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Production Calculation of Speed Frame or Simplex

Production Calculation of Speed Frame or Simplex
Rofiquzzaman Raju
Fabric Technologist,
B.J.Group, Mawna, Gazipur
Chittagong Textile Engineering College
Facebook: https://www.facebook.com/ERZRAZU




Speed Frame:
Speed Frame or Simplex is an important process in ring spinning. In this process fibers are converted into low twist lea called roving. So it is also called roving frame. The main function of roving frame is the attenuation of sliver. To draft the sliver to reduce weight per unit length. The sliver which is taken from draw frame is thicker so it is not suitable for manufacturing of yarn. By speed frame sliver are converted to roving. Which is appropriate for next process. Speed frame is used to the carded and combed yarn process but for the rotor spinning system this process can be eliminated.
Speed Frame

Simplex Production Calculation:
Problem: 1
Calculate the TPI (twist per inch) produced on a simplex with diameter of front roller 28 mm and its rpm be 30. The rpm of flyer is 1000.

Solution:

Here,

Dia of front roller = 28 mm = 2.8 cm = 1.1024 inch
rpm of front roller = 30
rpm of flyer = 1000
TPI = ?

We know,

Surface speed of front roller = π x Dia of front roller x rpm of front roller
= π x 1.1024 x 30
= 103.9 inch/min

                        Flyer speed or Spindle speed (rpm)
Twist or TPI = ………………......……………………
                             Delivery speed (inches/min)

    1000
= ……………
   103.9

= 9.63 (Ans)

Problem: 2
Calculate the TPI on simplex if the diameter of back roller is 15/16’’, rpm of B.R is 10, rpm of flyer is 1000 and draft is 6.

Solution:

Here,

Dia of B.R. = 15/16 = 0.9375 inch
Draft = 6
rpm of F.R. = 30
rpm of B.R = 10
rpm of flyer = 1000
TPI = ?

We know,

Surface speed of B.R. = π x Dia of B.R. x rpm of B.R
= π x 0.9375 x 10
= 29.45 inch/min

                      Surface speed of F.R.
Total draft = ………………………….
                     Surface speed of B.R.

=> Surface speed of F.R.= 6 x 29.45 = 176.7 inch/min

                        Flyer speed or Spindle speed (rpm)
Twist or TPI = …………………......……………….
                            Delivery speed (inches/min)

   1000
= …………
   176.7

= 5.66 (Ans)

Problem: 3
If Spindle speed = 1600 rpm, Roving count = 90 Ne, TM (Twist Multiplier) = 4.2, Efficiency = 85% then calculate the production of a speed frame in lb/hr.

Solution:

We know,

                      Spindle speed
Production = ……………..
                             TPI

TPI = TM√(Roving count)

Efficiency = 85% = 85/100 = 0.85

Now,

                     Spindle speed
Production = ……………..
                            TPI

   1600 x 60 x 1 x 0.85 x 120
= ……………………………………….
   4.2√.90 x 36 x 840 x 0.90

= 90.297 (Ans)


How to Select Yarn Count for Specific Fabric GSM

How to Select Yarn Count for Specific Fabric GSM
Rofiquzzaman Raju
Fabric Technologist,
B.J.Group, Mawna, Gazipur
Chittagong Textile Engineering College
Facebook: https://www.facebook.com/ERZRAZU



Yarn Count:
Yarn count is very useful to know the condition of yarn. I mean, yarn is thick or thin. So we can define count in the following way,

The yarn count is a numerical expression which indicates the coarseness or fineness of a yarn.

Fabric GSM:
GSM means Grams per Square Meter. Fabric GSM means weight of one square meter fabric in grams. GSM plays an important role in textile industry. It is widely used in case of knit fabric measurement. By this we can compare the fabrics in unit area which is heavier and which is lighter.

How do Select the Correct Yarn Count for Your Specific Fabric GSM?
How to select yarn count for specific fabric GSM is a very common and technical task for textile engineers. By the using following formula you can easily select the actual yarn count for knit the fabric. These are varying for fabric types.

Single Jersey:
Say, the require GSM is 160

Yarn count = (-0.141) X (GSM) + 50.22
= (-0.141) X (160) + 50.22
= -22.58 + 50.22
= 27.66

So, to knit 160 gsm single jersey fabric we need yarn count 27.66/s

Interlock:
Say, the require GSM is 220

Yarn count = (-0.206) X (GSM) + 80.56
= (-0.206) X (220) + 80.56
= -45.32 + 80.56
= 35.24

So, to knit 220 GSM Interlock fabrics we need yarn count 36/s

Pique:
Say, the require GSM is 220

Yarn count = (-0.146) X (GSM) + 57.16
= (-0.146) X (220) + 57.16
= -32.12 + 57.16
= 25.04

