Timber processing

D. B. McKeever and K. C. Jackson, "Economic Importance of the Timber Processing Industdes," ia R. W. Haynes, coordinator. An. Analysis of the Timber Situation in the United States, 1989—2040, General Technical Report RM-199, U.S. Department of Agriculture, Porest Service, Rocky Mountaia Porest and Range Experiment Station, Port Collins, Colo., 1990, Chapt. 4, pp. 59—78. 

Megharaj M, Singleton I, McClure NC. 1998. Effect of pentachlorophenol pollution towards microalgae and microbial activities in soil from a former timber processing facility. Bull Environ Contam Toxicol 61 108-115. 

Sanya Timber Factory is a large-scale timber processing enterprise that locates is Sanya, Hainan Island of China, In this factory there are two product lines imported from Sweden for 30,000m shaving plank and 40,000m mid-density fibre, and other workshops. About 100 tons wood waste is produced every day, which includes 35 tons wood powder, 10 tons leftover material, 10 tons sieving waste and 45 tons all kinds of bark. Due to the complicated sorts of timber waste, some of the wastes are used and others are disposed which causes severe problems of storage and pollution. 

Decided mainly by the power load characteristics of timber processing factory, the biomass power plant is required to operate except the overhaul of production line once a year. So the designed power output is up to 6.65 million kw.h/year. The current electricity price in Sanya is 0.55 Y/kw.h, so the production value of the power plant is about 3.48 million Y/year and the gross profit is 2.32 million Y/year. The profit forecasting is shown in Table 4. 

Wellons JD, Krahmer RL, Sandoe MD and Jokerst RW (1983) Thickness loss in hot-pressed plywood. Forest Products Journal, 55(1) 27-34 Welzbacher CR and Rapp AO (2002) Comparison of thermally modified wood originating from four industrial scale processes - durability. International Research Group on Wood Preservation. Document No. IRG/WP 02-20262 Wengert EM (1979) Lumber predrying a timely examination. Timber Process Industries, 4(9) 20-24... 

Timber processing Coal tar creosote Phenol, xylenols, PAH... 

Various incidents of pollution have been reported from industrial waste, effluents from sewage treatment plants, food processing plants along with biocides and toxic effluents from sawmills and timber processing areas. These effects are often enhanced by disposal of hazardous wastes in municipal landfills. 

Iron and steel manufacture Timber processing plywood... 

Carrington CG, Bannister P, Bansal B, Sun Z. Heat pump dehumidification of timber Process improvements. Proc. Conf. Institution of Professional Engineers, Vol. 2, Part 1, Dunedin, New Zealand, 1996a, pp 73—77. 

Printing-press industry and maintenance Track-vehicle industry and maintenance Ship building Timber processing... 

Creosote oils are by far the most widely used timber preservatives (see Wood). This use dates back to 1850. Eor the treatment of railway ties and marine pilings, the BetheU or fliU-ceU process is preferred. The timber to be treated is charged to a pressure cylinder, which is evacuated to extract the air from the wood ceUs. The cylinder is then filled with hot creosote and the pressure increased to 0.8—1 MPa (ca 8—10 atm) to force the oil into the ceUs. 

Total roundwood harvested increased by less than 300 million ft between 1986 and 1991 (Table 8). The value of all roundwood timber harvested in the United States in 1991 was estimated to be 19,370 million (Table 8). The value of roundwood timber is defined as the market value at local points of dehvery, ie, deUvered to a processing faciUty. 

Secondary Timber Products. Secondary timber products are products manufactured from primary timber products. Secondary products can be sold directly to the final consumer or can requite additional processing before reaching the final consumer. The wide diversity of products manufactured from primary timber products makes it difficult to precisely define secondary products. Lumber, for example, is clearly a secondary product because it is manufactured from roundwood and typically requites further processing before reaching its final use. Wooden furniture is considered a final product, not a secondary product because it is made from lumber or other secondary timber products. In general, products made from secondary timber products were not included in this analysis. 

Kemppainen and Shonnard compared the production of ethanol via fermentation-based processes starting with two lignoceUulosic feedstocks virgin timber resources or recycled newsprint from an luban area. For this piupose, they coupled a software-aided simulation of the fermentation process with impact assessment software. 

Mineral resources are nonrenewable resources, in contrast to renewable resources such as surface water and timber, which are or can be replenished naturally or artificially. The geological processes by which most mineral deposits form take a very long time. They can, in no way, be thought to replenish deposits extracted from the ground and dispersed by use. However, it is important to recognize that mineral resources are extendable with the help of advancing technology that develops uses for sources that were not readily usable or exploitable before, allows hidden deposits to be discovered, and enhances the efficiency of recovery and of use. 

In the United States, about 80% of the 23 million kg of technical PCP produced annually — or about 46% of worldwide production — is used mainly for wood preservation, especially utility poles (Pignatello etal. 1983 Kinzell etal. 1985 Zischke etal. 1985 Choudhury etal. 1986 Mikesell and Boyd 1986 USPHS 1994). It is the third most heavily used pesticide, preceded only by the herbicides atrazine and alachlor (Kinzell et al. 1981). Pentachlorophenol is a restricted-use pesticide and is no longer available for home use (USPHS 1994). Before it became a restricted-use pesticide, annual environmental releases of PCP from production and use were 0.6 million kg to the atmosphere from wood preservation plants and cooling towers, 0.9 million kg to land from wood preservation use, and 17,000 kg to aquatic ecosystems in runoff waters of wood treatment plants (USPHS 1994). There are about 470 wood preservative facilities in the United States, scattered among 45 states. They are concentrated in the South, Southeast, and Northwest — presumably due to the availability of preferred timber species in those regions (Cirelli 1978). Livestock facilities are often constructed of wood treated with technical PCP about 50% of all dairy farms in Michigan used PCP-treated wood in the construction of various components of livestock facilities (Kinzell et al. 1985). The chemical is usually applied to wood products after dilution to 5% with solvents such as mineral spirits, No. 2 fuel oil, or kerosene. More than 98% of all wood processed is treated with preservative under pressure about 0.23 kg of PCP is needed to preserve 1 cubic foot of wood (Cirelli 1978). Lumber treated with PCP retains its natural appearance, has little or no odor, and can be painted as readily as natural wood (Wood et al. 1983). 

Bethell Also known as the Full-cell process. A method for impregnating timber with a creosote preservative. The wood is first degassed under partial vacuum and then impregnated under a pressure of up to 10 atm. See also Rueping. 

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