Weaving Calculation & Useful Formulas

CHAPTER - 7 WEAVING CALCULATION & USEFUL FORMULAS: 7.1. Count: • A number indicating the Mass per unit Length OR • The length per unit mass of Yarn. • Expression of the fineness of Yarn. There are three Systems to Calculate Count - 1. Indirect System 2. Direct System 3. Universal System 1 Lea = 120 yd 7 Leas = 1 hank 1 Hank = 840 yds. or 768 meter 1. Indirect system Total No. of hanks per one pound is the count of that yarn (Ne) i.e. if 10 hanks (10 x 840 yds. or 7680 meters) weighs one Pound or 0.454 Kg, then the Count of Yarn in indirect system 10s or 10Ne. This System widely used for staple fiber spun yarns like 100% Cotton, Viscose, Polyester fibers and their blends. Higher the yarn Count i.e Ne the yarn is finer 2. Direct System Count = Weight in grams per 9000 meters of yarn In this system the yarn numbering is called as Denier (D) Higher the yarn number i.e Denier the yarn is coarser. 3. Universal System Count = No of grams per 1000 meters or per km of yarn. In this system count is called as Tex Poundsin Weight yards) (840 hanksin Length Count = Commonly used other numbering systems I. Nf - French count: - It is the No of 1000 meters length in ½ kg of yarn II. Nm - Metric system: - Count is the No of 1000 meters length per kg. of yarn. III. Worsted system: - Count is the No. of 560 yards in one lbs. IV. Linen system: - It is the No. of leas of 300 yards per pound V. Hemp, Jute, Flax: - Count is the No of 14,400 yards length per pound of yarn Conversion System English (Ne) to Denier (D) - Denier = 5315 / Ne English (Ne) to Tex - Tex = 590.5 / Ne French (Nf) to English (Ne) - English (Ne) = Nf x 1.181 7.2. Twist per Inch or meter (TPI or TPM)  To give strength to the yarn, certain twist is given in the yarn.  TPI vary according to end use of yarn. More twist for warp yarns, medium twist for weft yarns and less twist for hosiery yarns.  We calculate the twist as TPI or TPM.  Twist is given in ‘Z’ direction or ‘S’ direction.  If twist is given in CW direction it is ‘Z’ twist.  If it is given in CCW direction it is ‘S’ twist.  Single yarns are given ‘Z’ twist and double yarns are given ‘S’ twist.  Twist relation for double yarn TPI = 0.7 x Single yarn TPI 7.3. Multi-filament Yarns Multi-filament yarn are identified as 80/34/250, 80/34/0, 155/16/120 Here the first number denotes the Denier, second shows No. of filaments in the yarn & the last indicate No. of Twist per meter. 7.4. Winding Calculation Slub – catcher settings: a. Fixed Blade = Carded - (2.0 to 2.5) x Diameter Combed - (1.5 to 2.0) x Diameter b. Oscillating Blade = Smooth micro-set - 25% more than above c. Serrated Blade = 100% more than the above d. Electronic yarn clearer = 3 cm x 3 Diameter Diameter = inches )count x(281/ For Blended yarn = 10 to 15% more settings Yarn clearer efficiency = 100 present Faults remved Faults × Knot factor = faults bleobjectiona to due Breaks of No. faults)(at windingduring breaks Total Retained splice strength = yarnparent of strength 100 joint spliced of stength × Winding Tension = 0.1 x Single strength in grams Optimum spindles / winder N = 1 S y 4.8 + × OR Expected efficiency E = ( ) 9812 NS Y4500 +× × Expected production P = ( ) C9812 13Y ×+ / Winder per 8 hrs. in kgs Y = Length / Bobbin (meters.) B = breaks per bobbin S = Winding speed (meters./min) C = English count 7.5. Warping Calculations: Machine Efficiency E = SR 100R + × R = Uninterrupted running Time for 1000 meters (sec) = mtr/min in speed Machine 601000 × S = total of time, in seconds for which the machine is stopped for a production of 1000 meters. = T4 CL T3 L T2 400 T1 N B R + × ++ × × + B = End breaks / 400 ends / 1000 meters N = Number of ends. L = Set Length in 1000 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 / 1000 mtrs. Production in meters. per 8 hrs.(K) = 480 x mtrs / min x E / 100 Kgs. Production in Kgs. Per 8 hrs. = (K x N) / (1693 x English Count) Warping Tension = 0.03 to 0.05 x Single Thread Strength 7.6. Sizing Calculations: 1. Count Warp204.2 840 Ends Total 1.094 meter in Length Kg)(in weight Warp ×× × × = 2. 100 weight. warpsized-Un weight. warpSized- Un- weight warpSized %age uppick Size × = 3. Weight of size = Warp Weight x Size pick up % 4. 