Thesis (Ph. D.)--University of Canterbury, 2007. / Typescript (photocopy). Includes bibliographical references (p. 185-196). Also available via the World Wide Web.

Thesis (M.S.)--Oregon State University, 2009. / Printout. Includes bibliographical references (leaves 64-60). Also available on the World Wide Web.

Medium density fibre (MDF) board is used in various applications in the building-, furniture- and casket industry. The market is shared by solid wood and other flat panels, such as particle board and plywood. The market in South Africa forms part of the global market. Therefore it is possible to import MDF. The demand for MDF is driven by the building industry, the Consumer Price Index (CPI) and the exchange rate. The CPI is an indication of the consumer’s willingness to purchase furniture or to invest in property with subsequent growth in the building industry. The 2002 market in SA is 500 000m3 for particle board and 110 000m3 for MDF. The imported boards during this same period were particle board 10 000m3 and 22 194m3 for MDF. The extrapolated expected imports for 2003 would be 12 362m3 and 35 045m3 for particle board and MDF respectively. According to the empirical study the market increase for particle board and MDF, for 2003, will be 18%. That means that the particle board market will increase to 590 000m3 and the MDF market to 130 000m3. The 2002 production capacity was 648 000m3 (particle board) and 155 000m3 for MDF. The Sonae factory in White River can produce either particle board or MDF and this influences the production capacities. According to various International databases the requirements for SA in 2020 will be 984 000m3 for particle board and 569 000m3 for MDF. Quick calculation show a shortfall of 414 000m3 for MDF in 2020 when compared to 2002 production capacity. First mover advantage will give the mover the major market share in SA. The demand will be there. All the above calculations have been done without taking the 2010 World Football event in SA into consideration. The question is – all the current players are almost on par to make it happen. The company with the burning desire to make it work will find the finance and will have the controlling market share.

Thesis (Ph. D.)--Oregon State University, 1992. / Includes mounted photographs. Typescript (photocopy). Includes bibliographical references (leaves 159-166). Also available via the World Wide Web.

Abstract not available

Master of Science / Department of Grain Science and Industry / Xuzhi Susan Sun / Large amount of fiberboard are used for packaging applications every year, which generate a large amount of solid wastes causing environmental pollution if these packaging materials are not recycled. Also, a large amount of wood are needed for making fiberboard, which is limited resource in the earth. Reducing the weight of fiberboard and recycling the fiberboard materials are two methods to save quantities of wood fiber in fiberboard manufacture, which benefit the environment and economy. Besides, most adhesives used for producing the fiberboard contain environmental hazardous chemicals. It is necessary to develop new technology to produce cellulosic fiberboards with environmental friendly bio-based adhesives. The soybean is an agricultural product, and its resource is abundant. Soybean protein is a bio- material that offers an alternative to the existing synthetic adhesives to reduce petroleum dependence of the U.S. energy strategy. The newly developed soy-based adhesive is also competitive in cost. Material cost based on food-grade soybean protein is around 20 cents/Lb. The cost of commercial PF resin is about 14 ~ 17 cents/Lb. Price of hot-melt adhesive for fiberboard is around $6/Lb. In this study, soybean protein was modified with sodium dodecyl sulfate as an adhesive for two bio-based fiberboards products, medium density fiberboard by dry processing and light weight cardboard by wet processing. The mechanical and water soaking properties of these cellulosic fiberboards were stronger than or as same as commercial solid fiberboard. This research suggests that these cellulosic fiberboards with modified soybean protein based adhesive have great potential as alternative to current commercial fiberboard.

Underlying all my work is a tension between the painter and the builder. I love to paint. I love the lie inherent in paint: that it can make a picture plane masquerade as light, space, or recognizable place with recognizable figuration. I love how paint—particularly oil paint—can rest in gloppy piles, how it can drip, splatter, spread, or how it can squeeze out of paint tubes in long, stringy beads. I love how paint changes how we see an interior space or a three-dimensional form. Yet I also love building things—usually out of wood—measuring and cutting, fastening things together—all to serve a function or solve a problem. In every studio I have had, there has always been an arms race between my fine art supplies and my tools. My work during my three years at the Department of Art and Art History at the University of Texas at Austin has undergone some dramatic changes. In large part this paper will elaborate and evaluate the trajectory of these changes. Yet, in spite of these changes, the competing impulses to paint and to build have remained constant. This report will leave unanswered the question whether these two impulses can or should be reconciled, kept separate, or whether one should be sacrificed in favor of the other. The artist writing this report does not know at this point in time, and cannot hope to answer this question without making more work in a new context. This report instead will reveal how I arrived at the work I am making at the time of writing this report, and why I regard this new body of work as being about the “paint gap.” I define the “paint gap” as the distinction—mild or strong—between paint itself and the object or surface upon which paint is applied. / text

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 kommersiële 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.

