1. WoodsDepartamento de TecnologaMiguel Senz de Santa Mara 2007-2014

2. Wood as Engineering Material Wood is composed of cellulose, lignin, hemicelluloses, and minor amounts of extraneous materials contained in a cellular structure. Wood has been used as a natural material for homes and other structures, furniture, tools, vehicles, decorative objects, shipbuilding, bridges, cooperage, barn timbers, farm implements, railroad cross-ties, fence posts, and flooring. 3. Where do we get wood? Traditionally, wood has been extracted from the trunks of the trees, but nowadays we can get profit from branches and roots, used to obtain wood derivatives. Parts of the trunk: BarkCambiumSapwoodHeartwood 4. Woods Natural Woods (obtained directly from the trees) Manufactured Boards (obtained processing branches, shavings, sawdust and fibres) 5. Natural Woods Hardwoods, they usually grow slowly, 25 year or more. Softwoods, grow fast, 5-15 years Exotic woods (tropical woods), can be hard or soft and they come from tropical climates. Other trees, used to obtain materials other than wood 6. Natural Woods Hardwoods (Maderas Duras)Softwoods (Maderas Blandas)Oak (Roble)Poplar (lamo)Chestnut (Castao)Black Poplar (Chopo)Ash (Fresno)Pine (Pino)Walnut (Nogal)Fir (Abeto)Olive (Olivo)Birch (Abedul)Beech (Haya) 7. Exotic Woods Mahogany (Caoba)Ebony (bano)Sapelle (Sapelli)Teak (Teca)African Teak (Iroko)Gaboon or oukum (Okume)Brazilian Cherry (Jatob)Balsa 8. Other trees Cork Oak (Alcornoque), used to obtain cork.Eucalyptus (Eucalipto), used to obtain pulpwood, the basis of paper manufacturing. 9. Process CuttingDryingShaping 10. Manufactured boards Natural woods can't be used to obtain large pieces, almost larger than the trunk of the tree. Great amount of material is obtained from the branches and in the process of sawing. Some technologies make possible to obtain large layers of fine wood. 11. ChipboardMade from saw dust and chips, mixed and pressed with resins and additives. Can have two layers of fine natural wood or plastic. Sometimes the edges are covered with the same material, after the cutting. (Aglomerado) 12. Plywood Plywood is composed of thin sheets of natural wood, glued in layers to form a panel. Plywood always has an odd number of layers, with the fiber alternatively oriented(Contrachapado) 13. Fiberboard Made from wood fibres glued under heat and pressure There are three types: Medium density (MDF)High density (HDF)Low density (Tablex) 14. Measures of the boards I122 cm244 cm Strange measures, arent they? 15. Measures of the boards II4 ft = 122 cm8 ft = 244 cm Not in British units!