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Lumber Edging, Trimming & Grading Resource Toolkit

Description

This section provides an overview of hardwood lumber edging and trimming for possible efficiency and value recovery. General information of lumber hardwood edging and trimming process is also introduced. A background review of existing methods and tools available for this are provided followed by a short description of lumber visualization, edging and trimming tool which was developed at West Virginia University is given in this section.

Two men working with wood lumber

Lumber value can be increased by up to 20% through ideal edging and trimming (Bousquet 1989, Flann and Lamb 1966). The ideal edging is a subjective matter in absence of any objective criteria. However, ideal edging for hardwood lumber is a difficult to obtain due to complexities in the grading rules specified by National Hardwood Lumber Association (NHLA). Although these complexities, ideal edging is always desirable this is likely to increase the benefits. Although, machine based automated grading system are appearing, but due to complexities these are still in research phase (Kline et al. 2001) and manual lumber grading is still the widely used process in mills. Training these human grader is the only alternative at this moment to obtain the most appropriate idealistic grading. There are few computer based hardwood grading trainer tools (Kline et al. 1992, Klinkhachorn et al. 1994, bc_sideview Regaldo et al. 1992, Conners et al. 1997) which are designed for similar purpose. All the systems mentioned here can be used for training purpose. These systems are based on 2 dimensional display of pre-installed data for lumber piece on which users are allowed to trim and edge the lumber and compare the obtained value with the optimal one. These computer systems allow human to get the understanding of cutting strategies to reach at an ideal state after series of edging and trimming operations without physically destroying the lumber piece. These non-destructive simulations of edging and trimming exercise can help individuals to obtain better insights of grading, edging and trimming in lumber. However, these programs are limiting in some of the aspect of human-computer interaction at present days which can be summarized as following:

  • These systems do not have an easy work around or instruction on loading user’s own data. Users are limited to what has been provided by the system. Depending on conditions, humans have better feel of the edging and trimming works if lumber pieces are from their own inventory.
  • The graphics used to represent lumber use plain color to show wane, edge, clear-face and defects. A realistic picture showing grains of wood by species would make a better representation of the lumber.
  • The representation is two dimensional as against three dimensional to which human eyes are used to seeing different things including a lumber piece.
  • The provided viewing scale can be minimally altered against multiple viewing scale to which humans are used to in computer applications. In current days systems, views are scalable i.e. that can be enlarged or reduced as desired. Such scalability offers better interpretation from a given graphic.
  • Rotation of lumber piece is not offered in several of these systems and 3 dimensional rotations can help users target efficient edging and trimming.
  • Multiple pieces of lumber can be obtained from one original board. This is very important because it will increase lumber value at some case that original board shape is not very good or defects distribute at the central of board.

After reviewing these limitations of existing systems, a new 3-Dimensional lumber visualization edging and trimming tool was created and tested by employing advanced techniques in computer graphics and database application. This system has windows style formatting and functionalities with respect to viewing, zooming in/out, rotating and transposing. Users can add, delete the lumber piece from the system and compare the final results against the standard results obtained from a graded piece. An optimal algorithm was used to obtain the best edging and trimming solution, and the user can compare the results among manual cutting method, optimal cutting method, and NHLA grader estimation.

This software tool can run on computers currently operating on Microsoft windows. Contact us for more information about the software, installation instruction, and user guides.

References

  • Bousquet, D.M. 1989. Saving volume and making money at the Edger. Northern Logger and Timber Processor, June 1989.
  • Conners, R. W., Kline, D.E., Araman, P.A., Drayer, T.H. 1997. Machine vision technology in the forest products industry: A multiple sensor approach. Computer 30(7): 38-45.
  • Flann, I.B., Lamb, F.M. 1966. Effect of sawmill edging practice on the value of hard maple lumber. Forest Products Journal. 16(5):31-38.
  • Kline, D.E., Araman, P.A., Surak, C. 2001. Evaluation of an Automated Hardwood Lumber Grading System. In Proceeding of ScanTech International Conference, Seattle, WA, USA. 141-151.
  • Kline, D.E., Wengert, E.M., Araman, P.A. Klinkhachorn, P. 1992. Hardwood lumber edger and trimmer training system. Forest Products Journal. 42(1):53-57.
  • Klinkhachorn, P., Kothari, R., Annavajjhala, R. McMillin, C.W. TRSys: a hardwood lumber grading training and remanufacturing system. Forest Products Journal. 44(9):68-72.
  • Regalado, C., Kline, D.E., Araman, P.A. 1992. Optimum Edging and Trimming of Hardwood Lumber. Forest Products Journal 42(2):8-14.