Influence of Machining Parameters on the Structural Performance of Finger-Joined Black Spruce
Keywords:Wood machining, finger-jointing, structural performance, cutting speed, black spruce
AbstractIn Eastern Canada, black spruce (Picea mariana (Mill.) B.S.P.) has recently been introduced in the finger-jointing industry. However, little information is available on some of the key manufacturing parameters that influence the finger-jointing process. Therefore, the main objective of this work was to evaluate the effect of wood machining parameters on the ultimate tensile strength (UTS) of finger-joined black spruce in order to optimize the performance of the product. Parameters investigated in this study were the chip-load and the cutting speed. A feather profile was selected with an isocyanate-based adhesive and an end-pressure of 3.43 MPa. A factorial analysis showed a statistically significant interaction between cutting speed and chip-load on the UTS. Within the range of values studied, the cutting speed was the most significant variable affecting finger-joined black spruce. The influence of chip-load on the tensile strength of finger-joints was lower, being apparent only at lower cutting speeds. Results indicated that suitable finger-jointing could be achieved within a range of 1676 m/min and 2932 m/min of cutting speeds with a chip-load between 0.64 mm and 1.14 mm. However, within this range the best result was obtained at 2932 m/min cutting speed and 0.64 mm chip-load. Scanning microscope image analysis of the damaged cells confirmed the effect of cutting speed on the finger-jointing process. In general, the depth of damage was more severe as the cutting speed increased.
ACEco Precision Wood Tooling. 2000. Industrial Wood Tooling, Catalog and Technical Manual. Idaho, 61 pp.nAmerican Society for Testing and Materials (ASTM). 1995. Standard test methods for specific gravity of wood and wood-base materials. ASTM D 2395-93. ASTM, Philadelphia, PA. Pp. 348-355.nAmerican Society for Testing and Materials (ASTM). 1997a. Standard test methods of static tests of lumber in structural sizes. ASTM D 198-94. ASTM, Philadelphia, PA. Pp. 57-75.nAmerican Society for Testing and Materials (ASTM). 1997b. Standard test methods for evaluating adhesives for finger jointing lumber. ASTM D 4688. ASTM, Philadelphia, PA. Pp. 373-379.nBustos, C., R. E. Hernández, R. Beauregard, and M. Mohammad. 2002. Investigations on the wood machining parameters of finger-jointing process of black spruce. Pages 130-136 in Wan Mahmood Wan Ab. Majid et al. Proc. 7th World conference on timber engineering. Timber Construction in the New Millennium. Timber Joints. 12-15 August, Kuala Lumpur. Malaysia.nBustos, C., R. E. Hernández, and M. Mohammad. 2003a. Structural performance of finger-joined black spruce lumber with different joint configurations. Forest Prod. J.53(9):72-76.nBustos, C., R. E. Hernández, and M. Mohammad. 2003b. Effects of curing time and end-pressure on the tensile strength of fingerjoined black spruce lumber. Forest Prod. J.53(11/12):85-89.nCaster, D., N. Kutscha, and G. Leick. 1985. Gluability of sanded lumber. Forest Prod. J.35(4):45-52.nCollins, M., and B. Walford 1998. Recent research into structural fingerjointing. New Zealand Engineering. Construction and Construction Materials.53(6):24-26.nHernández, R. E. 1994. Effect of two wood surfacing methods on the gluing properties of sugar maple and white spruce. Forest Prod. J.44(7/8):63-66.nHernández, R. E., and N. Naderi. 2001. Effect of knife jointing on the gluing properties of wood. Wood Fiber Sci.33(2):292-301.nHernández, R. E., and L. F. de Moura. 2002. Effects of knife jointing and wear on the planed surface quality of northern red oak wood. Wood Fiber Sci.34(4):540-552.nHernández, R. E., and G. Rojas. 2002. Effects of knife jointing and wear on the planed surface quality of sugar maple wood. Wood Fiber Sci.34(2):293-305.nJokerst, R. W., and H. A. Stewart. 1976. Knife-versus abrasive-planed wood: quality of adhesive bonds. Wood Fiber8(2):107-113.nKretschmann, D. E., and D. W. Green. 1999. Lumber stress grades and design properties. Chapter 6. Pages 6.1-6.14 in Wood Handbook. Wood as an engineering material. General Technical. Report FPL-GTR-113. USDA, Forest Service, Forest Prod. Lab. Madison, WI.nKutscha, N., and R. Caster. 1987. Factors affecting the bond quality of hem-fir finger-joints. Forest Prod. J.37(4):43-48.nMurmanis, L., B. River, and H. Stewart. 1986. Surface and subsurface characteristics related to abrasive-planing conditions. Wood Fiber Sci.18(1):107-117.nMurmanis, L., B. River, and H. Stewart. 2000a. Standard grading rules for Canadian lumber. National Lumber Grades Authority (NLGA). Vancouver, BC. Canada. 238 pp.nNational Lumber Grades Authority. 2000b. Special products standard for fingerjoined structural lumber. NLGA-SPS 1. Vancouver, BC. Canada. 25 pp.nReeb, J. E., J. J. Karchesy, J. R. Foster, and R. L. Krahmer. 1998. Finger-joint quality after 4, 6 and 32 hours of knife wear: Preliminary results. Forest Prod. J.48(7/8):33-36.nRiver, B. and V. Miniutti. 1975. Surface damage before gluing-weak joints. Wood and Wood Products.80(7):35-38.nSAS Institute. 1998. SAS/Stat users guide, release 6.03 Ed. SAS Institute, Inc., Cary, NC. USA.nSelbo, M. L. 1975. Surfacing wood for gluing. Pages 60-61 in Adhesive bonding of wood. Tech. Bull. N° 1512. USDA Forest Service. Washington, DC.nSingh, A. P., C. R. Anderson, J. M Warnes, and J. Matsumura. 2002. The effect of planing on the microscopic structure of Pinus radiata wood cells in relation to penetration of PVA glue. Holz Roh-Werkst.60(5):333-341.nStehr, M., and S. Östlund. 2000. An investigation of the crack tendency on wood surfaces after different machining operations. Holzforschung54(4):427-436.nWisconsin Knife Works, Inc. 2000. Premium Cutting Tools, 07/00 Catalog. Beloit, WI. 112 pp.n
The copyright of an article published in Wood and Fiber Science is transferred to the Society of Wood Science and Technology (for U. S. Government employees: to the extent transferable), effective if and when the article is accepted for publication. This transfer grants the Society of Wood Science and Technology permission to republish all or any part of the article in any form, e.g., reprints for sale, microfiche, proceedings, etc. However, the authors reserve the following as set forth in the Copyright Law:
1. All proprietary rights other than copyright, such as patent rights.
2. The right to grant or refuse permission to third parties to republish all or part of the article or translations thereof. In the case of whole articles, such third parties must obtain Society of Wood Science and Technology written permission as well. However, the Society may grant rights with respect to Journal issues as a whole.
3. The right to use all or part of this article in future works of their own, such as lectures, press releases, reviews, text books, or reprint books.