Eastern SPF producters experience an average value loss of $10 to $16/mbf due to drying degrade. A clear understanding of how wood characteristics influence warp will make it easier to effectively modify drying processes to reduce these losses. The goal of this study was to categorize green lumber according to its potential to warp, dry the lumber using a typical industrial kiln schedule and assess whether pieces that either warped or remained straight were correctly identified. Experimental material was a sample of 440 black spruce 8-foot 2x4's from four grain defect groups. These were : 1) control, no grain defects; 2) cross grain but no compression wood; 3) compression wood but no cross grain; and 4) both cross grain and compression wood. Methods used to select lumber with either a high or low potential to warp were successful. Warp was found to be related to the severity of compression wood and cross grain in each piece. Lumber without cross grain or compression wood dried with very little warp. Lumber with both cross grain and compression wood had the lowest quality after drying.
Standard tooth designs for ripsaws carry a cutting edge which is square in relation to the saw blade axis. This saw tooth design proved to be satisfactory in the past when saws were heavy in kerf and sawdust was not considered as an important fibre source for pulp or other fibre based products. Forintek recognized that this tooth design is not optimum for achieving the best sawing performance and producing high quality sawdust for pulp. This report describes the results of extensive sawing experiments carried out in both the laboratory and in the sawmill to develop a new tooth design.
The average relative density of lodgepole pine trees from five sites in three regions of interior B.C. was determined using lumber from a previous joinery-yield study. The use of relative density as a predictor of a site's potential for machine-stress-rated (MSR) lumber was explored by comparing the MSR lumber yields for a high and a low relative density site. There was a significant difference in the average relative density of the sites within a region and between regions. The average relative density ranged from 0.39 to 0.42 with a standard deviation of 0.02 to 0.03. Relative density generally declined with increasing stem height. Logs from the lowest point (first 3.7 meters from stump height of 30 cm) in the stem were higher in relative density than the logs from the upper part of the stem. The yield of 2400f-2.OE MSR grade lumber decreased with decreasing log density. There was a positive and significant correlation between relative density on one hand and stiffness (MOE) and MSR lumber yield on the other. MOE was influenced only partly but significantly by relative density. The overall MSR yield for the high and low relative density sites was significantly different. The site with the higher average relative density gave higher yield of MSR grade 2400f-2.OE and lower rejects (lower than 1650f-1.5E grade), while the site with the lower average relative density produced a negligible amount of the high MSR grade and higher rejects. Trees with high relative density were necessary for producing the 2400f-2.OE grade. Therefore, assessing the average relative density of a site should also quantify the relative density of trees at the upper tail of the relative density distribution.
Glulam rivets (or Griplam nails) are high strength steel nails developed originally (in Canada) to connect glued-laminated timbers (glulam) by means of pre-drilled steel side plates. Glulam rivets are considered one of the most efficient connectors in wood construction mainly because of their high load carrying capacity. However, CSA-O86.1, Code for Engineering Design in Wood does not provide design values for glulam rivet connections with sawn timber. The Fastenings Subcommittee of the CSA Technical Committee (TC) on Engineering Design in Wood has identified a need to extend the use of glulam rivet connections to sawn timber with appropriate service condition factors, and to investigate the effect of plate thickness on joint capacity. This project involving testing and analysis of sawn timber glulam rivet connections was initiated in the 1990/91 fiscal year. Since then, progress has been communicated with members of the Glulam Rivet Task Group of the TC on Engineering Design in Wood. In the 1992/93 fiscal year, a) The testing part of the project was completed. Lateral load resistance and rivet withdrawal test data were analyzed to investigate the effect of species, loading type and direction, environmental conditions, density, waiting period between assembly and test, pre-drilling, and plate thickness; b) A revised draft of glulam rivet design section of CSA Standard O86.1 was prepared and distributed to Glulam Rivet Task Group members, and discussed in the November 1992 meeting of the Fastenings Subcommittee. Revisions will be finalized in the 1993/94 fiscal year; and c) Based on an invitation by the program committee of the International Workshop on Wood Connectors (held in Las Vegas, November 1992), a technical paper entitled "Canada overview - glulam rivets" was presented. In the 1993/94 fiscal year, data analysis will be completed, design values and factors will be proposed and discussed with members of the Glulam Rivet Task Group and then submitted to the Fasteners Subcommittee of CSA TC on Engineering Design in Wood for code implementation.
