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Latest news * * * 2006 * * * Archives
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New additives for WPC Chemtura is exhibiting "green" additives (coupling agents and lubricants) for WPC at Chinaplas 2008. Polybond® 1103 is designed for processes and applications requiring very low melt viscosity, while newly reformulated Polybond 3029 is said to be 50% more efficient than before. It will allow WPC manufacturers to use more recycled wood in the composite. Chinaplas 2008, which will take place next April in Shanghai (April 17-20, 2008 ), is expected to attract 1600 exhibitors. |
Recycled MDF and WPC products The UK government agency WRAP (Waste and Resources Action Programme) is funding a project to see whether a new use can be found for recycled medium density fibreboard (MDF). A great deal of MDF is currently landfilled and some is incinerated. Significant quantities of production waste MDF is also available. The aim of the project is to explore whether waste MDF could be used in place of virgin wood flour to make WPC. Special attention will be devoted to comparing the quality of the final products with that of the ones made from ordinary wood flour. The economics will also be examined. The project is actually being carried out by Impact Laboratories of Scotland. |
Two worries to be addressed at Seattle wood conference Speakers at the 42nd International Wood Composite Symposium in Seattle this year (March 31 to April 2) will address themes that have forced their way to the front pages of the world’s newspapers. |
WPC gets further recognition as a new European industry An industry becomes distinctly recognisable in various ways, by having a trade association, its own standards and its own awards. WPC in Europe now has awards for innovation, currently sponsored by Reifenhäuser. The first winners were announced at a Nova Institute conference in Cologne in early December 2007. The winner of first prize for the best product was Mehrwerk Designlabor for a novel lightweight shelving system. Werzalit came second with injection moulded square decking elements for extruded decking, and Wacker Polymer Systems was third with its flexible WPC for indoor applications. This involved using a PVAC ethylene copolymer binder to optimise the wood-like appearance. Wacker Polymer Systems has also made progress in the area of coatings and veneers.
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Additives for WPC Geoff Pritchard of Hackwell Group presented a paper on additives for use in WPC at Addcon 2007 in Frankfurt, Germany, on Sept 5, 2007. Details are available from the conference organisers, Rapra Technology Ltd. Pritchard said that although additives were expensive and initial purchase costs of WPC were already fairly high, certain additives were necessary to achieve good durability and they could extend product lifetimes to make real whole-life costs of buying WPC products competitive. Lubricants could also improve production economics.
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CTBA - AFOCEL Merger (France) On 1 June 2007, the French technical centre for wood and furniture, CTBA, which runs a biennial conference on WPC, announced a merger with AFOCEL, the centre for forestry and woodpulp. The new organisation will be called Institut technologique FCBA and will deal with forestry, cellulose, timber construction and furniture. Its website is www.fcba.fr.
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Spring 2007
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9th International Conference on Wood & Biofiber Plastic Composites - 21-23 May 2007 - Madison, USA An account of this event, written by Professor Pritchard of Hackwell Group, will appear in Reinforced Plastics magazine (published by Elsevier) in the summer or early autumn of 2007. Professor Pritchard gave one of the three plenary lectures at this important WPC event in the USA.
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Mounting evidence that WPC weathering resistance is not perfect It has long been suspected that WPC might show slight degradation in extreme climates. A leading manufacturer of the biocide zinc borate has now reported that micro-organisms can grow on the surface of WPC even in temperate climates provided that the moisture content reaches 25%. It had previously been thought that such high moisture levels were never reached in WPC, but apparently the outer surface layer can sometimes exceed this level. Normally moisture uptake tests measure the average moisture absorption, which is always much lower than the surface value and which seems reassuring. Moreover, other reports by different investigators indicate that even in extremely hot dry climates (as opposed to the more obvious hot wet case) the long term performance of WPC must be re-evaluated because microcracking can sometimes occur, creating an entry path for micro-organisms. These then seriously deplete the wood. However this is not meant to suggest that WPC is as vulnerable as wood. WPC remains a far more durable material than softwood for use outdoors wherever low maintenance costs and long lifetimes are valued and high strength is not a priority. In temperate climates, particularly when temperatures remain moderate throughout the year, WPC should present no real weathering problems. Most European countries are not as hot as the places where these degradation processes were detected, but there are a few spots where caution should be exercised. It is understood that zinc borate has not been submitted for approval for use in WPC in the European Union whereas it has in the USA. Other methods of guarding against weathering are available, not all of them involving a biocide, and many of them have already been researched at the laboratory level. Cost issues are likely to determine which type of protection is the more widely adopted commercially. The problems will arise, if at all, where WPC is used in very hot climates. It should be remembered that competitive materials (timber and concrete, for instance) also suffer degradation problems of various sorts.
