The corrugated cardboard collar is an important part of the Procona packaging system. The Procona containers are made in such a way that they remain sufficiently rigid under all circumstances. They can be stacked up to 94". Moreover the packages can be transported under refrigeration, for longer periods, e.g. in trucks. This means that the packaging should be very durable.

The ideal material for this situation is corrugated cardboard. It is inexpensive, can be recycled and is extremely rigid in this application.

Alongside the material use, there is also a specific design for the collar for the Procona packaging. Here are some details:

Folding line (1)

To ensure folding will happen at the correct location, all folding lines on the collar are "pre-folded". This means that the collar will fold by bending it backwards around the prefolded line.

Right hand flap (2)

The flap on the right side overlaps (on the outside) with the flap furthest to the left when the collar is inserted in the edge of the Procona container. This prevents the flowers in the container from slipping outside past the collar. Additinally, the sharp edges have been removed from the sides of the collar to help prevent damaged flower heads.

Corners left and right below (3)

The corners on the left and right side of the collar have been removed - the one on the left to ensure that the right flap fits easily on the edge. The corner on the right side has been removed to prevent it from catching behind the outer edge of the Procona container during insertion.

Printing (4)

All standard Procona collars carry a printed message comprising:

What is corrugated cardboard?

Corrugated cardboard is a packaging material made of paper and glue. It is made up of three layers of paper:

Paper types

There are various types of paper available for use in corrugated cardboard. The better the paper used the stronger the corrugated cardboard.

Kraft

Kraft fibres come from trees, and this is the best type of paper for corrugated cardboard. It is comprised of at least 80% unused kraft fibres. Kraft paper is used for the inside or outside of corrugated cardboard. Kraft's natural color is brown and it is whitened by bleaching or applying a white, chalk-based layer.

Liner

The quality of this paper type is lower than kraft paper. It is comprised of 100% recycled material. The liner typically has less than 60% used kraft fibres.

Semichemical

Semi-chemical paper is used for the corrugation. It is partly made up of short birch fibres (minimum 75%) and partly from recycled material. The short fibres make it ideal for use as corrugated paper.

Wellenstof

This paper is made of 100% recycled material. Kraft fibres are added to enhance the quality of the material. This paper is exclusively used for the corrugated layer.
 

Corrugation types

Alongside the types of paper used the rigidity of corrugated cardboard is also influenced by the type of corrugated cardboard. The type of corrugated cardboard is denominated in letters which show thickness and the number of corrugations per metre.

Box shape

The design of the box contributes to its rigidity. In general a standard box mainly owes its rigidity to its corners. The direction of the corrugation is also important for the general rigidity of the box.

Conditions for use

Corrugated cardboard is made of paper. Hence, the strength of the corrugated cardboard depends on the circumstances surrounding it. Moisture and paper do not go well together as damp paper loses much of its rigidity. Corrugated cardboard is made by gluing loose sheets of paper. Glue also loses strength in damp conditions.

Procona collars

Collars for Procona are made of C-corrugated cardboard. The type of paper used is the best available.

To monitor the quality of Procona collars Pagter Innovations has regular tests carried out by the independent Belgian Packaging Institute. These tests involve measuring the collars maximum load (compression) under severe conditions. This means two days conditioning at 20° Celsius (70° F) and 90% relative humidity. This is equivalent to the actual (extreme) conditions in which the collars are used. The Belgian Packaging Institute also investigates the composition of the collar - in terms of paper type and grammage.