Bimodal

A bimodal distribution is one that has two distinct peaks. In particle analysis, a bimodal size distribution means that two different particle sizes are present in significant quantities—for example, a mixture of fine and coarse particles. Such a distribution can result from mixing different materials, from agglomeration or comminution processes, or from selective separation. The graphical representation of a bimodal distribution shows two peaks, each marking the most common particle diameter.In filtration processes, a bimodal particle distribution poses special challenges: the larger particles usually quickly form a layer close to the surface, while the smaller particles can penetrate this layer and clog deeper pores. To control this behavior, pretreatment processes such as flocculation are used to bind the smallest particles to larger ones.Bimodality is also found in the pore structure of filter media. A bimodal pore network can offer a graduated structure: large pores ensure low pressure loss and mechanical stability, while smaller pores increase separation efficiency. The analysis of bimodal distributions requires statistical methods such as kernel density estimates or the fitting of mixture models. GKD takes such structures into account in order to develop fabrics that enable both high throughputs and fine separation.