Bale Management in Spinning: Blending | Mixing

To be successful in the spinning industry one must be alert on two factors which are the consistent quality of production and optimization of raw material expense. A judicious selection of cotton bales by testing, categorizing and blending homogeneously according to the characteristics of fiber for manufacturing precise good and consistent quality of yarn at minimum cost is said to be bale management.

Why Bale Management is Necessary?

• A method of accomplishing consistent yarn quality.
• It is adopted to reach essential value of yarn.
• Helps to lessening shade deviation of the finished products.
• Aids to compensate the deviation in characteristics of the raw constituents.
• It can be used to diminish fabric barre fault.
• This is generated keeping in mind, to deliver the preferred qualities in the end product.
• Prepared to shrink raw material budget at optimum level.

How Bale Management Minimizes Cost?

The following lists the cost saving possibilities:

• The essential fiber properties and a well-ordered blend combination ensure the use of an economical raw material which appropriately comprises all the requisition.
• The choice of correct raw material used together with a well control spinning process, which result in less processing disturbance such as end breaks. This will allow for higher processing speed and refer to reduction in manufacturing cost.

Process Sequences of Bale Management

• Collection of the samples from all the cotton bales.
• Identification of each bale by implementing numbering system.
• Conditioning the samples the for standard M.R. % for 24 hours.
• Using HVI (High Volume Instrument) and AFIS (Advanced Fiber Information System) test the sample.
• Entry the HVI and AFIS data into BIAS (Bale Inventory and Analysis System).
• If BIAS not available then use Microsoft excel or even manually analyse the HVI results.
• Generation of the mixing and blending plan.
• According to the mixing plan execution of the laydown plan.

 HVI and AFIS Test Result of Two Different Lot of Bale

Bale Mixing

Mixing can be defined as mingling of fibers together in some hap-hazard quantities so that the subsequent collaboration cannot be anticipated and difficult to reproduce.

Minimization of Mixing Cost

Example of Minmizing Bale Mixing Cost:

If three cotton prices Tk. 60.00, Tk. 70.00, Tk. 80.00 per Kg are used in a mixing in the proportion 25:25:50

Then average mixing cost = { (25 ×60) + (25 ×70) + (50 ×80) } / 100 = TK. 72.50/kg

If we consumed the fibers that prices Tk. 80.00/Kg, then the total expense will be greater. If we consumed the fibers that charge Tk. 60.00/Kg, Tk. 70.00/Kg, that would not fulfill the desires of buyer. But if we use the typical mixing, then these combined fibers will accomplish all requisitions of buyer. So it can be said that mixing process can minimize the cost of fibers.

Bale Blending

Blending can be defined as intermingling of different diversities or grades to yield certain quality which is why blending proportion can be forecast and easily replicated.

Importance of Blending

• Imparts the essential appearances to the end product (e.g.: PC, CVC)
• Compensate for dissimilarities in the qualities of the raw material.
• Lessen raw material budget cost.
• Expand processing performance such as compact end breakages.
• Attain end product by fluctuating color as fancy yarn (mélange yarn).

Types of Blending Operation and Process Stages

Difference Between Mixing and Blending

Frequently Asked Questions

1. How to select bales for laydown when there is a lot of test results to compare?

When the number of data collected from test result is enormous and it creates confusion to select the appropriate bales for the laydown then one simple data of HVI can help. This is referred to be as SCI or spinning consistency index. Minimum SCI value should be 120 for a fiber to be qualify for spinning. There is a formula for SCI.

The equation for the SCI value is:

Spinning Consistency Index(SCI) = -414.67 + 2.9 x Strength – 9.32x Micronaire + 49.17 x Length(“) + 4.74x Uniformity + 0.65x Rd + 0.36x +b

2. Can maximum accuracy in bale management keep 100% consistent quality yarn?

No. It is practically impossible to produce 100% consistent quality for any yarn type. The reasons behind is-

since the fiber length and diameter cannot be controlled all the time accurately that is why it is not possible to maintain consistent quality all the time.

3. Between blending and mixing which one is preferable?

Of course blending. Blending maintains the ratio of combination of fibers that is why it can be replicated easily. On the other hand, mixing doesn’t keep the ratio same which is why the quality deviates from lot to lot and order to order. Since keeping consistent quality is a major hack to be successful in spinning that’s why blending should be preferred than mixing.

4. Is there a machine for spinning fibers to yarn at home?

Yes. The best spinning wheel for beginners will allow you to spun fibers directly into yarns easily.

References:

1. W. Klein (2014). The Rieter Manual of Spinning – Volume 1: Technology of Short-Staple Spinning
2. Automatic Bale Opener UNIfloc A12
3. Bale Manager Module