Containerboard grades and how to go lighter

Containerboard grades

In our strive to make eco-friendly, lightweight containerboard components, we have studied and compared the different paper grades available on the market. Here's an overview based on CEPI's market definitions.

Virgin-based containerboard components

The expression virgin-based or fresh fibre containerboard, has traditionally been used for kraftliner and semi-chemical fluting.

Kraft paper is defined as “paper or paperboard whose fibre content has no less than 80% fibers obtained by the chemical sulfate or soda processes”. It is made with chemical pulp made from softwood and hardwood.

Semi-chemical fluting is divided into two subgrades, semi-chemical 1 and semi-chemical 2. Semi-chemical 1 is the strongest grade and generally contains more than 80% semi-chemical primary fibres. Using semi-chemical pulp generally leads to stronger components than when using recycled-based pulp.

However, there is now another fresh fibre based paper on the market, our new fresh fibre fluting medium Holmen INNR.

Source: CEPI, European list of corrugated base papers.

Recycled-based containerboard components

Recycled-based containerboard components normally consist of recycled liner, also called testliner, and recycled fluting medium in different grammages. 

Testliner is a predominantly recycled fibre-based paper, which can be classified from 1-4 depending on their burst index and SCT values. Testliner 1 is the strongest and testliner 4, is the weakest medium allowed to be called testliner. 

Recycled medium fluting comes in grammages from 100 g/m² and up. Within this category there are four subgrades; Medium 2, Medium 1, Medium high performance 1 and Medium high performance 2. Medium high performance 2 is the strongest and Medium 2 is the weakest.

Lightweight recycled medium (LWM) is a predominantly recycled fibre-based paper, that comes in grammages below 100 g/m². It can be used for low flute hights in lightweight containerboard and for packaging that doesn't require a lot of strength.

Source: CEPI, European list of corrugated base papers.