State & Private Forestry
Forest Products Laboratory
The Forest Products Conservation & Recycling Review is assembled and edited monthly by Adele Olstad and John Zerbe of the FPC&R; Technology Marketing Unit at the Forest Products Laboratory (FPL). Review contributions and correspondence may be sent to either Adele or John at the address below. For copies of FPL or North Central Forest Experiment Station publications,contact FPL Information Services at the same address.
The individual items included in the Review reflect the content and tone of the original articles. Inclusion of an item does not imply agreement nor endorsement by the U.S. Department of Agriculture of facts or opinions contained in any article. The Review does not evaluate the accuracy of the information reported. The use of trade or firm names in this issue is for reader information and does not imply endorsement by the U.S. Department of Agriculture of any product or service.
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Reminder: The Durability and Disaster Mitigation in Wood-Frame Housing Conference will be held November 6-8 at the Monona Terrace Convention Center in Madison, WI. The conference is sponsored by the Partnership for Advancing Technology in Housing (PATH) Consortium for Wood-Frame Housing, in cooperation with the Forest Products Society (FPS). The Conference will include a suppliers' showcase, displays of products and services offered by conference sponsors, and poster presentations related to durability and disaster mitigation. For more information, visit the conference website (www.forestprod.org/confpath.html) or contact the FPS Conferences & Meeting Department by phone (608-231-1361, ext. 201), Fax (608-231-2152), or e-mail (conferences@forestprod.org).
The 2000 Central Region Woodland Stewardship Conference for people in Iowa, Nebraska, Kansas, and Missouri will be held November 18 at the National Arbor Day Foundation's Lied Conference Center in Nebraska City. Four concurrent sessions will be presented each hour. Session topics include:
Program Coordinator Needed for National Network of Forest Practitioners to provide leadership for building the newly created National Community Forestry Center (NCFC). The Center offers research, education, and extension activities to people who live in forested and natural-resource-dependent communities. The position requires a Master's or Ph.D. degree in a field relevant to forest-based rural development; commitment to ecologically and socially responsible rural development; experience in a leadership and/or management role in a rural, regional, or national community development organization or complementary organization or business; understanding of research methodology and process; and ability to balance a diverse set of tasks under tight deadlines and attend to detail while focussing on a broader vision, to raise and administer funds from a diversity of sources and build and maintain successful relationships with grantors, and to work with diverse groups of people. The candidate must also have excellent writing, editing, and oral communication skills, as well as a willingness to travel extensively. Position responsibilities include fundraising and financial management, project management, organizational development and technical assistance, policy issues, and outreach and communication.
For more information on this position, contact Lee Williams by phone (530-284-1022), Fax (530-284-1023), or e-mail (lee@fcresearch.org). The deadline for applications is October 20. For an overview of NCFC, visit their website at www.fcresearch.org. Information about the National Network of Forest Practitioners can be found at www.nnfp.org.
Interested in "Big Tree" Facts? For example, where is the tallest tree in the United States and how tall is it? The answers to these questions, along with other facts about the largest known specimens of native and naturalized trees in the United States, can be found in The National Register of Big Trees 2000, published by American Forests magazine. Visit www.americanforests.org for information on how to obtain a copy.
At-Risk Youths Help Build Energy-Efficient, Low-Income Housing -- American Youth Works of Austin, TX, provides education and health services to young people on the edge of poverty. Through a youth project with Habitat for Humanity, the organization discovered that homebuilding can be used to teach mathematics, writing, and other important skills. The Habitat for Humanity project was so successful that American Youth Works launched Casa Verde Builders.
Casa Verde houses are said to be among the greenest, most energy-efficient in their market, and they have repeatedly received Energy Stars from the Austin Green Builder Program. The houses range from 980 to 1,150 ft² (91 to 107 m²) and typically sell for $75,000 to $85,000. All are located on Austin's economically depressed east side, where poor soil conditions require deep (e.g., 16-ft (5-m)) pier-and-beam foundations. Though Casa Verde houses have been built with structural insulated panels, steel studs, and Faswall composite block, current models are being framed with 2-by-4 finger-jointed studs spaced 24 inches (61 cm) on center.
