The basis of our understanding of forming comes from research on fibre suspensions and hydrodynamics in paper machine geometries. Examples of topics of interest are factors controlling fibre flocculation, the coupling between the fibre and liquid behaviour in turbulent flows, mechanisms controlling fibre orientation, the influence of chemical additives on the behaviour of suspensions, and the transport of filler particles in fibre networks. This type of work is frequently conducted in cooperation with scientists at the Royal Institute of Technology.   

The focus of our efforts is always to improve the papermaking process. The FEX pilot plant is an invaluable tool in this context since it allows us to investigate the dynamics of the forming process at industrial conditions. In particular, the closed white water system ensures that the impact of furnish composition and chemistry can be rigorously investigated. Consequently, a lot of the forming related activities are centred around this facility.

Among the research topics that currently receive attention are the coupling between the drainage pressure and the distribution of fibres, fines and filler material in the web, and ways to reduce structural variability in the sheet. The goal is to improve product properties by better controlling the web structure, and to enlarge the often tight operational windows on today’s production machines.

In our forming research, we employ state of the art measurement methods, like Particle Image Velocimetry and high-speed imaging. Several of the methods are in-house designs, like the SOFA-system for online analysis of the web structure, the sheet structure characterization methods collected in the S3Lab, and a system to measure the drainage pressure between the fabrics during twin-wire forming. Modelling and numerical simulations are also used to gain additional insights into the forming process.

Studies of headbox flow at Innventia.