Selection

Raw stoppers selection and a first classification is an automatized process, performed by optical devices. Stoppers sorting machines are set to identify defects on the lateral surface and on the two ends of stoppers, then they are sorted in visual quality classes according to criteria established by the Organization.

Sorting machine for stoppers (File wmv, 951 KB)

After the automated sorting, stoppers are selected again by manual selection.  Expert operators look stoopers through while they pass over a feeding roller. If a stopper does not look belonging the fixed quality class, it is rejected.

Manual selection.