Extrusion of Solid Wood Impregnated with Phenol Formaldehyde (PF) Resin: Effect of Resin Content and Moisture Content on Extrudability and Mechanical Properties of Extrudate
A new deformation technique of wood flow forming is promising for industrial uses of solid wood. Flow deformability, size stability, and good mechanical properties were obtained by using wood impregnated with low molecular weight phenol formaldehyde (PF) resin. In this study, to clarify the effect of the PF resin and moisture contents in wood on the flow deformability (extrudability) and the mechanical properties of the product (extrudate), a lateral extrusion was conducted by using wood impregnated with various contents of PF resin and three levels of moisture content. The results indicated that the extrudability of wood impregnated with PF resin improved with an increase in both PF resin and moisture content. The mechanical properties of the extrudate worsened with increases in the moisture content of the wood impregnated with PF resin. Because most of the water in the wood remained in the mold during the extrusion process, chemical changes of the wood substance and PF resin occurred due to steam forming under the high temperature and pressure of the extrusion. The steam worsened the mechanical properties of the extrudate.
Extrudability of Solid Wood by Acetylation and In-Situ Polymerisation of Methyl Methacrylate
Recently, a processing technique resembling plastic-type forming has been developed for solid wood. To improve the recyclability of the formed products, thermoplastics were used as a binder. In this study, a hydrophobic monomer of methylmethacrylate (MMA) was used as a thermoplastic binder and was impregnated into wood, then polymerised by heat to form polymethylmethacrylate (PMMA). The effects of wood acetylation, a hydrophobising treatment of wood, on the extrudability of solid wood impregnated with PMMA (wood-PMMA composite) during extrusion were investigated. The acetylated wood was found to swell much more after the PMMA treatment than the untreated wood. The extrusion loads obtained from capillary fluidity tests of the acetylated wood-PMMA composite were lower than those of untreated composite. The fluidity improvement by acetylation can be attributed to a weakening of the cohesive interactions in the wood polymer, and this is primarily caused by the acetylation reaction itself. When the acetylated wood-PMMA composite was repeatedly extruded, the starting load of the extrusion decreased with increasing extrusion repetitions, probably as a result of decreasing wood particle size.
Cuisine and Empire: Cooking in World History
List of Illustrations List of Tables Acknowledgments Introduction 1. Mastering Grain Cookery, 20,000--300 B.C.E. 2. The Barley-Wheat Cuisines of the Ancient Empires, 500 B.C.E.--400 C.E. 3. Buddhist Cuisines, 260 B.C.E.--4800 C.E. 4. Islam Transforms the Cuisines of Central and West Asia, 800--1650 C.E. 5. Christianity Transforms the Cuisines of Europe and the Americas, 100--1650 C.E. 6. Prelude to Modern Cuisines: Northern Europe, 1650--1840 7. Modern Cuisines: The Expansion of Middling Cuisines, 1810--1920 8. Modern Cuisines: The Globalization of Middling Cuisines, 1920--2000 Notes Bibliography Index