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Hackwell Group at WPC Symposium in Bordeaux Chris Foster, of Hackwell Group and environmental consultancy EuGeos, presented a paper on the evaluation of the environmental performance of WPC at the "Symposium International sur les Composites Bois Polymères" (March 2007, Bordeaux, France).
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WPC Made from Nylon The great majority of WPC is made from just three thermoplastic resins— polypropylene, polyethylene and PVC. This is because the WPC has to be processed below the temperature at which wood darkens and degrades, namely 200ºC. This has made the task of using high-melting resins like nylon very tricky. If it could be done, the mechanical properties of WPC would probably be improved. Fortunately there are several different types of nylon, distinguished by numbers, such as nylon 6 and nylon 11. The higher the number, the lower the melting point. The readily available nylon 6 melts at 215ºC but higher-numbered nylons could work. Researchers at Oregon State University in the US have tried nylon 12, which melts at 175ºC. (The grade they used was Grilamid L20G from EMS-Chemie North America). The MOR (modulus of rigidity) of the resulting WPC rose with increasing wood content to reach about 80 MPa at 60 wt % wood. They also made similar WPC with HDPE and PP. The MOR values for these were only about 20 MPa for HDPE and less than 30 for PP. So the benefit of using nylon was very great. Tensile strength showed a similar pattern, with 40 MPa at 60 wt% wood, again about four times the value for HDPE. The advantages for modulus of elasticity were not so great. The moisture absorption of the resulting WPC was not the main focus of attention, but nylons tend to absorb more readily than polyethylene. Some industry sources have suggested that it would be attractive to use post-consumer nylons from old carpets.
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Beologic Doubles WPC Production Beologic, a Belgian producer and developer of PVC, PE and PP based wood plastic composite compounds (WPC) expects to double its production capacity in March 2007 to 16,000 tonnes pa having completed an expansion this year to 8,000 tonnes. The 8,000 tonnes capacity, utilising four extruders already represents a doubling of capacity during 2006, with the planned 2007 expansion to 8 extruders confirming Beologic's position as Europe's largest producer of WPC compounds. Beologic claimed that it is ultimately aiming for a capacity of 40,000 tonnes per year of WPC compound. 20-30% of Beologic's current output is supplied to injection moulders with the bulk (70-80%) being supplied for extrusion applications. The largest of these is decking as well as flooring and cladding. However, completely new niche applications have also been found for Beologic's WPC compounds including poles in Venice canals with enhanced resistance to sea water exposure and replacement of aluminium poles used in the Belgian telecommunications industry for temporary traffic lights to combat the stealing of the metal poles for their scrap value. Work is also continuing on a number of new product developments including foamed WPC to reduce the relatively high WPC density, WPC products using polystyrene and polylactic acid (PLA) polymers and the incorporation of biocides. It has been claimed by Rio Tinto Minerals (USA) that there is clear evidence based on field exposure that the surface regions of WPC products can easily absorb the necessary 25% of moisture to harbour fungal species. Other areas of development at Beologic include improving flame retardancy of WPC so that it is closer to that of conventional PVC and even incorporation of perfume to provide a typical wood fragrance.
