Wood Plastic Composites An Overview Dr. R.Rangaprasad Product Application & Research Center Reliance Industries Limited IPI Seminar On Synthetic Wood Mumbai July 10 th 2003
Presentation Outline • Introduction to Wood Plastic Composites • Historical Development • Milestones in Commercialization • Technology Status • Benefits of wood plastic composites • Applications • Future markets & business opportunities
Definition Wood Plastic Composite ( WPC ) Any composite that contains wood & thermoset or thermoplastic Thermoset : Epoxy , Phenolics Thermoplastics: PE, PP, PVC, PS
Introduction • First Generation WPCs Recycled woodchips / flour & binder Designed for undemanding applications • New Generation WPCs High Performance products Good mechanicals High dimensional stability Complex shapes Extruded products with high dimensional tolerance
Introduction “ The new generation WPCs are produced by mixing wood flour or fiber & plastics to produce a material that can be processed like a conventional plastic & has the best features of wood & plastic”
Plastic Lumber • Recycled Plastics • Extruded profiles • May / may not include wood flour • Application – Sleepers on rail roads
Historical Perspectives • 1900 : Bakelite ( Gear shift knobs for Rolls Royce) • 1920: Birth of the WPC industry Marriage of plastic processing & forest products industry
Initial Impediments to Growth • Forest Product Industry Viewpoints – Alien to Plastic materials – Few common material & equipment suppliers – Only exposure to vinyl sidings – Lack of Market Knowledge & application areas • Plastic Industry Viewpoints – Conversant with mineral fillers & reinforcements – Aversion to wood & natural fibers
Wood as a filler: Plastic Industry’s Viewpoints • Low bulk density of wood flour vis-a vis plastics ( 0.5) • Low specific gravity of wood • Low thermal stability of wood • Tendency to absorb moisture
The Turn Around The last decade saw • Greater awareness from both sides • Success of several WPC products • Greater understanding of wood filler • Developments in compounding equipments • Development in additives • Emerging opportunities in large volume building application sector
Forest Products Industry: Change in Perception • WPCs :Products with little maintenance • Low maintenance : USP Of WPCs • Forest Product companies : Suppliers of WPCs Synergize knowledge of wood flour & core competence in building products
Milestones in The Commercialization Of WPCs Year Company Product 1975 G.O.R., Italy Woodstock patent 1983 American Woodstock 50% WF/PP sheets for thermoforming for auto interiors Lear Corporation 1990 Strandex Corporation Highly filled WPC extruded profiles& shapes 1991 AERT Later TREX 50 % WF/PE for deckboards, picnic tables etc 1993 Andersen Corporation WF reinforced PVC sub sills for French doors & window lines
Technology Status of WPCs Market Potential • Global market size : 320,000MT in 2000 • Expected Volume : More than double in 2005 Wood Filled Composites Natural Fiber Filled Composites
Technology Status Of WPCs Material Attributes Thermoplastic Material End-Use PE Virgin & recycled Exterior building components PP Virgin Automotive Profiles PVC Virgin Building profiles & decking & windows
Technology Status Of WPCs Polymer Attributes Selection of Thermoplastic matrix * Inherent properties of polymer * Product requirements * Availability * Cost
Technology Status Of WPCs Attributes of wood • Wood flour : Particulate, l/d 2:1 to 4:1 • Wood fiber : Reinforcing, l/d greater than 24:1 • Commonly used species : Pine, Maple Oak • Typical particle size : 10 to 80 mesh • Price : Indian Rs. 15 to 20/- per Kg • Price : Imported Rs. 35 to 45/-per Kg
Technology Status Of WPCs Manufacture & Processing • Two stage Process: Compounded pellets & shaping • Commonly Used processing Techniques Sheets & profile extrusion Thermoforming Compression Molding Injection Molding • New Trend In-Line Compounding & Processing
Salient Features of Extrusion of WPCs • Two stage Process - compound & shaping • Two Extruders in tandem Twin screw Compounding and shaping
Extrusion of WPCs
New Developments In Equipments • American Maplan Corp : Counter rotating TSE, conical & parallel for direct extrusion • Woodtruder American Davis Standard ( Crompton): First Stage drying extruder & side arm extruder for injection of polymer melt into the main extruder. Up to 80 % wood flour • Wilmington Machinery: 375 tons two stage injection molding for foamed WPCs
Manufacturing Wood / PP Composites
Machinery For Wood PP Composites
Additive Developments Aid Growth of WPCs • Tailor-made lubricants • Non stearate & compatibilizer package • Special HALS • Antimicrobials • Blowing agents
Wood Filled PP
Application Benefits • Improved dimensional stability - increased strength • Lower processing temperatures - less energy used • Increased heat deflection temperature - reduced thermal expansion • Up to 30% reduced cycle time for injection moulded products - increased productivity • Approximately 10 - 20% lower specific gravity - lighter products • Reduced shrinkage - lower internal shear in pultrusion application • Low volumetric cost
Conventional 1.3 1.27 1.27 1.25 1.25 Fillers Vs Wood Filler 1.2 Weight 1.15 AWF Wood Flour Weight 1.1 Savings 1.1 Specific Gravity 1.05 40% Filled Resin - 1 Polypropylene Wood Flour Talc Calcium Fiberglass (AWF - 4020) Carbonate Fillers 5.0 4.5 Flexural MOE Versus Flexural MOE (GPa) 3.8 % 4.0 3.2 Wood Flour 3.0 2.2 2.0 2.0 1.0 0.0 20 30 40 50 60 % Wood Filler
Wood Filled PP Products
Wood Filled PP Products
Wood Filled PP Products
Foaming Expands Possibilities For Wood Fibre / PP Composites
Foaming Expands Possibilities For Wood Fibre / PP Composites
Breakthrough Technology “Plastic Steel from Wood Filled PP” • Expanded Oriented Wood filled PP • Low temperature die drawing • Synthetic Hardwood Technologies USA • Automotive side beams • Wood look – alike Product Flexural Modulus ( M Pa ) PP 1800 EOW PP 7585
Die Drawing Makes Plastic Steel From Wood Filled PP Material Flexural Strength Flexural Modulus (MPa) PP 48 1860 Wood 96 8946 O-PP 276 7585 EOW-PP 138 7585 Ram extrusion of PP / wood filled creates light weight wood-like material, even stronger than wood
Wood Fibre Adds Stiffness & Value To Tight Tolerance Tubes
Polypropylene Developments Wood Filled Repol PP for Door Trims
PVC / Wood Composites
Outlook For The Future • USA: 50 % growth rate of WPCs for building products • ASTM Standards for building products based on WPCs • Automotive : 15 % growth rate Innovation in processing & product performance
Summary The future of wood plastic composites will ultimately depend on many factors; including new product identification, product quality, consumer perception & performance of these materials !
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