Recipient Organization
UNIVERSITY OF WASHINGTON
4333 BROOKLYN AVE NE
SEATTLE,WA 98195
Performing Department
Sustainable Resource Management
Non Technical Summary
The overall goal of this project is to assess the potential of an innovative new technology, thermal modification (TM), to increase the value of western hemlock lumber by enhancing its physical and mechanical properties. If successful, this project would lead to the development of a series of innovative value added wood products (e.g., decking, fencing, siding and outdoor furniture) that would provide the foundation for the development of a value-added wood manufacturing cluster on the Olympic Peninsula. This project could also increase the pace and scale of restoration efforts within the Olympic National Forest and support forest restoration activities. This project will develop a methodology to assess whether thermal modification is appropriate for other low-value timber species in the Pacific Northwest as well as in other regions of the US. This project will also serve as a model for other rural, timber-dependent communities in the US where the supply of underutilized, low-value timber is plentiful (e.g., coal mining communities in rural Appalachia). This project includes an extension component and the results of the project will be presented at a TM workshop on the Olympic Peninsula. The workshop will include local entrepreneurs, government officials and economic development managers.
Animal Health Component
60%
Research Effort Categories
Basic
40%
Applied
60%
Developmental
0%
Goals / Objectives
This project is designed to use an innovative new technology to add value to low quality hemlock lumber by producing thermally modified hemlock that can be used to manufacture a wide variety of value-added outdoor wood products. The thermal modification process is designed to form the foundation for a manufacturing cluster that will attract a small entrepreneurs interested in manufacturing a variety of complimentary wood products. This manufacturing cluster will then help to drive economic development within rural, timber-dependent communities. The specific objectives for this project are to: a) verify that thermal modification can be used with western hemlock lumber, b) evaluate the impact of the thermal modification process on the physical and mechanical strength of hemlock lumber, c) develop a strategy to utilize thermally modified wood as a foundation for the development of a manufacturing cluster of related and complimentary value-added wood firms.The specific tasks of this project include: 1) obtain the hemlock lumber which will be donated by Interfor Inc., 2) prepare the control and test specimen, 3) thermally modify the test specimen, 4) evaluate the thermally modified (TM) lumber specimen, 5) conduct mechanical testing of the TM and control specimen, 6) analyze the mechanical testing data, 7) identify the appropriate end-use applications for thermally modified hemlock lumber, 8) conduct a design competition, 9) build prototypes based on the design competition, 10) conduct a TM workshop on the Olympic Peninsula, 11) develop a TM project website and 12) complete the final report and publish research papers.
Project Methods
Hemlock lumber will be donated by the Interfor sawmill located in Port Angeles on the Olympic Peninsula. Each eight foot piece of western hemlock lumber will be cut into two four foot specimens (a control and a sample specimen) that will be labeled and measured for size and straightness. Moisture content will be measured at 6 inch intervals along the length of each specimen. The sample specimens will be packaged and shipped to the Natural Resources Research Institute at the University of Minnesota in Duluth (UMD-NRRI) to undergo thermal modification while the control specimens will be shipped to the Composite Materials and Engineering Center at Washington State University. The research team at UMD-NRRI will thermally modify the hemlock lumber using one of the only pilot-scale TM kilns in North America. The hemlock lumber will be thermally modified at a high temperature (~170C) in a vacuum evacuated kiln in the presence of steam. During the thermal modification process, much of the hemicelluloses (sugars) in the wood are driven from the wood. Upon completion of the TM process, the samples will be conditioned in a standard environment with steam to a moisture content of approximately 4-5%. After conditioning, the TM samples will be plastic wrapped and shipped to WSU where they will be measured for size, straightness and moisture content and a UW researcher will evaluate the pre-post TM data to evaluate the impact of the TM process on lumber quality.The literature suggests that the TM process degrades the strength and machinability of the wood. For the end-use applications being considered for this project, that should not be a problem, but it is important to evaluate any strength reduction to ensure that this is indeed the case. The bending strength of the control and TM lumber specimen will be evaluated according to ASTM D198 to evaluate the influence of the TM process on the bending strength (MOE and MOR) of hemlock lumber (ASTM 2015). The size of the bending strength specimens will be set so that a 16-1 span to depth ratio is achieved for flexural testing in the flatwise direction. A total of 50 specimens from both the control and treatment groups (100 specimen total) will be tested. A third-point bending test to failure will be performed on the specimens using a 30-kip screw driven universal testing machine equipped with a 10-kip load cell and LVDT deflectometer. Load and deflection data will be continuously recorded to failure. The flexural properties (modulus of elasticity and modulus of rupture) will be computed as per the ASTM D198 standard. Following the mechanical testing, the machinability of the TM lumber will be evaluated using a variety of standard wood manufacturing processes including planing, sanding, moulding and nailing.The mechanical test data will be analyzed using a paired-sample t-test comparing the strength of the control samples to the paired TM samples to evaluate the impact of the thermal modification process on bending strength. We will also quantitatively evaluate the impact of thermal modification on the machinability of the TM samples. The results of the mechanical strength tests and the machinability tests will be used to help determine the most appropriate end-use applications for thermally modified hemlock lumber. For example, the results of the machinability testing may indicate that the ends of TM lumber need to be predrilled before using nails or screws.One important end-use application for which we want to use TM lumber will be to manufacture outdoor furniture. Since this project is looking to encourage small entrepreneurs to use TM lumber to manufacture outdoor furniture, one area where they will likely require support is in developing unique product designs. In a previous project that looked at using small diameter ponderosa and lodgepole pine from eastern Washington as a raw material for fences, CINTRAFOR sponsored a fence design contest that generated a large number of unique and innovative fence designs (CINTRAFOR 2010). The wooden furniture design contest will be directed towards universities and community colleges that have a program in art and wood furniture design (e.g., the Emily Carr University of Art + Design). Awards will be provided to the winning designers to encourage participation and the submitted designs will be used to develop a portfolio of innovative outdoor furniture designs that will be made available to the public on the project website. CINTRAFOR's previous experience in conducting a design contest was highly successful and generated a large number of creative fence designs.