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Predictions for the US Fencing Market At present the US fencing market is dominated by metal, especially in non-residential fencing, with wood coming second. According to the market research analyst Freedonia's latest report ("Fencing", Report No 2132, Nov 2006) the market as a whole is expected to grow to more than $6.5 billion by 2010, or 295,660 linear kilometres, with metal continuing to grow at an above average rate, with plastic and wood plastic composites also both having a share. The quantity of fencing made from wood plastic composites is currently very small but is forecast to grow. Fencing is one of the applications being developed by WPC producers in Europe, also. One of the main manufacturers of WPC fencing in Europe is Tilston Management Ltd (Cheshire, UK) who market their wood:polyethylene fencing product under the brand name Everfence™. This is produced by Tilston utilising extruded WPC from Vannplastic Ltd (near Chester, UK). Vannplastic Ltd are themselves significant producers of wood:polyethylene decking products, which are marketed under the brand name Maine Deck™.
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Commercial Applications and Technical Properties of Wood Plastics at Telford Polymer Association On November 1 2006 Geoff Pritchard of Hackwell Group made a presentation about the latest commercial applications and technical properties of wood plastics composites to the Telford Polymer Association at the Association's monthly meeting, which was held at the UK headquarters of Rapra Technology. Prof Pritchard identified lack of strength and stiffness and high thermal expansion as properties needing improvement, while low moisture absorption and workability were recognised as important advantages. A summary of this presentation can be downloaded from the Telford Association's website.The Association's presence in Telford is a reflection of the concentration of a number of polymer-based companies in the area (Shropshire). Some of the Association's members work for Rapra, part of the US-based Smithers group of companies, which carries out both laboratory consultancy and information provision relating to the plastics and rubber industries.
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Musical Instruments in Mouldable "Wood"
A company that produces mouldable wood, Technaro GmbH, is developing injection-moulded musical instruments. It is starting with harmonicas, flutes and accordions. Technaro GmbH, originally set up by the German Fraunhofer Institute, was spun off about eight years ago. Technaro's material is called Arboform, and major environmental advantages are claimed for it. It is essentially lignin mixed with natural fibres to produce a wood-like composite. Such compositions do not necessarily contain a petroleum-based thermoplastic resin binder and are rather different from "conventional" wood plastic composites. Other research to find a substitute for wood in musical instrument is being supported by the German government. These activities take place in a region with an exceptionally-high concentration of musical instrument manufacturers and involve several companies and research institutes. One of the project participants, Adler-Heinrich, a musical instrument manufacturer, is producing flutes from "liquid wood". The moulded liquid wood is water-resistant and can be washed hygienically. Another musical instrument company, Harmona, is working on accordions, where injection-moulding of small parts would enable more cost-effective production than the traditional manual method.
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Sale of Woodtruder Manufacturer
The US-based speciality chemicals company Chemtura (supplier of mainly plastics additives) was formed just over a year ago by a merger of Crompton and Great Lakes. Chemtura has now announced the sale of its majority holding in Davis Standard, the extruder company that makes the Woodtruder extrusion equipment used for extruding wood plastics composite. The purchaser is the private equity firm Hamilton Robinson, which already held a minority share.
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Additives: Animal Repellents from C-Tech At the AdCon plastics additives conference (October 17-8, 2006) organised by Rapra Technology Ltd in Cologne, Germany, Bruno Jacques of C-Tech Europe described his company’s non-toxic additives, designed to protect plastic products from being nibbled by rats, termites and other pests. Since WPC is often proposed for infrastructure applications where pests are a significant factor, it seems these additives could be of some interest to the WPC market. Possible applications include cable duct lids, fencing, waterfront and railway products. Jacques suggested that the idea of using non-toxic additives derived from predators’ urine was originally developed because of Hindu considerations for the sanctity of animal life (C-Tech’s headquarters is in India). However, American WPC with typically 50% resin is claimed to be resistant to termites, and it is too early to say whether European formulations with their higher wood contents still have enough resin in them to deter rats.
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Additives:Preventing Biofilm Formation The formation of films on WPC decking has often been observed, and it is usually recommended that the owner carry out regular cleaning operations. At the meeting mentioned above, Svoboda Tabakova of the Institute of Molecular Biology in Sofia, Bulgaria described how to suppress undesirable biofilm formation on plastic surfaces such as pipes, door knobs and handles etc by using appropriate additives. The two additives investigated (tetramethyl dithiooxamide and paraphenylene diamine) both showed good biofilm growth inhibiting ability.
