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Libroplantasingl

3LIGHT WEIGHT PACKAGING SORTING PLANTS CONTROL Light weight packaging sorting (kg) Light weight packaging input (kg) Effectiveness (%) = The effectiveness is calculated globally and for each material. The performance parameter does not eliminate the effect of the input material quality (total input includes non-requested or non-targeted materials collected in containers and arriving at the plant), while the effectiveness parameter does (as it considers only the requested or targeted material). This means that a plant with a low level of performance can have a high level of effectiveness in its process. In manual plants, 80% is considered an adequate global effectiveness value, while for automatic plants values of 85% or higher should be reached. Performance control for sorting operators An extensive database is currently available due to the continuous performance of performance improvement studies at sorting plants, which includes studies performed from 2003 to the present day. Specifically, in the studies performed at sorting plants the measurements made on activity by material and production by material have been analysed. These measurements are described below along with their importance in the analysis of the production at the sorting plants. The values obtained in these studies act as a reference point for controlling and analysing the performance of the sorting operators. • Average activity by operator (movements/operator and hour) Measurements have been made of the movements performed in two minutes by each sorting operator at the positive sorting stations. Extrapolating this to the movements performed by an operator in one hour allows calculation of the mean value of the activity by operator. In these calculations, primary and secondary sorting stations have been differentiated (table 4). Due to the variety of qualities of the selected materials, no reference value is supplied for the quality control stations. Activity values (movements/ operator and hour) for sorting operators. Table 4 Reference value Primary sorting 1,400 Secondary sorting 2,000 • Activity level for the selected material (movements/ operator and hour) The mean of the maximum value of fraction-related movements performed in one hour by a sorting operator has been calculated. The values found using an atypical value determination analysis have been eliminated. As it is well known that a single operator segregates several materials simultaneously, the partial activity for each (%)


Libroplantasingl
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