Wood-plastic composites applications

The improved physical and mechanical properties of the wood-plastic composites lead to a diversity of applications, e.g., automotive parts, furniture, construction (e.g., building panel, flooring veneers), toys, cutlery handles, industrial pattern, sports equipment, musical... 

Apart from PVC and other commodity plastics, engineering plastics and wood-plastic composites are used for specific advantages corresponding to specific applications. 

A new and fast-developing application is synthetic wood (i.e. wood-plastic composites WPC) made from rigid PVC heavily filled with wood flour, extruded in wood-like profiles that can be sawn, nailed and screwed just like natural wood. 

It is significant that in the excellent and detailed book by Hebeish and Guthrie (4) only 16 out of 342 pages are devoted to this subject. Of these, 7 are on wood-plastic composites which are mainly in-situs polymerized monomers and only partially grafted. Nevertheless, they are closely related and with worldwide industrial applications. Details of these have been discussed not only in the above references but numerous other reviews and reports (37,38). These should be consulted for further details. 

Wood Plastic Composites (WPC) In WPC applications, it was claimed that the addition of organic phosphate, zinc borate/boric acid, sodium silicate, or ATH to milled rice straw with a resin binder can produce a fire-resistant board.65... 

IMPREGNATION OF SOFT SOUND WOOD WITH MONOMERS, which are then polymerized in situ by 7 radiation, was a method used in many laboratories during the 1960s in an effort to obtain wood-plastic composites. The process was attractive in two respects there was a large choice of consolidants, and radiation-induced polymerization had many advantages. Various vinyl monomers are cured by 7 rays. By proper selection of the polymer or copolymer, materials can be tailor made for specific applications. The radiation process presents several advantages over the chemically catalyzed polymerization of monomers in wood. 

M. P. Wolcott and P. M. Smith, in Nachrichtenportal fur Nachwachsende Rohstojfe, 2004 Opportunities and challenges for Wood-Plastic Composites in structural applications (retrieved 28.05.2004). 

This chapter first gives an overview of cellulose raw materials and their molecular and supermolecular structures. The principles of shaping cellulose into fibres, films, and nonwovens by means of solution techniques are then outlined followed by a section on properties and market applications of these materials. Derivatives of cellulose are presented with special emphasis on thermoplastic cellulose esters, typical plasticizers, and promising reinforcing materials. Finally, recent developments and future prospects of cellulose materials are reviewed as far as the above applications are concerned. This book does not cover the important applications of cellulose and ligno cellulose fibres for reinforcing thermoplastics, like wood plastic composites (WPC) and natural fibre reinforced plastics (NFRP), since in these cases cellulose does not substitute a thermoplastic. 

Hills et al (1969) refer to two curious applications especially suited to the damp climate of England. One is to golf club heads, which are often stored under moist conditions with minimum ventilation. The second is to organ consoles in old cathedrals and churches where the atmosphere has become more variable since the recent introduction of central heating. In fact, one wood-plastic composite console is said to have been installed in an English cathedral. 

Shebani et al. [20] noted that removing extractives improved the thermal stability of different wood species. Therefore, using extracted wood for the production of wood-plastic composite (WPCs) would improve the thermal stability of WPCs. Because wood and other bio-fibres easily undergo thermal degradation beyond 200°C, thermoplastic matrix used in the composites is mainly limited to low-melting-temperature commodity thermoplastics like polyethylene (PE) and polypropylene (PP). However, the inherently unfavourable thermomechanical and creep properties of the polyolefin matrix limit some structural applications of the materials. 

Due to its low thermal stability, wood flour is usually used as filler only in plastics that are processed at temperatures lower than about 200 °C. The majority of wood-plastic composites use polyethylene as the matrix (Figure 15.2). This is, in part, due to that fact that much of the early wood-plastic composites were developed as an outlet for recycled film. Polypropylene is more commonly used in automotive applications, and polyethylene is more commonly used in exterior building applications. 

Wood will last for decades in exterior environments, especially if it is stained, painted, or otherwise protected. However, wood-plastic composites are not commonly protected. In fact, a common selling point for wood-plastic composites is that they are low maintenance material and do not require painting or staining in outdoor applications. 

Even PE, PP and polyvinyl chloride resins, still the most commonly used thermoplastic polymeric materials with wood, have low thermal stability above 200 °C. However, their inherently undesirable mechanical properties, such as the creep-resistant properties of the polyolefin matrix, have impeded further applications of the wood plastic composites (WPG) as structural composite materials. In attempts to overcome these drawbacks, attention has been given to the silane-crosslinking of wood/PE composites [38], the use of high-performance engineering thermoplastics such as Nylon 6 [39] as a single polymeric matrix, the modification of the matrix by incorporation of organoclay [40], and stretching wood/PP composites [41]. 

Processing wood plastic composites (WPG) into profiles by extrusion for building and construction applications is one of the most exciting bnsinesses of recent years. Growth observed is such that WPG applications are already very high (at least 30% a year in... 

In this chapter, several classes of biopolymers are discussed. First, biobased and biodegradable polymers are considered, together with wood plastic composites (WPCs) (Section 8.2). A field of increasing importance is the application of polymers in medicine, particularly their use in the human body (Section 8.3). 

Chapter 5 discusses in detail the current application of recycled PET. In particular, the applications of recycled PET are discussed in the fields of food packaging, construction, textile industry, injection moulding and other manufacturing processes, wood-plastic composites and so on. On the other hand. Chapter 6 describes the optical properties of polyolefins upon recycling. Optical properties of different plastics play a key role in packaging applications, so this chapter primarily focuses on the different structural aspects and properties of isotactic polypropylene. 

Application of Recycled Polyethylene Terephthalate in Wood-Plastic Composites... 

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