Plastic
Plastics have become part of everyday life. Some polymers were discovered fortuitously . A plastic or plain language a plastic is a mixture containing a base material (a polymer ) which may be molded , shaped, usually under heat and pressure to lead to a semi-product or be . The word “ plastic “derives from the Latin plasticus , itself derived from the ancient Greek πλαστικός ( plastikos , “on the modeling”), derived from the verb πλάσσειν ( plássein “mold, form”) which also derives the word plasma . Plastics cover a wide range of materials, polymer synthetic or artificial . It can be observed today on the same material properties that had never before been collected, such as transparency and impact resistance . The textiles ( son and fibers ) and the elastomers are not of plastic themselves. Generally, the polymer industry are not used to the “pure” state, but mixed with substances miscible or not in the polymer matrix. Typical structure of a formula : area = plastic polymer (s) Product (s) ( resin (s) base) + charges + plasticizer (s) + additives . There are many plastics and some are very successful business. Plastics come in many forms, parts injection molded , tubes , film , fibers , fabrics , sealants , coatings , etc.. They are present in many areas , even in the most advanced technology . Summary [ hide ] 1 History 2 Technique 2.1 Features 2.2 Chemical composition and general 2.2.1 Notions of Macromolecular Chemistry 2.2.2 Formulation of the polymer material 2.2.2.1 Additives 2.3 Properties 2.3.1 Thermal properties 2.3.2 Mechanical Properties 3 Transformation 4 Typology 4.1 Families of plastics 4.1.1 Thermoplastics 4.1.2 Thermosets 4.1.3 Elastomers 4.2 Polymers of three families of plastics 5 Economy 5.1 Production 5.2 Consumption 6 Bioplastics 7 Environment 7.1 Ecological Balance 7.1.1 Production Phase 7.1.2 Use phase 7.1.3 At the stage “waste” 7.2 Recycling 8 Notes and references 9 Annexes 9.1 Related 9.2 Bibliography 9.3 External Links History
The first high-strength engineering plastics have been produced from the milk . The Bakelite was a huge success from the year 1920 , here in the form Criminal Defense Attorney Chicago of the front of a radio. The casein of milk was used as a plasticizer in painting from the Middle Ages and perhaps much earlier. Plastics are practically born with the xx th century. Hundreds of researchers and tinkerers of genius are responsible for their development. The first plastic, artificial, resulting from the processing chemicals of natural polymers such as rubber, cellulose and casein (the macromolecular skeleton being preserved in this transformation). The first industrial plastic based on a synthetic polymer is Bakelite . The history of plastics goes back to ancient Egypt : fifteen centuries BC, the Egyptians were using glues containing gelatin , casein or albumin ; end of the xv th century, Christopher Columbus brought plants rubber called Cao ( wooden ) chu (crying) by the Indians ; 1736 : the naturalistic French Charles Marie de La Condamine and François de La Fresneau Gataudière discovered natural rubber in the Amazon basin by chance; 1835 : Henri Victor Regnault accidentally discovered the reaction electronic cigarettes of polymerization of vinyl chloride ; 1839 : The American Charles Goodyear discovered (quite by accident by the way) the process of vulcanization of natural rubber by sulfur ; 1862 : The English Alexander Parkes presents Parkesine (derived from cellulose), one of the oldest artificial polymers, during the Universal Exhibition in London . This discovery is the basis of the modern plastics industry; 1870 : The Hyatt brothers invented the celluloid (used balls Table Tennis ) is considered the first artificial plastic material, which dates back to 1856 . It is obtained by plasticizing the nitrocellulose (after the nitration of wood cellulose) by the hot camphor . It follows an embargo balls billiard in ivory during the Civil War the United States of America. But these ersatz low quality were soon replaced in 1890 by balls Galalith ; 1884 : Hilaire de Chardonnet invented the viscose in said solvent of cellulose acetate in Cell Phone Accessories the chloroform ; 1889 : a chemist French, Jean-Jacques Trillat , working on the milk casein, manages to harden and gets Galalith or “milk stone”. This material is harder than the horn , brighter than the bones and silky to the touch as ivory. Soon all the billiard balls will Galalith . In 1918 , began the manufacture of 
everyday items such as button, costume jewelery, cigarette holder or the pen; 1907 : the chemist Belgian , naturalized American Leo Baekeland ‘s phenol-formaldehyde resin (known as Bakelite ), the oldest synthetic polymers industry, produced by polycondensation of phenol and formaldehyde (family phenoplasts ) originally used for phone cases, razor shells, saucepan handles, electrical outlets, ashtrays, etc.. ; the same year, the chemist German Fritz Hofmann made the first rubber synthetic by polymerizing diene conjugates ; 1908 : discovery of cellophane by chemist Swiss Jacques Brandenberger; 1919 : German chemist Hermann Staudinger , Nobel Prize in Chemistry in 1953 , introduced the concept of macromolecule and then performs the polymerization of many monomers ethylene . It can be considered the father of macromolecular science; 1920 : Early studies of the reactions phenol-epichlorohydrin by Paul Schlack of the company IG Farben Industrie , leading to resin epoxy ; 1931 : first industrial production of polyvinyl chloride (PVC); 1932 : After more than twenty years of research , development by Otto Rohm and Haas, in collaboration with IG Farben, a large number of derivatives polyacrylic , with polymethyl methacrylate (PMMA), commercially known as the Plexiglas ; use: rear lights flashing and some covers of vehicle windows for air , fiber , neon signs;
Crates , plastic goods (based PE or PP) 1933 : obtained by radical polymerization of low density polyethylene (LDPE) (LDPE for Anglo-Saxon ) ( density of ~ 0.92) by the English engineers Eric Fawcett and Reginald Gibson of the company ICI , working under very high pressure at 200 ° C 1 . The polyethylene (PE) is the only polyolefin that can be obtained by radical ; 1935 : the polyamides (PA) (known as the Nylon ) came out of the specimens of American chemist Wallace Hume Carothers working for Du 
Pont de Nemours 2 . In 1938 , the company officially announced the discovery of a synthetic fiber “as strong as the steel , as fine as spider’s web, and a beautiful shine . ” This was the first high-performance engineering plastic, especially with a coefficient of friction low. Applications: proven in parachutes of GI at the time of landing , and then used in the manufacture of low , gear , cages, ball bearing , body drill , head mallet , plastic fasteners, soles of football boots; industrial production of polystyrene (PS) in Ludwigshafen , followed by a rapid development in Germany; 1936 : the company Rhone-Poulenc creates Rhodoïd , based on cellulose acetate; 1937 : Professor Otto Bayer first synthesized polyurethanes , also called poly carbamates 3 ; applications: adhesives, fiber Spandex , “ foam “mattress and cushions, seat car , etc.. ; 1938 : Roy J. Plunkett , an American chemist for Du Pont de Nemours, stumbled upon the polytetrafluoroethylene [molecular formula (-CF 2 -) n ] (PTFE) (best known under the trade name Teflon , present in the Gore-Tex ), an insulating that offers excellent chemical resistance and heat (stable up to 250 ° C in continuous operation, with spikes possible to 300 ° C ). Tight insulation, he served in the military nuclear industry, before covering the years 1960 and stoves in the kitchen frying (application of power stick ) seals . The Second World War exacerbated the need for raw materials : 1941 : resin “ melamine – formaldehyde , ” alias Formica , invaded the kitchen. This resin very hard part of the family of amino . It was developed in the years 1930 and 40 by firms such American Cyanamid , Ciba and Henkel , but without commercial success. Properties of high resistance to most chemicals, heat, light, with the abrasion and fire behind his success in the immediate postwar period . Amino resins are also used as adhesives / binders in the wood industry; the silicone (SI), heat-stable with non-stick properties, use in electrical industries, aerospace and biomedical ( electrical insulators and fluid damping in aircraft landing gears, plastic surgery , oil engine, sealants, paints , cosmetics , etc.. ) discovery of polyethylene terephthalate (PET) by JR Whinfield and J. Dickson. To cover its needs, Germany, quickly deprived of its resources latex natural, produced during the First World War rubber Buna t shirt design 4 , a rather poor substitute for this substance . His research into new plastics continued during the Second World War (including IG Farben made) and, in 1945 , the production of synthetic rubber was one million tons . From the Liberation , the momentum of science and technology to industry breathed by the war continued and new materials were synthesized such new polyamides, polycarbonate and poly acetal . Then the discovery of new materials became scarce: 1950 : first synthesis of copolymers of polystyrene , marking a significant improvement of the qualities of PS homopolymer (held at the shock in particular temperature limit of use, resistance to solvents, organic);
Polycarbonate: a transparent resin such as glass, strong as well. Used in shielding it with the helmet astronauts on the moon in 1969. 1953 : researchers Bottenbruch, Schnell and Krimm of Bayer AG discover the polycarbonate (PC), a polymer highly transparent and highly impact resistant. It equipped the helmet of astronauts to Mission 