So, to knit 220 GSM Pique fabric we need yarn count 36/s

1*1 Rib:
Say, the require GSM is 220

Yarn count = (-0.123) X (GSM) + 54.57
= (-0.123) X (220) + 54.57
= -27.06 + 54.57
= 27.51

So, to knit 220 GSM 1x1 Rib fabrics we need yarn count 28/s

Double Lacoste:
Say, the require GSM is 220

Yarn count = (-0.167) X (GSM) + 64.36
= (-0.167) X (220) + 64.36
= -36.74 + 64.36
= 27.62

So, to knit 220 GSM Double Lacoste fabrics we need yarn count 28/s

Lycra 1×1 Rib:
Let, required fabric GSM is 180

Yarn Count = (-0.119) GSM + 59.12
= (-0.119) x 180 + 59.12
= -21.42 + 59.12
=37.7

Lycra 2x2 Rib:
Say, the require GSM is 220

Yarn count = (-0.108) X (GSM) + 56.62
= (-0.108) X (220) + 56.62
= -23.76 + 56.62
= 32.86

So, to knit 220 GSM Lycra 2x2 Rib fabrics we need yarn count 32/s


How to Find Out Sewing Time with Machine RPM

How to Find Out Sewing Time with Machine RPM
Noor Ahmed Raaz
B.Sc. in Textile Engineering (CU)
Specialized in Apparel Manufacturing
Merchandiser
A.M.C.S Textile Ltd (AEPZ)
Email: raju.uttara105@gmail.com



Introduction:
Calculation of sewing time is an important task for industrial engineers. Because it will be effective to get actual time to be taken by a sewing operator to sew a specific length of seam. From this we can get an operator production efficiency easily. If you read article with concentrately then I think you easily calculate sewing time.
Sewing by an operator
Sewing by an operator
Estimation of Sewing Time Using Machine RPM:
Machine RPM means Revolution Per Minute of that machine. By machine RPM we can get time to sew a specific length of seam with specific Stitch per Inch (SPI). Before calculating garments sewing time by using machine RPM, an industrial engineer should confirm about the below points: 

  • Stitch per inch (SPI) of the garments,
  • Seam length in inch of the garments,
  • Sewing machine RPM (Revolution per minute).
Now by using the below formula, an industrial engineer can easily calculate the required garments sewing time from machine RPM.

Machine cycle time or sewing time (in second),

   Stitch per inch (SPI) x Seam length in inch x 60
= ……………………………………………………………
                 Sewing Machine RPM

If we see an example then concept will be clear,
Example:
If a plain stitch sewing machine RPM is 1400. How much time needed to sew a 40 inch length seam, where stitch per inch (SPI) is 8?

Solution:

Here,

Sewing machine RPM= 1400,
Seam length in inch= 50”,
Stitch per inch (SPI) = 8.

We know that,

Machine cycle time or sewing time (in second),

   Stitch per inch (SPI) x Seam length in inch x 60
= ………………………………………………………
                  Sewing Machine RPM

   8 x 50 x 60
= …………………
       1400

   24000
= …………
   1400

= 17.14 sec

So. Sewing time of that machine is 17.14 sec.


Poly Bag Consumption in Garments Industry

Poly Bag Consumption in Garments Industry
Mayedul Islam
Merchandiser at Fashion Xpress Buying House.
Badda, Dhaka, Bangladesh.
Email: mayedul.islam66@gmail.com


Introduction:
Poly bags, commonly known as polythene bags, have a variety of uses in many industries. But it has great use in garments industry. It is used to contain garments destined for export or to merchandise so that apparels remain intact and they could not obtain dust, dirt or moisture. Poly bag consumption is an important matter in apparel merchandising. Because it also keeps effect on total pricing of order. In previous article we have discussed on costing of poly bag for merchandisers.
Poly bag in garment industry
Consumption of Poly Bag:
For consumption of poly bag, apparel merchandiser should know the following information.
  1. Poly bag length in inch
  2. Poly bag width in inch
  3. Thickness of poly bag in gauge,
  4. ½ flap of poly bag
  5. Print on the poly bag
Using formula, we can easily calculate the poly bag consumption in garment industry.

Poly bag consumption (for 1000pcs in kg),

   (Poly bag length + ½ Flap) x Poly bag width x Thickness of poly bag
= ……………………………….…………………………………………..……
                                                    3300

Note: 3300 is a constant number for 1000 pcs

For clearing this formula, I’m giving an example. I think it will be helpful to understand this formula.

Example:
Suppose, for a garments export order (100,000pcs), the buyer “GAP” suggests the below information about the poly bag.

Length of poly bag- 40”,
Poly bag width- 30”,
Thickness of poly bag- 170 gauge,
½ flap of poly bag- 3”,

Now you have to calculate the poly bag consumption for the above order.

