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Roll service-life optimisation using paper quality measurements for condition indication
Dissertation (MEng (Mechanical Engineering))--University of Pretoria, 2004.
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| Format: | Thesis |
| Language: | English |
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University of Pretoria
2013
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| _version_ | 1867613698807300096 |
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| access_status_str | Open Access |
| author2 | james.meikle@sappi.com |
| author_browse | james.meikle@sappi.com |
| author_facet | james.meikle@sappi.com |
| collection | Thesis |
| dc_rights_str_mv | © 2004, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. |
| description | Dissertation (MEng (Mechanical Engineering))--University of Pretoria, 2004. |
| format | Thesis |
| id | oai:repository.up.ac.za:2263/31075 |
| institution | University of Pretoria (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:40:17.184Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository |
| publishDate | 2013 |
| publishDateRange | 2013 |
| publishDateSort | 2013 |
| publisher | University of Pretoria |
| publisherStr | University of Pretoria |
| record_format | dspace |
| source_str | UPSpace — University of Pretoria Institutional Repository |
| spelling | oai:repository.up.ac.za:2263/31075 Roll service-life optimisation using paper quality measurements for condition indication james.meikle@sappi.com Mr C J Stander Meikle, James Stewart Newton UCTD Kraft paper Nip load Paper quality Press roll cover Time based and wear Condition-based Moisture Maintenance Monitor Neural network Dissertation (MEng (Mechanical Engineering))--University of Pretoria, 2004. Paper machine sheet dewatering by roll pressing is critical in the establishment of uniform moisture profiles, as well as other mechanical properties of the paper during manufacture. Roll cover profiles are maintained within specification by removing and regrinding the rolls after fixed periods in service. However, analyses of historical data revealed a high variance in the cover wear rates suggesting the use of a condition-based approach to maintenance. In general excessively uneven wear of the cover profile leads to a reduction in press nip load and an increase in paper moisture content. Papermaking process dynamics, however, result in the moisture content also being influenced by other factors including headbox profile, press felt condition and stock variables such as furnish and consistency. The interrelationships between these variables are highly complex and are thus ideally suited for solution by Artificial Neural Networks. With this work a Neural Network model was used to learn the relationships between these variables based on measurements made in a production environment. The model was shown to successfully model the papermaking process and the influences of press roll wear on paper moisture content. The methodology developed allows the progression of cover wear to be monitored using the moisture profile of the paper produced until quality limits are reached, and the roll is replaced on condition. Comparisons indicate significant benefits of the condition-based approach over conventional methods. Furthermore, the same method can be applied to other nipped rolls, such as roll-coaters and soft-calendars, provided the network is customised for those applications. Mechanical and Aeronautical Engineering MEng (Mechanical Engineering) restricted 2013-09-09T12:01:36Z 2006-08-03 2013-09-09T12:01:36Z 2004-10-09 2004-08-03 2005-07-27 Dissertation Meikle, J 2004, Roll service-life optimisation using paper quality measurements for condition indication, MEng dissertation, University of Pretoria, Pretoria, viewed yymmdd < http://upetd.up.ac.za/thesis/available/etd-07272005-150936/ > http://hdl.handle.net/2263/31075 http://upetd.up.ac.za/thesis/available/etd-07272005-150936/ en © 2004, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. application/pdf University of Pretoria |
| spellingShingle | UCTD Kraft paper Nip load Paper quality Press roll cover Time based and wear Condition-based Moisture Maintenance Monitor Neural network Roll service-life optimisation using paper quality measurements for condition indication |
| title | Roll service-life optimisation using paper quality measurements for condition indication |
| title_full | Roll service-life optimisation using paper quality measurements for condition indication |
| title_fullStr | Roll service-life optimisation using paper quality measurements for condition indication |
| title_full_unstemmed | Roll service-life optimisation using paper quality measurements for condition indication |
| title_short | Roll service-life optimisation using paper quality measurements for condition indication |
| title_sort | roll service life optimisation using paper quality measurements for condition indication |
| topic | UCTD Kraft paper Nip load Paper quality Press roll cover Time based and wear Condition-based Moisture Maintenance Monitor Neural network |
| url | http://hdl.handle.net/2263/31075 http://upetd.up.ac.za/thesis/available/etd-07272005-150936/ |