Bale Management | Mixing and Blending

Bale Management

1. Testing, sorting, and mixing bales according to fiber properties for producing specific good quality yarn at minimum cost is called bale management.
2. By this method, a few bales are selected for daily mixing as per fiber quality and end-use in such a way that day-to-day mixing has the same consistency of fiber quality.
3. If bale management is absent, a lot to a lot of variation will occur, and this will produce color variation and a barre effect in the finished fabric.

{getToc} $title={Table of Contents}

Mixing and Blending

Mixing: Mixing could be thought of as combining fibers together in some haphazard proportions whose physical properties are only partially known so that the resultant mixture has only generally known average physical properties that are not easily reproducible.

Blending: Blending is based on the measurement of important fiber properties(i.e. length, strength, cleanliness, etc.) and quantitatively proportioning and combining the compatible properties under controlled conditions in such a way that the physical properties of the resultant blend can be predicted and reproducible.

Blending then is based on the principles of measurement and proportion while mixing is not.

Bale Management

Objectives of Mixing and Blending

Mixing and blending are performed mainly for the following reasons:

1. Give the characteristics to the end product (e.g. blending of synthetic fibers with natural fibers produces the desired easy-care character)
2. Compensate for variations in the characteristics of the raw materials (even cotton of a single origin exhibits variability and must be blended)
3. Reduce the raw material costs (blending with relatively cheap raw materials)
4. Influence favorably the behavior of the material during processing (improve the running characteristics of short-staple material by admixture of carrier fibers.
5. Achieve effect by varying color, fiber characteristics, and so on.

Types of Mixing or Blending

1. Bale mixing (6 - 60 bales): Before the blow room.
2. Flock blending: Within the blow room
3. Lap blending (4 - 6 laps): Using the doubling scutchers.
4. Web blending: At the ribbon lap machine
5. Sliver blending: At the draw frame / At the sliver lap machine
6. Fiber blending: At the card/At the rotor spinning machine.
7. Roving blending: At the ring-spinning machine (for wool fiber)

Bale Mixing

This is carried out at the start of the process - for both natural and synthetic fibers. If the cotton is mixed by hand, then we called this stack mixing. In this system, the first bale is opened and spread over a large area of the floor. The second bale is superimposed over the first. The thickness of the layers depends on the composition of the blend. After the stack is made, the cotton is allowed to stand for a minimum of 12 hours for acclimatization. The stack is removed vertical manner from top to bottom for thorough mixing. The air temperature inside the mixing and blow room area should be more than 25°c and the RH% should be around 45-60%. During opening from the bale, the tuft size can be as low as 10 gms.

Cotton fibers are also mixed automatically by different automated machines without breaking the bales manually. Here few bales are placed on both sides of the machine longitudinally. The machine traverses longitudinally and extracts the fibers from the bales into the duct for mixing.