[Source: Energy Design Update, July 2000]
Marketing Strategies for Sustainable Forest Management in Africa -- The country of Ghana in tropical Africa provides an example where sustainable timber production depends on improved marketing practices and improved technology. Although Ghana has an extensive lumber and plywood industry, the allowable cut in results in an insufficient timber supply for keeping industrial plants running at full capacity. Moreover, the plants often compete solely on price for commodity products, which tends to lower the value of the comparatively scarce resource in Ghana. A paradigm shift is also occurring, where the former emphasis on exploitation is changing to an emphasis on sustainability.
Another problem that affects sustainability is reliance on lesser-used species. The situation has been further confused by a series of tropical hardwood boycotts in several European countries (e.g., the UK, Germany, and Holland). The primary objective of these boycotts is to reduce the demand for tropical hardwood in order to coerce firms and governments in the tropics to adopt sustainable forest management practices and policies. However, the most recent export statistics from Ghana indicate that the boycotts have had little impact, and export earnings from forest products have increased substantially since the start of the boycotts. It could be argued that rather than coercing government and industry leaders into compliance with environmentalist objectives, the boycotts have diminished the influence of environmental groups.
Improved marketing techniques can provide managers in the forest products industry with the opportunity to move towards a basis of sustainability in a number of ways. Marketing functions that deserve more emphasis include greater access to market information, certification of sustainability, and market development for lesser-used tropical timber species and for nontraditional forest products.
[Source: Philippine Lumberman, September-October 1999]
Forest Products Society Call for Papers -- Two Forest Products Society (FPS) technical interest groups (Energy Generation and Conservation, Wood and the Environment) will cosponsor a joint technical session on woody residue and waste for bioproducts during the annual FPS meeting in June 2001. Papers relating to the improved use of low-value wood and fiber for energy or value-added bioproducts are being solicited. Papers covering the use of small-diameter and submerchantable trees and species, recovery and recycling of wood and wood-based products, and manufacturing residue are encouraged. Suggested topics include the use of biomass for producing electrical energy, biomass-based fuels and other chemicals, composite materials, and economic incentives and environmental issues for the use of woody residue and waste products.
Authors must submit a 1-page, single-spaced abstract outlining the content and estimating the time required for the presentation (15 or 30 min). Citation of authors, in order of seniority, should include professional titles, affiliations, addresses, phone and fax numbers, and e-mail addresses. Also, the person(s) presenting the paper should be identified. Abstracts and correspondence must be mailed, faxed, or e-mailed prior to November 1, 2000. For additional information, contact John Shelly, University of California Forest Products Laboratory, by phone (510-215-4210), Fax (510-215-4299), or e-mail (john.shelly@ucop.edu). Additional information on the meeting can be found at the FPS website (www.forestprod.org/).
The 2000-2001 Recycled Pulp and Paper Mill Directory has been published by Progress in Paper Recycling (PPR). The directory lists U.S. and Canadian mills that use recovered paper or deinked market pulp as raw materials. A suppliers/vendors/services listing is included. For more information, contact Mahendra Doshi of PPR at 920-832-9101.
[Source: Resource Recovery Report, July 2000]
Furniture From Scrap -- Wooden Man, a company formed in California 7 years ago by two former actors, has been successful in building furniture from scrap wood. The company has grown to a 13,000-ft² (1,209-m²) factory with 23 woodworkers and master carpenters. Wooden Man recently received a $450,000 recycling market development loan from the California Integrated Waste Management Board. For more information, contact Wooden Man at 310-515-0241.
