Is the CLT Market an Opportunity for the US Hardwood Industry?

Transcription

1 Is the CLT Market an Opportunity for the US Hardwood Industry? Henry Quesada Associate Professor and Extension Specialist Department of Sustainable Biomaterials Virginia Tech Yellow Poplar CLT panel at Virginia Tech

2 Main barriers for hardwood CLT ANSI/APA PRG-320 Raw material cost Raw material manufacturing Hardwood Lumber Supply Chain Machining of hardwood CLT panels Adhesion of hardwood lumber Sustainability of hardwood timber Other issues Barriers

3 ANSI/APA PRG-320 standard Accepts only softwood lumber ASLC/PS 20 or CLSAB/CSA O141 standards Specific gravity must be 0.35 and higher Grades #2 for parallel and #3 for perpendicular layers Moisture content should be 12%+-3% Thickness 5/8 <t<2 Most hardwood lumber produced to 4/4 thickness Board width in major axis shall not be less than (1.75)x(t) Board width in minor axis shall not be less than (3.5)x(t) Custom grade CLT is possible if comply Values (MOE, f t, f b, f c, f v, f s ) Barriers

4 Raw material cost Softwood lumber is less expensive than hardwood lumber Shorter harvesting cycles Higher production volumes Standardized products Less energy consumption More automation Opportunity for lower-value hardwood grades Common and industrial grades Barriers Morgan Lumber. Red Oak, VA

5 Raw material manufacturing Lumber output analysis: study by Virginia Tech in Common and higher YP lumber: Appearance market 3 Common and lower YP lumber: Potential for CLT market A mix-production strategy could be required to supply the hardwood CLT market Need to train personnel on structural grading system for hardwoods Most commercial hardwoods have NDS values Agencies have developed structural grading systems for hardwoods but they are not used Currently only NHLA grading system for most sawmills Virginia-Carolina. Emporia, VA Barriers

6 Supply chain A 50,000 m 3 CLT plant requires at least 21.2 million BF per year 3 Common and lower YP lumber could make #2 and #3 structural grade Average hardwood sawmill produces between 20 to 35 million BF per year Industry is fragmented There is almost no vertical integration in the hardwood industry Consistency of lumber supply would be difficult Quality: dimensions, moisture content Lead times Just-in-time Stora Enso. Ybss, Austria Barriers

7 Machining of hardwood CLT panels Machining operations require in CLT manufacturing: Planning Finger jointing CNC routing Sanding/finishing Issues impacting machinability of wood Wood anatomy: density, porosity, cell structure Grain direction Moisture Kinematics of the cutting process Machine conditions Other factors: temperature, humidity, biological rotting, damage of the surface CNC processing of CLT panels. Austria Barriers

8 Adhesion of hardwood CLT Differences between hardwoods and softwoods related to adhesion* Surface chemistry Impact by ph, Acidic, and Fatty acid extractive contents Hardwoods have lower acidity and lower concentration of OH-groups Acidity: might act as catalyst for the reaction OH-groups might required to form stable urea or urethane bonds when using isocyanate based adhesives. Swelling and shrinkage behavior Beech shows a faster water uptake. Hence; higher swelling and shrinkage movements Oak and locust have a very limited water uptake because tylosis *Konnerth, Kluge, Shweizer, Miljkovic, and Gindl-Altmutter Survey of selected adhesive bonding properties of nine European softwood and hardwood species. Eur. J. Wood Prod. 74: Barriers

9 Adhesion of hardwood CLT Differences between hardwoods and softwoods related to adhesion* Structural differences Diffuse,, ring-poruos structures might impact penetration of adhesive Penetration is regulated by: adhesive fluid properties, anatomical characteristics, permeability of the wood, and processing conditions Kind of penetration: Lumen penetration depends on the viscosity of the adhesive vs Cell wall penetration depends on the chemistry and molecular size of adhesive components Species with low swelling and shrinkage behavior are regarded as bondable. Present low delamination values and induced stresses are reduced. Yellow poplar and Birch Barriers *Konnerth, Kluge, Shweizer, Miljkovic, and Gindl-Altmutter Survey of selected adhesive bonding properties of nine European softwood and hardwood species. Eur. J. Wood Prod. 74:

10 Sustainability of hardwood timber Natural forest vs plantation forest Most of softwood timber grows in plantations, about 40 years Most of hardwood grows in natural forest, about 80 years There is indication that production yields are higher for softwood plantations Growth rates of hardwoods (estimated by the US Forest service) are twice of harvesting rates Shenandoa National Park. Waynesboro, VA. Barriers

11 Other issues Logistical issues Density of hardwood species Some hardwood species are heavier than softwoods This could increase transportation costs and installation times at about 30% Cost of CLT plant 30,000 m 3 CLT capacity plant, around $15 million KLH new building, Austria Barriers

12 Main drivers for hardwood CLTs Niche markets Research on hardwood CLTs Low-value hardwood timber availability Growing interest in green building construction Technology Industry experience Use of character white oak in furniture. Poland Drivers

