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1 Dr. David Briggs Professor, Forest products & Operations Research Director, Stand Management & Precision Forestry Cooperatives College of Forest Resources,

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Presentation on theme: "1 Dr. David Briggs Professor, Forest products & Operations Research Director, Stand Management & Precision Forestry Cooperatives College of Forest Resources,"— Presentation transcript:

1 1 Dr. David Briggs Professor, Forest products & Operations Research Director, Stand Management & Precision Forestry Cooperatives College of Forest Resources, University of Washington, Seattle, WA Forest Products

2 2 Outline I.Resource Background II.Context for Wood Product Discussion III.Structural Lumber Products IV.Structural Panel Products V.Wood-Nonwood Composites File: ESRM 101/ESRM_101_Forest_Products Last update: February 13, 2006

3 3 I. Resource Background A.Global Consumption of Wood & Other Materials B.Forest Resources in the US and WA C.Harvest & Harvest Use in the US & WA

4 4 Softwood (Conifer)

5 5 Hardwood

6 6 A. Material Consumption (2005) Wood is the dominant material used by man Industrial Roundwood = wood for fuel (cooking, heating, etc) + industrial roundwood Industrial roundwood = wood (logs) for lumber, veneer, pulp, etc.

7 7 Global Wood Harvest & Use 3.425 billion m 3 (~ 2.1 billion tons)  World  51% fuelwood (cooking & heating) 49% industrial roundwood (logs) (7%) utility poles, pilings, posts, log homes, etc (26%) sawlogs & veneer logs lumber, veneer (plywood, etc.) chips sold to industries below (10%) pulp & paper thinnings, tops & low quality logs from trees harvested for other products does not include chips from other wood industries or recycled fiber (5%) OSB, MDF, hardboard, etc. US 16% fuelwood 84% industrial roundwood

8 8 B. Forest Resources in the US & WA

9 9 B. Ownership of Forest Land

10 10 Public Land Ownership in WA

11 11 Ownership of Timber Volume Volume is on Timberland Much of the volume on USFS and Other Public land is currently unavailable

12 12 Volume by DBH Class: OR & WA Ave dbh harvested in 1976 = 27.5 inches Most mills cannot process large diameter trees Ave dbh harvested in 1997 = 16.1 inches Median log diameter = 11.4 inches Most of large diameter timber is on public land and is unavailable

13 13 Washington –Supplies 5.4% of US total –7.9% of softwood –1.1% of hardwood B. Harvest Removals

14 14 Sources of logs in WA by landowner type increasing decreasing

15 15 Utilization of Removals

16 16 What size? What properties? II. Context for WOOD PRODUCTS

17 17 joists wall framing Long, “deep” pieces “Quality” driven by  strength & stiffness (design values)  straightness (dimensional stability) beams 1. Construction dominates US wood use

18 18 Solid-sawn softwood lumber consumption Construction (Residential & Non-Res.) – 52% of Consumption Repair and Remodeling – 30% of Consumption

19 19 2. Tree/log size is getting smaller 16 inch ave tree dbh DNR 11.4 inch median log diameter in 1998; (Spelter FPL-RP-611, 2003) 12 inch diameter @ top of 5 m butt log 19 rings Age of tree ~ 30 years

20 20 3. Trees of a given size can be grown in less time Juvenile wood : (red + yellow) –red + yellow (cross-hatched) –lower specific gravity (density) – Higher microfibril angle – Lower stiffness & strength – More shrinkage Age = 70 Age = 30 Much more product from the fast grown tree will be from the juvenile wood core 70 years 30 years

21 21 4. Visual grades do not assess wood properties Percent Distribution of Douglas-fir Log Grades: (WA DNR Sales Cut volume. Dual Scaling Study in 2000) No correlation between visual log grades and properties of wood inside! >= 12 inches log diam. <= 2.5 inch knot diam. No rpi limit Source: _____. 2001. Critique of cross-Border Comparisons Relating to British Columbia in the Department of Commerce’s Preliminary Determination. In the matter of: Countervailing Duty Investigation of Certain Softwood Lumber Products from Canada. Joint Report by H&W Saunders Ltd and Wesley Rickard, Inc. to Province of British Columbia and the BC Lumber Trade Council. Folio # 3. >= 6 inches log diam. <= 3 inch knot diam. No rpi limit A diameter sort! Quality is very variable