This report provides the results of a pilot study into the load-carrying capacity of a bolted steel plate-to-wood connection subject to cyclic loading. The connection consisted of a timber main member (amabilis fir) with two steel side plates bolted to the main member using two bolts. Bolt sizes investigated were 3/8, 1/2 and 3/4 inch. Subsidiary studies were carried out to determine the embedment strength of wood for the bolts used in this study and the bending properties of the bolts. The results will be used in a planned study of the force reduction factors to be used in the seismic design of timber structures.
The basic wood properties of 45-year-old second-growth sitka spruce were examined to determine if rapid growth produces poor wood quality. Five dominant and codominant trees were sampled from each of four stands with stocking densities of 520, 640, 1080, and 1520 stems/ha. Stem size, extent of live crown, yearly wood relative density trends, and longitudinal shrinkage were measured.
This report documents the development of a strategy for research in durability for the next five years. The bulk of the document is concerned with the market information required by a task force of the Building Systems Technical Advisory Committee to identify critical technology/information gaps threatening existing markets, limiting market expansion, or access to new markets. Opportunities for adding value to wood products by enhancing durability are also addressed. Each major subject area is further subdivided according to the end use to which the products will be put using the Hazard Class system. The last section of the report outlines the strategy developed as a result of the input provided by the task force. The proposed mix of research over the next five years is 40% on termite proof lumber, 20% on modelling durability, 20% on environmentally benign treatments and 20% contract research.
This study was prompted by two considerations; first the possibility that sorted amabilis fir (commonly known as balsam) might be marketable as a more treatable wood species, and second, the need for an explanation for batches of hem-fir which are unusually difficult to treat (refractory). Preliminary studies at Forintek and elsewhere had shown that preservative penetration in amabilis fir was greater than in western hemlock. It was necessary, however, to quantify this difference and determine if it was common to the entire B.C. coastal region. Sorted amabilis fir and western hemlock from five coastal B.C. sawmills (20 boards per mill and species) was planed to nominal 2 x 4 inch dimension, cut into one short length and four end-matched sub-samples. Half the end-matched sub-samples were conventionally incised and half were double-density incised. From each group, half were CCA-treated with a three hour pressure period and half were treated with a six hour pressure period. Without incising, amabilis fir exhibited 80% deeper penetration and higher preservative retention by analysis than western hemlock. Unincised amabilis fir came close to meeting the proposed Canadian standard for residential decking. Conventionally incised amabilis fir met the Canadian standard for wood in ground contact. In contrast none of the sorted western hemlock from the five sawmills met the standard even when double-density incised and given a six hour pressure period. These results suggest that there is an opportunity for species separation to produce a treatable amabilis fir product and a higher strength pure western hemlock product. Furthermore, these results provide an explanation for the variation in the treatability of hem-fir. It appears that this is greatly dependent on the ratio of hemlock to amabilis fir. On the B.C. coast hem-fir averages 80% western hemlock and 20% amabilis fir, however, these proportions can vary from 0 to 100% in the material sampled. Refractory batches of hem-fir may simply be low in amabilis fir. Compared to amabilis fir, no other Canadian wood species can be so easily treated to the lumber standard with conventional incising. Sorting and treating pure amabilis fir would therefore result in a dramatic improvement in the ability of the Canadian wood preservation industry to meet Canadian and American standards.