Apollo 11 in 1969 . Use: in more than 80% of visors helmet , CDs , bottles unbreakable, automobile headlights, roof profile, windows phone booth , bullet-proof glass, chassis, laptops, etc.. ; German chemist Karl Ziegler and his team accidentally discovered a catalyst for the linear polymerization of ethylene (or ethene ) under moderate pressure (about 2 to 3 MPa ), producing the high-density polyethylene (HDPE, density ~ 0.95) to the low degree of branching ; 1954 : a year later, the chemist Italian Giulio Natta develops, using the catalysts “Ziegler”, the polypropylene (or polypropylene) isotactic (PP or PPi to differentiate it from syndiotactic polypropylene initials of PsA). Ziegler and Natta shared the Nobel Prize in Chemistry in 1963 through their work in polymer science. Note: The atactic PP is of little economic interest; 1955 : the work of the Phillips Petroleum Company on the polymerization linear coordination under relatively low pressure of ethylene, due to stereospecific catalysts, providing HDPE ; 1961 : Commercialization of Estane ( BF Goodrich ), a polyurethane thermoplastic (TPU English). Another example of thermoplastic elastomer (TPE or TPR in English): the block copolymer (copolymer block ) SBS or poly ( styrene -b- butadiene -styrene-b); 1965 : discovery by researchers Stephanie Kwolek and Herbert Blades of the firm Du Pont de Nemours of a “super-nylon”, the Kevlar , a fiber aramid light and particularly resistant 5 : tear and shock: vests and bullet-proof glass, anti-drilling; Fire: helmets and jackets of firefighters , oven mitts, etc.. His great success in this area is also due to the prohibition of asbestos ; to corrosion (sails, ropes of oil); in the year 1990 , the terpolymer ABS tends gradually to replace the resin “melamine-formaldehyde.” This is a more noble material than polystyrene, widely used in coating equipment appliances (Suction), toys for rigid covers, sometimes packaging ( lids ), in accessories bathrooms and industry ; the ABS version is also available in translucent (M-ABS ABS said transparent); it is metallizable by electroplating to mimic the aluminum ; use: cosmetic containers … ; it can be blended with polycarbonate to form a polymer alloy PC / ABS (names Anjablend A , Bayblend , Pulse ) (car parts). The Noryl is another example of polymer-polymer ; 2000 : Development of conductive polymers intrinsic , researchers Alan Heeger , Alan MacDiarmid and Hideki Shirakawa were awarded the Nobel Prize in Chemistry. Last thirty years, cars, trains and Articles appliances (washing machines …) have steadily become lighter in metal and improve performance through the auto insurance quotes provision of plastic materials 6 . The reinforced plastics ( composites ) [resins typically polyester and polyepoxide reinforced fiberglass ( glass : d ~ 2.5)], with lighter resistance equal than steel or aluminum, and corrosion-resistant, are non-traditional materials. Some types are increasingly used in the aviation sector 7 . New plastics ever more respectful of the environment (recycling and biodegradability improvement), less dependent on oil (cost reduction), heat-stable, transparent, unbreakable, non-flammable or original are developing. Related article: Bioplastic . Technique
Features The properties of plastic materials continue to improve. There is growing use of plastic parts instead of metal, often more expensive, more sensitive to corrosion, or heavier. Some technical characteristics differ significantly from those of metals: the density of unexpanded plastic is much lower than that of metals (excluding magnesium ): 0.83 (case of poly-4-methyl-pentene-1 designated PMP ) to 2.15 (PTFE) with a , 2 as a mean value. The density of a polymer is directly related to the degree of crystallinity . In addition, the stiffness and strength increase with the rate; transformation temperature lower: usually between 100 ° C (the PS is easy to work: extrudable at 85 ° C ) and 300 ° C (the PC is injected to 300 ° C ). Bioplastics are processed 160 to 200 ° C , against about 220 ° C for compounds common equivalent; elasticity higher (up to 800% of elongation at break for HDPE); thermostability of thermoplastic polymers well below that of metals. Few plastic resistant to more than 250 ° C for long periods in the air. Structural changes, particularly among thermoplastics, can broaden the field of use to the heat low or high temperatures; modulus of elasticity lower (the modulus of the LDPE is low: E ~ 200 MPa , in contrast, amino resins have a very high modulus). Increasing incorporation of fibers increases the tensile modulus and tensile strength ( tenacity ) of the composite. The thermal expansion of materials is inversely proportional to their modulus traction . The expansion coefficient of thermoplastic polymers is higher than that of metals; held (or resistance) to chemical agents: in general, polymers are resistant to acids and bases [high chemical inertness of PTFE and PE (due to its structure paraffin )]. However, they are sensitive to solvents (good performance of PTFE, PBT and PA-6, 6); polymers behave in a viscoelastic . Indeed, they show simultaneously properties elastic in nature and viscous . In the latter case, the material flows in response to stress ; some plastics are damping vibration ; examples: ABS, SIS block copolymer [or poly (styrene-b- isoprene -b-styrene )]… ; Interest vibroacoustic ; most thermoplastic polymers amorphous non- loaded (not colored …) are transparent (PMMA, PC, PS “crystal”, etc.. ) some plastics show a high resistance to impact (PC, PET, PMMA, etc.. ) some are resistant to abrasion (PTFE, rigid PVC, polyamides, PET, amino, etc.. ). PTFE has a coefficient of friction tailor made suits particularly low, which allows it to be a solid lubricant . Matrices organic are thermal and electrical insulators, as well as reinforcing fibers (except carbon fiber ) 8 : the thermal conductivity of polymers is about one hundred times lower than that of metals, so a lot of plastics, particularly mosses, are used as insulation; electrical conductivity very low plastics traditionally used for the isolation of son and cables (PTFE, HDPE). Physical characteristics mean some common thermoplastic polymers 9 . Code Density Degree of crystallinity (%) Tg (° C) Tf and Tr (° C) 10 T max (° C) 11 Module E (G Pa ) ABS 1.04 to 1.12 0 85-125 105-120 70-85 2.5 PA-6 1.13 50 52 215 85 A PA-6, 6 1.14 50 57 260 90 1.5 PC 1.20 0 150 220-250 120 2.4 PE-HD 0.95 80-95 -110 124-135 90 0.8 to 1.2 PE-LD 0.92 50-70 -110 100-125 70 0.15 to 0.3 Amorphous PET 1.30 0 65-80 255 100 2.7 Crystalline PET 1.40 40 65-80 260 100 4.1 PMMA 1.18 0 105 130-140 60-90 3 PP 0.91 60-70 -10 165 100 1.3 PS “crystal” 1.05 0 80-100 100 60 3.2 Rigid PVC 1.38 0-5 80 100-120 65 2.4 Chemistry and general composition Notions of Macromolecular Chemistry
Plastics ready often consist of long chains carbon 12 . They are usually derived from fossil fuels (oil, natural gas, coal). Various substances (fillers, plasticizer (s) and additives), the proportion by mass may be a majority, are incorporated during manufacture. The base material (resin) is a polymer 13 . Resins, plastics come from intermediate products (ethylene, propylene , acetylene , benzene , etc.. ) whose raw materials are petroleum (especially by scrabble word finder the process of steam cracking of naphtha ), the gas 14 and the coal . A polymer is a substance composed of macromolecules . A polymer chain consists of a large number of monomer units . The viscosity and the strength of a polymer increases with the degree of polymerization (DP n), it defines the length of the chains 15 . If the degree of polymerization is greater than 3000, the product is a plastic material ; DP up to six million. The plastics are synthesized by polymerization of monomers or ( pre- ) polymers: dimensional polymers (linear or branched ) result from the polymerization of monomers bivalent ; three-dimensional polymers are formed by polymerization of monomers whose average valence greater than two , or by cross-linking (chemical or physical) of linear polymers. Polymerization is a process important in the chemical industry because the resulting polymers must have the desired properties, including durability, chemical resistance vis-à-vis many products, elasticity, transparency and mechanical resistance and thermal. There are two types of polymerization : the polymerizations in stages , involving polycondensations (eg leading Medifast coupon code to polyamides, the reaction proceeds by elimination of simple molecules, especially water) or polyaddition (eg to produce polyurethanes). The resulting polymers often contain heteroatoms catenary , such as polyamides with the atom of nitrogen ; the chain polymerization . Depending on the active center , there are the radical polymerization , cationic , anionic or coordinative (in this fourth case, the propagating active center is a complex coordination between the monomer and one atom of transition metal such as titanium or zirconium ) . This second category is mainly monomeric vinyl which leads to polymers consisting of chains – C – C -. To improve certain properties, plastics trade are sometimes composed of a base resin modified by another resin or elastomer (interest of copolymerization). There is no two-dimensional macromolecules prepared by synthesis. There are four methods of preparation of polymers: bulk polymerization, solution, suspension and emulsion . Examples include thermoplastic polymers PE, PVC and PS may be synthesized by these four methods of polymerization. The copolymerization providing the ABS are norfolk island holidays most often by the process in aqueous emulsion, with the formation of micelles . Formulation of the polymer material It plays an important role. The fillers, plasticizers and additives are incorporated and dispersed in the matrix resin to improve its characteristics (thermal resistance, fire, chemical, shock or aging, density , color , etc.. ) or its implementation (flexibility …) 16 . The formulation should be nontoxic . A safety data sheet (MSDS) preparation may need to be provided to the user.
