Different Tricot Structures with Guide Bars

Different Tricot Structures with Guide Bars
Rofiquzzaman Raju
Fabric Technologist,
B.J.Group, Mawna, Gazipur
Email: rtextile.finance@gmail.com



Fabric produced with two fully threaded guide bars:
In order to produce a warp knitted fabric it is necessary to obtain the information regarding its production.

Many different data items are involves such as-
  1. Information describing the knitting m/c; number of guide bars, m/c gauge, width of the needle bed and special attachments used
  2. Information concerning the type and count of yarn threaded I each guide bar
  3. Lapping movement of each bar
  4. The run-in per rack of each bar
  5. Threading information if the guide bars are not fully and uniformly threaded
  6. Fabric quality and weight
  7. The finishing process
Types of Tricot Structures:
  1. Two bar tricot fabric
  2. Locknit fabric
  3. Reverse locknit
  4. Satin fabric
  5. Sharkskin
  6. Queenscord
A short description of the above tricot structures are given here....
1. Two bar tricot fabric:

Lapping diagram:
Chain notation-

1-2/1-0//                   1-0/1-2//
  • The bar tricot is the simplest two bar structure and uses a minimum amount of yarn
  • Lapping movement of two guide bar in opposite direction and makes closed lap
  • The two laps balance each other exactly as they cross diagonally in between each wale, producing upright overlaps
  • It tends to have poor cover and in fire denier and in continuous filament yarn it tends to split between the wales either during tentering or button-holing, especially if acetate or triacetate yarn is used
  • Run-in ratio is 1:1
2. Locknit fabric:

Lapping diagram:
Chain notation-

2-3/1-0//             1-0/1-2//
  • It is the most popular of all warp knitted structures and accounts for 70-80% of total output
  • Front guide bar – 2 needle space shogging movement i.e. closed lap cord structure and back guide bar – closed lap tricot structure i.e. 1x1 lapping movement. But lapping movement of two guide bar is opposite
  • The longer underlaps of the front bar improves extensibility, cover, opacity, drape and handle of fabric
  • Used to produce lingerie and intimate apparel
  • Shrinkage is generally between 20-30%
  • Its tendency to curl towards to face and back can be reduced by heat setting
  • An elasticity fabric for lingerie may be produced on the same gauge, using 40 denier nylon and 40 denier spandex.
  • Stretch lingerie can be knitted in the same gauge using 44 dtex elastane and 44 dtex nylon
  • A knitting width of 168″ can be finished between 92 and 100″
  • The finest lingerie can be knitted in E44 gauge from 22dtex polyester with a wt of 46.1gm/m2.
  • Run-in ratio is 3:4
3. Reverse locknit:

Lapping diagram:
Chain notation-

1-2/1-0//                             1-0/2-3//
  • Reverse locknit known as reverse jersey in the USA
  • Semi staple or semi structure
  • Front guide bar tricot structure and back guide bar cord structure and lapping mover are opposite
  • It has reduced extensibility and no curling
  • Because of the short front guide bar, underlaps, it has a lower shrinkage in finished width.
  • It has lesser extent than locknit
  • It is fully reverse of locknit
  • Run-in ratio – 4:3
4. Satin fabric:
 
Lapping diagram:
Chain notation-

3-4/1-0//                          1-0/1-2//

Lapping diagram:
Chain notation-

3-4/1-0//                          1-0/1-2//
  • Lapping movement of front guide bar – longer than locknit structure i.e. closed satin stitch and back guide bar – same to locknit structure of back guide bar. i.e. Tricot structure
  • Lapping movement of two guide bars are opposite
  • Technical face is comparatively very lustrous and smooth
  • Greater elasticity and extensibility and very comfortable to wear
  • The long floats produce a lusturious light reflective surface. When threaded with continuous filament yarn
  • Run-in ratio is 5:9
6. Sharkskin:

Lapping diagram:
Chain notation-

1-2/1-0//                                  1-0/4-5//

Lapping diagram:
Chain notation-

1-2/1-0// 1-0/3-4//
  • Sharkskin is the completely reverse of satin fabric
  • Front guide bar- Tricot structure & Back guide bar – Satin stitch
  • Sharkskin is produced by increasing the back guide bar under lap to three or four needle spaces
  • Properties of this fabric is completely different from satin fabric
  • Not shrinkage; produce more rigid and heavier fabric
  • Technical back side is rough surface
  • Normally useful as a point base
  • Run-in ratio is 5:3
7. Queenscord:

Lapping diagram:
Chain notation-

1-0/0-1//                             3-4/1-0//
  • Front guide bar – chain stitch & Back guide bar – 3 and 1 or 4 and 1 movement
  • The front guide bar makes the shortest possible underlay, the pillar stitch tightly ties
  • Greater rigidity than sharkskin
  • Fabric shrinkage only 1-6%
  • Loops are not balanced
  • Less change of dimension of fabric
  • No difference between final width and knitted width
  • Pin stripe effect if colored yarn in front guide bar
  • Run-in ratio is 9:5 
 

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