100 Length. warpsized-Un Length. WarpSized- UnLength WarpSized %ageStretch × − = 5. × × = 840 (lbs.) weight warpSized yardsin length Warp Ends Total Countyarn Sized 6. % Moisture Content = 100× Yarn Sizd of Wt. Yarn Dried Oven of Wt. - Yarn Sized of Wt. 7. % Stretch = 100 Reading Counter Feed Reading Counter FeedReading counterDelivery × − 8. % Droppings on loom = PNY 454 C D 840000 ×× × × D = Dropping in gms. C = English Count Y = Length woven (yds.) N = Number of Ends P = % size add on 9. Invisible Loss % = 100 issued size of Amount yarn on added size of Amount - issued material size ofAmount × 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 10. Max. Speed of machine (meters / min) = Ends of Number Count English 1000 Cylinder of No. × × 11. Wt. Of Warp in gms / mtr = Count English 0.6 Ends of No. × 7.7. Weaving Calculations 1. Reed Count It is calculated in stock port system. No. of dents in 2 inches is called Reed Count 2. Reed Width 3. Crimp %age 4. Cloth Cover Factor 1. Count Warp EPI factorcover Warp = 2. countWeft PPI factorcover Weft = 3. 28 Wt.C.F.Wp.C.F. Wt.C.FWp.C.Ffactorcover Cloth × −+= 5. Maximum EPI for particular count 1. For plain fabrics = Count14 × 2. For drill Fabrics = 6 4 28Count ×× 3. For satin fabrics = 7 5 28Count ×× 4. Other design = repeat/endsrepeat / onsintersecti of No. diameteryarn /1repeat/Ends + × 5. Yarn diameter. = Count28 1 × %age crimpWeft 1 EPI count Reed + = 100 lengthCloth lengthCloth -length Warp %age Crimp Warp ×= 100 %age crimp weft 100 h Cloth widt WidthReed + ×= 100 h Cloth widt h Cloth widt-lengthWeft %age crimpWeft ×= 6. Weave Density a) Warp Density = KTex cm / Ends ×× = < 250 b) Filling Density = KTex cm / Picks ×× = < 350 c) Weave Density = 100 - F.D. 100) -dencity (Weft 100 - F.D. 100)-dencity (Warp 50 × × + d) Effective weave density = W. D x K of loom width x K of Design = < 72 Wp / filling - K Loom Width - K Weave Design - K Cotton = 1.00 140 cm - 0.99 Plain1/1 = 1.00 Polyester/Cotton = 1.03 180 cm - 1.00 Twill 1/2 = 0.87 Viscose Filament = 1.17 190 cm - 1.01 Matt, Gabardine 2/2 = 0.82 Polyester Filament = 1.22 220 cm - 1.02 Drill 1/3 = 0.77 250 cm - 1.08 Satin 1/4 = 0.69 330 cm - 1.15 360 cm – 1.20 7. 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: clothgiven in count Warp cloth expectedin count Warp cloth given in EPI Cloth Exp.in EPI × = 2. To change the count without altering the denseness: clothgiven in Count cloth given in EPI Cloth exp.in EPI Cloth Exp.in Count 2 ×         = 8. Warp requirement to weave a cloth a. Waste%age Count x 840 crimp% 453.59 1.0936 ends Total gms/mtrsin weight Warp × × × × = b. Waste%age %age Crimp Count x 840 PPI x 453.59 x inchesin R.S. gms/mtrsin t Weft Weigh ××= c. inchesin S. R. x PPI 0.9144 x 1848count x x Weft kgsin Weft wt. weight given weft with the mtrsin length Cloth =         For Silk and Polyester i. %age Waste Crimp% 9000 (Denier)Count ends Total mtrsgms/ in weight Warp ×× × = ii. %age Waste% 9000 (Denier)Count PPI inchesin RS mtrsgms/ in t Weft weigh ×× × × = Crimp Allowance for count in Bleached and Dyed Fabric: ⇒ Count becomes 4% ⇒ FinerDyed counts become max 6% Coarser 9. Fabric production calculation 1. diameterpully Loom diameterpully Motor RPMMotor Speed Loom ×= 2. 100 Production Calculated Production Actual %age Efficiency Loom ×= 3. 100 tYarn weigh Dryed tYarn weigh Dryed -t Yarn weigh %ageRegain Moisture ××= 4. 100 tYarn weigh tYarn weigh Dryed -t Yarn weigh %ageContent Moisture ××= Type of Yarn Moisture Regain% Moisture Content% Cotton 8.50 7.83 Jute 13.75 12.10 Silk 11.00 9.91 Rayon, Viscose 11.00 9.91 Wool 17.00 14.50 Nylon 4.20 3.78 Polyester 5. Count Warp 1693.6 meter.in length Tape ends Total Kg.in weight Warp × × = 6. Count Weft 4301.14 PPI metersin Length Cloth meters-centiin RS Kg.in t Weft weigh × × × = 7. 25.6 CountWeft PPI Count Warp EPI GSMin ht Cloth weig ×       += 8. 34 Sq.Meter)per (Grams GSM Yard Sq.per (Ounze) Oz. = 10. Material measurement: To calculate the length of any rolled fabrics, this formula gives the nearest accuracy. L = t d) (D d) (D 0.0655 + − Where L = Length of material (Feet) t = Thickness of fabrics (inches) D = Outside diameter (inches) d = Inside diameter (inches) 11. Weight of yarn in a cloth: The weight of cloth manufactured on looms 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.) Where as Weight of warp in lbs. = Count Yarn Warp840 Yds. in Length Tape Ends of No. Total × × Also Weight of weft in lbs.