1 / 21

Wood 120 – Lumber Volume

Wood 120 – Lumber Volume. Lab #1 - 2013. Lumber volume. In sawmilling, lumber is most often measured by the “board foot” or “fbm” (Foot Board Measure). . 1fbm =  1 foot x 1 foot  x 1 inch A thousand fbm is written “Mfbm” A million fbm is written as “MMfbm”. Log Scaling in Cubic.

deva
Download Presentation

Wood 120 – Lumber Volume

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Wood 120 – Lumber Volume Lab #1 - 2013

  2. Lumber volume • In sawmilling, lumber is most often measured by the “board foot” or “fbm” (Foot Board Measure).  1fbm =  1 foot x 1 foot  x 1 inch A thousand fbm is written “Mfbm” A million fbm is written as “MMfbm”

  3. Log Scaling in Cubic • Logs in BC are usually measure in cubic meters • Smalian’s Formula is the standard used in BC Robert Fürst – Wood 120

  4. Au Smalian’s Formula • Vol = h/2 (Ab + Au) • Where: • H = Height • Ab = cross section area at base • Au = cross section are at top • Area (Ab or Au)=(d² x 3.14)/4 h Ab Robert Fürst – Wood 120

  5. Excel Example Area (Ab or Au)=(d² x 3.14)/4 Robert Fürst – Wood 120

  6. Foot Board Measure 12 inches 12 inches 1 inch Board foot = 12 inches wide, 12 inches long, 1 inch thick = 1/12 ft3

  7. Largest sawmill production capacity600 MMfbm (Houston, BC) Average BC sawmill capacityapprox. 150-200 MMfbm Price of softwood lumber$250-275/Mfbm Price of hardwood lumbere.g. sugar maple $4/board foot

  8. Quick conversion factors • Millimeters to Inches multiply by 0.03937 • Inches to Millimeters multiply by 25.4 • Meters to Feet multiply by 3,281 • Feed to Meters multiply by 0.3048 • Square Meters to Square feet multiply by 10.764 • Square Feet to Square Meters multiply by 0.0929 • Cubic Meters to Board Footage multiply by 423.79 • Board footage to Cubic Meters multiply by 0.0023596 Robert Fürst – Wood 120

  9. Volume of lumber - Conversion • When calculating board footage from metric sizes, it is necessary to convert the metric size to imperial measure before you begin the calculation • Example: 10 pieces - 27mm thick - 105mm wide - 3 meter long • 1 mm = 0.039937 in, ; 1 meter = 3.281 ft. 10 pieces x 27 x 0.03937 x 105 x 0.03937 x 3 x 3.281 12 = 36 board feet Robert Fürst – Wood 120

  10. Lumber Recovery Factor (LRF) • Definition: LRF is how many board feet of green/rough sawn lumber are produced out of one cubic meter of wood. • The units of LRF are board feet per cubic meter. LRF typically ranges between 200 to 300 board feet per cubic meter.

  11. 318 296 275 254 FBM/m3 233 212 Recovery % 50 55 60 65 70 75 Lumber Recovery Factor (LRF) LRF depends on: Size of logs entering the mill Quality of log – defects, grade Equipment used in a mill

  12. British Columbia Sawmill Lumber Recovery Factors LeadingMills Average LRF (bf/m ) 3 271 BC Mills +17% 231 (BC MoF, 2005)

  13. Standard Thicknesses

  14. Target Thickness Minimum dimension required to achieve desired final size given unavoidable reductions in size during manufacture.

  15. Fibre Recovery - Percentage Finished lumber (kds4s)      47% Chips                                 34% Sawdust & chip fines           9% Shrinkage                            4% Shavings                              6% Robert Fürst – Wood 120

  16. Lab Assignment Sawing – LRF – Log Volume Robert Fürst – Wood 120

  17. Lab Tasks - Sawing • Calculate the log volume of the sample log (m3) • Make 2 horizontal reference cuts #1 #2 Robert Fürst – Wood 120

  18. Lab Task - Sawing • Rotate log 90°, cut reference cut, saw boards #4 #3 Robert Fürst – Wood 120

  19. Lab Task - Sawing • Cut the log into 2” thick boards Robert Fürst – Wood 120

  20. Lab Tasks - Sawing Wane • Rip each individual board to 4” wide components • Grade each board (No wane, no loose knots, no end splits longer than 2”, no center board) • Calculate the volume (in bf) of the 2/4 material recovered • Calculate the LRF in % Robert Fürst – Wood 120

  21. Document your Findings of the Lab • Write a brief report describing all of your findings of the lab and explain what caused the fairly low LRF. Please be specific! • Submit all of your calculations as required • Due date: • Group 1: 28th November 2013 • Group 2: 5th December 2013 • Please e-mail your report to Mr. Sheng Xie E-Mail: xiesheng@gmail.com Robert Fürst – Wood 120

More Related