Impaction
Many situations in which agricultural products are mechanically conveyed during food
processing offer the opportunity for control of insects by shock, abrasion and impaction.
The principle was developed over 70 years ago for use in the flour milling industry and
impaction machines such as the “Entoleter” became a routine fixture in facilities such as
flour mills (Pagani et al., 2006). In the Entoleter, flour falls between two rapidly spinning
discs. Centrifugal force pushes the flour to the edges of the discs where it impacts a row of
steel pegs mounted on the rims, and is thrown against the outer steel casing before falling
into the basal receiving hopper. The material passing through the Entoleter thus encounters
two major impactions and this effectively controls all free living insect stages. Impaction
machines can also kill a high percentage of insects such as weevils developing inside cereal
kernels (Vincent et al., 2003; Beckett, 2010).