13 Niche markets Partnering with an architectural firm Katerra; for example Offer special or custom grade hardwood CLT panels for interiors Large cities offer an opportunity for these niche markets Portland, Los Angeles, Seattle, New York, Chicago, Philadelphia More CLT public buildings are needed: Only one in WV, a second in process in OR CLT shelters: during storms or after storms Social housing In the US international markets (containerized solutions) Franklin Elementary School, WV. Source: Charles Judd. Drivers

14 Research on hardwood CLT in the US Virginia Tech, WVU, University of Tennessee Harwood CLT using Yellow Poplar: shear, bending, delamination, fire, and acoustic tests Virginia Tech Potential of hardwood sawmills to produce CLT raw material Virginia Tech Drivers and challenges of CLT manufacturers in Western Europe WVU Hardwoods CLTs (parts I and II): tests and manufacturing Other projects by private entities: IKD/SmartLam, AHEC Yellow Poplar CLT panel at Virginia Tech Drivers

15 Research on hardwood CLT in the US Mechanical Property Testing Indicated That a 3-Layer Yellowpoplar CLT had similar strength to a 5-Layer Southern Pine CLT Failures of the Yellow-poplar CLTs were delamination of bondline (explosively) compared to rolling shear of Southern Pine CLTs Stiffness of 3-Layer Yellow-poplar CLT was similar to 3-Layer Southern Pine CLT Bondline shear tests produced much higher values CLT panels being tested at Virginia Tech

16 Research on hardwood CLT in the US Shear Analogy Model results 3 layer CLT. Thickness of lumber is 1 3/8 and 12 wide panel Configurations Yellow poplar, #2 in L and #3 T White Oak #2 in L and #3 in T Red maple #2 in L and #3 in T Beech-birch-Hickory #2 in L and #3 in T V1: No. 2 Douglas fir-larch lumber in L and No. 3 Douglas fir-larch lumber in T V3: No. 2 Southern Pine lumber in L and No. 3 Southern Pine lumber in T F b S eff,0 (lbf/in 2 ) EI eff (10 6 lbf/in 2 ) Ga eff (10 6 lbf/ft) F s (lb/q) eff (lbf/ft) 1, ,704 1, ,586 2, ,470 2, ,293 2, ,117 1, ,938

17 Research on hardwood CLT in the US What is missing? Practical and commercial application of structural grading rules for hardwoods NELMA, WWPA, NSLB Test panels for all hardwoods with NDS values and compare to Shear Analogy Model results Fire testing Impact testing Issues with gluing Connections testing IKD/SmartLam panels

18 Low-value hardwood timber availability Low utilization of species such as: Specific gravity > 0.35 at 12%: Basswood (0.37), Aspen (0.38), Yellow Poplar (0.42), Sycamore (0.49), Sweetgum (0.52), Red Maple (0.54), Beech (0.64) Mechanical properties of most of these species are well known and documented: National Design Specifications (NDS), visually graded lumber and timber ASTM standard D 2555, wood strength values ASTM standard D 245, structural grades and related allowable properties for visually graded lumber US forest service (through Wood Innovation Grants) encourages the utilization of low-value timber species Drivers

19 Growing interest in green building construction CLT market will grow up to 3 million m 3 New demographics are more sensitive to environmental issues Sustainability, renewability, recycling, etc CLT properties are very attractive Renewable, low carbon-foot print Lighter Insolation Construction times Aesthetically pleasant Umass Amherst CLT building. Source: Tom Chung Drivers

20 Technology Information technologies allows for project integration Traceability: Architect, CLT plant, and building contractor There are multiple suppliers and support for CLT equipment Austria, Slovenia, Germany, USA, Canada Finger joint lines Planners Presses CNC routers Material handling equipment Temporary storage New developments in adhesive systems LignaTrade Show. Hanover, Germany Drivers

21 Industry experience CLT industry started commercial production around 2000 Mature industry in Western Europe Market acceptance Several CLT manufacturers On-going effort to develop an UE standard for CLTs European situation is different Vertical integration, for instance is very common but potential investors in US can learn Construction codes CLT panel manufacturing in Austria. Drivers

22 An example: Maggie`s Oldhman in UK Design by drmm architects and supported by AHEC Yellow poplar CLT panels( 27.6 m 3, 20 panels) TM yellow poplar for exterior cladding 1.1 m 3 of ash for decking Manufactured by Zublin (Germany) Lumber produced by Middle Tennessee Lumber in random widths Zublin required 140 mm Zublin: It meant interrupting a system mainly set up for softwood CLT Maggie s Oldham building. Source: AHEC Drivers

23 Acknowledgements Appalachian Hardwood Center at WVU for facilitating log yield data Brian Bond, Daniel Hindman, Sailesh Adhikari, Virginia Tech Omar Espinoza, University of Minnesota Work funded through: US Forest Service Grant 16-DG Softwood Export Council (SEC) travel grant USDA NIFA Grant