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dc.contributor.advisorWolfaardt, J. F.
dc.contributor.authorJansen van Vuuren, Hendrikus
dc.date.accessioned2016-01-27T13:14:24Z
dc.date.available2016-01-27T13:14:24Z
dc.date.issued2003-05
dc.identifier.urihttp://hdl.handle.net/11660/2237
dc.description.abstractEnglish: The use of recycled fibre to produce paper is increasing due to improved processes and consumer pressure. However, recycled fibre has slow drainage rates because of fines and residual starch. Slow drainage reduces machine speed, production rate, energy demands of the drying section and water consumption. Amylases have been used previously on mill scale to degrade residual starch in paper and improve drainage. This study evaluated commercial amylases to degrade starch and improve drainage. The enzymes BAN 480L, Duramyl 300L, Fungamyl 800L, Termamyl 120L and AMG 300L were used to treat recycled pulp and the influence of pH, temperature and shear forces was tested on the enzymes. BAN 480L and Duramyl 300L displayed activity over a wide temperature range, while Duramyl 300L had activity over a wide pH range. Termamyl 120L, BAN 480L, Duramyl 300L and Fungamyl 800L showed good tolerance to shear forces. The influence of BAN 480L, Duramyl 300L and Fungamyl 800L was tested on strength properties of pulp. Enzymatic treatment had no negative effect on Bursting Index, Tearing Index, Air Permeance and Handsheets Drainage Time. In some cases, strength properties improved. Laboratory-scale drainage evaluation (Canadian Standard Freeness, Drainage Time, Vacuum Drainage Time and the Water Retention Value) showed no significant improvements despite reduction of starch content. Pilot trials were conducted with different pulp grades and at different consistencies. Paper and backwater samples were evaluated for changes in moisture, starch content and Chemical Oxygen Demand (COD). The COD levels of backwater did not increase after enzymatic treatment. The reductions in starch and moisture content of paper indicated that amylases could improve papermaking, but that mill-scale trials were required to quantify possible benefits. Duramyl 300L was applied in a mill trial to treat K4 pulp for production of 195 Flute. Temperature, pH, starch, COD, Total Dissolved Solids (TDS), and moisture were measured at different sampling points. The machine speed, steam consumption, moisture and strength properties of the product were also recorded. Secondary starch degradation of 66 % was achieved and moisture of the trim and jumbo roll was reduced. Machine speed and steam consumption did not improve and no significant influence on strength properties was found. The backwater COD and TDS increased, but were still within control limits. Longer trials should be conducted in future to focus on optimisation of enzyme dosages and production of other fluting grades. The impact of the enzymatic treatment on effluent quality and microbial fouling should also be investigated.en_ZA
dc.description.abstractAfrikaans: Die gebruik van herwinde vesel om papier te produseer neem toe as gevolg van verbeterde prosesse en druk van verbruikers, maar herwinde vesel lei tot stadige dreineringstempo’s as gevolg van kort vesels en residuele stysel. Stadige dreinering verminder die spoed van die papiermasjien, die produksietempo, energievereistes van die drogingsproses asook waterverbruik. Amilases is voorheen in ‘n meule gebruik om residuele stysel in papier af te breek en sodoende dreinering te verbeter. In hierdie studie is kommersieële amilases evalueer om stysel af te breek en dreinering te verbeter. Die ensieme BAN 480L, Duramyl 300L, Fungamyl 800L, Termamyl 120L en AMG 300L is gebruik om die herwinde pulp te behandel en die invloed van pH, temperatuur, en sleurkragte is op die ensieme getoets. BAN 480L en Duramyl 300L het ensiemaktiwiteit oor ‘n wye reeks temperature getoon, terwyl Duramyl 300L ook aktiwiteit oor ‘n wye pH reeks getoon het. Termamyl 120L, BAN 480L, Duramyl 300L en Fungamyl 800L het goeie weerstand teen sleurkragte getoon. Die invloed van BAN 480L, Duramyl 300L en Fungamyl 800L op die sterkte-eienskappe van pulp is getoets. Ensimatiese behandeling het geen negatiewe effek op Barsindeks, Skeurindeks, Lugdeurlating en Dreineringstyd van toetsvelle gehad nie. In sekere gevalle is die sterkte-eienskappe verbeter, ten spyte van die afbraak van stysel. Laboratoriumskaal dreineringstoetse (‘Canadian Standard Freeness’, Dreineringstyd, Vakuumdreingeringstyd en Water Retensiewaarde) het nie betekenisvol verbeter nie, Proewe op loodsskaal is onderneem met verskillende grade van pulp en teen verskillende konsistensies. Papier en monsters van dreineringswater is geneem en die voginhoud, styselinhoud en Chemiese Suurstof Behoefte (COD) is bepaal. Die COD-vlakke van die dreineringswater het nie toegeneem na ensimatiese behandeling nie. Die verlaging van stysel- en voginhoud het aangedui dat amilases moontlik tot ‘n verbeterde papiermaak proses kan lei, maar dat ‘n evaluasie op volskaal wel nodig is om die moontlike voordele te kwantifiseer. Duramyl 300L is aangewend in ‘n meuleproef om K4-pulp te behandel vir die produksie van 195 riffelbord. Temperatuur, pH, stysel, COD, Totale Opgeloste Vastestowwe (TDS) en voginhoud is gemeet by verskillende punte. Die spoed van die papiermasjien, verbruik van stoom, voginhoud en sterkte-eienskappe van die produk is ook aangeteken. Ses-en-sestig persent van sekondêre stysel is afgebreek en die voginhoud van die afvalpulp en jumbo-rol is verminder. Die spoed van die papiermasjien en die verbruik van stoom het nie verbeter nie en geen betekenisvolle verandering van sterkte-eienskappe is waargeneem nie. Die COD en TDS van dreineringswater het toegeneem, maar was steeds binne perke. Langer meulproewe moet in die toekoms onderneem word om te fokus op optimalisering van die ensiem-toediening en produksie van ander grade van riffelbord. Die impak van ensimatiese behandeling op die kwaliteit van uitvloeisel en opbou van mikrobes moet ook vasgestel word.af
dc.language.isoenen_ZA
dc.publisherUniversity of the Free Stateen_ZA
dc.subjectPaper industryen_ZA
dc.subjectMicrobial enzymes -- Industrial applicationsen_ZA
dc.subjectWood-pulp -- Biotechnologyen_ZA
dc.subjectWaste paper -- Recyclingen_ZA
dc.subjectAmylaseen_ZA
dc.subjectDrainageen_ZA
dc.subjectRecycled fibreen_ZA
dc.subjectStarchen_ZA
dc.subjectBiotechnologyen_ZA
dc.subjectEnzymeen_ZA
dc.subjectDissertation ((M.Sc. (Microbial, Biochemical and Food Biotechnology))--University of the Free State, 2003en_ZA
dc.titleApplication of amylases for the improvement of water drainage from recycled pulp fibreen_ZA
dc.typeDissertationen_ZA
dc.rights.holderUniversity of the Free Stateen_ZA


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