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Competition for WPC WPC is intended to compete with wood, UPVC and MDF but competition from recycled plastics also needs to be taken into account. At the recent Recycling and Waste Management Exhibition in Birmingham, England (September 2006) there was a wide range of product-specific waste bins on display, designed to encourage people to sort the articles they want to throw away, making recycling easier and cheaper. Companies were also offering recycled plastics for use in the same type of applications that WPC is usually recommended for. Now Milestone Design of Yorkshire, UK has started offering kitchen fitments that use solid board made from recycled plastic. The worktops are made from recycled vending-machine coffee cups and the cupboard doors from recycled yoghurt pots. However, Milestone acknowledges that conventional woodworking tools cannot be used with some plastics, whereas WPC can be easily worked. It can be difficult to control the colour of recycled plastics too, if the original articles were dark. However, Milestone has found considerable interest from universities concerned with providing kitchens for student accommodation units.
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Global WPC Producer Making Large-Area WPC Boards JER Envirotech (Vancouver, British Columbia), one of Canada’s leading manufacturers of wood plastic composites, has announced that its new factory near Kuala Lumpur, Malaysia is now able to produce panels from thermoplastic resin and locally-available rice husks .(The WPC industry has made it easier to employ rice husks for making durable goods). Ernie Calica, general manager and vice-president of its Asian division, claims that JER Envirotech was the first company to produce large area (4 feet by 8 feet, or 1219 by 2438 mm) WPC boards on a commercial basis. This new production facility in Malaysia is a joint-venture, with JER Envirotech having the majority shareholding and Asia Pacific Microspheres the remainder. JER Envirotech claims to be aiming to achieve a truly global WPC operation and is currently also engaged in setting up facilities in both India and the Philippines in addition to those in Canada and Malaysia.
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Gamma Radiation of WPC Components The German company Beta Gamma Service (BGS) is developing and promoting the use of gamma irradiation to improve wood plastics composites. Unlike many processes which involve treatment of the raw materials, it is applied to the fabricated products after they have been moulded or extruded. Properties improved are said to include the modulus, hardness, and water resistance. The effects of gamma irradiation treatment on unfilled resins have been fairly extensively researched for various reasons, and its application to WPC was proposed in the scientific literature a few years ago as a possible alternative to the use of compatibilisers, as mentioned in the 2003 Hackwell Report on wood plastics composites.
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Wood as a Filler for Rubbers Most of the wood flour used in polymers is currently used in polyolefins and PVC, and very little has been done to develop wood as a filler for elastomers. Recently, though, researchers at Sofia University (Bulgaria) have investigated the use of wood as a filler in rubbers, and have found it to be compatible with a wide range of synthetic elastomers such as SBR, butadiene-acrylonitrile and polyisoprene. They have now examined the effect of wood on the cure rate of natural rubber. Ordinary wood flour does not seem to have an adverse effect on the cure time of natural rubber. In some experiments they pre-treated the wood with ammonia or a corona discharge. Wood appears to improve the stiffness of the rubber, but not the strength.
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Wood Treatments Not to be Banned A number of regulations have restricted the use of wood treatments in recent years.
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Another Big Player Enters European WPC Business UPM of Finland claims to be the world's biggest producer of paper, and therefore it is well placed to deal in other cellulosic materials, including wood plastics composites. Finland is short of WPC producers at present, although there has been some interest with the setting up of a WPC Development Centre by Conenor. UPM has now decided to enter the market and it has already bought the 100th Fiberex extruder to be sold by machinery market leader Cincinnati for use in WPC extrusion. The Fiberex design is believed to be the one most favoured by European WPC producers over the past few years. UPM's Markku Koivisto will head a new venture to make WPC products, starting with floor edge strips. Following Deceuninck's recent entry to the European market, which by all accounts has been highly successful, the WPC market in Europe is now gathering speed.
