10 th International Conference on Progress in Biofibre Plastic - PowerPoint PPT Presentation

10 th International Conference on Progress in Biofibre Plastic Composites Toronto, Ontario May 12-13, 2008

Pe Percept ception: ion: wo wood d particles icles in W n WPC PC are encap ncapsulat sulated ed in p n plastic stic Op Opti tical l mi microsc oscop opy y of of WPC cross oss-secti ection on Vi Visi sible le wo wood od p parti ticl cles es enc ncapsula apsulated ted in r n resin sin

WPC are designed to be continuously exposed to an exterior environment Decay fungi growth Warping Dimensional changes

The objective of this work was to demonstrate the water absorption process in WPC exposed to exterior conditions and to laboratory testing

Formula lation tion Ingr gred edie ients ts #5 #5 #6 #6 #12 #12 #13 #13 51 51 48 48 66 66 63 63 Pine wood od (20 mesh) 45 45 45 45 30 30 30 30 HDPE 3 3 3 3 Lubricant bricants/ s/Compatibi ompatibiliz lizers rs 1 1 1 1 Talc 0 3 0 3 Zinc c Borate rate 6 x ½ x ½ 6 x ½ x ½ 6 x 1 x 1 6 x 1 x 1 Board ards s Cros ross-se sect ction ion (in)

Comparison of Water Absorption at Equilibrium for Experimental and Commercial WPC's 50 45 40 Water Absorption (%) 35 30 25 20 15 10 5 0 A1 A2 C D1 D2 F1 F2 G1 G2 H #5 #6 #12 #13 Experimental Commercial

Comparison of kinetics of water absorption for experimental materials and commercial WPC’s 0.4 A 0.35 12 13 0.3 Water Absorption (%) D 0.25 0.2 0.15 0.1 40% A, D – Commercial WPC H, G – Commercial WPC 0.05 35% H 12, 13 – Experimental WPC 5, 6 – Experimental WPC Water Absorption (%) 30% 0 5 Start 6 hours 1 day 7 day 10 day 11 day 14 day 17 day 21 day 25% Length of Immersion 20% 6 15% G 10% 5% 0% Start 6 hours 1 day 7 day 10 day 11 day 14 day 17 day 21 day Length of Immersion

Water Absorption for Selected Commercial and Experimental WPC Exposed in Hawaii for 1 Year Sunny 20 Shadow 18 Water Absorption (%) 16 14 12 10 8 6 4 2 0 A4 A5 B1 B2 D1 D2 F1 F2 G1 G2 #5 #6 #12 #13 Experimental Commercial

Specimen Sp cimen pre repara aration tion Sp Specimen cimen pre repara aration tion #5 and d #6 #12 12 and and #13 13 b b a c c a d d • 8th International Conference on Woodfiber-Plastic Composites, Madison, WI, May 23-25, 2005 • www.polymerengineering.ca Author: M. Gnatowski "Water Absorption by Wood-Plastic Composites in Exterior Exposure"

Water Absorption for Experimental WPC Exposed in Vancouver, BC after 21 and 46 Months Sunny 21 Months Shadow 21 Months Sunny 46 Months Shadow 46 Months 40 35 Water Absorption (%) b 30 25 20 15 10 5 0 #5 #6 #12 #13

Moisture Content for Experimental WPC Exposed in Vancouver, BC after 21 and 46 Months Sunny 21 Months Shadow 21 Months Sunny 46 Months Shadow 46 Months 40 35 Moisture Content (%) 30 MC Decay Initiation 25 20 15 10 5 0 #5 #6 #12 #13

Water Distribution in Experimental WPC #5 Exposed in Vancouver, A Site (Sun) 5A 46 Months Exposure 18.0 1 5A 21 Months Exposure 15.5 11.1 2 9.2 Wafer Number 5.7 3 c 2.6 5.5 4 2.6 9.8 5 6.3 12.0 6 13.2 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 Water Absorption (%)

Moisture Content in Wood of Experimental WPC #5 Exposed in Vancouver 60 #5A 21 Months Exposure (Sunny) #5B 21 Months Exposure (Shadow) #5A 46 Months Exposure (Sunny) 50 #5B 46 Months Exposure (Shadow) MOISTURE CONTENT (%) 40 30 MC DECAY INITIATION 20 10 0 0 2 4 6 8 10 12 DISTANCE FROM SURFACE (mm)

Water Distribution in Experimental WPC #13 Exposed in Vancouver, A Site (Sun) 33.4 1 27.1 23.2 2 19.2 13A 46 Months Exposure 21.8 3 14.4 13A 21 Months Exposure 19.4 4 11.2 Wafer Number 16.1 5 9.7 14.5 6 9.2 c 14.1 7 14.9 8 9.2 16.4 9 10.1 18.8 10 12.1 21.2 11 16.2 22.6 12 20.8 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 Water Absorption (%)

