Wood supply

Wood is converted to pulp by mechanical and chemical actions, which constitute the pulping process. Their selection depends upon the type of wood supply available and the pulp qualities desired. Pulps can be characterized on the basis of the unbleached pulp yields achieved by the pulping process used, i.e.. the yield of oven-drv (OD) pulp obtained from oven-dry debarked wood. 

Pulpwood also is plentiful in such countries as Canada and the Russia and abundant tropical forests exist in such countries as Brazil. Adequate wood supplies exist in Scandanavia as well. Silvicultural practices in the Scandanavian region, coupled with intensive utilization of harvested materials, have prevented undue scarcity in that geographic area. 

The 96 m3 (3,390 cu.ft.) of wood that were delivered in September and October correspond to about 43 metric tons. If we set the calorific value of one kilogram of wood equal to that of half a kilogram of coke, then 43 metric tons of wood correspond to 21.5 metric tons of coke. On the basis of this relationship we can equate the calorific value of the coke and wood supplied with a total of (607 + 21.5=) 628.5 metric tons of coke. 

Potash, as potassium carbonate is referred to in the industry, is the name derived from the methods originally used for recovery of this potassium salt from wood ashes. About 1 tonne of crude potassium carbonate was recovered from the water leachate of the ash generated from the burning of some 400 tonnes (more than 200 cords) of hardwood [22]. Perhaps because of the availability of a large wood supply, Canada was the world s largest potash exporter during much of the first half of the 19th century. 

Most softwood plantations produce wood of passably quality, reasonably quickly and at acceptable cost. Mediocrity should not be equated with something shoddy. Wal-Mart sells goods cheaply, but they need not be shoddy. However, there has to be much greater attention to quality control (of which tree breeding is a crucial filter). The boundary between acceptable and unacceptable is more finely balanced and the choice of threshold values for performance is critical. A mediocre material is vulnerable, not because it is mediocre, but because part of the population is less than mediocre. The desire to off load, i.e. to sell as acceptable, that portion of the wood supply that is less than mediocre is an irresistible temptation (Gaunt, 1998). 

Traditionally plywood has required a much higher grade of log than was necessary for the manufacture of other wood panels, so those nations with an unsuitable wood supply have had to import plywood although now there are manufacturing construction grades that use a poorer and smaller log type. 

J. K. Meil, Environmental Measures as Substitution Criteria for Wood and Nonwood Building Products, in The Globalization of Wood Supply, Processes, Products, and Markets, Forest Products Society Proceedings 7319, pp. 53-60 1994. 

When the scale of the production is not large the oven can be built in the yard of a house, but in large scale production the place must be selected near the wood supply to reduce the labour of carrying the wood. 

Many aspects of wood weathering are not completely understood. A complete understanding of the mechanisms involved in outdoor weathering would aid in developing new pretreatments and finishes to enhance wood durability. The ever-changing commercial wood supply and the introduction of previously unused species at increasing frequency pose particular challenges to the use of modern wood finishes. A detailed study of the various interactions that affect the performance of wood materials is needed to protect wood products when they are used outdoors. 

Despite the success of many adhesives in a variety of applications, other challenges still exist with wood adhesives. How can we get equal performance out of a lower cost adhesive As the wood supply changes from old growth wood to more juvenile wood, how do we develop the proper adhesives, and how do we address performance standards when the wood itself is weaker ... 

A recent study for the American Puipwood Association evaluated the world wood supply and demand situation to the year 2000 (7). The United States was identified as one of the countries which will need more wood than it can supply. However, the study concluded that we have the potential to not only eliminate the expected deficit but also to become a net exporter of forest products. To accomplish this goal, we will need to increase utilization of current growth as well as increase productivity on all available lands. 

Chipping of Round Wood (applied to 30 percent of wood supply)... 

J. Balsiger, J. Bahdon and A. Whiteman, The utilization, processing and demand for rubberwood as a source of wood supply, in Paper Series FAO, Rome, 2000, 50, 75. 

Forest plantations are a remarkable source of wood on a global scale. Based on [26] one can estimate their potential wood supply to be some 1.75 billion m in 2005. In Western and Central Europe, however, wood supply from short rotation crops is marginal. In Sweden, Hungary, and Poland some 10000 hectares are stocked with willow and black locust whereas in other European countries short rotation crops are cultivated on a few hundred to thousand hectares. 

---