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Improving the Deviro panel : technical enhancements of a wood fibre-cement composite from paper mill de-inking sludge

Thesis (MScFor)--Stellenbosch University, 2004. / ENGLISH ABSTRACT: This research focuses on the utilisation of de-inking sludge from a tissue mill to produce
a wood-fibre inorganic composite called the Deviro panel. The study is based on the SA
provisional patent 95/9594 by Ysbrandy and Gerischer' and the further research
conducted by Crafford'. The patented Deviro panel contains up to 70% de-inking sludge.
Cement and a cement extender serve to fortify the composite. The panel's fibre content of
25-30% is significantly greater than encountered in commercial fibre inorganic
composites which contain 8-12% fibre by weight.
The physico-mechanical characteristics of the Deviro panel compare favourably with
resin bonded wood-fibre composites, but less favourably compared to conventional wood
and wood-fibre inorganic composites. These properties are strongly dependent on panel
density. For instance flexural strength being directly proportional while dimensional
stability and hygroscopicity being inversely proportional to density.
After confirming the results from the preceding work by Crafford, further improvements
were investigated through chemical and curing enhancements. For instance, an
autoclaving treatment during the curing period showed an increase in flexural strength.
Addition of water glass could be associated with bulking of the panel, which resulted in
increased flexural strength and a slight reduction of density. Panel density could be
significantly reduced by the addition of Perlite, while inhibiting the concomitant
reduction in strength.
In addition a pilot production process was developed to produce 1m2 panels, which
exhibited similar curing characteristics as the smaller panel units. / AFRIKAANSE OPSOMMING: Hierdie navorsing handeloor die gebruik van ontinkingsslyk van 'n sneespapier meule
om die Deviro paneel, 'n houtvesel anorganiese saamgestelde produk, te produseer. Die
studie volg uit die SA voorlopige patent 95/9594 deur Ysbrandy en Gerischer en verdere
narvorsing deur Crafford'. Die gepatenteerde Deviro paneel bevat tot 70%
ontinkingsslyk. Sement en sement-byvoegmiddels dien om die saamgestelde produk te
versterk. Die paneel bevat 25-30% vesel wat aansienlik meer is as ander kommersiƫle
anorganiese saamgestelde produkte wat 'n vesel inhoud van 8-12% het.
Die megamese eienskappe van die Deviro paneel is vergelykbaar met houtvesel
saamgestelde produkte waar hars as kleefiniddel dien, maar vergelyk minder gunstig
teenoor konvensionele hout en houtvesel anorganiese saamgestelde produkte. Die paneel
se eienskappe is afhanklik van sy digtheid Buig sterkte is eweredig terwyl dimensionele
stabiliteit en hygroskopisiteit omgekeerd eweredig aan die digtheid van die paneel is.
Die voorafgaande werk van Crafford is eers gestaaf voordat veranderinge aan die
chemiese samestelling en drogingsmetodes van die paneel nagevors is. Daar is
byvoorbeeld bevind dat, deur die paneel te outoklaveer gedurende die set periode, dit lei
tot 'n toename in buig sterkte. Die byvoeging van water glas kan swelling laat plaasvind
wat 'n afname in buig sterkte en 'n afname in digtheid tot gevolg het. Digtheid kan ook
aansienlik verlaag word deur die byvoeging van Perlite terwyl 'n dienooreenkomstige
verlaging in buig sterkte tot 'n mate voorkom word.
'n Loods produksie proses is ook ontwikkel om 'n 1m2 paneel te vervaardig wat dieselfde
eienskappe toon as die kleiner paneel.

Identiferoai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/49988
Date January 1900
CreatorsMostert, F.
ContributorsGerischer, G. F. R., Stellenbosch University. Faculty of AgriSciences. Dept. of Forest and Wood Science.
PublisherStellenbosch : Stellenbosch University
Source SetsSouth African National ETD Portal
Languageen_ZA
Detected LanguageEnglish
TypeThesis
Format138 pages : illustrations
RightsStellenbosch University

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