Moisture Content in Wood of Experimental WPC #13 Exposed in Vancouver 60 #13A 21 Months Exposure (Sunny) #13B 21 Months Exposure (Shadow) #13A 46 Months Exposure (Sunny) 50 #13B 46 Months Exposure (Shadow) MOISTURE CONTENT (%) 40 MC DECAY 30 INITIATION 20 10 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 DISTANCE FROM SURFACE (mm)

A A B B Wood MC in surface (0 to 5mm) and inner zones (15 to 18 mm and 10 to 12 mm) of A and B commercial samples immersed in water for up to 215 days Forest Products Journal, Vol 54, No. 12, December 2004 Weihong Wang and J.J. Morrell, Oregon State University

Conditioning Methods  Water soaking  Boiling  Steaming at a temperature over 100 o C  Exposure to elevated humidity at room or elevated temperature  Pressure/vacuum treatment  Cycling exposure with two or more of the methods described above

Effective methods of acceleration of water absorption by wood plastic composites  Size reduction  Increase in temperature

Water Absorption of WPC #5 (in 3.5mm Wafers) Immersed in Water at Different Temperatures 20 80 o C (176F) 18 16 60 o C (140F) Water Absorption (%) 14 40 o C (104F) 12 10 8 6 23 o C (73F) 4 2 0 0 50 100 150 200 250 300 Hours

Water Absorption of WPC Board #5 Immersed in Water at Different Temperatures Vs. Samples Exposed in Exterior Conditions 20 80 o C (176F) Hawaii 12 Months 18 Vancouver 21 Months Vancouver 46 Months Water Absorption (%) 16 14 12 60 o C (140F) 10 Vancouver Sun and Shadow 40 o C (104F) 8 Hawaii Shadow 6 Vancouver Sun Hawaii Sun 4 Vancouver Shadow 2 23 o C (73F) 0 0 2 4 6 8 Days

Water Distribution in Experimental WPC #5 Exposed in Vancouver (Sun) for 48 Months Vs. Water Immersion for 8 Days at 60 o C 27.9 1 18.0 Water Immersion at 60C 20.1 #5 46 Months Exposure 2 11.1 Wafer Number 4.0 3 5.7 c 3.3 4 5.5 17.8 5 9.8 25.2 6 12.0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 Water Absorption (%)

Water Distribution in Experimental WPC #5 Exposed in Vancouver (Sun) for 48 Months Vs. Water Immersion for 8 Days at 40 o C Water Immersion at 40C 21.6 1 18.0 #5 46 Months Exposure 11.7 2 11.1 Wafer Number 2.4 3 c 5.7 2.3 4 5.5 12.8 5 9.8 22.4 6 12.0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 Water Absorption (%)

Moisture Content in Wood of Experimental WPC #5 Exposed in Vancouver (Sun) and Immersed in Water at 40 o C and 60 o C for 8 Days 60 #5A 46 Months Exposure Water Immersion at 40C 50 Water Immersion at 60C MOISTURE CONTENT (%) 40 30 20 10 0 0 2 4 6 8 10 12 14 DISTANCE FROM SURFACE (mm)

Water Absorption of Experimental WPC #5 Exposed in Vancouver (Sun) and Immersed in Water at 40 o C for 8 Days Following 5 Days of Conditioning 35 #5A 46 Months Exposure Water Immersion at 40C 30 Water Immersion at 40C (Conditioned) WATER ABSORPTION (%) 25 20 15 10 5 0 0 2 4 6 8 10 12 14 DISTANCE FROM SURFACE (mm)

Water Absorption of Experimental WPC #5 Exposed in Vancouver (Sun) and Immersed in Water at 60 o C for 8 Days Following 5 Days of Conditioning 35 #5A 46 Months Exposure Water Immersion at 60C 30 Water Immersion at 60C (Conditioned) WATER ABSORPTION (%) 25 20 15 10 5 0 0 2 4 6 8 10 12 14 DISTANCE FROM SURFACE (mm)

Water will permanently accumulate in extruded Wood Plastic Composite  boards exposed to exterior conditions. Water accumulation seems to increase with the increase of the exposure  period. Moisture content in the wood of composites may reach and exceed the fiber  saturation point at approximately 25% MC within the zone of a few to several millimeters from the board surface. The range of this zone seems to increase over exposure time and depends on composite composition. Laboratory simulation of water absorption by WPC in exterior exposure can  be conducted by controlled immersion in warm water followed by conditioning at elevated temperature after sealing the specimen surface. Simulation conditions will depend on composite composition and simulated exterior exposure conditions.

PE PEC C Sta Staff ff David Lesewick Kate Mao Beverley Start