The flow of a packed HPLC sample column using perfectly spherical particles has a very predictable performance when used to separate molecules. In addition, the manufacturing of a column with only truly spherical particles would be predictably consistent. However, as a result of some HPLC column packing particles having an irregular shape, packing geometry can become irregular itself and may express as non-uniform performance of the final product from column to column, lot to lot.
The percentage of irregular packing and fines can alter the consistency of performance of the column and make HPLC columns much more expensive to manufacture because of the additional care and expertise required in achieving consistency in production. Possible downtime in production can result if incoming lots of materials contain varying percentages of irregular particles.