Production Lines (direct extrusion): • Cincinnati Konos 38 & Fiberex 58 (up to 80kg/h) Lab scale • Conical co-rotating twin-screw extruder (up to 250kg/h) Production scale Raw material: • Post industrial wooden waste • Polymer matrix materials: pre-mixed PVC (Solvay) dry-blend, PP (Borealis) General condition: • Melt quality(1 -5): 3 (sufficient plasticized in venting zone) • Smell: minor smell (like in typical industrial wood-production plants) • Assessment of extruded products: mostly perfect samples • Uncolored sample color: Medium to dark brown Proceedings of the 1st International Conference on Processing Technologies for the Forest and Bio-based Products Industries. Salzburg/Kuchl, Austria, 07-08 October 2010 Post industrial wooden raw material as natural fiber base for wood plastic composites (WPC) based on PVC and PP matrix material Dipl.-Ing. Sven WOLF 1,2 , Ing. Mag. Dr. Peter HAUSBERGER 1 , Ing. Mihaly SZAKACS, BSc. 1 1 FH-Technikum Wien, Institut für Advanced Technologies, Hochstädtplatz 5, Vienna, AUSTRIA 2 extruwood GmbH, Industriepark 22, Pasching, AUSTRIA What is WPC? „Wood plastic composite“ consists of: •Wood fibers (50-80%) •Additives (up to 5%) •Polymer matrix material: PE, PP, PVC (complementary percentage) What is „post industrial wooden raw material“? Reprocessed wood from used products like: •Medium/High-density fiberboards (MDF/HDF) •OSB: Oriented strand board •Three-layer slab, … Background Design of experiments Target: To prove the concept of using post industrial wooden raw material for exterior WPC profiles Selected results Density WPC: between 900 and 1400 kg/m³ MDF: between 600 and 800 kg/m³) WPC have a higher density than its single components due to compacting and compression of porous wood structure (cavities are filled with matrix polymer) Test profile for the production of material samples on lab scale: TRIAL PLAN PVC WOOD CONTENT PP 50 % 50 % 45 % 55 % 40 % 60 % 40 % 70 % 30 % 75 % 25 % 80 % 20 % Advantages of using post industrial wooden raw material for WPC: • low price • large quantities • stable in quality • low cost on logistics • well documented origin Challenges • contamination with resin • higher dust content ≥60% outdoor-use => important technical issues: Weatherability, water absorption, fading Growing market demand leads to increased consumption of tropical woods. Usage of WPC can substitute this demand Outlook Essential Properties: • Improved Strength (against Plastic) • Reduced swelling and absorption of water (against wood) • Wooden-like visual appearance and haptic This project was supported by the EU under the CORNET directive 0 5 10 15 20 25 30 50% 55% 60% 65% 70% 75% 80% fiber content water absorption [%] PVC based WPC PP based WPC off-set binding forces 0 5 10 15 20 25 30 0% 1% 2% 3% coupling agent ratio water absorption [%] PP based WPC 70% fiber content 2 hours 24 hours 168 hours 336 hours 672 hours Water absorption: With optimized production and recipe formulations, post industrial waste wood and PVC based WPC will come close to natural wood in many properties Especially due to high strength and reduced creep behavior constructive wood engineering might be possible with those developments Creep behavior: PP based WPC PVC based WPC optimized PVC based WPC 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 bending strength [Mpa] PP based WPC PVC based WPC optimized PVC based WPC 0 1 2 3 4 5 6 7 8 9 10 felxural modulus [Gpa] PP based WPC PVC based WPC optimized PVC based WPC 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 impact strength [KJ/m²] Optimization of mechanical strength by processing and recipe: Decking; 57% Siding; 11% Other applicatons; 32% WPC product market share EU Decking; 40% Molding & trim; 29% Landscaping & outdoor products; 11% Fencing; 10% Other applications; 10% WPC product market share US 0 20 40 60 80 100 120 140 160 180 200 bending strength [MPa] spruce pine larch oak ash teak maple opt. WPC beech thermo beech thermo ash 0 20 40 60 80 100 120 140 160 180 200 4 6 8 10 12 14 16 bending strength [MPa] flexural modulus [GPa] Change of mechanical properties after weathering: flexural modulus after artificial weathering 0 2 4 6 8 0,0% 1,5% UV-Stabilizer [%] flexural modulus [GPa] 0 h 1000 h 66% 71% bending strength after artificial weathering 0 20 40 60 80 0,0% 1,5% UV-Stabilizer [%] bending strength [Mpa] 0 h 1000 h 89% 82% impact strength after artificial weathering 0 1 2 3 4 5 6 0,0% 1,5% UV-Stabilizer [%] impact strength [KJ/mm²] 0 h 1000 h 98% 100%