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  • 2.7-COTTON VALUE ADDITION-COTTON BALE PACKAGING

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  • Cotton bale packaging

    Chapter 2 - Cotton value addition - Cotton bale packaging 

     
     
    Cotton is packaged, stored and transported in units called bales. A cotton bale consists of cotton fibres removed from cottonseed during the ginning process and packaged for convenient handling, storing and transporting. Bales are formed at the end of the ginning, drying and cleaning process by accumulating cotton fibres in a chamber called a press box. While being held in the press box, bulk cotton fibre is compressed by hydraulic rams typically creating forces up to 4 million N (newtons). Straps or bands are added at the press box to contain cotton fibres to form the bale.*

    Historically, bale sizes and densities have been specified based on a compromise between requirements for efficient storage, optimum space and weight for transport, and energy required for compression. Additionally, ease of opening and mixing bales for textile processing is an essential requirement, especially as mills become more automated. Early in the history of cotton production and ginning, most cotton producing areas of the world devised their bales and pressing capacity for the benefit of their domestic mill customers. Since the earliest mills typically were located near the same region as the gins, there was no efficiency to be gained by producing high density bales. In the past century, cotton has been traded more internationally, which has demanded additional efficiencies for dimensions, densities and mill opening requirements.

    Packaging and labelling requirements also have changed over the past century. A shift has been made from heavy steel bands and buckles and heavy jute fabrics toward more technically advanced bands, fabrics and films. Practically all wrapping and strapping materials have realized significant improvements in performance while decreasing shipping weights.

    *The newton (N) is the unit of force defined in the International System of Units. One pound force = 4.448 N and 1 kg force = 9.806 N. Forces of cotton bale compression vary greatly depending on the size of bale and density pressed. For example, the force required to press a 330 kg bale, typical of many Egyptian bales, will be much higher than that required to press a 180 kg bale, typical of a bale of Ugandan cotton.