In the papermaking process, chemical manufacturing aids are used, as well as fibres and fillers. Reduced process performance and serious production failures are caused by neutralisation reactions between the manufacturing aids and anionic detrimental substances. These can be due to deposits on machine parts, specks in the paper, machine downtime owing to web breaks, etc. Increased chemical consumption and higher effluent loads may originate from these substances and these effects increase the costs of paper and board production, and its impacts on the environment. In addition, the energy consumption is higher. The project is expected to provide solutions for more effective control of detrimental substances in the papermaking process that originate primarily from fibrous materials. The measures will reduce production costs and make an important contribution to quality consistency.
The objectives of the project are:
1. to characterise detrimental substances originating from fibrous materials. Based on this data, strategies to control anionic trash will be elaborated using suitable inorganic and organic chemicals
2. to develop new chemicals, mainly based on inorganic compounds, for optimum efficiency in trash reduction. Appropriate dosage conditions will be chosen and methods will be developed for efficiency assessment
3. to improve the performance of the paper and board production processes, despite an increasing closure of the paper-machine systems
4. to develop new diagnostic systems for detrimental substances by the optimisation of available systems for each of the production processes and for the prevailing influence of the process conditions.
Progress to Date
1) The characterisation of detrimental substances and white waters in paper mills has been completed.
2) The development of modified additives in laboratory scale has been completed.
3) Laboratory tests of the modified chemicals and minerals regarding their efficiency are in progress.
4) The production of new chemical aids in pilot scale for the pilot paper machine trials is in progress.
5) The development and implementation of a computer based diagnostics system is in progress.
Deposits and supplementary data were collected in the partner paper mills, and analysed and classified. Based on the results, a deposit inventory was developed including a description of the deposits and the analysis results, allowing the identification of deposit sources.
New products (based on modified minerals and aluminium compounds) for removing detrimental substances in the paper manufacturing process were developed by the chemical suppliers.
Laboratory trials were carried out with the most promising products to assess the efficiency for removal of anionic trash.
Based on the results of the laboratory efficiency tests, the three most promising products were selected to be produced in larger amounts for studying on a pilot scale paper machine.
To aid the development of a computer-based diagnostics system, three different procedures for analysing web break conditions were developed and tested.
Scientist responsible for the project
Dr REINHARD GRENZ
Germany - DE
Phone: +49 891 214672
Fax: +49 891 2146105
- DEPARTAMENTO DE INGENIERIA QUIMICA, UNIVERSIDAD COMPLUTENSE DE MADRID, Spain - ES