This page contains a Flash digital edition of a book.
16 ANDRITZHEIMBACH


Pulp Paper & Logistics


Efficient clothing for the future


Solutions are being developed by Heimbach for the implementation of single shoe presses that provide higher productivity through the use of higher pressures in the press zone


marketplace forces decision makers to focus on higher productivity and efficiency. These factors themselves are just as relevant when investing in a new paper machine. But what use is the most modern machine, if its clothing cannot keep the pace with technology? A detailed consideration of clothing makes particular sense in the relatively rare single shoe presses. It is undeniable that single shoe presses (SSP) are still very rare. At present there are just 13 machines worldwide working with this technology. This should be surprising because on the one hand an SSP offers a variety of economic options for a wide variety of paper grades. On the other hand, the paper industry must also have or has to be ready with highly-efficient clothing solutions for such machines in order to take advantage of the best possible potential presented by this technology.


T


Dewatering with shoe presses The facts are that while conventional roll presses have a press zone length of 20- 50mm, in shoe presses (SP) this is much larger, at around 120-330mm. Also, SPs work with surface pressure, while conventional solutions dewater with line pressure: Dry content of more than 50 per cent is easy


November/December 2016


he pace of globalisation continues to accelerate and an increasingly competitive


Figure 1: Development of new show press installations over the years


to implement with an SP. This benefits the entire production process, bearing in mind: if we increase the dry content of the sheet before entering the dryer section (TP) by just 1 per cent, this corresponds to a production increase of about 5 per cent – or respectively less energy consumption for drying.


Efficiency in dewatering The road to success for the innovative SP began with its introduction in 1980: in the meantime more than 1,000 paper machines fitted with an SP can now be found globally


(see Figure 1). Almost 15 per cent of the SPs currently running came into operation since 2012, which shows how current this technology actually is. Although most SPs are used in the production of packaging paper and containerboard, over the years the technology has also become increasingly interesting for producers of graphic papers (e.g. newsprint and reprographic paper): it’s worth considering verifiable figures that prove production costs with an SP are up to around 40 euros a tonne lower (calculated over all grades) than machines running without an SP.


Decisive felt combination The development and application engineers at Heimbach also know just how important it is in SSP projects to find the optimum combination of felts for the customer: The dictum ‘married couple’ has prevailed, which is a good description, forcing them to see the top and bottom felts as a ‘couple’ with SPP, when paper makers want to extract the most out of the felt. On the one hand, the felt couple must allow an enormous amount of water to be discharged in the SSP, whilst at the same time also produce a very smooth paper quality. Actually,


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36