Production of pellets ( compounding or compounding in English) from the formulat (formulated polymer) uniform, using a mixer-extruder and extruder. The pellets will be used, for example, injection molding. We distinguish (not exhaustive): of (the) resin (s) basic : bring cohesion to the material; the charges : reducing the cost of the room, improve some mechanical properties or properties specific to more than 100% incorporation in the bulk polymer material for some plastisols . The improvements are even more pronounced than the grain size is fine. There are: loads of mineral origin (often used) powder: calcium carbonate natural 17 , silica natural synthetic silica (amorphous, agent thixotropic ), Plastic Storage Bins talc , clay , kaolin , carbon black , graphite , barite (d ~ 4.4) , barium ferrite, etc.. , organic loads: wood flour (low cost) or fruit peel, pulp, starch (improves biodegradability), dry rubber (shock), etc.. , metal fillers: the organic matrix to partially conductive (adding powders or flakes of aluminum, copper, zinc, etc.. ) fibrous reinforcing fillers: to improve the mechanical properties, heat resistance and dimensional stability of the composite material (low shrinkage ) (fiberglass, mica …) 18 , non-fibrous reinforcing fillers, the spherical fillers most commonly used are the “beads” hollow glass: relief (because beads hollow ), better rigidity and resistance to compression of the resin loaded new applications: nano-clay (very fine), incorporated up to 5% (for nanocomposite bottles and packaging) Grains : improving the recyclability (up to 50% incorporation), Linen : to increase the hardness of polypropylene; (s) plasticizer (s) : diluent (s) low volatility (s) of low molecular weight in the solid state , or state liquid (more or less viscous) to the compound obtained in particular more flexible , more resilient, reduce the glass transition temperature and the temperature of implementation ; added (s) in varying proportions (a small proportion of incorporation up to 50% in some plastisols) ( phthalates , adipates, sebacates, phosphates , polyesters, etc.. ) the additives . Additives In general, they increase significantly a specific property and are incorporated in small proportion. Many of them have locksmiths not been a comprehensive assessment of security in terms of toxicology and ecotoxicology (in Europe by the EFSA ). Lack of international regulation and pending the application of Regulation REACH , they are essentially authorized and controlled at national level. In Europe, the list of additives in Directive 2002/72/EC relating to plastic materials and articles in contact with food will become a positive list (products not listed will be banned) 1 st January 2010. A provisional list to date is 19 . Examples of additives: system of cross-linking (to synthesize three-dimensional polymer) allow the formation of a three-dimensional network (reticulation) from linear polymers; contains hardeners, catalysts , accelerators, etc.. 20 ; stabilizers : retard degradation of the polymer stabilizers oxygen ( antioxidants , such as certain phenols to steric hindrance or diphenylamine 21 ; for ABS, PE, PS, etc.. ), with the ozone (antiozonants, for example polymers from of butadiene ), heat stabilizers for the implementation and the heat resistance in use (for PVC, PMMA …), light (anti- UV , such as absorbers and UV quenchers ) 22 ;
Of flame retardant additives are included in the resin electrical or electronic components 23 . Ease of processing, tolerances, stiffness and temperature resistance are forced to comply, after application. flame : reduce or prevent the phenomena of combustion (up to 10% incorporation) ( alumina hydrate , phosphonates …) required each time the security is at stake because most plastics are particularly flammable , must be stable over time, little or no toxicity 24 ; blowing agents : get a product-foam (cellular component sparse, density up to 0.005), a gas can be released by chemical decomposition of the agent under the action of heat (insulation, car seats and steering wheels , etc.. ) lubricants : to facilitate the implementation by increasing the slip (up to 2% of incorporation) ( wax , calcium stearate …) Proponents of membership : improve adhesion on glass, fiberglass or metal ( silanes , titanates, compounds containing groups Polar , etc.. ) colorants ( pigments insoluble solids in the polymer, such as carbon black or metal oxides , or organic dyes 25 -soluble polymer) to a color; antistatic agents : countering the dust deposits by making the conductive plastic surface, in fact, most polymers are poor electrical conductors; fungicides and bactericides : resist the attack of microorganisms ( aseptic ), especially in humid conditions; Solvent : paint ( coating ), adhesives … Some components are multifunctional 26 . Properties Thermal properties
Structure-properties: linear chains (case of thermoplastic polymers, left diagram) and network molecules (thermosets, right) Polymers can be classified into two types, depending on their behavior to heat the thermoplastic (linear polymers, branched or not) and thermosets [three-dimensional polymer (crosslinked)] 27 : heated to a temperature high enough (above their glass transition temperature Tg or melting Tf), the polymer thermoplastics are in the state “melted” (as fluid or deformable ) and Denver Divorce Attorney are therefore likely to flow under the action of a constraint. This enables them to format using standard techniques (thermoforming, extrusion, injection, etc.. ). The operation can be repeated several times; polymers thermoset cure ( crosslink ) during a first heating (or possibly at room temperature). In the field of paints, it is a property often exploited. Heat input can initiate a polymerization reaction that creates three-dimensional bridges between the polymer chains and hardens the material irreversibly. Mechanical properties Thermosetting polymers are often rigid and fragile , while the thermoplastic polymers and elastomers show a poor mechanical strength greatly affected by temperature. With regard to the molecular structure, polymer materials solid are either: semi- crystalline [presence of crystalline regions ( crystallites and spherulites ) and there is a range of fusion narrow allowing a rapid transition from a solid or pasty in the fluid state, by raising the temperature] with heterogeneous morphology ( Examples: PE, PPi, PA, thermoplastic polyesters, POM [(-CH 2 -O-) n ], PTFE); is amorphous , showing a gradual softening by temperature rise (PS and its copolymers, PMMA, PC, PVC 28 , etc.. ). Notice the influence of tacticity : an atactic polymer (PMMA, PS macromolecular chain …), which has a geometric shape irregular, can not crystallize, unlike an isotactic or syndiotactic polymer. The structure of the polymers is related to the thermomechanical properties. For example, when implemented by injection, amorphous plastics are more tolerant [process easier, shrinkage ( shrinkage in English) lower cooling] that the semi-crystalline (they have a tendency to crystallize) 29 . The degree of crystallinity of a polymer influence the mechanical properties (Young’s modulus increases as the rate of crystallites increases. Conversely the limit of elastic deformation decreases). It is generally accepted that the properties of an engineering plastic are optimal when the average crystallinity combines the mechanical and thermal resistance of the crystalline phase to the resilience of the amorphous phase (almost 50-60%). Most thermoplastic polymers are not used above 120 ° C , temperature at which softening occurs (for amorphous) or merger (for semi-crystalline), which removes the mechanical properties. The amorphous thermoplastic polymers are used below their Tg, the state glassy . In principle, thermosets have better thermomechanical behavior (to heat, fire, creep , low shrinkage, etc.. ) and chemical and thermoplastics. The best are thermosetting thermostable. When plastics are found in service, we realize they are subject to the constraints that cause distortions in some cases can lead to rupture . The service behavior of materials defines their use properties . It is important to know the intrinsic properties (inherent in the materials) to make a judicious choice of the material best suited to perform the functions assigned to it. The strength of materials is the science that will, from properties of each material, define the characteristics and conditions of use of each. The mechanical properties are intrinsic properties of materials and are set from of testing comparative standard. In general, we use the standard ISO , ASTM and DIN , standards or “houses” when the tests are directly related to use properties. The mechanical properties are then used to predict the final properties of the finished objects. However, some structural features related to the processing of plastics, such as the degree of crystallinity, corporate clothing the orientation of macromolecular chains, or internal stresses resulting from the conditions of implementation and cooling, can influence the properties of the object. These properties are called transformation properties . We can summarize the material properties as follows: intrinsic properties (specific material); transformation properties (depending on the methods and conditions of implementation); use properties (defined by the terms of use). A large number of mechanical tests used to characterize the resulting plastic analysis techniques such metals as far as elastic modulus , the tensile strength and the elongation at break .