[Source: Resource Recovery Report, July 2000]
Recovering Construction and Demolition Debris -- The key to reducing landfill dependency isn't simply recovering materials, but being able to sell what is recovered. As a result, municipalities have targeted a recoverable portion of the waste stream with good end-markets; namely, construction and demolition (C&D;) debris. Why recycle C&D; waste? Here are a few reasons:
Salvage for on- and offsite use. Materials such as historic fabric and architectural items from historic buildings can be recovered prior to demolition, stored, reconditioned, and incorporated into new structures. Light fixtures, wood partition walls, and decorative masonry units have materials whose value and aesthetic appeal warrant the time and expense required to reuse them.[Source: Waste Age, July 2000]Dismantling prior to demolition. By dismantling a building prior to mechanical demolition, municipalities can recover a wealth of materials such as old-growth timbers, red brick, and windows for reuse and recycling. These materials can be transported to other building projects or sold. For example, the Metropolitan Waste Authority in Portland, OR, conducted a salvage operation prior to the selective demolition of an old Sears, Roebuck and Co. store. By allowing a local lumber company to recover the store's hardwood flooring, the authority not only diverted the flooring from the landfill but also provided a business opportunity for the lumber company.
Onsite crushing and grinding. Wood and green waste materials can be ground onsite, saving landfill tipping fees and transportation costs.
Source separation for offsite processing. Building projects are completed in phases, starting with site construction, continuing with roof installation, and ending with interior finish work. Materials generated during new construction may therefore yield homogenous loads of debris such as lumber during framing and drywall during sheetrock installation.
Mixed C&D; debris loads for offsite processing. Mixed C&D; processing facilities are becoming more prevalent across the United States. In many cases, these facilities have a simple setup: C&D; debris is dumped on the sorting floor and removed with loaders, with grappling equipment, by hand, or on conveying systems with picking stations. In addition to this basic operation, such facilities may have grinders or a crushing plant for processing large volumes of concrete, asphalt, wood, and green waste. Some setups have more advanced, automated setups that use loaders with grapplers and pulverizing heads, as well as high-capacity mechanical equipment (screeners, horizontal grinders, or tub grinders; conveyor systems; vibrating floors; and flotation tanks). These automated systems still may employ picking stations with manual sorting. Although basic processing setups may only achieve a C&D; recovery rate of 50% or less, automated setups may achieve recovery rates as high as 90%. However, to justify the expense of building and operating an automated system, facilities require a steady stream of C&D; materials to generate tipping fee revenues.
New Wood Fireplaces Banned in San Jose, CA -- On June 20, San Jose became the largest Bay Area city to take an official stand against wood smoke pollution when it joined Petaluma, Los Gatos, and Palo Alto in adopting a fireplace ordinance. The ordinance is directed particularly at zero-clearance fireplaces and applies only to new homes and remodeling projects. It allows installation of gas-burning fireplaces, EPA-certified wood stoves and inserts, and pellet appliances.
Luna Salaver, spokeswoman for the Bay Area Air Quality Management District, said, "Most people don't realize that wood smoke is a major source of air pollution." In the winter months, wood smoke makes up 40% of the particulate pollution in Bay Area air, rivaling the amount contributed by car exhaust. According to Salaver, communities considering a similar ban include Los Altos, Berkeley, and Morgan Hill, as well as Contra Costa County.
[Source: Hearth & Home, August 2000]
Objections to Residential Standard for Indoor Air Quality -- The National Association of Home Builders (NAHB) has raised objections to the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) Standard 62.2, which describes minimal measures for ventilation and acceptable indoor air quality in low-rise residential buildings. The Standard was approved unanimously by the ASHRAE Board of Directors and is slated for public review in the next couple of months. The vote reconfirms ASHRAE's commitment to human health as a core value.
The NAHB objects to the standard, stating that mechanical ventilation is generally unnecessary in new homes and will add unnecessary costs to the price of building and buying a new home. NAHB brought forward 10 motions to modify the proposed standard, of which the Standard's technical committee approved 7--all of which deal with relative minor clarifications and exceptions (e.g., clarifying that continuously operating bath fans can be used to meet the whole-house ventilation requirement).
[Source: Energy Design Update, July 2000]
Bioenergy Plantations Advocated to Improve Forest Sustainability -- According to Dr. Rodel Lasco, Director of the Environmental Forestry Program of Los Baños College of Forestry and Natural Resources, University of the Philippines, converting part of 2 to 6 million hectares (4.9 to 14.8 million acres) of grassland and degraded areas into bioenergy plantations can help accelerate the reforestation efforts of the country. Recent figures show that the current reforestation effort is minimal--less than 100,000 hectares (247,100 acres) per year. Bioenergy could be utilized in power generation as well as fuel for cooking.
