Fabric programming
KEY WORD G.S.M. Yarn Count. Stitch length. Yarn Diameter. Fabric Width. Machine gauge. Needle gauge. Wales space. Needle pitch.
What is fabric? Fabric is a manufactured assembly of fibres and yarns that has substantial surface area in relation to its thickness and sufficient cohesion to give the assembly useful mechanical strength. Fabrics are most commonly woven or knitted but the term includes Assemblies produced by felting, lace making, net making, non woven processes and tufting. Our Study basically is on knitted fabric specification and machines which are related to knitted fabric production.
How we analyze fabric? In the analysis of woven fabric specification we consider ends per inch, picks per inch, yarn count (warp & weft), and fabric width In case of knitted fabric specification GSM, stitch length is mainly considered. Target of this training Our target is to find out the easy process to get decision about yarn count selection, loop length selection, machine Diameter selection & machine gauge selection for required G S M By this process we can get decision about yarn count, loop length, machine gauge, and machine diameter for the single jersey, Rib and interlock fabric.
Catchy solutions Venkatramani. Gireesan Contact: +919940839662 e-mail:
[email protected]
Fabric programming
Aims of the Training Find out relation between yarn count and GSM. Find out the logic of selection of stitch length. Selection of machine diameter and machine gauge to get specific width of fabric. Find out the finished fabric width. TERMINOLOGY AND DEFINITION WALES PER INCH: Wales per inch means how many numbers of Wales are present in one inch, it is very important for calculation of knitted fabric GSM and fabric properties. COURSES PER INCH: Courses per inch mean how many numbers of courses are present in one inch. It is also very important for calculation of knitted fabric GSM.
STITCH LENGTH: Stitch length is theoretically a single length of yarn which include one needle loop and half the length of Yarn (half of a sinker loop) between that needle loop and the adjacent needle loops on either side of it. Loop exists in course in course length and it is that which influence fabric dimension and other properties including weight.
MEASUREMENT OF YARN COUNT: A different way to find out the count of the yarn. At first unravel a considerable no yarn from the fabric. Then measure the total length of the yarn and measured the weight of that no of yarn. From these weights, we find out the count of the yarn. The equation we followed is as follow: Count =
n * L * 453.6 Wt *36* 840
Where, n= number of yarn in bundle.
L= length of yarn.
Wt= weight of yarn.
Catchy solutions Venkatramani. Gireesan Contact: +919940839662 e-mail:
[email protected]
Fabric programming
MEASUREMENT OF GSM: GSM =
Ks * Tex Stitch length (mm)
Stitch length =
Ks * Tex GSM
Ks =
GSM * Stitch length Tex
Where, Ks is a constant. Its value is different for different fabric structure and fabric type. There are two formulas for calculating the GSM of a knitted fabric. i.e. First formula is GSM =
Course per inch * Stitch length * 39.37 * 39.37 * Tex 1000 * 1000
GSM =
WPI * CPI * SL(mm) Count (Ne)
CPI =
x 0.9155
Count (Ne)*GSM WPI * SL (mm)
x 0.9155
Some reference for Ks value Fabric Type
Color
Value of Ks
Single jersey
Average
19.55
Single lacoste
Average
22.4
Double lacoste
Average
22.75
Polo pique
Average
25
Plain interlock
Average
39.3
1×1 Rib
Light
24.5
1×1 Rib
Average
26.5
2×1 Rib
Average
28.3
Catchy solutions Venkatramani. Gireesan Contact: +919940839662 e-mail:
[email protected]
Fabric programming Flat back rib
Average
81
3 Thread fleece
Average
40.92
To find suitable yarn count for Required GSM Name of the fabrics
Equations
Single jersey
Yarn count = (-) 0.141 GSM + 50.22
Pique
Yarn count = - 0.146 GSM + 57.16
Double lacoste
Yarn count = - 0.167 GSM + 64.36
1 x 1 Rib
Yarn count = - 0.123 GSM + 54.57
Lycra 1 x 1 Rib
Yarn count = - 0.119 GSM + 59.12
Lycra 2 x 2 Rib
Yarn count = - 0.108 GSM + 56.62
Interlock
Yarn count = - 0.206 GSM + 80.56
To find suitable GSM for yarn count Name of the fabrics
Equations
Single jersey
GSM = -6.879yarn count + 350.4
Lycra single jersey
GSM = -4.9716 yarn count + 354.56
Pique
GSM = -6.6737 yarn count + 386.44
1 *1 Rib
GSM = -7.9731 yarn count + 437.66
Lycra 1 * 1 Rib
GSM = -8.2839 yarn count + 494.08
Lycra 2 * 2 Rib
GSM = -9.1216 yarn count + 519.05
Interlock
GSM = -4.778 yarn count + 388.41
Catchy solutions Venkatramani. Gireesan Contact: +919940839662 e-mail:
[email protected]
Fabric programming
EQUATION FOR DETERMINING FABRIC WIDTH: Fabric width = No. of wales * Wales space.
= No. of needle * Wales space.
= πDg * Wales space
D= Cylinder diameter. g = Gauge. Fabric width = No. of needle FOR CALCULATING YARN DIAMETER:
Catchy solutions Venkatramani. Gireesan Contact: +919940839662 e-mail:
[email protected]
Fabric programming In case of minimum loop length there is no space left in interloping area. i.e. stretched due to tension the wales space become less than 4d (d is the yarn diameter) When loop length is increased the space into the interloping area are increased as a result wales space becomes wider. It may be up to 5.2d
D=
0.91 √ne
D = √Tex 26.7
Fabric Type
Yarn count
Stitch length (mm)
Colour
M/c DIA
M/c Gauge
Finished diameter (inch)
Finished GSM
18s/1 20s/1 24s/1 26s/1 28s/1 30s/1 34s/1 40s/1
2.94 2.98 2.68 2.66 2.70 2.68 2.40 2.44
White White White White Average Average Average Average
26 30 30 30 26 30 26 24
24 24 24 24 24 24 24 24
30 33.5 32 31 25 30 24 20
220-230 200-210 175-185 160-170 150-160 130-140 125-135 100-110
18s/1 24s/1 26s/1 30s/1
3.00 2.64 2.60 2.50
Average Average Average Average
30 30 30 30
24 24 24 24
46 40 36 34
245-255 210-215 200-210 180-190
Plain S/j
Single lacost
Catchy solutions Venkatramani. Gireesan Contact: +919940839662 e-mail:
[email protected]
Fabric programming
CONVERSION FOR YARN
M/C Gauge
Ne
18 20 22 24 26 28 30 32
14/1 - 24/1 18/1 – 26/1 20/1 – 30/1 24/1 – 34/1 26/1 – 40/1 30/1 – 50/1 34/1 – 60/1 40/1 – 70/1
Catchy solutions Venkatramani. Gireesan Contact: +919940839662 e-mail:
[email protected]
