14 HEIMBACH


Continuous conditioning of forming fabrics


Chris Kershaw* and Hans J. Struck* provide some general observations on the use of high-pressure showers to keep forming fabrics conditioned


Pulp Paper & Logistics


Fig. 1 Water jets onto a single layer fabric, such as Primoflex from Heimbech


operation, paper machines can justifiably described as ‘sensitive giants’. Perfect functioning of each single component is a prerequisite and adds to the performance of the paper machine as a whole. This will lead to the best paper quality, high production output, optimum runnability, maximum


W


ith technical diversity and highly-complex technologies involved in their


efficiency and, last but not least, to a high degree of user friendliness and the best possible working conditions for operators. This article details the process and impact of conditioning forming fabrics with high-pressure shower systems. By understanding and taking this into consideration, faults and even damage or financial loss can be identified and rectified as early as possible in the forming section. Conversely, poor


Fig. 2 Water jets onto a double layer fabric, such as Primoplan from Heimbach


conditioning of forming fabrics may only become apparent much further down the line of the paper production, sometimes as late as on the reel. In a case study it is also shown


how far reaching the effects of malfunctions can be and that, at their point of impact, may be mistaken as only a marginal issue. Laboratory analysis of fabric damage can be used to pinpoint faults and to diagnose possible causes. The relatively minor corrections required to deal with the


problem show the high correlation between cause and effect. Individual paper machine


production parameters will of course influence the high-pressure shower system. Therefore we will focus on how to avoid situations known to have caused major problems on-machine.


1. General conditions for the functioning of high-pressure shower systems The purpose of high-pressure shower systems in the forming


Fig. 3 Water jets onto a triple layer SSB fabric, such as PRIMOBOND from Heimbach


May 2013


Fig. 4 Laminar water jet


Fig.5 Turbulent water jet


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