Blending may be defined as a condition in which every fibre characteristic is found in the same proportion as in the original blending within every unit cross section of the yarn .Fibre blending has been practiced since the beginning of the cotton textile industry due to the variation in the physical properties of cotton fibres like scrapple length, fineness, strength & cleanliness.
Blending in Spinning Mill
Objects of blending
- To achieve uniform quality of product for a longer duration.
- To improve processing performance, increase yarn strength.
- To reduce & control cost of production.
- To facilitate the cotton for regaining its moisture content lost during baling.
Blending procedure
Stages in Blending operation, Blending is carried our three stages:
- Metering determination & precise establishment of quantities of the individual components.
- Mixing that is bringing together of the metered quantities.
- Intermingling distributing the components evenly in the body of fibres.
Types of blending operation
|
Blending type |
Process stage |
| Bale Mixing | Before the blow room |
| Flock blending | Within the blow room |
| Lap blending | By using scatters |
| Web blending | At the ribbon-lap m/c or the blending |
| Sliver blending | At the D/F,the sliver-lap m/c the comber |
| Fibre blending | At the card or the OE- spinning m/c |
| Roving blending | At the Ring Spinning m/c |
Blending Techniques
To achieve homogeneous blend the following techniques were adopted.
- Lap Blending
- Card Blending.
- Bin Blending.
- Hand-stock Blending.
- D/F Blending.
- Massive Blending.
Here detailing about some common technique of blending
Lap blending
The blending technique is still used successfully to permit the blending of cotton of contrasting fiber properties to produce a variety of end users. A doubling scutcher is requires, this has a conveyor lattice in feed on which from four to six laps could be laid. The lap sheets from these laps passed doubled through a beater position followed by pair of cages &lap winding device.
Advantage of Lap blending
Procedure very good transverse blends & also a good longitudinal blend.
- It is very easy process.
Disadvantages of Lap blending
- Blend proportions are limited.
- Need for control of lap wt.
Card Blending
Blending by doubling with laps at the card is sometimes used in high production cards. The procedure involves use of a double lap roll attachment whose feed rolls are positively driven by a link chain by the regular lap roll gear.
Advantages of Card Blending
- Most intimate blend is obtained.
- This method is used to randomly mix two laps differing in color.
Disadvantages of Card Blending
- It can’t be obtained from wide range.
- Controlled metered blending can’t be carried out.
- Only make a previously proceeded blend more intimate.
D/F Blending
With D/F blending the card slivers are doubled at the drawing process in a predetermined fashion. The percentage of the blending depends on the number of slivers processed. In processing of cotton this method is not used for blending purposes, but it is the most popular method for blending man-made fiber fiber with cotton.
Advantage of D/F Blending
- Suitable for blending two different cotton qualities.
- Provide best blend in the longitudinal direction.
- Working procedure is not complex.
Disadvantage of D/F Blending
- Require additional blending passage.
- Stripiness may be produce in the finished product.
- Poor transverse blending in the product.
- Fiber heterogeneity produced.
Written by
Engineer Sheikh Nurja
B.Sc engineer of textile
Merchandiser at buying house
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