 grams

0.03527 ounces

Pounds

0.0648 grams

Grams

0.03527 grains 15.432 grains

Kilograms

35.274 ounces

15432 grains

1000 grams

16.0 ounces

7000 grains

453.59 grams

Pounds

Kilograms

0.001 kgs 2.2046 pounds 0.4536 kgs

CONVERSION TABLE FOR LINEAR MEASURES Yard Yard

Feet

Inches

Centimeter

Meter

3 feet

36 inches

91.44 cms

0.9144 meter

12 inches

30.48 cms

0.3048 meter

2.54 cms

0.254 meter

Feet

0.3333 yards

Inches

0.0278 yards

0.0833 feet

Centimeter

0.0109 yards

0.0328 feet

0.3937 inches

Meter

1.0936 yards

3.281 feet

39.37 inches

0.01meter 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 file:///D:/textile cal/TEXCALTEXT detail.mht

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BLOW ROOM (1)

% trash in cotton - % trash in lap Blow-room Cleaning Efficiency% (CE) = ------------------------------------------% trash in cotton

(2)

Lint in waste (%) = 100 - CE

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

(5)

Total Draft in Card = (Feed Weight in g/m) / (Sliver Weight in g/m)

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(6)

TEXTILE CALCULATIONS

Actual draft

Wt. per yard of lap fed = -----------------------------------------------Wt. per yard of card sliver delivered

Length of card sliver delivered (7) Mechanical draft = ---------------------------------------Length of lap fed or Draft constant of card machine = -----------------------------------------Draft change pinion (8)

Actual draft is always greater than the mechanical draft in carding because it is the carding waste% that increases the actual draft.

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 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)

(Middle)

L - delivery speed in m/min effy - efficiency Ne - english count Nd - No of delvieries (5)

Prodn In Kgs / Hr = (FRD x Fr. rpm 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

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(2)

TEXTILE CALCULATIONS

FRS = Fr. rpm 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)

Single yarn strength (gm) RKM = ----------------------------------Tex number of yarn

(8)

Ring bobbin content = 3.1 LD2 (L = Lift in inch, D = ring dia in inch)

(9)

Doubling bobbin content = 3.7 LD2

(10)

Corrected count

(11)

Weight per yard of roving fed Actual draft of ring frame = ----------------------------------------------------------Weight per yard of yarn delivered on bobbin

(12)

=

Actual count x (1 + Present regain) -----------------------------------------------1 + Standard regain

Mechanical draft of ring frame =

=

Surface speed of front roller -------------------------------------Surface speed of back roller Draft constant -------------------------Draft change pinion

(13) Twist contraction % = It is basically the percent shortening in length of yarn between the front roller and the bobbin. The length at the front roll is taken as 100%. For example 5% twist contraction means, the yarn length on the bobbin is 95% of the length at the file:///D:/textile cal/TEXCALTEXT detail.mht

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front roll.

=

Yarn count at front roll - yarn count at bobbin ------------------------------------------------------------ x 100 Yarn count at front roll

(14)

TC%

(15)

Example of twist contraction given yarn; Count on bobbin = 10s Twist contraction = 5% 10 x 1.00 Yarn count at front roll = -------------- = 10.53s 95%

(16)

Mechanical draft is always greater than actual draft in ring spinning? It is necessary to draft the roving to a finer yarn count at front roll that what is to be bobbin. Because due to twist contraction of yarn, the count of yarn on bobbin becomes coarser than the count of yarn at front roller.

(17)

Twist per inch (TPI) Twist multiplier or Twist factor = ---------------------------Ö Count (Ne)

(18)

TPI = Twist multiplier x ÖCount (Ne) or

(19)

Twist constant of ring frame TPI = ------------------------------------Twist change pinion

(20)

Turns per metre (TPM) = Twist factor ÖNm

(21)

TPI = TPM x 0.0254

(22)

Ring Traveller Speed Ring Traveller Speed in m/Sec= (Spindle Speed x Ring Dia in mm x 3.14)/ (60 x 1000) Actual ring traveler speed ? Assume, spindle speed Ring Diameter

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= =

9,000 rpm 57 mm 6/15

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TEXTILE CALCULATIONS

Front roll delivery Package circumference

= 64 metre/min. = 102 mm (avg)

Front roll delivery (m/min) x 1000 Traveller lag (rpm) = Spindle speed - —————————————— Package circumference (mm) 14x1000 = 900 - ———— 102

= 8363 rpm

Traveller lag 900 – 8863 = 137 rpm Uncorrected traveller speed (m/sec.) : Spindle speed x Ring diameter (mm) x p = —————————————————— 1000 x 60 9000 x 57 x 3.142 = ——--—————— = 1000 x 60

26.8 m/sec.

