Powder handling concerns

There are two primary concerns with powder handling that cannot be overlooked when scaling processes achieving reliable flow and maintaining blend uniformity. To address these issues when scaling processes, knowledge of how powders flow and segregate is required. 

For each of these different process steps, we will review the key equipment parameters that affect the flowability of a bulk solid. These typical handling steps serve as good examples to illustrate the concerns with powder handling but virtually any solids handling application analyzed the same way. 

Since disperse dye powders supplied to the dyer have been treated already to render them essentially non-dusting, dustiness problems are mainly of concern during dye manufacture [92]. Nevertheless, some dyes remain inadequately treated, or after an initially adequate treatment they may deteriorate during storage, thus giving rise to hazards in handling associated with excessive dustiness. Methods of assessing dustiness have been reviewed [92]. 

CONCERNS WITH POWDER-BLEND HANDLING PROCESSES... 

The second method is the tumbler treatment or coating of powders. So far as the handling of substrate is concerned, the tumbler coating of powder and the tumbler coating of small-size substrates are the same. However, many detailed factors involved in these reactors are not the same, and it is better to deal with these two processes separately. 

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