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 materialDipl.-Ing. Sven WOLF1,2, Ing. Mag. Dr. Peter HAUSBERGER1, Ing. Mihaly SZAKACS, BSc.1
1FH-Technikum Wien, Institut für Advanced Technologies, Hochstädtplatz 5, Vienna, AUSTRIA 2extruwood 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
DensityWPC: 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 productionof 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 industrialwooden 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
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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
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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
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opt. WPC
beech
thermo beech
thermo ash
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Change of mechanical properties after weathering:flexural modulus after
artificial weathering
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66%71%
bending strength afterartificial weathering
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