Corrected Traveller speed (m/sec.) :

Traveller speed (m/sec) –

Ring dia (mm) xp x Trav. Lag (rpm) ————————————————— 60 x 1000

57x 3.142 x 137 = 26.8 - ———————— = 26.39 m/sec. 60 x 1000

(23) Weights of ring travellers No. 1 and 1/0. For No. 1 = 90 grains / 100 travellers For No.1/0 = 80 grains/100 travellers

WINDING 1.

Slub catcher settings : a.

Fixed Blade = Carded - (2.0 to 2.5) x diameter Combed - (1.5 to 2.0) x diameter

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b.

Electronic yarn clearer = 3 cm x 3 diameter = 1/( 28 x Öcount )

Diameter in inch for Blended yarn

= 10 to 15% more settings 2.

Yarn clearer efficiency = objectionable thick faults removed by slub catcher = Total objectionable thick faults present in yarn before winding

Number of x 100

Total breaks during winding (at faults) 3.

Knot factor = No. of breaks due to objectionable yarn faults Strength of spliced joint x 100

4.

Retained splice strength = Strength of parent yarn

5.

Winding Tension = 0.1 x Single yarn strength in grams 4500 x Y

6.

Expected efficiency E

= S x N (12 + 98)

7.

Winder’s workload (0.17 min/operation on conventional winding m/c = 2300 operations per shift of 8 hours where, 1 creeling or 1 piecing = 1 operation 1 doffing = 2 operations

8.

Winder’s workload on autoconer (0.08 min per operation) = 4800 operations/shift of 8 hours where, 1 bobbing feeding = 1 operation 1 doffing (manual) = 4.5 operation Y B S C

(9)

= Length/Bobbin (metres) = Breaks per bobbin = Winding speed (metres/min) = English count

Production in Kgs / 8 Hrs = (0.2836 x L x Effy x Nd) / (Ne)

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L - delivery speed in m/min effy - efficiency Ne - english count Nd - No of delvieries (10)

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

WARPING R x 100 1.

Machine Efficiency E = R+S R = Uninterrupted running time for 1,000 meters (in sec) 1000 x 60 = Machine speed in mtr/min. S = Total of time in seconds for which the machine is stopped for a production of 1,000 meters B X N X T1 T2 T3 = R + --------------- + ----- + ---------- + T4 400 L L xC B = Ends breaks/400 ends/1,000 meters N = Number of ends L = Set length in 1,000 meters C = Beams per creel Timing of activities in seconds are : T1 = To mend a break T2 = To change a beam T3 = To change a creel T4 = Miscellaneous Time loss/1,000 mtrs.

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2.

Production in metres per 8 hrs. (K) = 480 x mtrs/min x E/100 kgs.

3.

Production in Kgs. per 8 hrs. = (K x N)/(1693 x English Count)

4.

Warping Tension = 0.03 to 0.05 x Single thread strength

SIZING Length in metre x 1.094 x Total ends 1.

Warp weight = (in kg.)

x 100 840 x 2.204 x Warp count Sized warp weight - Unsized warp weight

2. 3.

Size pick-up %age

=

x 100 Un-sized warp weight

Weight of size =

Warp Weight x Size pick up % Sized warp length - Unsized warp length

4.

Stretch %age =

x 100 Un-sized warp length Total-ends x Warp length in yards

5.

Sized yarn count

= Sized warp weight (lbs) x 840 Wt. of sized yarn - Wt. of oven dried yarn

6.

%age Moisture= content

x 100 Wt. of sized yarn Deliver counter reading - Feed counter reading

7.

%age Stretch = 100

x Feed counter reading 840,000 x D x C

8.

%age Droppings = on loom

x 100 454 Y x N x P

D = Dropping in gms. Y = Length woven (yds.) P = % size add on 9.

C = English Count N = Number of Ends

Invisible Loss% = Amount of size material issued - Amount of size added on yarn =

x 100 Amount of size issued

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TEXTILE CALCULATIONS

Steam, Consumption (Sizing M/c) = 2.0 kg/kg of sized yarn (Cooker) = 0.3 kg/kg of liquor (Sow box) = 0.2 kg/kg of yarn No. of Cylinder x 1,000 x English count 10. Max. Speed of machine (metres/min)

= Number of ends Number of ends x 0.6

11. Wt. of warp in gms/mtr = English count

WEAVING 1.