The racking performance of light-frame shear walls subjected to monotonic and cyclic loading is the focus of this thesis. The sheathing materials investigated are oriented strandboard (OSB), hardboard, fiberboard, and gypsum wallboard. The objectives of this study were to (1) obtain and compare performance characteristics of each sheathing material; (2) compare the effects of monotonic loading versus the cyclic loading response; (3) investigate the contribution of gypsum in walls with dissimilar sheathing materials on opposite sides of the wall; and (4) study the effects of using overturning anchors. The monotonic tests, which incorporated the use of hold-downs, were performed according to ASTM E564. Half of the cyclic tests were performed with hold-downs, and half were performed without hold-downs. The cyclic tests were performed according to the recently adopted cyclic testing procedure ASTM E2126. A total of forty-five walls were tested with various configurations. The size of the walls was 1.2 x 2.4m (4 x 8ft). Two tests were performed with each sheathing material subjected to each type of loading: monotonic, cyclic with hold-downs, and cyclic without hold-downs. Two tests were then performed with OSB, hardboard, or fiberboard on one side of the wall and gypsum on the other side of the wall to study the effects of using dissimilar sheathing materials on the shear walls. The OSB and hardboard exhibited similar performance, and were the strongest of the four sheathing materials. Fiberboard performed better than gypsum, but worse than OSB and hardboard. In general, the performance indicators decreased when the walls were subjected to cyclic loading. The contribution of gypsum to walls with hold-downs was significant, but was not linearly additive. The use of hold-downs had a large effect on the performance of the walls. All shear wall performance indicators decreased when hold-downs were not included, with an average reduction of 66% in the peak load. / Master of Science

Medium density fiberboard (MDF) production uses thermomechanically refined fiber processed under shear with high pressure steam. The industry evaluates fiber quality with visual and tactile inspection, emphasizing fiber dimensions, morphology, and bulk density. Considering wood reactivity, the hypothesis is that a variety of chemical and physical changes must occur that are not apparent in visual/tactile inspection. An industry/university cooperation, this work studies effects of refining energy (adjusted by refiner-plate gap) on fiber: size, porosity, surface area, surface and bulk chemistry, fiber crystallinity and rheology, and fiber interaction with amino resins. The intention is to reveal novel aspects of fiber quality that might impact MDF properties or process control efficiency, specific to a single industrial facility. In cooperation with a North American MDF Douglas fir plant, two refining energies were used to produce resin and additive-free fibers. Refining reduced fiber dimensions and increased bulk density, more so at the highest energy. Thermoporosimetry showed increases in sub-micron scale porosity, greatest at the highest energy. Mercury intrusion porosimetry (MIP) revealed porosity changes on a higher dimensional scale. Brunauer-Emmett-Teller gas adsorption and MIP showed that refining increased specific surface area, more so at the highest energy. Inverse gas chromatography showed that the lowest refining energy produced surfaces dominated by lignin and/or extractives. The highest energy produced more fiber damage, revealing higher energy active sites. A novel rheological method was devised to study fiber compaction and densification; it did not distinguish fiber types, but valuable aspects of mechano-sorption and densification were observed. Refining caused substantial polysaccharide degradation, and other degradative effects that sometimes correlated with higher refining energy. Lignin acidolysis was detected using nitrobenzene oxidation, conductometric titration of free phenols, and formaldehyde determination. Formaldehyde was generated via the C2 lignin acidolysis pathway, but C3 cleavage was the dominant lignin reaction. Observations suggested that in-line formaldehyde monitoring might be useful for process control during biomass processing. According to rheological and thermogravimetric analysis, lignin acidolysis was not accompanied by repolymerization and crosslinking. Lignin repolymerization must have been prevented by the reaction of benzyl cations with non-lignin nucleophiles. This raises consideration of additives that compete for lignin benzyl cations, perhaps to promote lignin crosslinking and/or augment the lignin network with structures that impart useful properties. Fiber/amino resin interactions were studied with differential scanning calorimetry (DSC) and X-ray diffraction (XRD). All fiber types, refined and unrefined, caused only a slight increase in melamine-urea-formaldehyde (MUF) resin reactivity. Generally, all fiber types decreased the enthalpy of MUF cure, suggesting fiber absorption of small reactive species. But DSC did not reveal any dependency on fiber refining energy. According to XRD, all fiber types reduced crystallinity in cured MUF, more so with refined fiber, but independent of refining energy. The crystallinity in cured urea-formaldehyde resin was studied with one fiber type (highest refining energy); it caused a crystallinity decrease that was cure temperature dependent. This suggests that resin crystallinity could vary through the thickness of an MDF panel. / PHD / Medium density fiberboard (MDF) is a wood-based composite which is widely used for making kitchen cabinets and furniture. In the process of making MDF, wood particles are softened under steam pressure and under high temperature and pressure, inside a refiner, mechanically cut into wood fibers. Wood fibers are then mixed with adhesive and additives then hot-pressed and form the final board. In the MDF industry, wood fiber quality has significant effect on final board properties and is evaluated based on visual and tactile inspections. The research hypothesis is that, during the refining, a variety of chemical and physical changes must occur that are not apparent in visual/tactile inspection. An industry/university cooperation, this work studies effects of refining energy (adjusted by refiner-plate gap) on fiber: size, porosity, surface area, surface and bulk chemistry, fiber crystallinity and rheology, and fiber interaction with adhesive. The intention is to reveal novel aspects of fiber quality that might impact MDF properties or process control efficiency, specific to a single industrial facility. It was found that refining had significant effect on wood fiber properties: increased surface area, porosity, and changed the surface energy; and also on wood fiber chemistry: significant degradation in wood fiber main chemical components: poly saccharides and lignin. These changes also had effect on fiber/adhesive interaction. Therefore the hypothesis was confirmed that MDF fiber quality must involve more than a simple visual/tactile evaluation and the effect of refining can be detected on other fiber quality aspects. However more research needs to be conducted to test and find feasible new methods for fiber quality evaluation.