The effect of forming element induced energy on the material distribution, structure, and structural properties of the paper web

This feature presents the results of a study into the impact of various forming elements - foils and VID - on the structure of the wet web. Web structure influences the mechanical and optical properties of paper. The VID system reduces two-sidedness in i) fibre orientation : this makes for a more dimensionally stable sheet. Fibre orientation influences anisotropy which is a characteristic of machine-made papers and a principle cause of curl and cockling. ii) fines distribution : this improves dimensional stability and the printability of fine papers. However, the use of traditional foil elements results in better internal fibre bonding which results in a slightly higher ZDT or out-of-plane strength. ZDT strength influences the converting and printing performance of paper.