Solution:

Poly bag consumption (for 1000pcs in kg),

   (Poly bag length + ½ Flap) x Poly bag width x Thickness of poly bag
= ……………………………….……………………………………………………
                                                 3300

   (40 + 3) x 30 x 170
= ……………………………
             3300

   43 x 30 x 170
= ………………….
        3300

   219300
= ……………
    3300

= 66.45

66.45 kg per 1000pcs poly bag.

So, for 1000pcs poly bag, LDPE polymer needed 66.45kg.

For 100,000pcs poly bag, LDPE polymer needed = (66.45 × 100) = 6645kg.


Fabric Consumption for Basic T-shirt

Fabric Consumption for Basic T-shirt
Mayedul Islam
Merchandiser at Fashion Xpress Buying House.
Badda, Dhaka, Bangladesh.
Email: mayedul.islam66@gmail.com



Introduction:
Fabric consumption is an important task for garments merchandiser. Because 50% cost for garments making is fabric. If fabric consumption and calculation is not correct then company will face to huge loss. There are two formula or process of fabric consumption for basic t-shirt. One in Centimeter and another in Inch. They are given below.

Sketch of t-shirt
Calculation – 01: Formula in Centimeter:
Suppose one of T-shirt’s Body length (72+4) cm, Slib length (23+2) cm, Chest length (Dia) (53+2) cm and G.S.M 180. Determine the fabric consumption for the basic T-Shirt.

Solution:

Here, Body Length = 76 cm
Sleeve Length = 25 cm
Chest Length = 55×2=110 cm (For both side)

We get,

                                   (Body length + Sleeve length) x (Chest x 2) x G.S.Μ
Fabric consumption = ……………………………………………......………….. Kg
                                                                  1000 x 10000

   (76 + 25) x (55x2) x 180
= …………………………………
          1000 x 10000

    101 x 19800
= …………………
      10000000

   1999800
= ………………….
   10000000

= 0.19998 kg

The amount of fabric is just for 1 piece. Generally 12 pieces are counted with one.

Fabric consumption for 1 Dozen = 12×0.19998 kgs
= 2.399 kgs

Fabric consumption for 1 Dozen 2 kgs and 399 gms.

Calculation – 02: Formula in Inch:
Here, Body Length = (28+ 1) inch
Sleeve Length = (9+1) inch

Chest Length = (21+1) inch =22 inch×2
= 44 inch

G.S.M = 180

According to formula,

                                   (Body length + Sleeve length) x (Chest x 2) x G.S.Μ
Fabric consumption = ……………………………………………….........……….. Kg
                                                                 1550 x 1000

  (29 + 10) x (22x2) x 180
= …………………………………..
        1550 x 1000

    308880
= ………………….
   1550000

= 0.199920 kgs

The amount of fabric is just for 1 piece. Generally 12 pieces are counted with one.

Fabric consumption for 1 Dozen = 12×0.199920 kg
= 2.391 kg

Fabric consumption for 1 Dozen 2 kg and 391 gm. 

Relation between Finished GSM and Yarn Count of Various Fabrics

Relation between Finished GSM and Yarn Count of Various Fabrics
Rofiquzzaman Raju
Fabric Technologist,
B.J.Group, Mawna, Gazipur
Email: rtextile.finance@gmail.com



Introduction:
GSM’ means ‘Gram per square meter’ that is the weight of fabric in gram per one square meter. It is one kind of specification of fabric. Count is the coarseness or fineness of yarn. There are important relation between yarn count and GSM in knitted fabric. In this article there are some relation are given for different fabrics.

Table-1: Relation between finished G.S.M. and yarn count of s/j and rib fabric


Single  Jersey

Rib
Yarn count
Finished G.S.M.
Yarn count
Finished G.S.M.
18 s
220-230
18 s
280-290
20 s
200-220
20 s
260-280
24 s
180-190
24 s
240-250
26 s
160-170
26 s
230-240
28 s
150-160
28 s
220-230
30 s
140-150
30 s
200-220
34 s
120-130
34 s
180-200
 Table-2: Relation between finished G.S.M. and yarn count of knitted fabrics

Interlock
Lycra  S/J
Yarn count
Finished G.S.M.
Yarn (Lycra) count
  Finished  G.S.M.
34 s
250-270
30 s +20D
    190-200
36 s
230-250
34 s+20 D
    180-190
38 s
200-210
38 s+20 D
    160-170
40 s
190-200
40 s+20 D
    150-160
 Table-3: Relation between G.S.M. and yarn count of fleece fabric and double lacoste

Fleece  Fabric (100% Cotton)
Double  Lacoste
Yarn count
G.S.M.
Yarn count
 G.S.M.
34s+34 s+10 s
260-270
22 s
240-260
30 s +34 s+10 s
280-290
24s
220-240
28 s+30 s+10 s
290-300
26 s
200-220
26 s+30 s+10 s
310-320
28 s
180-200
24 s +30 s+10 s
340-350
30 s
160-180