Characterization of mechanical stress-strain curve for a sample set of three standard materials Mechanical analysis and rheology are based on tests including tensile , compression , shear , bending and torsion . The analytical equipment includes devices for measuring the melt flow index (for thermoplastic polymers) (MFI, melt flow index in English) 30 , the devices of traction , the strain gauges , analyzers DSC , the viscosity ( rotational type, cone-plate or capillary) (for thermoplastics) analyzers DMA (the latter two instruments are dedicated to measures dynamic ) devices Izod and Charpy , etc.. As for the solid polymers, a simple uniaxial tensile test to measure certain mechanical properties. The materials are divided according to their stress-strain behavior in three general categories: rigid (often low ductility and low impact resistant), plastics or elastomers. The chart entitled “Mechanical characterization” obtained in a tensile test shows three categories: the curve A illustrates the stress-strain in a rigid polymer (high modulus) whose failure occurs almost simultaneously with the yield strength . The polymer was a brittle (low auto transport elongation); Curve B shows that the behavior of some plastic materials is similar to many metallic materials: the elastic deformation is followed by an initial plastic deformation. The material is tough (high elongation); Curve C shows an elastic deformation in a wide range of deformation, engagement ring the mechanical behavior is typical of an elastomer. Plastic materials have mechanical properties influenced by the following main factors:
Influence of Temperature pattern for a sample of plastic at different temperatures temperature; the cohesion of polymers; changes in molecular mechanical properties of polymers; their processing conditions. Overall, the elastic modulus and elongation at break of rigid polymers are determined in the same way as in the case of metals. The yield strength Re plastic polymers on the curve is equivalent to the maximum value of the stress being at the end of the linear elastic region. In addition, the tensile strength Rm is the stress resulting in rupture, it may take a value greater than or less than Re It is important to note that the mechanical properties of thermoplastic polymers and elastomers are highly dependent on temperature (see chart entitled “Influence of temperature”), external constraints and time of observation. An increase in temperature puts a thermoplastic behavior to a rigid and brittle ductile and tenacious. Transformation
Single-screw extruder for the continuous production of an extruded rod from chiropractic marketing the mass of melted formulat More than any other material, plastics offer a wide range of processing techniques. The initial products [complete formulations (also called polymeric materials) compounds] are in the form of granules, powder, pellet, paste or liquid. Materials hygroscopic (PA, ABS, PBT, laser hair removal PMMA, etc.. ) undergo a pre-drying (for baking) before implementation to avoid failure due to moisture on the plastic parts. States plastic or viscous are needed to implement the techniques for shaping polymeric materials. Processors perform the finished objects for users with equipment and materials supplied by the producers of polymers or compounders.
Two-material injection molding of thermoplastic granules fed by 31 The shaping of thermoplastic polymers differs from that of thermosets: compression molding is the hot molding type of thermosetting polymers. Avoid caking (reaching the “freezing point”) of the material before the molding operation is completed. The curing time of thermosetting limit the production rates of industrial type; calendering (passing the material between two heated cylinders), extrusion (passing through a chain ) and injection molding processing techniques are typical thermoplastic polymers. These compounds allow for shorter cycle times.
Film (based on a mixture co polyester – PLA ) obtained by extrusion-blowing There are: Coating of various materials (metals, fabrics …) Extrusion of cables, plates, profiles, tubes 32 , calendering , extrusion , calendering, extrusion-blowing and extrusion known cast (making films), coextrusion (multilayer films), extrusion sheathing (cables); Injection 33 , injecting water or gas-assisted, two-material; Blow molding , injection blow molding and rotational molding : to create the hollow bodies (bottles, toys, etc.. ) Thermoforming , pressure forming; Foam (PUR, PS foam); Spinning melt (PP, PET, PA, PE, etc.. ) Sintering (PTFE, to 370 ° C , the polyethylene ultra-high molecular weight UHMWPE designated by English 34 , and PI );
The plastic can be molded and blow molding of complex shapes in industrial series ( plastics ). The plastic bottles are made in this way, using techniques very similar to those used for glass bottles. Molding , compression-compression transfer, casting, injection: techniques applicable to thermosetting; RIM ( Reaction Injection Molding ) (dedicated to thermosetting polyurethane resins, the reaction (crosslinking) takes place in the pan ); Pultrusion , contact molding , continuous lamination, press molding, filament winding, injection: manufacture of composite materials ; Machining with the tool; Plastic welding (for hot blade, friction, high frequency , etc.. ) Granulation ( milling parts for recycling); Greater (or densification) [recovery, by reforming, waste thin layers (films or equivalent)]; Coated media from plastic powder: fluidization , process electrostatic , powder coating , spray torch (for the latter technique, a certain matter decomposition is inevitable); Metallization : electrolytic , vacuum silver (deposit by reduction of silver nitrate ); Pre-surface treatment by corona discharge oxidant ozonizer process ( corona ) before printing . Type
Main article: Classification of polymers . A distinction is generally (not composite ) thermoplastic consumer, said convenience (excluding textile fibers); thermoplastic semi-technical and technical (non textile fibers); other thermoplastics free ipad (textile fibers); Thermoset molding; other thermosetting (paints, varnishes , adhesives, binders for plywood or for abrasive , various coatings, etc.. ) 35 . Other possible classifications: according to their origin (natural polymers, artificial and synthetic ), physico-chemical family (thermoplastics, thermosetting thermostable elastomers), their structure [linear polymers (or dimensional) and three-dimensional] 36 . Families of plastics Thermoplastics Plastic materials made of polymers with linear or branched chain are normally fuses. Thermoplastic polymers (or Polyplast, thermoformable) are deformed and are shaped under the influence of heat , keeping this form by cooling (analogous to the wax of candles ). This allows reversible recycling: the objects are ground and “Revised” to develop further. Thermoplastics are also soluble in specific solvents, allowing their use as coatings and adhesives. To fix ideas, most industrial linear polymers have molecular weights close to 10 5 g • mol -1 . A linear macromolecule can have a length that exceeds one-tenth of a micrometer, its lateral dimensions remaining thousand times lower. Synthetic textiles ( son and fiber ) are still thermoplastic. They appeared in 1940. There are currently more than forty types of synthetic textiles and more auto insurance quote than a thousand brand names to designate them. Thermosets The polymers thermoset take their final shape after the chemical reaction (polymerization) accompanying their transformation. The obtained three-dimensional network gives its character to the finished product of thermal irreversibility. The structure made with a thermosetting resin can vary and is geometrically fixed (analogy of a cooking egg ). The compound will be more three dimensional, it will be more rigid , brittle, insoluble and infusible. Example: copolymerization of polyester unsaturated in the presence of styrene. The resulting structure is ultimately the finished product is so infusible and non-convertible non-recyclable. Elastomers