In Bolinao, Pangasinan, a 3-MW power plant operating at 65% efficiency could consume 25,000 tons of wood. If an Ipil-ipil plantation yields 20 to 25 tons/hectare per year, 1,000 to 2,000 hectares (2,471 to 2,965 acres) are needed to supply the dendothermal power plant. Thus, for every megawatt of electricity generated, 330 to 440 hectares (815 to 1,087 acres) of land need to be reforested.
Apart from boosting the country's greening efforts, tree farms offer several local, national, and even global benefits. These include soil conservation, protection of watersheds, biodiversity conservation, socioeconomic rewards, and amelioration of global warming effects.
[Source: The Philippine Lumberman, February 2000]
Second-Stage Drying Improves Efficiency of Drying Southern Pine -- Tests at the University of Minnesota have shown that second-stage drying, a process in which latent heat from a dry kiln is captured and used to heat a smaller secondary kiln, has the potential to save energy and may also cost significantly less than standard drying procedures. Because Southern Pine is highly permeable, it can be dried efficiently and quickly by high-temperature drying without appreciable degrade. At higher temperatures, air can hold more water vapor; therefore, less makeup air is required for the kiln. During drying, ventilation is required to remove moisture-laden air from the kiln. Unfortunately, venting causes much potentially usable energy to escape from the system in the form of steam. Green Southern Pine lumber typically has a moisture content of approximately 100% on an ovendry basis. After kiln drying, moisture content is approximately 15% (19% maximum). Therefore, with an approximate ovendry wood density of 2,600 lb (1,179 kg) per 1,000 board feet, 2,200 lb (998 kg) of water per thousand board feet are removed during drying.
The latent heat of vaporization contained in this amount of water vapor is about 2.2 million Btu, about as much heat as contained in 8.2 gallons (31 liters) of No. 2 fuel oil or 53 lb (24 kg) of natural gas as burned in a steam boiler (~80% efficiency). Any attempt to condense the water vapor in the kiln results in immediate return of heat energy. By locating heat exchangers in the dry kiln, it is possible to capture a portion of that heat energy that would otherwise be vented to the atmosphere. Condensing steam may also lower the volatile organic compound (VOC) emissions from a kiln.
By the concept of second-stage drying, a secondary kiln is located adjacent to the primary kiln. A bank of heat exchangers separates the two chambers. In this case, the latent heat of vaporization from the water vapor in the primary kiln is captured by the heat exchangers and is transferred to the secondary kiln. A small amount of sensible heat is also conducted through the heat exchangers, based only on the air temperature difference between the primary and secondary chambers.
During tests, conditions in the primary kiln were maintained at 250°F (120°C) dry bulb and 212°F (110°C) wet bulb. These temperatures correspond to a wood moisture content of approximately 3.8%. This wet-bulb temperature is slightly higher than that commonly used in high-temperature Southern Pine kilns (180°F (~82°C)). The wet-bulb temperature was elevated to increase the condensing efficiency of the exchangers.
Three different second-stage chambers were built with three types of heat exchangers next to the primary kiln wall. Results showed that 10 Btu could be collected each hour from each square foot of heat exchanger area per °F temperature difference between the second-stage chamber and the primary dry kiln. (1°F = 0.56°C.) Second-stage kilns must be run at lower temperatures than required by primary kilns. A practical temperature at which to operate the second-stage kiln is 150°F (66°C). This temperature promotes second-stage drying and is favorable to condensing water vapor in the primary kiln.
Replacing an entire 1,076-ft² (100-m²) kiln wall with a heat exchanger and locating a second-stage dryer adjacent to it could potentially capture 415,000 Btu for each hour of operation. This energy savings equates to about 3.7 gallons (14 liters) of No. 2 fuel oil or 24.2 lb (11 kg) of natural gas per hour burned in a typical steam boiler.
