Mare Dynamics

New success of MARE in deposit control

Author: MARE SpA

Dear Reader of TissueMAG,
lately we have been on these pages describing our results in yankee coating chemistry. In this occasion, we would like to describe our capabilities in terms of Deposit Control and some excellent results MARE obtained in this field, in particular in the field of organic deposit control.

Our company is able to offer a full range of chemical programs to control the formation of organic deposits (namely pitch&stickies) directly in the stock preparation or passivating the surface of the clothing of the paper machine. In case where the organic contamination is very high, deposit control strategies in the process can be supported by chemical programs cleaning the clothing of the paper machine without the need for a machine stop. The action of our chemical programs for deposit control can also be integrated projecting a proper cleaning of the machine frame and internal circuit through a boilout during scheduled shutdowns.

Detail of the SMARTJET system.

In general, organic deposit control is based on a dispersion fixation approach, where a dispersant will be applied in the thick stock, for example in the pulper, and a fixative will be fed later in the system, for example in the mixing chest or machine chest. Dispersion approach may be integrated or substituted by a detackification strategy, mainly based on inorganic or polymeric substances which eliminate the ‘tackiness’ of the pitch stickies surface. This approach will be preferred in systems with very high contamination, such as mills using poorly cleaned deink pulps or 100% waste paper, where the number and size distribution of organic particles is very high even from the very first stages of the stock preparation.
Our experts will bring into your mill all the expertise and ‘know how’ needed to choose the correct strategy to your specific problem.
Some Case Histories follow.

 

Case history 1

A tissue mill was having repeated problems with stickies accumulation on the forming wire.
The only solution was to stop the machine and run batch-down cleanings. MARE introduced the application of the product TR SY 400.
The chemical was applied batch-on-the-fly, no machine stop was needed. The treatment was first applied on a side of the wire to show the cleaning capability of the chemical, then on all the width of 5.8 meters of the clothing. The wire came out clean with the use of a few dozenths of litres of cleaning aid. The total operation didn’t take more than 30 minutes. It was demonstrated the chemical is not carried into paper at all due to its volatility.

On the left hand side of the picture you can see the headbox internal surfaces before the application of our MARECLEAN BS 900 in the process, on the right hand side after.

Case History 2

A mill was experiencing a high level of stickies accumulation on the wire due to combined use of poorly washed deink pulp and short fibre polluted with evident pitch contamination. The wire was treated with our chemical TR CC 30, which provided soon a barrier against stickies on the fabric. Lost time for shut down cleaning was reduced from 2 hours a day to 2 hours every week.

 

Case History 3

A mill was experiencing severe clothing contamination due to the use of converting rejects contaminated with glues and industrial adhesives in general. For this reason it was not possible to increase the percentage of converting rejects on production over 2 % – 3 %.
With the addiction of MD PAPER GR, inorganics based detackifier, it has been possible to increase the amount of converting rejects up to 9 % – 10 % while maintaining a suitable runnability.

A comparison is shown between the appearance of the internal surfaces of a mixing chest, before (left hand side) and after (right hand side) the application of our MARECLEAN BS 900 in the process.

Case History 4

A tissue machine was suffering form pitch&stickies deposits in the short loop and fabrics.
These problems were completely solved by adding the chemical MARECLEAN BS 900 to the virgin fiber and broke pulper, to white water and to the polydisk spray bar. The fixative MAREFIX LP 250 was also added to the mixing chest and the chemical MARECLEAN FC 737 was added batch-on-the-fly by a spray bar into the nip between the felt and a turning roll.
Clothing cleaning by chemical programs can be combined with state-of-the-art spraying technologies which allow the application of chemicals in specific sections of wires and felts.
An example of this technology is the SMARTJET system newly released by FOMAT. With this technology it is possible to apply the chemical treatment only on a specific section of the clothing. The cleaning head comprised five nozzles head which can be rotated by 90° degrees in order to modulate the intensity of the cleaning action.

Functional and process solutions for paper industry

 

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