The elastomers are highly deformable, they are characterized by the ability to withstand large deformations (up to about 1000% ) before rupture. The elastomeric polymers are amorphous or crystalline martial arts denver nature with remarkable properties as elasticity, damping and sealing (air, water). They are thermoplastic and thermosetting become by vulcanization . They are used typically crosslinked, and usually at a temperature above the temperature of transition glass, the rubbery plateau; use: the manufacture of gum tires [containing mainly natural rubber (NR) iPhone Unlock and copolymer of styrene-butadiene (SBR), conveyor belts , pipes, hoses , pads, rubber mountings , gaskets , sealants , medical gloves , shoes, etc.. Polymers of the three families of plastics The use of prevailing reserve the term plastic three major families of materials, thermoplastics, thermosetting plastics and techniques 14 , including the structure, physicochemical properties and implementation (behavior under the action of heat and pressure) are mining jobs totally different. Thermoplastic resins are commonly used industrially. Thermoplastics Codes ISO 1043-1 Some trade names 37 Polymers (common name) Industrial production since 38 ABS Afcoryl, Bayblend ( Alloy PC / ABS), Cycolac, Isopak, Lastilac, Lustran, Novodur, Polyflam, Polylac, Polyman, Ronfalin, Terluran, Toyolac, Ugikral, Vestodur Copolymer, acrylonitrile-butadiene-styrene (family of styrene ) year 1950 CA Cellidor A, Cellon, Plastic Containers Lumarith, Rhodialite, Rhodoïd , Setilitte, Trialithe Cellulose acetate ( cellulose ) 1927 EPS Afcolène, Depron , Hostapor, Polyfoam, Roofmate, Sagex , Styrocell, Styrodur , Styrofoam , styrofoam, Vestypor Polystyrene foam (styrene) year 1950 PA Akulon, Altech, Amilan, Bergamid, Capron, Durethan, Eratlon, Ertalon, Grilamid, Grilon, Igamid, Kevlar , Latamid, lauramide, Maranyl, Minlon, Miramid, Nomex , Nylatron, Nylon , Nypel, Orgamide, Perlon, Polyloy, Radiflam, Radilon, Renyl, Rilsan , Schulamid, Sniamid, Stanyl (PA-4, 6), Staramide, Starflam, Tactel, Technyl, Trogamid, Ultramid, Versamid, Vestamid, VYDYNE, Zytel Polyamides 39 1938 (aliphatic PA), 1961 (aromatic or aramid PA: Nomex) PBT Arnite, Celanex, Crastin, Deroton, Hostadur, Pocan, PTMT, Tenite, Ultradur, Vestodur Poly (butylene terephthalate) ( polyester saturated) 1969 PC Apec, Axxis, Durolon, Gerpalon, Latilon, Lexan , Makrolon , Panlite, Plaslube, Polyman, Sunglass, Tuffak, hcg diet plan Xantar Polycarbonates 1956 PE Alkathène, Alketh, Dyneema , Eltex, Hostalen, LACQTENE, Lupolen, Manolène, Marlex, Moplen, Plastazote , polythene Sclair, Stamylan, Stamylex, Supralen, Surlyn 40 , Tupperware , Tyvek , Vestolen A Polyethylene (poly olefin ) 1939 (LDPE), 1955 (HDPE) PET Arnite, Baydur, Bidim, Dacron , Diolen, Ektar, Ertalyte, Hostadur K and A, Kodari, Melinex, Mylar , Pocan, Radita, Rhodester, Rynite, Tenite, Tergal , Terphane, Terylene , Trevira, Ultradur Poly (ethylene terephthalate) (polyester saturated) 1946 PMMA Acrigel, Altuglas, Altulite, Bonoplex, Corian , Deglan, Limacryl, Lucite, Metacrilat, Oroglas, Perspex, Plexiglas , Resale, Vitroflex Poly (methyl methacrylate) ( acrylic ) 1933 POM Acetaver, Bergaform, Celcon, Delrin , ERTACETAL, Hostaform, Kematal, Kepital, Kocetal, Ultraform Polyformaldehyde (poly acetal ) 1958 PP Amoco, Appryl, Carlone, Eltex, Hostalen PP, Luparen, Moplen, Novolen, Oléform, Polyflam, Profax, Propathene, Prylène, Stamylan P Trovidur PP, P Vestolen Polypropylene (polyolefin) 1957 (PPi), 1992 (PPs) PS Carinex, Edistir, Empéri, Gedex, Hostyrène, Lacqrene, Luran, Lustran, Lustrex, Noryl ( alloy PPO / PS), Polyflam, polystyrene, Riviera, Styranex, Styroflex, Styron, Trolitul, Ursa, Vestyron Polystyrene (styrene) 1935 PVAC Elvacet, Hostaflex 41 , Mowilith, Rhovyl, Vinnapas, vinyon 41 Poly (vinyl acetate) ( vinyl ) 1928 PVC Benvic, Breon, Corfam, Darvic, Duraform, Dynel 42 , Garbell, Gedevyl, Hostal, Lacovyl, Lacqvil, Lucolena, Lucovyl, Lucalor, Lucoflex, Micronyl, Mipolam, Nakan, Saran 43 , Skai , Solvic, Téfanyl, Trovidur, Ultryl, Vestolit, Vinidur, Vinnol, Vinnolit, Vinoflex, Vinylite Poly (vinyl chloride) (vinyl) 1931 SAN Elvax, Lacqsan, Luran, Lustran, Restil, Vestoran Copolymer styrene – acrylonitrile (styrene) year 1950 Thermosetting ISO 1043-1 Codes Some trade names Polymers Industrial production since 38 EP Araldite , Devcon, DER, Doroxin, Epikote, Epon, EPOTEK , Epotuf, Epoxin, Eurepox, Lekutherm, Lopox, Rutapox Polyepoxides 1946 MF Formica, formica , Hostaset MF, Melochem, melops Melamine – formaldehyde ( amino ) year 1920 PF Bakelite , Cascophen, canvas bakélisée (Celoron), laminated paper, wood, Bakelite, Fluosite, Hostaset PF Luphen, Micarta, Peracite, Trolitan, Tufnol Phenol – formaldehyde ( phenolic ) 1910 PUR Baydur, Bayflex, Baygal, Cyanapren, Daltoflex, Definal, Desmodur, Desmolin, Estolan, Lupranate, Lupranol, Luvipren, Moltopren, Napiol, Scurane, Urepan, Voranol, Vulkolian, Vulkollan Polyurethanes crosslinked 1940 UF Aerodux, Beckamin, Cascamite, Hostaset UF pollop, Prystal, Urochem Urea – formaldehyde (amino) 1923 UP Hostaset UP, Leguval, Palatal, Pregmat, Ukapon, Vestopol Polyester unsaturated 1950 Engineering plastics ISO 1043-1 Codes Some trade names Polymers Industrial production since PTFE Algoflon, Ertaflon, Fluon, Gaflon, Halon, Hostaflon, Polyflon, Soreflon, Teflon , Voltalef Polytetrafluoroethylene ( fluorine ) 1942 The polyimides , the polytetrafluoroethylene and silicones can be classified as heat-stable 44 or engineering polymers. Economy
The economic importance of plastics prevails in industrial chemistry. Their discovery is such that their current consumption volume is higher than that of metals. Production With a world production of about 54 million tonnes in 2001, polyethylene [(-CH 2 -) n ] is the synthetic polymer used as 45 . The most common are then polyvinyl chloride [(-CH 2 -CH (Cl) -) n ], polypropylene [(-CH 2 -CH (CH 3 ) -) n ], polyethylene terephthalate (PET), polystyrene, polyamides and acrylics. PET and poly (bisphenol A carbonate) (PC, engineering thermoplastic) are booming since the 1990s. The total production of PET was around 18 million tonnes in 2001. Consumption The largest consumption markets affect building , the packaging and the electricity – electronics . Per capita consumption was 92 kg in Western Europe in 2000. Bioplastics
The market for biobased polymers [polymers for which a portion of the raw materials come from renewable resources (especially the corn , the wheat , the eucalyptus and potato )] has expanded significantly over the past ten years. The bioplastics market contain between 30 and 100% renewable resources. The use of biomass renewable mitigates global warming by reducing emissions of greenhouse gases ( CO 2 ). Bioplastics on the market are 20 to 30% more expensive than the original plastic petrochemicals . However, the increase from “renewable resources” associated with increased production volumes will lead to an offer economically attractive. These materials are often made of starch (polymer abundant, inexpensive and easily transformable) and fiber (natural) of wood, flax, hemp , of sisal or jute . Bioplastics are confined to limited uses, primarily in the packaging (eg, replacing PET ), which concentrates 90% of the activity 46 . Environment