Reed Count : It is calculated in stock port system. EPI Reed width = 1 + Weft crimp %age No. of dents in 2 inches is called Reed Count

2.

Reed Width : 100 + Weft crimp %age Reed width = Cloth width x 100

3.

Crimp % age : Warp length - Cloth length Warp Crimp %age

=

x 100 Cloth length

Weft length - Cloth length Weft Crimp %age =

x 100 Cloth length EPI

4.

Warp cover factor = ÖWarp Count PPI

5.

Weft cover factor = ÖWeft count Wp.C.F. x Wt. C.F.

6.

Cloth cover factor = Wp.C.F. + Wt.C.F. -

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28 7.

Maximum EPI for particular count : a.

For plain fabrics = 14 x ÖCount

b.

For drill fabrics

= ÖCount x 28 x 4/6

c.

For satin fabric

= ÖCount x 28 x 5/7 Ends/repeat x 1 / yarn diameter

d.

Other design = No. of intersections / repeat + ends/repeat 1

8.

Yarn diameter = 28 x ÖCount

Weave Density 1.

Warp density = Ends/cm x ÖTex x K = < 250

2.

Filling density = Picks/cm x ÖTex x K = < 350 (Warp density - 100) x F.D.- 100

3.

Weave Density = 50 + (Weft density - 100) x F.D.- 100

4.

Effective weave density = W.D. x K of loom width x K of Design = < 72

To change the count and number of thread/inch, keeping the same denseness of the fabric : 1.

To change the EPI without altering the denseness :

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EPI in given cloth x Ö Warp count in expected cloth EPI in Exp.Cloth = 2.

Ö Warp count in given cloth To change the count without altering the denseness : EPI in exp. cloth2 EPI in exp. cloth =

x Count in given cloth EPI in given cloth

Warp requirement to weave a cloth : Total ends x 1.0936 x 453.59 x crimp% 1. Warp weight in gms/mtrs. = Waste

2.

x 840 x Count

Weft weight in gms/mtrs. = R.S. in inches x 453.59 x PPI = 840 x Count

%age

x Crimp %age x Waste %age

Weft wt. in kgs. x Weft count x 1848 x 0.9144 3.

Cloth length in mtrs.with = the given weft weight

PPI x R.S. in inches

For Silk and Polyester :

1.

Warp weight in gms/mtrs. = Total ends x Count (Denier) =

x Crimp% x Waste %age 9000

2.

Weft weight in gms/mtrs. = RS in inches x PPI x Count (Denier) = 9000

x Crimp% x Waste %age

Allowance for count in Bleached and Dyed Fabric : ¨

Count becomes 4%

¨

Finer Dyed counts become max.6% Coarser

FABRIC PRODUCTION file:///D:/textile cal/TEXCALTEXT detail.mht

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Motor pulley diameter 1.

Loom speed = Motor RPM x Loom pulley diameter

2.

Actual production Loom Efficiency %age = ----------------------------- x 100 Calculated production

3.

Yarn weight - Dryed yarn weight Moisture Regain %age = --------------------------------------------- x 100 Dryed yarn weight

4.

Yarn weight - dried yarn weight Moisture Content %age = -------------------------------------------- x 100 Yarn weight

5.

Total ends x Tape length in metre Warp weight in Kg. = ---------------------------------------------1693.6 x Warp count

6.

RS in centimetres x Coth length in metres x PPI Weft weight in Kg. = ---------------------------------------------------------------4301.14 x Weft count

7.

EPI PPI Cloth weight in GSM = ----------------- + ----------------- x 25.6 Warp count Weft count

8.

GSM (Grams per sq. metre) Oz (Ounce) per sq.yard = ------------------------------------34

Material measurement : For calculating of length of any rolled fabrics :

L =

0.0655 (D - d) (D + d) ------------------------------t

Where, L = Length of material (feet) t = Thickness of fabrics (inches) D = Outside diameter (inches) d = Inside diameter (inches)

Weight of yarn in a cloth : file:///D:/textile cal/TEXCALTEXT detail.mht

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TEXTILE CALCULATIONS

The weight of cloth manufactured on loom depends upon the weight of yarns in the warp and weft : ends/inch, picks/inch and the weight of size on the warp. Therefore, Cloth weight = Weight of warp + Weight of weft + Weight of size (All in lbs.) Total No. of Ends x Tape length in yds. Where as Weight of warp in lbs = ---------------------------------------------------840 x Warp yarn count

Also Weight of weft in lbs. = Length of cloth (yds) x Picks/inch in cloth x Reed width (inch) = ----------------------------------------------------------------------------------840 x Weft yarn count

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