[Source: Timber Processing, September 2000]
Residential Structural Design Guide: 2000 Edition -- The increasing complexity of homes, the use of innovative materials and technologies, and the increased population of high-hazard areas of the United States have introduced many challenges to the building industry and design profession. These challenges call for the development and continual improvement of efficient engineering methods for housing applications as well as the education of designers in the uniqueness of housing as a structural design problem.
The Residential Structural Design Guide was prepared by the NAHB Research Center, Inc. The work was sponsored by the U.S. Department of Housing and Urban Development and co-funded by the National Association of Home Builders (NAHB) as an initial effort to document and improve the unique structural engineering knowledge related to housing design and performance. The Guide complements current design practices and building code requirements with value-added technical information and guidance. In doing so, it supplements fundamental engineering principles with various technical resources and insights that focus on improving the understanding of conventional and engineered housing construction. Thus, it attempts to address deficiencies and inefficiencies in past housing construction practices and structural engineering concepts through a comprehensive design approach that draws on existing and innovative engineering technologies in a practical manner.
The Guide consists of seven chapters: (1) describes basic substance of American housing, including conventional construction practices, alternative materials, building codes and standards, role of design professionals, and experience with performance problems and successes, particularly as related to natural hazards; (2) introduces basic engineering concepts on safety, load path, and structural system response of residential buildings, subassemblies, and components to various types of loads; (3) addresses design loads applicable to residential construction; (4) and (5) provide step-by-step design procedures for various components and assemblies that constitute the structure of a home; (6) describes design of light-frame homes to resist lateral loads from wind and earthquakes; and (7) addresses design of various types of connections in a wood-framed home important to overall function. The Guide includes additional resources and references.
The Guide is posted on the PATH (Partnership for Advancing Technology in Housing) website at www.pathnet.org/resource/residential.html.
A Wood-Plastic Conference devoted to developments in equipment, processes, and materials for natural fiber-plastic composites will be held December 5-6 in Baltimore, MD. For more information, visit the conference website at www.plasticstechnology.com.
Engineered Wood Makes Its Mark in Railroad Environment -- When the Buffalo & Pittsburgh Railroad needed to replace 192 lineal feet (59 m) of deteriorated bridge stringers, they opted to utilize Trus Joist's Parallam® parallel strand lumber (PSL). This decision marked the first application of Parallam® PSL in a railroad environment. The decision to choose this product was based on its reasonable cost and availability in large sizes.
According to John Falstrom, eastern transportation products manager for Trus Joist, cost effectiveness is just one of the reasons railroaders are beginning to consider Parallam® PSL as a viable substitute for sawn wood ties and stringers. A major benefit is the product's treatability-it accepts treatment through the entire cross-section. According to Falstrom, this thorough treatment translates into durability, making the engineered wood roughly twice as strong. And, because of the manufacturing process, the material has a low moisture content (8%) that allows it to be treated as soon as it is produced, which reduces inventory for treaters and railroads. Another attractive quality is that Parallam® PSL stringers are uniform in dimension and strength. Because the stringers are square, they don't have to be shimmed at the pile caps; they weigh about the same as solid wood stringers, and they can be handled with conventional boom trucks.
Don Schwabe, marketing manager for industrial operations at Trus Joist, stated that for a short-term niche, Parallam® PSL will be used in bridge structures such as stringers, pile caps, and bridge timber. The product would address the issue of the new 286,000-lb (84,370-kg) cars now required by Class I. Schwabe believes that a change is taking place requiring structures to be stronger, and Parallam® PSL is a solution to that problem.
[Source: Crossties, May/June 2000]
Wooden Bridge Project -- The Merle Bridge, a unique structure in France, is the second longest wooden bridge in Europe. It spans a 177-ft (54-m) valley and links the banks of the Maroone River 100 ft (30 m) below. The new structure replaces the previous steel suspension bridge. Wood was chosen over less expensive metal designs because the local population wanted a bridge that fit into the ambience of the location, which includes the nearby ruins of a 13th century castle. The architectural requirement was for a rustic, simple, and timeless design. The result was a construction 189 ft (58 m) long, 32 ft (10 m) wide, and 82 ft (25 m) high. A glued-laminated technique was used to build the structure; members up to 82 ft (25 m) long were constructed and initially assembled in workshops near Paris. They were then shipped by truck and reconstructed like a giant Erector set. Douglas-fir was chosen because of its good mechanical properties and performance in terms of natural durability. Another advantage to using Douglas-fir was its wide availability; the region has many trees in the required 70-yr maturity range.
