Fig. 1 – Technological performance of a blowroom line and influencing factors

The first volumes of the Rieter Manual of Spinning are mainly focused on the treatment of cotton.

The task of the blowroom line is to:

And this has to be done:

  • with very careful treatment of the raw material;
  • with maximum utilization of the raw material;
  • while assuring the optimum level of quality.

The relationships between the scope of tasks and the influencing factors are shown in Fig. 1.

The requirements mentioned here are standard for all blowroom lines; for modern high-performance lines the following are added:

  • high operational efficiency;
  • high economy;
  • high flexibility;
  • machines of ergonomic design, i.e. safe and easy to handle, maintenance friendly, reproducible and stable settings.

Considering the overall costs of a ring spinning plant, the share of the blowroom line with about 5 to 10% is not very relevant. It is, however, very significant in respect of raw material treatment, e.g. the best possible utilization, the avoidance of deterioration, and optimum preparation for further processing.Looking additionally at the cost structure of a yarn in which the raw material accounts for about 50 - 70%, it is clear that there is no better way to reduce costs than via the raw material. And this can be done, e.g., with a modern high-performance blowroom line, as it enables a somewhat cheaper material to be used than with an older blowroom line. The main saving potential, however, is achievable with the introduction of professional and competent raw material management. It enables the raw material to be selected to conform exactly to requirements, and also guarantees the optimum preparation and utilization of the raw material. The latter is not so easy to achieve with regard to one of the tasks of the blowroom, i.e. cleaning the raw material. Foreign matter cannot be eliminated without simultaneous extraction of good fibers. This is unavoidable, only the amount of good fiber loss can and must be influenced.

Another big problem with conventional blowroom lines is the deterioration of the raw material:

  • about 50% of all shortcomings in the yarn;
  • about 50% of all quality reducing factors;
  • andaround 50% of all yarn break causes can be traced back to the operation of the blowroom and cards.

All the above-mentioned facts are what makes the blowroom line so very important.

Errors or negligence in selection, composition or treatment of raw material in this section can never and by no means be corrected in the subsequent process stages.