= Count YarnWeft 840 (inch) Width Reed Cloth in inch / Picks (Yds) Cloth of Length × × × 7.8. YARN QUALITY & OTHER PARAMETERS 1. Yarn Appearance: The Visual Effect obtained by viewing a sample of yarn wound with a designated traverse on a black board of designated size. ♦ Nep: a tightly tangled mass of unorganised fiber ♦ Slub: an abruptly thickened place of yarn ♦ Thick place: a yarn defect where the diameter is greater than the adjoining segments and extending for 6 mm ♦ Thin Place: a yarn segment where the diameter is 25% lesser than the average diameter of yarn ♦ Fuzz: Untangled fibers that protrude from the surface of the yarn ♦ Bunch: a yarn segment not over 6 mm in length that shows abrupt increase in diameter caused by more fibers matted in this particular place ♦ Method: yarn wound on hylam black boards wound for fixed wraps per inch as per count compared with standard reference boards. ♦ Grades: Above ‘A’ to below ‘D’ - The imperfections increase from Grade ‘A’ and the maximum in grade ‘D’. Average index of five boards of five graders. 2. Yarn Evenness: ♦ Unevenness: Variation in the linear density of a continuous strand or of a portion of a strand. ♦ Apparatus: Uster–Evenness Tester ♦ Principle: Difference in the capacitance variation. Lower the Count lower the Imperfections. One km of yarn is run through two capacitance plated at specific speed (fixed as per the count). The capacitance variation is integrated and expressed as % unevenness (U%). The imperfections are counted and are reported per kilometer. 3. Linier Density of Yarn: ♦ Expression of the fineness of Yarn ♦ A number indicating the mass per unit Length or the length per unit mass of Yarn ♦ Direct system: Denier, Tex (Weight Of Unit Length) ♦ Indirect System (Units of Lengths) per (Units of weights) 4. Count Test – Apparatus ♦ Wrap reel ♦ Balance ♦ 120 yards of yarn / 100 meters of yarn wound in a wrap reel and weighed . ♦ From the weight, the count is calculated. 5. Single Thread Strength Testing ♦ Force Required to break a single strand of yarn of unit length ♦ Apparatus - Single thread Strength Tester ♦ RKM ♦ %Elongation 6. Lea Stength Testing ♦ Lea Breaking Strength ♦ The Force required to break one lea ♦ Unit –pounds ♦ Count Strength Product ♦ Apparatus –Lea Tester 7. Principles Of Tensile Testing ♦ Constant Rate of Loading: The Rate of change of Load is constant – Uster Dynamat ♦ Constant rate of Traverse: The pulling clamp moves at a constant rate – Lea – Pendulum tester ♦ Constant rate of Extension:Rate Of change of Specimen length is constant – Statmat 8. Twist Testing ♦ Direction Twist ♦ S –Twist: When Held in vertical position, the spiral confirm in slope to the central position of the letter ‘S’ ♦ Z –Twist: When Held in vertical position, the spiral confirm in slope to the central position of the letter ‘Z’ ♦ No of Turns (Twists) per Unit length ♦ Single Twist [...]... they were abstracted By this means we can estimate the length of warp required to give the length to cloth and from the weft regain we can estimate the length in Reed or length of each pick of weft In weaving ordinary classes 10% of cotton goods warp regain between 4% and according to the structure, while the weft regain is usually about 5% These figures apply to grey cloths only In finished goods,... sample If the fabric is a coloured woven material, such as a poplin shirting or a zephyr check, the warp and weft patterns must be abstracted For the ordinary kinds of cotton fabrics the contraction during weaving makes the cloth stand about 4 ends per inch closer in the cloth than in the reed and there is a gain of about 2 picks per inch from the loom to the warehouse table Thus if a cloth is required to . CHAPTER - 7 WEAVING CALCULATION & USEFUL FORMULAS: 7.1. Count: • A number indicating the Mass per unit Length OR • The. number denotes the Denier, second shows No. of filaments in the yarn & the last indicate No. of Twist per meter. 7.4. Winding Calculation Slub – catcher settings: a. Fixed Blade = Carded -. Cylinder of No. × × 11. Wt. Of Warp in gms / mtr = Count English 0.6 Ends of No. × 7.7. Weaving Calculations 1. Reed Count It is calculated in stock port system. No. of dents in 2