Plastics and Wood

Most coating methods described in Sections 8.3.1 8.3.5 are also suitable for plastics and wood. The resistance to solvents and heat as well as the electrical conductivity of the plastics or wood must, however, be borne in mind. 

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

Although the details are beyond the scope of this book, health problems can be caused by solids and liquids suspended in water (for example, in waste-tailings streams) or in air (for example, in stack-emission plumes). Specific potential hazards have been associated with a diverse spectrum of colloidal materials, including synthetic chemicals, coals, minerals, metals, pharmaceuticals, plastics, and wood pulp. Limits for human exposure for many particulate, hazardous materials are published [504,505],... 

The HDH (Hauptverband der Holz und Kunststoffe verarbeitenden Industrie) is the lead association of German furniture, woodworking, plastic and wood-based industries. Its members include 13 special associations, 10 regional associations and 3 confederacy associations. 

Glass, carbon, stoneware, brick, rubber, plastics, and wood are common examples of nonmetals used as materials of construction. Many of the nonmetals... 

The interface between plastic and wood fibres strongly influences the mechanical properties of a plastic/wood fibre composite. A means for evaluating the effectiveness of surface treatment on the wood fibres in the PVC/wood fibre composites is presented that investigated the adhesion between PVC and laminated wood veneers. Wood veneers were first treated with gamma-aminopropyltriethoxysilane, dichlorodiethylsilane, phthalic anhydride, and maleated PP for surface modification. The chemical modification made on the wood surfaces was then characterised by different complementary surface analytical techniques X-ray photoelectron spectroscopy and surface tension measurements. 63 refs. 

Anthracene and phenanthrene are stereoisomers that are crystals in pure form. Anthracene is a pale yellow crystal, while phenanthrene exhibits a yellow to brown hue. Besides its common name, anthracene is referred to as anthracin, green oil, or paranaphthalene. The compound is commercially produced by recovery from the coal tar distillation fraction known as anthracene oil or green oil. Anthracene is the key ingredient in the production of anthraquinone. However, it and phenanthrene are also used for the manufacture of dyes, fibers, plastics, and wood preservatives. ° Phenanthrene, also known as phenanthrin, can be produced by high-temperature fractional distillation of coal tar oil. It is additionally used for the oxidation of diphenic acid for use in polymers, as well as the production of chemical softeners, explosives, and some pharma-ceuticals. Recent research has extended the application of both isomers to scintillation counters, semiconductors, and photoconductors. ... 

Ivanov, A., Potapov, Yu., and Alimov, S. About the Equation of Non-linear Creep of Some Plastics and Wood, Proceedings of Higher Institutes of Learning no. 6 (1968), (in Russian). 

Water absorption showed a rather complex quantitative pattern for composites of HDPE, wood flour, and talc. Evidently, the higher the plastic content and the talc content, the lower the water absorption. However, in the triple system when talc also replaced plastic, and wood fiber content increased, the relationship with water absorption was not that simple, particularly when weight and volume percents of the ingredients were considered. For example, after 4000 h of water immersion, the composition of 44% HDPE, 27% wood flour, and 27% talc (the balance was a lubricant) absorbed 6% water (w/w). A slight increase of HDPE content to 47%, with a concurrent increase of wood flour to 40% and decrease of talc content to 10% gave 11% of water absorption. A sharp decrease of HDPE content to 25%, with both a concurrent decrease of wood flour (36%) and increase in talc (36%) resulted in 13% of water absorption. Finally, a composition with 28% of HDPE, 54% of wood flour, and 14% of talc absorbed 20% of water [6-8]. 

WPCs, based on polyolefins, have one principal problem related to their integrity It is commonly a blend of a hydrophobic plastic and hydrophilic wood (or hydrophilic cellulosic fiber). Hence, the adhesion between them is poor, the interface between plastic and wood filler is typically weak, and it fails to optimally transfer stress between the two phases, when loaded. Lubricants help to solve the problem however, there are means to further improve bridging the interface by employing other mechanisms. 

