Slub Yarn: Types, Production and End Uses

What is Slub Yarn?

Slub yarn refers to yarn that has been purposely spun with slubs (thicker sections along the yarn) while it was once seen only as a defect, slub yarn is now intentionally created to give fabric more personality.

Slub Yarn: Types, Production and End Uses

Affect the visual effect of slub yarn:

There are four factors are affect the visual effect of slub yarn. They are:-

• Number of slubs per kilometer (NSm)
• Diameter (dia) of slub
• Length of slub
• Distance between slub.

Fig: Parameters of slub yarn

All these parameters are selected by computer. Slub vision software is used for this purpose.

Types of slub yarn on the basis of visual effect:

• Pattern/regular slub yarn
• Non-pattern/irregular slub yarn
• Multicount slub yarn
• Both are pattern and non-pattern slub yarn.

Suppliers of slub yarn attachment m/c:

• Amsler - Germany
• Jiangyin CF Tex Tech Co Ltd - China
• Caipo - Italy
• Pinter - Spain
• Slub-O-Generator of Fancytex - Gwalior, India, etc.

Some ring frame machine manufacturer are supplying the ring frame with inbuilt mechanisms for slub and multicount yarns. Some popular machine manufacturers are-

• Marzoli - Italy
• Zinser - Germany
• Toyota - Japan, etc.

Production of slub yarn in ring frame:

1. In the ring frame, there is a servo motor with slub gear and another with twist gear.

2. Back and middle rollers get motion from the same gearing and the front rollers get motion from separate gearing.

3. Slub is produced by the speed variation of back and middle rollers.

4. Break draft is always maintained properly, otherwise roving breakage will be created.

5. Back roller speed will be increased continuously after a certain time. As a result more material will be feed, whereas during that time the draft of front zone remains constant. So a thick place in the final yarn will be created after a certain time.

6. The controller controls the following:-

• After how much time (mili second) the speed of back roller will be increased.
• How longer the increased speed will remain.
• Amount of speed that to be increased.

7. Twist gear is optional, the speed of front roller is fixed when twist gear is not used.

8. Twist is controlled by changing the speed of front roller.

 Production of slub yarn in ring frame 

Fig.: Production of slub yarn in ring frame

In rotor spinning, slub is produced by the speed variation of feed roller. When the feed roller speed is increased, the over feed takes place and as a result slub is created.

End uses of slub yarn:

Slub yarn is used in traditional fabrics such as upholstery, lace, curtains and household fabrics in general. But it is becoming more popular in the production of denim on ring spinning, shirting and knitwear.