- Attrition during pneumatic conveying is a problem faced by the industry for a long time. This paper first evaluates a few experimental test rigs and procedures and then presents extensive experimental investigation with most of the parameters affecting attrition. The parameters are categorized into material strength, operation parameters and bend structure. It is shown that air velocity, loading ratio, bend flexibility and number of collisions are the main factors influencing the rate of attrition. Most of them are in the hands of the designer and operator to control the attrition.