22 22 5. Engineered wood products (EWP) are replacing traditional products More efficient yield from smaller trees Can combine wood “elements” from different trees to create products with uniform, targeted properties Overcomes limitation of small tree size on product dimensions Improves straightness and stability

23 23 Many EWP’s use lumber & veneer that is stress-rated for stiffness and/or strength glulam Glulam, I beam & joistLVL, I-beam & joist glulam LVL, I-beam & joist

24 24 Stress-rating measures stiffness

25 25 Stress-rating Technology: Lumber & Veneer Ultrasonic test Mechanical test

26 26 Stress-rating Technology: Logs and Trees acoustic velocity estimates stiffness Fibre-gen ST 300 Fibre-gen HM 200™ TreeSonic Fakopp

27 27 EWP designers place high & low rated “elements” where needed to achieve a specified product strength/stiffness Low High

28 28 Other EWP’s combine small elements, resins, plastics, etc. to get homogeneous, stiff, strong composites. Strand lumber OSB, I-beam & joist Parallam lumber Wood/plastic

29 29 III. Structural Lumber Products A.Solid-sawn lumber B.Engineered composite lumber 1.Laminated & Finger-jointed lumber 2.Lumber from veneer 3.Lumber from strands 4.I-beams & joists C.Competitors: steel, concrete

30 30 A. Solid-sawn softwood lumber

31 31 WA: 13% of US Softwood Lumber Production Production increasing but number of mills is decreasing  a few large highly efficient ones

32 32 Log Size/Quality & Mill Technology 11.4 inch median log diameter in 1998 (Spelter FPL-RP-611, 2003) Difficult to get large lumber dimensions from small trees/logs

33 33 Tree/log size limits ability to get pieces needed for large, open room spans joists Wall framing S 4 L quality is driven by  strength & stiffness design values  straigtness

34 34 Quality is highly variable from tree to tree Variability due to biology of how trees grow & produce wood Leads to non-uniform performance of solid-sawn lumber Age = 70 Age = 30 red (natural): high average, high variation, low safe design value Blue, green (engineered) low variation & higher design values

35 35 B. Engineered composite lumber products 1. Glued Laminated Lumber (GLULAM beams) (APA the Engineered Wood Association) Composed of wood laminations, or "lams," bonded together with strong, waterproof adhesives. “lams” are typically lumber two inches or less in thickness and can be a variety of species.

36 36 Glulam Applications: Residential (APA the Engineered Wood Association)

37 37 Glulam Applications: Nonresidential (APA the Engineered Wood Association) Large open areasCurved arches Bridges

38 38 2. Finger-jointed/Edge Glued Lumber Composed of small pieces, often salvaged from slabs, edgings, and end trims from lumber manufacture) bonded together with waterproof adhesives. Finger-join end to end, then edge to edge to get wider pieces, then top to bottom to make thicker pieces

39 39 2. Lumber from Veneer Laminated veneer lumber (LVL), also called structural composite lumber (SCL) is created by layering dried and graded wood veneers with waterproof adhesive into blocks of material known as billets that are cured in a heated press. The billet is then sawn to various dimensions. In LVL, the grain of each layer of veneer runs in the same direction, rather than cross-lamination which is typical of other engineered wood products such as plywood. LVL out-performs conventional lumber when either face- or edge-loaded and is virtually free from warping and splitting

40 40 LVL Applications (APA The Engineered Wood Association) LVL glued side-by side to make thicker beam LVL in flanges of I-beams & joists LVL in standard lumber sizes

41 41 3. Lumber from Strands Oriented strand lumber (OSL), parallel strand lumber (PSL) and similar products are manufactured from waterproof heat-cured adhesives and long, rectangularly shaped wood strands that are arranged in parallel to the length of the product. Strand products are made as large, continuous mats or billets, that are sawn into various dimensions. (APA the Engineered Wood Association)

42 42 OSL Applications (APA the Engineered Wood Association) Headers Framing The lumber analogue to oriented strand board but longer strands more alignment made to mimic lumber sizes & uses

43 43 Parallam Longer strands (from veneer) pressed into a large (20x20) cross-section continuous billet. Sawn off to desired length and ripped to beam and column sizes. Can see this at new CUH building.

