How to Refine our Pulps
Refining can affect fibres in any combination of the following:
- External fibrillation
- Internal de-lamination and swelling
- Micro-compressions along the fibre length
- Fibre shape is changed - depending on conditions, it may curl or it may straighten
- Colloidal material is removed
- Fines are generated
- Fibres are cut
Most users of our pulps wish to maximize the reinforcing contribution of the fibres, and this means they are trying to develop the best tensile strength without shortening the fibres or slowing down the paper-machine drainage. By careful selection of reinforcing fibres these papermakers have been able to optimize other aspects of their machine furnishes, such as formation, opacity, recycled content and most importantly, cost.
Because the natural attributes of our fibres (thin walls, highly collapsible) favour the rapid development of tensile strength, these fibres now enjoy a world-wide reputation for their reinforcing abilities. However, the type of refining used to develop the reinforcing strength can make a significant difference too, and to understand this we need to consider the impact of refining intensity.