Mixing and Blending of Fibers in Spinning process

Updated: Jan 8, 2021


Mixing:

It is an operation where different cottons of certain known physical properties (like staple length, fineness, and grade) are combined to achieve a mix with average characteristics. Mixing is a haphazard operation. So, the characteristics of one mixing cannot be reproduced.

Example: Low grade cotton + High grade cotton = Mixing.


Types of Mixing:

1. Weight mixing

2. Volume mixing

3. Bin mixing

4. Hand stock mixing

5. Hopper mixing

6. Card mixing

7. Lap mixing

8. Sliver mixing

9. Automatic mixing



Weight Mixing:

In this process different qualities of cotton fibers are weighed and put together.

Volume Mixing:

In this process different qualities of cotton of known volumes are put together.

Bin Mixing:

In this process cotton flocks are transferred from bale opener to a pipeline which is of 10" dia. and passed it to bins, these fiber flocks are transferred into the bins from the delivery boxes.

Hand Stock Mixing:

In this process cotton flocks from different bales are manually collected and put together. This is one of the oldest methods and generally used in high count yarn production.

Hopper Mixing:

In this method, mixing is done in hopper bale opener machine. Hopper bale opener picks the cotton from different bales and deposits on a lattice where mixing action takes place.

Card Mixing:

In this method mixing action is carried out in high production carding machine. Two different cotton laps are fed to carding machine to achieve mixing.

Lap Mixing:

In this method to obtain mixing double scutcher is used. Which consist of one breaker scutcher and one finisher scutcher. Different grade and different qualities of laps are produced in breaker scutcher. Four lap stands are placed before the finisher scutcher. Hence, mixing can be achieved in different ratios.

Sliver Mixing:

In this method different carded slivers are fed to draw frame to carryout doubling action and obtain mixing.

Automatic Mixing:

In this method cotton fibers are mixed automatically by different automated machines, without bale breaking manually. Here, the number of bales is placed both side of longitudinally. The m/c moves in traversing mo. for mixing.


Blending:

It is the manufacturing of products containing different fibers of known characteristics in various proportions. Fibers of known physical properties are blended under controlled conditions so that the resultant blend could be reproduced. The blending operations is based on exact measuring of all fiber properties and correct proportions.

Example: 50% polyester + 50% cotton = Blending.

Nylon + cotton = Blending.



Types of Blending:

1. Bale mixing.

2. Flock blending.

3. Lap blending.

4. Web blending.

5. Sliver blending.

6. Fiber blending.

7. Roving blending.


Bale Mixing:

This process is carried out before Blow-room. Bale mixing is done for both natural and man-made fibers. For this process 6 to 60 bales are placed one after the other for simultaneous flock extraction. The blend obtained by this process is unsatisfactory in the longitudinal direction due to uncontrolled extraction of flocks and danger to deblending.

Flock blending:

This process is carried out within the blow-room process. This process takes place in an uncontrolled manner, naturally, and to a smaller degree.

Lap blending:

To carry out this process a double scutcher is required. 4-6 laps are fed through conveyer lattice. The blend obtained through this process will have high longitudinal and traverse blends.

Web blending:

To carry out this process ribbon lap machine or blending drawframe is used. By use of drawframe controlled blending can be obtained by bringing together components web form instead of sliver form. This process gives a good longitudinal blend as well as transverse blend which is obtained with sliver blend.

Sliver blending:

Carried out on drawframe and it provides best blend in longitudinal direction.

Fiber blending:

This process is carried out at the card or the OE spinning machine. This is the most intimate blend is obtained if individual fibers are brought together. This can be achieved only on the cotton card (to a small degree), on the woolen card (something intensively), and in rotor spinning (over short length only).

Roving blending:

This process not majorly used in short-staple spinning mills. Two different ravings are fed to ring spinning machine, here fibers do not blend with drafting, but the yarn is twisted with one or another component.


Difference between Mixing and Blending:


Objectives of Mixing / Blending:

I. To achieve uniform quality of yarn throughout its length.

II. To reduce the cost of production.

III. To achieve functional and end use requirements.

IV. To improve process performance.

V. To facilitate the cotton for regain its moisture content lost during baling.



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