Correct felt permeability: how open do press felts need to be?

In order to remove water from the sheet in the press section, water must flow easily into the press felt. On the other hand, at the exit of the press nip, water must be kept from flowing back into the sheet. These conflicting demands ensure that felt permeability is always a compromise between good dewatering and re-wetting.

This whitepaper gives background information on felt permeability and describes hands-on tools to determine and optimize the permeability of felts which are running in the machine.

Read More
Marcel Lensvelt
Solving Guiding Problems on Forming Fabrics

When a forming fabric doesn’t want to run straight it usually causes many problems and costs. In the worst case it actually runs into the machine frame and the fabric is completely destroyed. But also continuous strong guiding corrections lead to excessive fabric wear and hence high costs. This article explains the principles of forming fabric guiding and gives the papermaker tips on how to systematically solve guiding problems.

Read More
Marcel Lensvelt
Poorly maintained tension gauges may cause severe damages

Almost every paper mill using forming fabrics has one: a mechanical tension gauge to measures the tension of Paper Machine Clothing, mostly forming fabrics. When these instruments are not in a perfect condition they can cause serious problems on the paper machine like torn fabrics, too narrow and/or too long fabrics and bearing failure.

Read More
Marcel Lensvelt
No Risk, No Future

This whitepaper aims to create awareness of the risk-avoiding strategies that put paper mills and paper machine clothing (PMC) suppliers in dire straits. Close cooperation between paper mills and suppliers can be a good thing for creating and improving efficiency. But when the papermaker and PMC supplier become chained to each other, it makes them both inapt to become the innovators they need to be for the survival of our industry. This paper presents several guidelines for executing trials on paper machine clothing and includes a case study of a paper mill, which is rewarded for its willingness to run innovative trials with its machine clothing.

Read More
Marcel Lensvelt
Pulsation study with the FiberScan

A board machine regularly has problems with unstable streaks. It comes up suddenly and is uncontrollable. It leads to unsaleable paper quality and many sheet breaks, hence much production loss. The streaks are fluctuations of high and low basis weight in machine direction and are completely parallel over the full sheet width.

This whitepaper describes how the cause of this problem was identified and solved with the help of a Feltest FiberScan.

Read More
Marcel Lensvelt