[Source: The Northern Logger & Timber Processor, May 2000]
Hazelnuts a Source of Taxol -- Scientists have announced that hazelnuts can be used to extract the active chemical ingredient of the cancer-fighting substance, Taxol. The nuts carry only one-tenth the chemical that can be obtained from yew trees, but the finding is promising to pharmaceutical companies competing with the current exclusive manufacturer of Taxol. Production of the new source is still in the laboratory stage.
[Source: Arbor Day, July/August 2000]
The Food and Agriculture Organization (FAO) of the United Nations has published a series of technical papers on nonwood forest products. The latest in the series, Non-Wood Forest Products From Conifers (No. 12), discusses traditional and contemporary uses of products from conifers. It is organized according to the part of the tree from which products are obtained (e.g., whole tree, foliage, bark and roots, resin, seeds, and cones). The information is intended to be of assistance in identifying opportunities for management and production of nonwood conifer products. Other papers in the FAO series include:
Virginia Tech's 19th Oak Drying Workshop on December 5-7 is targeted toward beginning operators who are drying hardwood lumber in steam or dehumidification dry kilns and predryers. Topics to be covered include the basics of hardwood lumber drying, kiln and predryer operational techniques, use of drying schedules, practical techniques for equalizing and conditioning (stress relief), causes of and cures for drying defects, and quality control procedures. For additional information or registration materials, contact Fred Lamb by phone (540-231-7256), Fax (540-231-8868), or e-mail (fml195@vt.edu).
The Southern Saw Mechanics Workshop, sponsored by Mississippi State University, will be held November 9-10 in Memphis, TN. For additional information, contact Phil Steele at 662-325-8083 or psteele@cfr.msstate.edu.
Unique Use of Glulam Arches for Potash Storage Buildings -- Western Archrib of Edmonton, Alberta, Canada, serves many markets with glulam products. In the mid-1960s, the firm played a major role in the development of the potash industry in western Canada by supplying the arches for large storage facilities. These buildings were typically 200 ft (61 m) wide and 700 to 1,800 ft (244 to 549 m) long. These large-span arches were suitable for potash storage because wood is not corroded or abraded by potash. Steel is badly corroded by salt. The company has also provided the structural arches for the massive Neptune Terminal in Vancouver to store potash prior to loading it onto ocean freighters.
Over time, Western Archrib has doubled the capacity of its fingerjointer feeding table while becoming more automated wherever possible. The company currently has 80 employees; 20 years ago, before the automation process was begun, twice as many workers were needed to make the same volume of product. The fingerjointer saws a joint pattern on each end of the boards, applies the glue, matches boards end to end, then conveys the fingerjointed lumber to the radio frequency (RF) tunnel. Once in the tunnel, the glueline is heated to about 210°F (99°C), causing each fingerjoint to cure in about 30 seconds. After passing through the RF tunnel, the fingerjointed lumber is crosscut to the exact length required.
The fingerjoints and beams undergo a number of stress and bonding tests throughout the manufacturing process to meet international building standards. The March 2000 forecast of the APA-The Engineered Wood Association predicted that North American glulam output will rise from 331 million board feet in 1999 to 350 million in 2000 and 465 million by 2005. According to Archrib chairman Jim Gargey, "Demand is cyclical. Church arches were popular in the 1960s and 1970s. They weren't so popular in the 1980s, and now they are back again."
[Source: Wood Technology, July/August 2000]
Contents
Please send any questions or comments to
aolstad@fs.fed.us.
Contact-Name: Adele Olstad
Contact-Phone: 608/231-9329
Document-Date: 2000 October 16
Abstract: September 2000 Issue of FPC&R; Review