In addition to being the source of a high consumption of oil and emission of greenhouse gases , plastics problematic environment when they are not subject to screening and to a recycling treated, especially when they contain chlorine (eg PVC ) and heavy metal toxicity such as lead or cadmium . Here it is accumulating bottles in the bushes of the desert of Sinai . Ecological balance If ecobalances bottles wedding ring and many items are still being debated, some impacts are recognized. Production phase The fossil fuel (oil) used to manufacture plastics are major sources of greenhouse gas emissions . Many additives toxic ( lead , cadmium in particular) were used for the manufacture of certain common plastics such as PVC. Directive 2000/53/EC of the European Union now forbids the use (lead, cadmium, mercury , chromium VI). Use phase Of chemicals , especially present in Wire Cart Covers the plastic, would be “at the forefront of the accused” in the fall of the quality of sperm (reduced by 50% since 1950) and diseases related to the reproductive system through endocrine disruptors . On November 25, 2008, the French Government (through the IRESP , research structure created by the INSERM and 20 partners, and the AFSSA ) organized a symposium on the theme “ Chemical environment, reproduction and development of child “. The main compounds implicated are phthalates and bisphenol A (BPA) 47 , two substances found in some plastics. Among the most casino controversial figure additive bisphenol A, a strong presence in plastics including food and bottles of 90% in 2008. BPA is a suspected endocrine disruptor. The American Medical Association published a study in October
2008 concluded that electronic cigarette an increase in the concentration of BPA in the urine of 39% increased risk of diabetes and cardiovascular disease . In Canada, all baby bottles containing BPA have been withdrawn from the market, under the precautionary principle . In Europe, the EFSA considers that the doses of BPA absorbed by the babies are too small to be dangerous . Some manufacturers of baby bottles (Dodie, Advent Group Philips ) decided in 2008 to manufacture BPA Free Bottles sold but more expensive 48 . The emanation (release) of certain plastics in the urban habitat is known 49 . Stage “waste”
Plastic waste ingested by an albatross, probably caused his death Plastics, unlike the natural polymers are not degradable and poorly biodegraded . Among the final products of degradation, some of their additives are endocrine disruptors , and other ( heavy metals , dyes, or stabilizers) are toxic and not biodegradable. In the 1980s, it was found that millions of tiny fragments of plastic were present even in the Southern Ocean , well south of the Antarctic convergence in the Ross Sea 50 . It has been found in all seas. It is unclear what environmental impacts they may have medium to long term, especially when they break down into small particles. Plastics become floating marine debris , which, even in remote areas (more than 2000 nautical miles from the nearest continent for the Midway Islands ), killing of protected species and threatened species. The plastic bags eaten by turtles who mistake them for jellyfish are only examples. Another problem is that many albatrosses die, the gizzard and stomach full of dozens of toys and plastic objects, which they ingested at sea or their parents have brought to the nest. These objects are made by parents to their chicks as if they were food (they were covered with eggs and edible marine organisms) and unlike bone or bones swallowed by birds, they can not be dissolved by the digestive juices of any animal, nor out of the stomach of chicks or adults who end up dying. The albatross chicks are so many to die of starvation after eating sometimes dozens of plastic items ( caps , pieces of pens , gadgets and other children’s toys, debris containers, etc.. ) 51 . According to a study published in 2011 by the Institute of Oceanography in San Diego (California), in 2009 there were server monitoring pieces of plastic ingested a fish out of 10 in the North Pacific, and fish living in the average depths by ingesting 24 000 t / year about 52 . On the north shore of the Mediterranean , off the major cities, solid waste, consisting of 75% plastic, infect the seabed. The sea turtle , an endangered species for the IUCN , choking with plastic bags it takes for jellyfish 53 . The combustion of most plastics releases many pollutants and toxic, especially when it comes to PVC ( organochlorines including dioxins and furans , as well as heavy metals, such additives anti- UV and dye ) [ref. needed] . See also the article “ Garbage Patch North Pacific . ” Recycling
Principle of recycling: thermoplastic materials, unlike thermosets or elastomers, can be recovered, crushed and processed for reuse (here in China ). The recycling is a process of treating materials that can reintroduce in the production cycle of a product, the materials which compose 54 . The issue regarding the recycling of polymers is mainly engagement rings due to the fact that they are rarely used alone. To facilitate editing, industrial processes often use plasticizers and fillers. However, new methods to recycle the polymers end of life. Because of their high calorific value, they allow for incineration to obtain energy recovery (electricity or heat for industrial or domestic). One can also proceed by: treatment mechanics (washing, sorting, grinding , separation); thermo-chemical treatment ( solvolysis , pyrolysis , chemical reaction). Most of the product packaging of everyday life are made of plastic. Many of the polymer processing steps are required for this. Each operation adds value to the product. The trend is that the cost of recycling increases dramatically if you want a Nutrisystem Coupons material of high purity. To assist recycling of disposable items, the Society of the plastics industry in 1988 has developed a marking system for each type of plastic, resin identification code . Using this system packaging is marked with a triangle arrowhead, within which is a number indicating the type of plastic: Resin Identification Code thermoplastic PET or PETE: Polyethylene terephthalate : usually used for bottles of mineral water, soft drinks and fruit juices, packaging, blisters , padding. Potentially unsafe for food use 55 ; HDPE or HDPE: high density polyethylene : some bottles, and more generally semi-rigid packaging. Considered safe for food use; PVC or V: Polyvinyl chloride : used for pipes, tubes, furniture , garden, flooring, window profiles, shutters, detergent bottles, oilcloth. Potentially unsafe for food use (may contain dioxin, bisphenol A, mercury, cadmium); LDPE or LDPE: low density polyethylene : tarps, garbage bags , bags, films, flexible containers. Considered safe for food use; PP: Polypropylene : used in industrial motor (equipment, bumpers ), toys, and food industry (packaging). Considered safe for food use; PS: Polystyrene : plates of thermal insulation for buildings , food containers (Styrofoam) disposable cups and cutlery, CD cases, packaging (foam and films), toys, kitchen utensils , pens, etc.. Potentially dangerous, especially In combustion (contains styrene); Or O OTHER: any plastic other than those named 1 to 6. Includes, for example, polycarbonate-based plastics, polycarbonates of bisphenol A are potentially toxic
Plastic Model Jump to: navigation , search
This article is an outline on Thurs . You can share your knowledge by improving it ( how? ) as recommended by the related projects . The plastic model is a model most often presented as a kit to assemble and decorate yourself. It is usually produced by injection molding of polystyrene , or thermoforming resin. It often includes items made from other materials such as rubber or metal used for the photoetched details difficult to reproduce molded plastic. Summary [ hide ] 1 History 2 Scales 3 Techniques 4 Brands History
It was after World War II, when the base material became aware that the idea was launched by Airfix (established 1948 ), a company British mold. Its first model kit was a tractor Massey Ferguson . Following the success of this type of product, it produces small-scale boats and the first kit plane in 1953 : the Spitfire Supermarine Mk.1, scale 1 / 72. This is a huge success which will give rise to competition immediately. The scale will be adopted as a standard for this type of model. Companies such as Revell, Monogram , Italeri and Faller appeared at that time.