44 44 4. Wood I-beams, joists & trusses I-joists are comprised of top and bottom flanges of various widths united with webs of various depths. The flanges resist common bending stresses, and the web provides outstanding shear resistance Flanges may be solid-sawn lumber or structural composite lumber (LVL) for Web may be plywood or oriented strand board (OSB). (APA the Engineered Wood Association)

45 45 4. Wood I-joists & trusses LVL or machine stress graded lumber flanges & oriented strand board web

46 46 C. Competitors: Steel, Concrete, etc. Require much more energy to produce than wood Much greater demand for fossil fuels Much greater carbon emissions

47 47 IV. Structural Panel Products A.Plywood B.Oriented Strand Board C.Structural Insulated Panels D.Particleboard E.Fiberboards

48 48 A. Plywood Veneer manufacture Sheet Grain in any sheet is perpendicular to adjacent sheets Manufactured from thin sheets of cross-laminated veneer and bonded under heat and pressure with strong adhesives.

49 49 Wall & Roof Sheathing, sub-flooring, siding (APA the Engineered Wood Association)

50 50 Overlaid Plywood Concrete formsSkid-resistant surfaces Billboards, highway signs

51 51 B. Oriented Strand Board (OSB) OSB is manufactured from waterproof heat-cured adhesives and rectangular-shaped wood strands that are arranged in cross-oriented layers. Produced in huge, continuous mats, which are sawn to standard panel sizes OSB is a solid panel product of consistent quality with no laps, gaps or voids A structural wood panel with many of the strength and performance characteristics of plywood. (APA the Engineered Wood Association)

52 52 OSB Surfaces OSB rough side up for traction OSB smooth side

53 53 Wall & Roof Sheathing, sub-flooring, siding (APA the Engineered Wood Association)

54 54 C. Structural Insulated Panels (SIP) Thick insulating foam between plywood or OSB panels

55 55 D. Particleboard INPUT: Sawdust, planer shavings, etc., by-products of other wood industries, not logs Same process as OSB & LSL but smaller wood elements Usually 3 layers of particles: those in center are coarser than those on surfaces

56 56 Particleboard Uses melamine overlay  shelving, table tops, etc. flooring or floor underlayment Veneered for furniture and cabinets

57 57 E. Fiberboard (pulped fibers) 1.Hardboard 2.Insulation board 3.Medium density fiberboard (MDF)

58 58 1. Hardboard

59 59 2. Insulation board Low density SG g ~.27-.43  17-25 lb/ft 3 Generally flat sheets Process –Similar to wet process hardboard but no hot press is used –Product thickness is controlled by a simple roller after which the panel is dried Uses –Exterior walls of houses  apply panels over the studes and under the siding –Acoustical ceiling tiles –CELOTEX panels used in interior wall partitions in buildings; has been largely replaced by gypsum board

60 60 3. Medium Density Fiberboard (MDF) Medium Density Fiberboard (MDF) is a grainless composite panel product made from extremely fine wood fibers and manufactured in sheets of various dimensions. It is ideally suited for a wide variety of woodworking applications including cabinets, shelving, furniture, store fixtures, moulding and flooring. Temple-Inland

61 61 MDF, exterior siding and trim

62 62 V. Wood – Non-Wood Composites A.Wood & Gypsum B.Wood & Cement C.Wood & Plastic D.Wood & Fiberglass, Metal, Kevlar, …

63 63 A. Wood/Gypsum Composite: drywall Interior wall board –“drywall”, sheetrock Gypsum with paper surface: US Gypsum mixed with recycled paper fiber and pressed into a wallboard panel: Europe

64 64 B. Wood/Cement Composites: Siding Hardi-plank: cement, sand, & wood fiber; simulated wood grain

65 65 Wood/Cement Composites: Roof Tile Wood Fiber & cement Molded to simulate cedar shake top bottom

66 66 C. Wood/Plastic Composite: “Lumber” Recycled plastic shopping bags & recycled wood fiber from paper Molded into lumber shape Decks, park benches, etc. Poor chemical bonding Low strength & stiffness Degrades –Ultraviolet –Water gets in to the wood particles which swell & shrink –As opens up, wood decay starts

67 67 Combine Wood Flour with Plastics & Extrude New  Wood Materials Engineering Lab at WSU Wood flour, plastic resins, additives –Excellent chemical bonding –High strength & stiffness Extruded into various shapes Decks (Ex Trex and others), windows Siding & roofing products under development

68 68 D. Wood, Metal, Glass, Vinyl, etc. (Weathervane Windows) Modern high efficiency windows –Pre-finished exterior skin; vinyl or aluminum –High efficiency glass –Solid wood on interior for natural look –Hollow extruded exterior frame of wood-plastic composite; negligible shrink & swell

69 69 Questions?


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