Corrugated production

Corrugated board is a material made of one or several layers of fluted corrugated sheets (gofra) glued with two flat linerboard sheets above and below.

A box made of corrugated board has a complex-shape configuration and is made with a technique of platen or rotary cutting ensuring higher quality and accuracy. The most popular boxes of this type are various kinds of trays (for packing of agricultural produce and various drink bottles). Corrugated board package has to ensure integrity of packed products during all transportation and handling operations.

The following types of corrugated board are manufactured:

• T — single wall corrugated paperboard consisting of two flat linerboard sheets and one fluted corrugated sheet;
• P — double wall corrugated board consisting of three flat linerboard sheets with two exterior sheets and one internal sheet with two fluted corrugated sheets.

Corrugated board is manufactured with micro, mini, medium and large flutes of unbleached board or white coated board. The main raw-material for corrugated board production is liner and fluting. A BHS corrugator installed at a new corrugated box plant of Ilim Group is intended to produce single and double wall corrugated board with B, C and E (micro) flutes.

The corrugator's productivity	140 million m 2 of corrugated packaging per year
Rated Range of Products	single wall corrugated board.
Estimated Weight of Corrugated Board	550 g/m 2
Working Width	2,500mm

Corrugated Board Production Technology

The technological process of corrugated board production includes a number of operations.

For production of single-faced corrugated board:

• placement of paper and board rolls on rolling units;
• unreeling of paper and board rolls;
• moistening of paper for fluting and preliminary heating of paper and board;
• fluting of paper;
• application of glue to the tops of fluted paper on one side;
• gluing of fluted paper with board for flat linerboard sheets with formation of single-faced corrugated board;
• storage of single-faced corrugated board.

Production of single wall and double wall corrugated board involves the following operations:

• placement of board rolls on rolling units;
• preliminary heating of board;
• application of glue with a gluing machine;
• gluing of single-faced corrugated board with a preheated linerboard with subsequent formation of single wall and double wall corrugated board;
• drying of corrugated board.

After unreeling, the paper sheet is driven to the single facer, where the paper is corrugated with the help of two steam-heated corrugating rollers, and then, starch glue is applied to one side of the flute tops.

Next, the linerboard sheet goes from the heater to the single facer, where the corrugated sheet and linerboard are joined, forming a single-faced corrugated board.

The single-faced corrugated board is then loop-stacked to provide a certain stock and ensure continuous operation of the corrugator. Following the stacker, a single-faced linerboard sheet passes through the heater and goes to the gluing machine, where the starch glue is applied and a single-faced corrugated board is joined with another sheet, forming a single wall corrugated board. To produce two-wall corrugated board the corrugator has another single facer.

The glued corrugated board then goes to the corrugator’s drying unit, where excess moisture is eliminated and two layers become firmly glued to each other. The unit's outlet is fitted with rotary cutters necessary for elimination of substandard samples and transition to the next order (changing of a sample's dimensions).

The finished corrugated board sheet goes to a special slitter-scorer, where it is cut into strips of a set width with a simultaneous edge-cutting and formation of lines for the next bending of a sheet for box formation. Afterwards, the sheet is cut into pieces of a set length forming a single wall corrugated board sample fully ready for further processing. The sheets are then fed to the processing lines.

Corrugated Board Box Production Technology

For production of corrugated board boxes, four Martin (France) technological lines have been installed at a new box plant of Ilim Group. Depending on the type and purpose of the boxes, their structure and dimensions, appropriate samples go to the relevant technological lines.

Independent lines have the same layout and a preset order of technological operations.

The box production process involves the following operations:

• Piece-by-piece feeding of samples to the line;
• Printing of a text or image on the box's exterior surface;
• Cutting of different elements;
• Folding of samples and their subsequent gluing;
• Counting and binding of formed box stacks;
• Manufacturing of additional components at a separate production line.

Corrugated board sheets samples are driven to self-feeders of production lines, from where they go the samples acceptance desk. The samples then go to the line printing sections, where printing is performed.

The printed box sample is then fed to the creaser-die-cutting section, where slots and flaps are cut and creaser-lines are traced. After that, the samples go to the glue and box-folding station. After being folded and glued, boxes go to the automatic box pile counting section. Formed piles are fed to a conveyer and then on to the packing desk for binding with a polypropylene strip. Tied piles are placed on pallets forming a shipment pack. By means of a roll-table system, the shipment pack is driven to the unit where they are packed with a Stretch tape. A finished shipment pack is fed to the storage line, from where it is taken with a fork-lift for transportation to the finished products warehouse.