“Cluster” parts of an aircraft kit In France, Heller , founded in 1955 who proposed in 1957 his first kit: the Caravelle scale 1 / 100. In the year 1970 , Japanese firms appear as Hasegawa and Tamiya occupying mainly the market today. Firms in Eastern Europe, Russia and China have emerged more recently. Scales
Many of the scales is composed of multiples of 12 to facilitate the conversion of measurements from imperial Anglo-Saxon foot is composed of 12 inches, themselves divisible by 12, resulting in a very simple calculation scales as 1 / 12, the 1 / 24, 1 / 48, 1 / 72, and so on. Scales tend to unify different types of models: Aircraft: 1 / 24, 1 / 32, 1 / 48, 1 / 72 and 1 / 144 being the most common, that of 1 / 400 are reserved for large multi-engine models; Military vehicles: 1 / 35, 1 / 48, 1 / 72, 1 / 76; Auto: 1 / 12, 1 / 20, 1 / 24, 1 / 25, 1 / 32, 1 / 43; Motorcycles: 1 / 6, 1 / 9, mainly 1 / 12 and sometimes 1 / 24; Boat: 1 / 96, 1 / 350, 1 / 450, 1 / 700. Trains: usually 1 / 87 ( HO scale ), and 1 / 64 (S scale). The static model trains are quite rare, the firm Revell has produced few, some firms offer craft kits running gear to climb, most often cars and cars ( Meridian Models (UK), PBL (United States) …). The scenery for model railways (stations, houses …): 1 / 87 (H0), 1 / 160 (N), 1 / 220 (Z). Trucks: mainly 1 / 24 and sometimes 1 / 43 (Heller) Techniques
Various techniques are used by designers to mimic the reality of the model: the airbrush, the drybrush, juices, pastels. These techniques are often used to simulate wear, soiling, damage or rust on a model. Brands
This article or section contains one or more lists . The latter would benefit from being written in paragraph form synthetic. Many brands still active, or no longer exist, have marked the history of model building (kits to mount): Aber (Photodécoupe) Academy Accurate Miniatures Airfix Amt Aoshima Dexter Dragon Eduard (Photodécoupe) Eduard (Model) EMHAR Frog (English brand no longer exists) Fujimi Gunze Sangyo Hasegawa Hobby Boss Heller ICM Imex Italeri Legend Production (detailing set in resin) Lindberg denver injury lawyer Lion Roar Matchbox (English brand no longer exists) Monogram MR Hobby Pegasus Protar (Italian brand no longer exists) Poach (Italian brand no longer exists) Revell Skif Smer Tamiya model Tasca Trumpeter Verlinden Voyager (Photodécoupe) Zvezda Plastic bag Jump to: navigation , search
Plastic bags
Use in Industry The plastic bag is a blend of plastic sheeting which is open at one end to accommodate content. The most common is the shopping bag , bag offered, sold or loaned by the shops to their customers to facilitate the transport of their purchases . There is also a garbage bag , the vacuum bag , the Publisac and even airbags , which are plastic bags. The plastic bag is, in 2010, consisting mostly of polyethylene original oil , but alternatives biosourcées develop. Summary [ hide ] 1 Manufacturing 2 Evolution 3 Challenge 4 Alternatives 4.1 The oxo-biodegradable polyethylene 4.2 The green polyethylene 4.3 The Néosac 4.4 Corn starch 4.5 The PHA biopolymers 5 Regionalism 6 electronic cigarette review Collection 7 Notes and references 8 Appendices 8.1 Related 8.2 External Links Manufacturing
Extrusion-blowing (high density): vertical cylindrical bubble in the production of bags pastiche Plastic bags are produced by the process of extrusion-blowing . We extrude a parison thin wall which is then inflated with air pressure, it thus forms a continuous flow sheath inflated a plastic film, cooled, will be wound and then be printed and heat sealed at one end. The most common bag, called the “bag strap,” a cost of about 1 euro cent piece. Evolution
Until the 1960s, everyone was shopping with her bags . In the 2000s, after decades of generosity, most supermarkets gradually accustom their customers to do without free bags or reduce their consumption. This allows retailers to save money, develop good communication on the environmental theme and to avoid the introduction of restrictive government measures such as tax as determined in Ireland. It should however be noted that, as in Ireland, supermarkets sell more garbage bags since many shopping bags were playing this role. Dispute
Symbol contained in a plastic bag to prevent choking Their widespread use by supermarkets has led some areas such as Corsica to take action against plastic bags because, abandoned in the wild, they disfigured the landscape . Similarly, in Mayotte , the single-use plastic bags have been banned since 1 January 2006 by the prefecture. In December 2005 , a law passed two by the French National Assembly attaches to an st January 2010 the date on which all non-plastic bags biodegradable shall be prohibited. However, in December 2006, the European Commission believes that this text does not comply with Directive 94/62/EC, which requires a How to lose weight recovery of waste from packaging without imposing composting. Also in 2010, non-biodegradable plastic bags are still available to fund the major supermarkets in metropolitan France. In France each year 15 billion bags are distributed out of cash in stores, or about 500 bags per second and 83,000 tons of waste for disposal. 150 million of these bags (one bag per cent) end up on the French coast and are the cause of death of some animals that choke trying to eat them, especially turtles and marine mammals who mistake them for jellyfish and cephalopods ( squid , for example). For example, in 2002, an autopsy by the GECC 3 of a minke whale found stranded in Lestre showed that its stomach contained about twenty plastic bags, an area of 3.95 m² on the ground once spread 4 . A shopping bag is made of 1 second , has an average use of 20 minutes and put 400 years to decompose in nature [ref. needed] . According to Hugo Verlomme 5 : “[...] contrary to what one might think they [plastic bags of cash] represent only 1.4% of 5.6 million tonnes of plastic consumed in France. ” Even if the entire world production of plastics uses in all in all only 4% of annual consumption of oil, plastic bags come from many of petroleum , non-renewable resource whose production is brought to stagnate or even decrease in the coming decades 6 . Alternatives
The oxo-biodegradable polyethylene There are many words to characterize degradable plastics “degradable,” “totally degradable” and “oxo-biodegradable”. All these terms are similar and incorporate technology similar to that used by the EP additive. Biobased plastics are not necessarily biodegradable and biodegradable plastic can be of petrochemicals . The common characteristic is a primary degradation based on oxidation, accelerated by the combined action of light, heat, mechanical stress and oxygen. Other terminologies are “biodegradable” and “hydro-biodegradable.” These terms define the modes of degradation based on the presence of a biologically active environment, such as compost, where the destruction and consumption of the material are based on microbial activity. Oxo-biodegradable products are broken down in most environments including biodegradable products. The reverse is, for against, not necessarily true. The polyethylene (PE) is naturally biodegradable. Agent degrading pro is introduced into the mixture at the time of manufacture. This will change the behavior of the plastic film to make oxo-biodegradable. By promoting chemically break down the molecular chains hydrocarbon component material, it becomes oxidized by air, heat, and biodegradable and bioavailable. In case of withdrawal in the wild, after 14 to 16 months (the duration is programmable) depending on weather conditions, it becomes fragmented, fragile, it loses its mechanical properties and ceases to be a polymer, it becomes hydrophilic and biodegradable, that is to say assimilated by the microorganisms in the soil until its total disappearance. This phenomenon, called oxo biodegradation begins manufacturing and is irreversible. It leads to a total degradation of the additive product at the end of the programmed period of use, leaving only water, CO 2 and biomass. The additives used in the composition of the plastic films were tested by different laboratories stringent European specialist in their field to ensure the absence of harmful effects on the environment. Some additives are products suitable for food contact (EU and United States) 7 and biodegradation tests performed according to standard EN 13432 guarantee its complete disappearance. Biodegradation, often questioning, is now proven by numerous publications and was determined according to the protocols provided by the ISO. However, these films, the lower CO 2 during biodegradation, are not certified to date by the standard EN 13432 . However, these films are compostable because they contain heat-inducing can meet the tests of disintegration under compost standards by ensuring high quality compost. The green polyethylene In June 2007 , the Brazilian company Braskem announced Bankruptcy the certification STD Test of a polyethylene “green” synthesized from of ethanol derived from sugar cane . The analysis of the life cycle of this material