Knitting

Process Flow chart of Knitting (Circular):

Sample Fabric

Design analysis

Machine Selection

Machine Setting for the Required Design

Knitting of the Fabric

Conform Required Quality

Withdraw the Rolled Fabric and Weighting

Inspection

Delivery

Types of Raw Materials….

Types of fabric

Machine Description

DIFFERENT PARTS & THEIR FUNCTION OF CIRCULAR KNITTING MACHINE:

Creel: Creel is a part of knitting machine. Here yarn package are store and ready to feed in the machine.

 VDQ pulley : It control the quality of the product. Altering the position of the tension pulley changes the G.S.M. of the fabric. If pulley moves towards the positive direction then the G.S.M is decrease. And in the reverse direction G.S.M. will increase.

Pulley belt: It control the rotation of the MPF wheel.

 Brush: It clean the pulley belt.

 Tension disk: It control the tension of the supply yarn.

 Inlet &Outlet stop motion: It stops the machine when yarn breaks.

 Yarn guide: It helps the yarn to feed in the yarn feeder.

 Feeder ring: It is a ring where all feeders are placed together.

 MPF: It gives the positive feed to the m/c.

 Feeder: It helps yarn to feed into the m/c.

 MPF wheel: It control the speed of the MPF.

 Needle: It helps the yarn to create a loop and by this way fabric are produced

 Needle Track: Where all needle are placed together in a decent design.

 Sinker: It helps to loop forming, knocking over & holding down the loop.

Cam: It is a device which converts the rotary m/c drive into a switable reciprocating action for the needles & other elements

 Sinker ring: It is a ring where all sinkers are placed together.

 Lycra attachment: lycra is placed here & feeding to the m/c.

. Lycra stop motion: It stops the m/c when the lycra is break.

 Cam box: Where the cam are set horizontally.

 Inverter: It is the heart of the circular knitting m/c. It control the speed of the m/c.

. Cylinder/Dial: Needle track are situated here.

 Screen: It is a digital screen which show the all m/c information & we can give command to the m/c.

Cylinder balance: It helps the cylinder to set in a proper alignment.

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 square 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

Typical Parameter For Knit Fabric:

Sample Design& Cam Arrangement

Knitting Fabic Fault Cause and remadies

Method of Increasing Production

—1. By increasing m/c speed:

  Higher the m/c speed faster the movement of needle and ultimately production will be increased.

—2. By increasing the number of feeder:

  If the number of feeder is increased in the circumference of cylinder, then the number of courses will be increased in one revolution at a time.

—3. By using machine of higher gauge:

  The more the machine gauge, the more the production is. So by using machine of higher gauge production can be increased.

—4. By imposing automation in the m/c:

   a) Quick starting & stopping for efficient driving system.

   b) Automatic m/c lubrication system for smoother operation.

   c) Photo electric fabric fault detector

—5. By imposing other developments: 

a)Using creel-feeding system.

b)Applying yarn supply through plastic tube that eliminates the possibilities of yarn damage.

c)Using yarn feed control device.

d)Using auto lint removal.