Textile Calculations and Equations

DIFFERENT FABRIC GSM AND THEIR REQUIRED YARN COUNTRib without lycra... Interlock without lycra -Fabric G.S.M Yarn Count Lacoste without lycra -Fabric G.S.M Yarn Count... Density Calcula

TEXTILE CALCULATION & EQUATION

Name : MAZADUL HASAN SHESHIR

ID: 2010000400008

Batch: 13th Batch (Session 2009-2013)

Department: Wet Processing Technology

Calculation and Equation

Basic Conversions (Spinning)

Count Conversion Table (Spinning)

Draft & TPI Formulas

Efficiency Percentage (Spinning)

Cleaning Efficiency (%)

Efficiency (%)

Twists per inch

PRODUCTION CALCULATION FORMULAS

PRODUCTION FORMULAS

Yarn Count in Direct system

System

Yarn Count in Indirect system

Excellence of fiber quality by combing :

Fabric ( Knitting & Weaving ) Calculation and Equation

SIZING

Calculation:

Required Chemical &no of Mixing of Sizing Recipe:

Production is calculated in accordance with the following

equation-Production calculation:

1 Production = no of needle x no of feeder x RPM x stitch length/ yarn count

Production per shift in KG at 100% efficiency

Where,

Ks = knitting constant Count = linear density of yarn GSM = gm per square meter Another formulae is :

Stitch length = (Tex × Ks) / GSM

Ks is a constant Its value is different for different fabric structure and fabric type Ks is calculated and estimated as below:

Ks = (GSM x Stitch length) / Tex

Production calculation:

Ks = (GSM x Stitch length) / Tex

Relation between yarn count and m/c gauge seen in different m/c.:

GSM Calculation

DIFFERENT FABRIC GSM AND THEIR REQUIRED YARN COUNT

Rib without lycra

Interlock without lycra

-Fabric G.S.M Yarn Count

Lacoste without lycra

-Fabric G.S.M Yarn Count

Yarn Dyeing

Calculation and Equation

Production Calculation of Yarn singeing machine:

Length = Count * Weight

= Count * Weight * 840 yards

= (Count * Weight * 840) / rpm yards per minute

= (Count * Weight * 840) / rpm * 60 * 8 * 3 yards per day

= (Count * Weight * 840) / rpm * 60 * 8 * 3 * 0.914

=……X…meter/day

Production Calculation of reeling machine:

Production Calculation of hank to cone winding machine:

Length = Count × Weight = Count * Weight × 840 yards = (Count × Weight × 840) / rpm yards per minute = (Count × Weight × 840) / rpm × 60 × 8 × 3 yards per day = (Count × Weight × 840) / rpm × 60 × 8 × 3 × 0.914 =……X…meter/day

GSM Calculation:

WPI = 32 CPI = 45 Stitch length = 3 mm Yarn Count = 20’S Ne

No of Needle = π × Machine Diameter (D) × Machine Gauge (N)

Production Calculation Of Yarn Dyeing Machine :

Production of the machine is 146.407 Kg/Shift.

Note: If any parameter in this calculation is changed then production capacity per shift will be changed.

Package Density Calculation (Yarn Dyeing):

Formula

Density Calculation for Several Counts (Yarn dyeing):

1**Before Pressing

• Yarn Quality: 30/1 cc

• Package Height (H) = 162mm = 16.2cm

• Total Package Dia (D1) = 162mm = 16.2cm

• Total Package Weight (W1) = 1.38kg = 1380gm

• Spring Weight (W2) = 0.185kg = 185gm

• Spring Dia (D2) = 65 mm = 6.5cm

2 **After Pressing

Yarn Quality: 30/1 ccPackage Height (H) = 145mm = 14.5cmTotal Package Dia (D1) = 165mm = 16.5cmTotal Package Weight (W1) = 1.38kg = 1380gmSpring Weight (W2) = 0.185kg = 185gmSpring Dia (D2) = 65 mm = 6.5cm

**So we can sure that after pressing for every count, yarn package density will be increase

Density Calculation for Several Counts (Yarn dyeing):

Length Calculation in Package:

To maintain the constant package density same length of yarn should be wound to all the packages of a batch or lot The dyeing machine capacity is calculated on weight, so it is necessary to maintain the uniform weight throughout the packages To do this for a definite count of yarn following calculation is followed,

