Wood-plastic composites additives

Clariant introduces licocene coupling agent for wood-plastic composites. Addit Polym [trade journal—Elsevier] March 2007. 

In addition, ABS that has been recovered can be recycled into high value composites without separation from impurities. This has been exemplified with wood-plastic composites that contain ABS as matrix polymer. Both virgin ABS and recycled ABS were used and the properties of the materials were compared (126). In order to increase the performance, coupling agents were used, all based on grafted maleic anhydride. 

Anonymous. Wood-plastic composite growth taking off in Europe... while strong WPC growth continues in the USA.. Additives for Polymers (5) 9—11 (2006). 

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... 

U.S. Pat. No. 6,632,863 [115] (by Crane Plastics Company, Timber-Tech) discloses a wood-plastic composition manufactured as feedstock pellets comprising 55-90% cellulosic material such as wood flour and wood fiber, 10-40% of polyolefin such as HDPE, LDPE, and polypropylene, and 0-35% total of additive(s), such as lubricants and inorganic fillers, such as talc and mica. 

J. Markarian. Wood-plastic composites current trends in materials and processing. In Plastics Additives Compounding, September-October 2005, pp. 20-26. 

B. Sigworth, L. Walp, R. Bacaloglu, and R Kleinlauth. The role of additives in formulating WPC. In The Role of Additives in Formulating Wood-Plastic Composites, The Global Outlook for Natural Fiber Wood Composites 2003, New Orleans, LA, December 3-5. 

Rheology of Filled Plastics and Wood-Plastic Composites There are very few data published on rheology of filled plastics or multicomponent plastic-based composite materials. Most of them, in addition to those cited above, are related to long glass or graphite fiber-filled plastic [17-20]. 

Viscosity and the Power-Law Index of Wood-Plastic Composite Materials Let us consider in more detail how fillers tend to make the system more shear thinning, that is, to decrease the power-law index. At lower shear rates or frequencies, neat plastics often exhibit a Newtonian plateau, that is, a higher apparent power-law index, and in the presence of fillers, the plateau often turns upward or even disappears. In other words, the addition of filler often makes the power-law plot more steep, that is, shifts it to a more uniform straight line dependence of viscosity verses shear rate (or frequency). 

Intelligent additive solutions for wood plastic composites, supplier product guide (TEB0040/062006). Struktol. 

Rothlin O. Processing wood-plastic composites place new demands on feeders. Plastics Addit Compound [trade journal—Elsevier Ltd.[ luly/August 2007. 

The mechanical properties of Wood-Plastic-Composites substantially depend on the quality of the raw material, the composite and the manufacturing process. The density of WPC lies between 0.9 and 1.4 g cm and is higher than that of one of the two components, plastic and wood, alone. The porous wood structure is densified during the production process and plastics and additives partly penetrate into the cavities. Thus, water absorption is made harder, and the material swells less and more slowly. ... 

J. Rizvi, and G.M. Semeralul, Glass-fiber-reinforced wood/plastic composites. /. Vinyl Addit. Technol. 14, 39-42 (2008). 

Professor Pritchard has organised the technical programmes for Rapra s annual Addcon conferences on additives and modifiers since 1996, and has written market reports for Rapra on particulate fillers and PVC. He has also contributed to the Hackwell Group s 2003 report on wood plastics composites. 

Several additives are susceptible to microorganisms, notably certain PVC plasticisers, especially the epoxy oils and esters, polyesters and sebacates. Most aryl plasticisers are more resistant than their alkyl equivalents. Natural fillers such as starch and wood flour are also attacked, although if the particles are fully encapsulated by resin they will have considerable protection. This is important for wood-plastics composites, currently being promoted as potential substitutes for wood, MDF and even UPVC. It is possible for microorganisms to attack certain lubricants such as polyethylene waxes and pigments. 

ExxonMobil Chemical s Exxelor compatibilisers include maleated PP and maleated elastomeric ethylene copolymers. They improve the impact strength of wood plastics composites, but there needs to be at least 50% wood in the composition to see the full effect. They also improve the water absorption and allow the wood content to be increased from 50% to 60%, giving better mechanical properties with no net increase in materials costs. Some of these additives are also recommended for use in polymer blends such as PA/ABS or PA6/PA6-6. 

The authors found that the depression of glass transition temperature (Tg) due to the addition of plasticiser is substantially reduced by the loading of wood flour. In addition, various wood-plastic composites were compounded into different colours, and several pairs of the compounds with different rheological properties were extruded in single and twin-screw extruders to see whether any wood-patterns are developed. When the differences in the shear viscosity and the Tg of the two compounds were too large, the incomplete plasticisation of the higher viscosity component was observed due to the lower viscosity component. It was found also that distinct wood-patterns were only developed both inside and on the snrface of the extruded prodncts for the pairs of the composites with optimal differences in both viscosity and plasticiser content. 

B. Sigworth. Additives for wood-filled polyolefins. Coupling agents. In Progress in Woodfibre-Plastic Composites Conference 2002, Toronto, Canada, May 23-24, 2002. 

G. Capocci, U. Stadler, and M. Reyes. Anti-staining and anti-fungal additives for wood-fiber-plastic composites. In Conference Proceedings of the Global Outlook for Natural Fiber Wood Composites 2004, Intertech, Portland, ME, New Orleans, LA, December... 

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