Knitting Equation

WPI:

Wales per inch is called WPI.

CPI:

Course per inch is called CPI.

Needle calculation:

Single jersey circular knitting machine needle = ∏DG

Rib/Inter lock /Double jersey circular knitting machine needle

= ∏DG×2

(two needle bed is here)

Single bed flat knitting  m/c’s  needle = width× gauge

V bed flat knitting m/c’s needle = 2× width× gauge

Here,

D = cylinder diameter

G = Machine gauge

Needle pitch = 1/G.

GSM:

Grams per squire meter of the fabric are called GSM.

GSM = {WPI× CPI ×(39.37)2×stitch length (mm)×Tex /1000×  1000}g/m2

Stitch density = (WPI × CPI )inch-2

                        = (WPC ×CPC) cm-2

No of sinker = No of needle

No Wales =No of needle

No of course = No of feeders

                      =No of yarn (per revolution of cylinder)

Course per minutes = No of feeders ×cylinder rpm

Course length = yarn required for each course.

                          = No of needle × stitch length

Fabric width = wale spacing ×Total no of Wales

                       = (1/WPI ×No of Needles) inch

                       = (No of Needles/WPI× 39.37) meter

For single jersey fabric = (∏DG/WPI×39.37) meter (open width)

                                      =(∏DG/WPI×39.37) meter/2(Folded/Tubular width)

For double jersey fabric = (2 × ∏DG/WPI×39.37) meter (open width)

                                             

                         = (2×∏DG/WPI×39.37) meter/2(Folded/Tubular width).

Fabric Length =Course spacing ×Total course pr hour

                        = {(Feeder× cylinder rpm× 60)/CPI} inch/hour

                        = {(Feeder× cylinder rpm× 60)/CPI ×39.37} m/hour