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Freeze-Thaw Can Degrade WPC Mechanical Properties The outdoor durability of WPC has been widely praised, but long term testing reports are still scarce. One specific threat to durability is temperature changes. In the past, outdoor winter conditions such as freeze-thaw cycles were thought not to damage wood plastics composites. (A freeze thaw cycle is usually considered as consisting of water uptake followed by the freezing and thawing of the absorbed water). Michigan University workers Jeannette M Pilarski and Laurent M Matuana subjected both PVC-based and polyolefin-based WPC to a lab test consisting of a modification of ASTM D 6662-01. Each freeze-thaw cycle consisted of a water soak to equilibrium at 21 ºC, followed by freezing for 24 hours, then thawing for 24 hours. Fifteen cycles (said by the authors to be an extreme condition) produced a fall of 49% in the modulus of elasticity (MOE) and 21% in the modulus of rupture (MOR) of maple wood polyolefin composites. The pine wood equivalents lost 5% MOR and 37% MOE. The cycles increased the number of pores and their size, although the density of the WPC either stayed the same or slightly increased. The interfacial bonding decreased. PVC materials showed rather similar trends. The researchers believe their results are relevant to the construction uses of WPC. Hackwell Group analysts point out in their latest Report that substantial falls in the mechanical properties of WPC have been reported after water uptake alone, without freezing. It is important to note that the residual strength of the wet WPC still compares well with that of competing wood substitutes, some of which have a much greater tendency to absorb water than WPC. The reversibility on drying of the property changes also has to be further investigated.
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Cheaper WPC Raw Material Available in Germany A new plastics recycling plant in Germany will recycle post-consumer plastics waste and produce material for making wood plastics composites. Clean Value Plastics has adapted a process sometimes used for waste paper. The plant's 3000 tonnes a year output is expected to sell at around Euro250/tonne ex-works. Speaking at the Kassel conference, managing director Michael Hofmann said the new process will enable WPC to compete with medium density fibreboard.
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Ikea's Rocking Chairs Made from WPC The German machinery company Coperion exhibited Ikea's rocking chairs made from wood plastics composites at the Kassel meeting in Germany recently. The chair is made in six pieces that can be assembled together without tools. Scandinavia Wood Fiber makes the WPC compound, which is then moulded by Nolato STG in Sweden. The PS Ellan chair is available in three colours (black, turquoise and white) but its colouring is achieved by mass pigmentation instead of paint.
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Entek Extruders: European Sales Re-Organisation
ENTEK Extruders, a division of ENTEK Manufacturing Inc, based in Lebanon, Oregon, USA has closed its sales operations in Europe and will handle sales of machines for Europe from Entek HQ in Oregon. In the past Entek has sold a number of its extruders to European manufacturers of Wood Plastics Composites via a UK sales office and selected agents in Europe.
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WPC Architectural Panels in 'Rainbow' Colours
Trespa International BV, a global manufacturers of architectural flat panels, has introduced new finishes. Trespa's panels can be given special metallic finishes that make their colour appear to change during the day as light impinges on it from different angles. The company claims that its "'Mystic Silver' passes through all shades from yellowish to bluish green and achieves a metallic look. 'Mystic Green' changes from a warm yellowish green to cold turquoise green with hints of silver and metal. Natural daylight and the sun create depth and give a mystical quality where formality is replaced with the more free-flowing organic imagery of nature" Some of Trespa panels are made of WPC, using thermosetting resins reinforced with wood fibres. They are manufactured under high pressure at relatively high temperatures, using electron beam curing, and they have an integrated decorative surface.
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2005
Polyolefin Business Re-Organisation Resin Prices Rise Steeply in 2005 and US Hurricane Damage Piles on the Pressure Lack of Antioxidant Caused Warranty Claims Wood Plastic Composites Continue to Generate Interest First WPC Conference in Germany New Product Development Centre for WPC New Market Report on Plastics Additives Strandex licensees produce well over 100,000 tonnes /year Freeze thaw not a problem after all Any colour so long as it’s brown Hackwell sees need for big application, big players and a close check on quality WPC Conference in Bordeaux (March 2005) WPC and mineral fillers 2004 Life Cycle Assessment of Wood Plastics Composites UK Government gives a lift to environmental technologies UK construction industry explores WPC Lubricant manufacturers attracted to WPC Entek claims nearly 4 tonnes an hour New compatibiliser for wood-polyethylene composites More producers looking at WPC Progress with rotational moulding |