In this machine length is pre selected For different count of yarn different length of yarn is pre selected This is due to maintain the constant package weight and package density

Package density Calculation

We know package density ρ = mass (m)/volume (v) gm/cc

Volume= π (R2-r 2) h

R= outer radius of package R= inner radius of package h= height of package Now we consider a sample of 40/1 cotton yarn whose

R=4.138 r= 1.59 h=15.24 Mass m=1000gm

Production calculation of RF Dryer :

Length of RF Dryer = 13m

At 28rpm it takes 21 min 9 sec to pass this length

Along this length it can accommodate 416 package 416kgs

So at 21 min9sec or 1269sec it can dry 416kgs

So in 1hr or 3600sec it can dry = 416×3600/1269 kg/hr

Knit Dyeing

Calculation and Equation

Calculations related to batch section:

Now, when a gram per linear meter is low then meters per chamber will be more Thus, fabric loading should be reduced to avoid jamming in the winch In this case 80-85% fabric

loading is given But when gram per linear meter is more then rope length will reduce and in this case up to 90% fabric loading can be given

Calculating the chamber loading

In the following table are listed general recommendations covering rope cycle times and speeds for a wide range of fabrics:

Fabric Rope cycle times in minutes

Preparation and storage of stock dyes and chemicals

Available stock solution:

1. Red-0.1%, 0.5%, 1%, 2%

2. Yellow-0.1%, 0.5%, 1.0%, 2.0%,

3. Blue- 0.1%, 0.5%, 1.0%, 2.0%

Preparation:

 To prepare 0.1% stock solution, it necessary to mix 0.1 gm dye with 100cc water

 To prepare 0.5% stock solution, it necessary to mix 0.5 gm dye with 100cc water

 To prepare 1.0% & 2.0% stock solution similar procedure is followed

 To prepare 10% stock solution of soda ash, it necessary to mix 10 gm soda with 100cc water

Stock Solution Making Procedure (Dyeing lab)

For solid,

X gm chemicals/dyes/auxiliaries in the 100 ml water is called x% stock solution

For liquid,

X ml/cc chemicals/dyes/auxiliaries in the (100 - x ml/cc) water is called x% stock solution

Conversion formula from percentage to g/l is as

g/l = Required amount (%)× 10

Recipe Calculation

Dyes and chemicals measuring formula for laboratory:

The amount of dye solution (ml) is calculated as follow –

The amount of chemical soln (ml) is measured as follow –

Fabric Type GSM Pump Speed % Reel Speed(MPM)

Polo Pique, Back Pique

& Bubble Knit

MONTHLY EFFICIENCY OF KNITTING FLOOR:

Daily production – 6500 kgs Approx

Daily production capacity – 10000 kgs approx

So, monthly production – 6500 x 30 kgs

Monthly production capacity – 10000 x 30 kgs

So, Monthly production efficiency = (6500x30x100)/ (10000x30) %

= 65%

Calculation and Equation

COSTING OF THE PRODUCT: Let

Packing cost = $0.05Production cost of fabric=$6.15Fabric price (with 25% margin) =$7.79

Fabric consumption/ doz

= (Body length + Sleeve length +10) x Chest length x 2 x GSM x12 /10000000

Cost of Trims (with 5% Process loss) = $2.36

Production Cost of Garments/ doz=$36.09

Garments Price/doz (with 25% Profit) =$45.12

COSTING OF THE PRODUCT:

Costing of Men’s shirt

Fabric consumption for a dozen of shirt π × L size of basic shirt.═

Width of body of shirt 1/2 chest═

Consumption of a body shirt:

═{1/2 chest× (body length) ×2} / 36× fabric width (Sq inch) ═25"×33"×2 (Sq inch )

{Let assume fabric width 25"effective width 25"−1" 24"}═ ═

Fabric length 25×33×2 / 44 inch═

Fabric consumption 25×33×2 / 44×36 yds═

Consumption of sleeve (length of sleeve × width sleeve) ×2 sq inch═

Sewing threads consumption:

It is calculated by measuring the total of different kind of seam Normally sewing threads consumption per shirt , 120m

So, sewing threads consumption per dozen,

═120 × 12

═1440m

Costing of Men’s shirt

Total = $ 28.80 / Doz = $ 2.40 / pcs.

How can we get Fabric Consumption & Fabrics Price?

