A corrugator is a set of machines designed to bring together three, five or seven sheets of paper to form single, double or triple wall board in a continuous process.
The 3 key stages:
- Corrugating the flutes and securing to a single liner
- Adding the outside liner to make a rigid board
- Cutting the board to the correct size
Three sheets of paper (containerboard) are unrolled simultaneously on the corrugator: the inner liner, the outer liner and in the middle, the medium (also called fluting).
The medium sheet is given a "wave". This corrugation is obtained by pressing the sheet under heat through grooved metal rolls. This operation gives the paper its fluted shape in the single facer.
Starch is applied to the tips of the flutes on one side, the outer liner and the inner liner are glued to the tips of the corrugated medium sheet of paper.
The Corrugated board comes out of the corrugator .
The conversion process - the line convertor
This final stage of the process consists in printing and then slotting, folding and gluing the corrugated board to manufacture a corrugated container.
Different operations are carried out according to the customer’s specification and according to the type of packaging.
The converting process varies according to the type of packaging.
Whatever the type of packaging, printing on corrugated sheets is always possible.
The flexographic print process is commonly used for printing on corrugated.
This process uses the "relief printing" technique and is characterised by:
- High processing speed
- High level of quality
- And an excellent quality/price ratio
Printing can be done « in-line » or « off-line ».