Mould and stain became troublesome problems on lumber manufactured at a coastal British Columbia sawmill, and the difficulties were suspected to be a fault of the mill's antisapstain treatment. Forintek technical staff visited the sawmill and planer mill and used two procedures to gather assessment. Firstly, boards were pulled from spray box chains after spray treatment and one-inch square samples were punched from four faces of these boards for chemical analysis of DDAC, one of the active ingredients in the formulation being used. With a large number of samples, this procedure quantitatively assessed DDAC retention levels at points along boards. Secondly, fluorescent dye was added to the spray solutions and special paper strips were stapled along the length of boards prior to treatment in the spray box. The paper strips were then retrieved for examination under ultraviolet light. This procedure is largely a qualitative one, showing the pattern of spray coverage over the whole board. Liquid samples of the treatment solutions were taken from both the sawmill and planer cross chain day tanks to determine their DDAC concentrations.
Softwood sawmill designers, engineers and managers may benefit from computer simulation analysis of proposed and existing sawmill systems. Simulation models exist that allow users to construct and execute discrete event simulations, but these have incorporated compromises or limitations that reduce the accuracy of the results, or preclude special considerations and observations. The proposed microcomputer discrete event simulation model will allow for real log shapes, explicit lumber orders, learning curves and catastophe scheduling with emergency actions and transient response analysis.
Le projet visait la modelisation du positionnement des billes de bois au premier debitage. L'objectif etant de developper de nouvelles methodes de simulation du comportement des appareils et des strategies usuelles de positionnement des billes au premier debitage. Dans un premier temps, une analyse du processus de sciage et des appareils a ete effectuee en rechechant les caracteristiques essentielles a modeliser. Par la suite un ensemble d'algorithmes de nature geometrique a ete developpe de maniere a modeliser les positionneurs existants. Deux methodes de construction des algorithmes ont ete etudiees : la calcul des angles formant une suite de transformations applicables a la representation geometrique initiale des billes et la recherche d'un nouveau referentiel. Cette derniere methode fut examinee en profondeur; son implantation et les resultats generes ont permis de visualiser les effets des differents positionneurs. Les algorithmes resultant du present projet ont d'ailleurs ete integres au prototype du modele de simulation du sciage presentement en developpement au groupe Forintek-Laval.
Red pine coupons treated with chromated copper arsenate (CCA-C), ammoniacal copper arsenate (ACA), modified ammoniacal coper arsenate, ammoniacal copper zinc arsenate (ACZA) and ammoniacal zinc arsenate (AZA) to various retention levels have been in service for 14 years at the West Vancouver marine test site. Similar coupons treated with CCA-C, ACA and creosote have been in service for apporximately 8 years at Shediac Bridge and Whitehead Island, the two marine test sites in New Brunswick. This report summarizes the performance results to date ant attempts to compare relative performances of the various preservatives in Atlantic and Pacific coastal waters.
In developing biocontrol technology against sapstain, Forintek identified ten potential biocontrol fungi, Identification of the metabolites that these leads produce will aid in understandng their mechanisms of biocontrol, facilitate product development, and is essential for regulatory acceptance. Identified as a concern with some of the lead fungi is the possiblity that they may produce mycotoxins of the trichothecene- or gliotoxin-type. ELISA's were developed for the detection of T-2 toxin. T-2 toxin was detected from a known producer, but it was not detected from the lead organisms under the growth conditions tested. Candidates were screened for production of gliotoxin and related metabolites by HPLC and TLC. EL 9 and 10 produced gliotoxin. EL 8 did not produce this mycotoxin, but a structurally-related metabolite. Siderophores have been implicated in resource capture and competition mechanisms of biocontrol. Universal and specific assays for the detection of siderophores was established. Production of hydroxamate-type siderophores was detected for all the leads, EL1 to EL10, when grown in liquid media. Production of siderophores by three staining fungi was also detected. Methods of isolation of siderophores in the iron-free and iron-complex forms and profiling by HPLC methods have been established. The characterization of these materials is continuing
In developing biocontrol technology against sapstain, Forintek identified ten potential biocontrol fungi. Identification of the metabolites that these leads can produce will help in understanding their mechanisms of biocontrol, facilitate product development, and is essential for regulatory acceptance. Identified as a concern with some of the lead fungi is the potential that they may produce mycotoxins of the trichothecene- or gliotoxin-type.