Photooxidation of plastics and wood-plastic composites (WPCs) was described in principal detail in the preceding Chapter 15. It was emphasized that photooxidation acts in a synergism with thermooxidation of the materials, speeding up an oxidative degradation of WPC products, particularly being exposed to direct sunlight. 

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]. 

The chief uses of the polysulfide crude rubbers are in (1) rollers for applying ink, paint, and lacquer (2) hose to carry gasoline, solvents, and paint (3) putties for metal, glass, plastics, and wood (4) paper coatings for gadiets (5) plasticizer for sulfur cements (6) molded compounds in contact with fuels and (7) fabric coatings for diaphragms. 

The metal, plastic, and wood are at the same temperature, but the metal feels colder. That s because metal is a better conductor of heat, and it conducts heat away from your body faster than plastic or wood do. This also explains why you can reach into the oven and touch the cake you re baking but not the metal cake pan. 

Two examples are used to explain where the use of plastics is appropriate in car bodies, and where metals are more appropriate. Comparisons between plastics and wood are difficult, since different processing methods apply, and certain designs are optimum for each material. A design optimised for injection moulding in plastic (Sections 13.5 and 13.6), is neither suitable for anisostropic materials like wood, nor easy to construct. 

Some of the ingredients, mainly additives existing in various construction materials can slowly evaporate (as outlined in Section 7.5.3), and/or breakdown, meanwhile releasing different chemicals. In construction materials, plastics and wood are our main concern. 

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. ... 

Chem. Descrip. Epoxidized soya oil acrylate Uses For use in inks and coatings on p r, plastics and wood Features Good flow, adhesion, and exc. pigment wetting Properties Gardner 10 color m.w. 1200 vise. 25,000 cps add no. 15 tens. str. 1000 psi tens, elong. 20%... 

Uses Urethane-actylic in silk-screen inks tor plastics, laminating adhesives, clear coating for paper, plastics, and wood Features Good exterior durability, flexibility, toughness and adhesion,... 

Uses Urethane tor topcoats on wide variety of substrates ind. concrete, metal, plastic, and wood... 

Chem. Descrip. Aliphatic urethane diactylate/monomer blend Uses Urethane-acrylic in plastic and wood coatings Features Dilution of urethane oligomer with Photomer 4061 (TPGDA) to facilitate easier handling and applic. tough and abrasion resist. Properties High m.w. 

However, a correctly specifically manufactured and configured stoker is an excellent combustor of cellulose waste such as (1) wood—shredded trees to sawdust (2) garbage—refuse-derived fuel (3) bagasse—sugarcane residne (4) industrial residue—paper, plastics, and wood (5) furfural residue (6) peanut shells and (7) shredded tires. Most of these fuels can be bnrned without auxiliary fuel with proper attention to fnel moisture, design heat release, combustion air system design, and preheated air temperature. Cogeneration and the emphasis on renewable fuels have driven increased use of these fuels. Size distribution of the fuel is important from the standpoint of efficiency, availability, and low emissions. 

Trex is a manufactured substitute for wood compounded from post-consmner plastic and wood. 

Wood fiber - recycled plastic composite lumber is a relatively new development and is similar to PS addition to plastic lumber because the potential exists for improved mechanical properties and dimensional stabilities. Wood fiber addition can serve as an excellent reinforcement for plastics, and wood fibers are abundant, lightweight, nonabrasive, nonhazardous and inexpensive. An effort is being made to examine the incorporation of treated and untreated aspen fibers into recycled HDPE milk bottles [Yam et al., 1990]. The work has shown tensile strength and Izod impact strength below that of HDPE alone when aspen fiber is added. Tensile modulus and flexural modulus are increased significantly above HDPE alone with the addition of wood fiber. Dispersion of the fiber in the resin has been reported as a dominating factor in the process thus far. 

The elements can be classified as metals, nonmetals, and metalloids. Most of the elements are metals. We are familiar with them because of their widespread use in tools, construction materials, automobiles, and so on. But nonmetals are equally useful in our everyday life as major components of clothing, food, fuel, glass, plastics, and wood. Metalloids are often used in the electronics industry. 

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