Poly bag costing :

Total Length X width X Thickness

= 36cm X 28cm X 10mm

= 10080/72000

= 0.14pcs/lb

Fabrics Price:

Total Fabric Need 5.00 Kg × $ 6.00 = $ 30.00

Trim/ Accessories (Minimum Charge) = $ 2.50

Cutting & Making Charge (C.M) = $ 5.00

Printing Charge (If any) = $ 0.00

Embroidery Charge (If any) = $ 0.00

Buying Commission (If necessary) 5% = $ 1.97 Final/Total = $ 39.47/12

Costing of a garment:

Fabric cost + Accessories cost + Trimming cost + Production cost + Transport cost + Commission + Profit

Consumption of T-Shirt:

Equation:

{(Body length + Sleeve length) × Chest} × 2 × GSM ÷ 10000 ÷ 1000 × 5000

Solution:

Body Length = 50 + 6 (Allowance) = 56 cm

Sleeve Length = 15 + 3 (Allowance) = 18 cm

Chest = 37 + 3 (Allowance) = 40 cm

GSM = 180 cm

= {(56 + 18) × 40} × 2 × 180 ÷ 10000 ÷ 1000 × 5000

= 532.8 kg

Collar depth =2.5 cm × 2 = 5 cm GSM = 240

= {(44 + 5) × 5} × 2 × 140 ÷ 10000 ÷ 1000 × 5000

= 58.8 kg

Total = 532.8 + 58.8 kg = 591 kg

Collar & Cuff measurements

Consumption of bottom part:

Equation:

Length*(width*4)*G.S.M÷10000÷1000*12Length=53=8=2=63cm

1.5705kg

Costing process:

Finish fabric cost: (Yarn price + Knitting cost + dyeing cost)

Body fabric cost: (Total fabric consumption + Total yarn consumption)

Cost of making (CM):………$

Accessories cost:……… $

Overhead cost………$

Others cost:……….$

Buyer commission:……….$

Total cost $

Costing process:

PRICE OF THE PRODUCT:

Generally price of product is determined by the required profit adding to the total expenses So,

Price of products

= (Direct expenses + Indirect expenses + Factory Overhead) + Required profit

MARKER EFFICIENCY: The marker planner measures his success by the efficiency of the marker plan The following formula is used to measure the efficiency:

Marker efficiency=Area of the pattern in the marker plan/ Total area of the marker plan X 100%.

MARKER EFFICIENCY:

STANDARD TIME = Normal time + Allowances

= Normal time + (Normal time ×Allowances)

= NT (1+ Allowances)

In garments production world, the terms SMV or SAM used frequently

 SMV stands for Standard Minute Value

 SAM for Standard allocated minute or Standard Allowed Minute

SMV CALCULATION:

SMV calculation of a basic T-shirt from a time study sheet of a garments industry Following formulas are

use- Normal time = (Average observed time) × (Performance rating factor)

 SMV (Standard Minute Value) = Basic Time + (Allowances × Basic time)

= Basic Time× (1+ Allowance)

 Allowances are assumed for this calculation is 20%

SMV

Target Production /Hour = (No Of worker -1) x 60 / SMV

SMV = standard Mean Value (the Time Required to Complete garments by sewing )

SMV =( Basic time +Allowance )

To select sewing thread, thread size or number is very important The number which is used to express the fineness of a sewing thread is called sewing thread number or ticket number It has 2 system as follows-

Cotton system : It is derived from English cotton system.

Cotton ticket number in Ne = ( Yarn count in Ne / Number of ply ) x 3

Metric system : It is derived from Metric count system.

Ticket number in Nm = ( Yarn count in Nm / Number of ply ) x 3

sewing thread number or ticket number

Equation For Find Yarn Count (If GSM is Known)

Find out Required Yarn Count (If GSM is Known)

Per Yards Fabric price

Equation :

= GSM / 43” X Width / 1000 X Per kg Prize

=Result [This the Equation define per yards Fabric price ]

Meter To Yards

Equation :

= Length /36 / 2.54 X 1000

=Result [ It is converted Meter To yards ]

Textile Testing

Calculation and Equation

Four point grading system

Over 3 inch but not over 6 inch 2 point Over 6 inch but not over 9 inch 3 point

Four point grading system

Shrinkage Test:

Spirality test: