Roll slitting is a technique heavily used
by Converters (industry). The converter industry normally refers to companies
who print, coat and laminate materials. A typical converter is a company
manufacturing producing flexible packaging material for packaging food. This
may involve purchasing large rolls of plastic film such as biaxially orientated
polypropylene (BOPP) which is then printed to the customer's design and coated
with cold seal adhesive for use on high speed packaging machines. This material
is printed and coated in wide, large diameter rolls for maximum efficiency. The
rolls are then slit, using a slitting machine, into smaller rolls of the size
to be used on the packaging machine.
For harder materials, such as sheet metal,
blades cannot be used for the slitting machine. Instead a modified form of
shearing is used. Two cylindrical rolls with matching ribs and grooves are used
to cut a large roll into multiple narrower rolls.