remains low, but the efforts of ski accessories researchers are continuing. The Néosac The Néosac, invention of French origin, is a bag polyethylene additive which is, according to its promoters, biodegradable . It has the same strength as the classic bag but its chemical composition would make it “biodegradable” because it breaks up into pieces of smaller and smaller until it disappears after about three months. Environmentalists question the real biodegradability of the new polyethylene additive and criticize the Néosac to leave in the nature of the plastic particles, may be invisible, but potentially harmful. While the bio-uptake of the particles of polyethylene (PE) is recognized as possible, that is to say that it is possible that this polymer is divided into fragments small enough to pass the membranes of micro-organisms in soil or water, provided there is no study indicating the safety of polyethylene in an accumulation in the food chain. However the current tests do not suggest otherwise. The argument of the proponents of Néosac is that it acquires its biodegradability by oxo-degradation. The oxo-degradation is a process of fragmentation under the influence of heat and light, that the addition of additives in the PE to speed and control (1 year in normal use, a few months in country temperate in the environment) in the case of Néosac. The second issue raised by environmentalists is the potential harmful effects of additives included in the Néosac as the previous generation of EP additive, used for agricultural mulching, used as additives to promote the fragmentation of dithiocarbamates, which are now banned. There are to date four metal salts capable of inducing oxo biodegradation normally found in nature, plants, and fish. In addition, the use of the neologism “biofragmentation” (which is not due to the association Néosac but the press) to discuss the oxo biodegradation is misleading: this is the biofragmentation including the products of plant resources. One is chemical, the other is made by hydrolysis . Corn starch An invention original Italian can make bags with Judaica Bat Mitzvah Gifts a combination of the starch of corn and aromatic aliphatic polyester derived from oil. The manufacturing process and production machines are the same as polyethylene, except that the raw material is replaced by pellets made from corn starch. This is guaranteed, according to the manufacturers, non-GMO, which is unverifiable for imported products. The bags products like plastic ones but have different mechanical strength. They are indeed sensitive to moisture and therefore unfit for transport of water overloaded. Manufacture biscuit smell. These bags are part of the original plant (~ 30%) and partially from oil (~ 70%). The share of petroleum origin is necessary to the flexibility of the product, it is absent from the rigid type container products. The bags are fully biodegradable in a few months, but generate strong eutrophication of water ( microalgae green that kill wildlife). On the other hand, the current manufacturing cost is three times that of polyethylene. The Mater-Bi , trade name granules copolymer based on corn starch, can also manufacture most plastic products currently. There are also processes involving other grains or starch potatoes . Relevant Life Policy The PHA biopolymers This section is empty, insufficiently detailed payday loan or incomplete. Your help is welcome! The biopolymers PHA are made from micro-organisms, and they therefore have the advantage of not being made from oil 8 . Bags made of biopolymers PHA, designed by Italian scientists of Science and Technology Park of Sicily, were presented in 2010 at the World Exhibition in Shanghai 9 . Regionalism
Often referred to as “pocket” the plastic bag, in the regions of southern France and “pouch” in Britain or New Caledonia . In Franche-Comte , in Lorraine and in western Switzerland , we speak of “Cornet” or possibly “plastic cone.” Also referred to as “exchange” in Roussillon, Bearn or “nylon” in Marseille . Collection
The Association of collectors of plastic bags advertising (ACSPP) assembled a collection of unique advertising 24 000 plastic bags (SPP) to keep this object. Its founder started the collection in 1984, is formalized in the Guinness Book of Records in 2001. As a guarantee of continuity, he created the association “ACSPP” in 2002 in Toulon. A collector is a plastic bag saccuplastikophile . The ACSPP organized in 2009 in Toulon, a conference on “The plastic bag advertising, guilty or victim? ” 10 . On this occasion, a White Paper 11 was published on the blog 12 . To create another form of collection, the artist Claude Picard-Briand performs works from plastic bags, advertising bags and routing 13 . Another artist, Caroline Avias 14 , passionate pink, composed several works with over a thousand plastic bags as “The Pink Room” presented in 2010 at Chateau de la Roche-Jagu .
Plastic bottle Jump to: navigation , search A plastic bottle is a container for containing, protecting and transporting liquids. The plastic offers great convenience of preparation (manufacture of bottles in the bottling plant, no transport of empty bottle as for glass) and weighing up to ten times less than glass, reducing enormous release of CO 2 in the transport of liquids. The first plastic bottles appeared in the year 1960 , they were PVC and used for food and household goods. They are made by the process of blow molding . Summary [ hide ] 1 Polymers used 1.1 The PVC 1.2 HDPE 1.3 The PET 1.4 The PC 1.5 The PP 1.6 The PLA 2 Economy 3 Alternatives to plastic bottles 4 References 5 Appendices Polymers used
PVC
PVC or polyvinyl chloride , in its rigid (unplasticized) was used since the late 1960s until the 1990s, but the chlorine radical is transformed during combustion into hydrochloric acid. These vapors are toxic and, because of the low flue-gas incineration of the time, were the cause of acid rain have damaged some forests. PVC has been replaced by the PET bottles for drinking water. Do not confuse the rigid PVC bottles with PVC which is capable of releasing elements plasticizers that have been added: the phthalates , but since the 1990s, even Italy has abandoned phthalates in food contact materials, as classified as carcinogenic potential ; DEHA or adipate, bis (2-ethylhexyl) phthalate (in) or DOA (di-octyl adipate) which is much less dangerous than the DOP (di-octyl phthalate); the bisphenol A (BPA) that can be a residue of developing certain plasticizers. HDPE
HDPE, or HDPE, high density polyethylene : semi-rigid bottles, opaque bottles used for milk and bottles of liquids to maintain. PET
PET, or polyethylene terephthalate , also abbreviated PETE, is the most widely used material for bottles of sparkling water. Appeared in 1992, PET has replaced PVC in the late 1990s, for bottles of water , reducing by one third the weight of the bottles (30 g for a bottle of 1.5 liter PET, against 50 g for PVC bottle of the same capacity). PET is sufficient gas barrier for packaging carbonated water. PET bottles are produced by hot forming of a preform. This is achieved by injection. PET bottles may leach traces of antimony trioxide , used as a catalyst in the polymerization of HDPE . However, the maximum values measured are in the range of 0.5 mg / l, ten times less than web hosting reviews the European standard which is 5 mg / l of antimony 1 . The PC The PC or polycarbonate is, unlike the foregoing materials, like glass sterilizable. This quality as its price intend to use reusable bottles. This is the material of choice for baby bottles . For packaging of milk, it is found in Germany and Austria, the bottles are then recorded. They are absolutely unbreakable, which is very popular in supermarkets (less risk, less waste). Note, however, the presumption of toxicity of BPA, a component of polycarbonate, residue of the polymerization. See “Risk of Plastic BPA” in the article on the bottle. The PP The PP or polypropylene , is emerging in the development of the bottles. The PLA PLA or polylactic acid is advertised as the answer to the invasion of green PET bottles. Some pay day loans brands ( Biota Brands in the United States, bankrupt or Vegetal & Mineral Water Champagne) opted for the compostable material. But composting, which effectively reduces the volume of waste landfilled or incinerated, is sometimes considered ill-suited. The bottles that are beyond the composting may disturb the recycling of failing to distinguish PET, this distinction would require investments in existing technologies from the recycling industry. Biodegradation of a Bioplastic anaerobic generates methane , a powerful greenhouse gas emissions (almost 23 times more than CO 2 ), it is necessary to compare this record (produced with plastic plants and composted) with that of plastic produced with fossil fuels and then buried or incinerated. An alternative end of life products in PLA is the recycling process Loopla society Galactic and is used to reprocess the materials based on PLA into lactic acid by removing the other components, this system is of course particularly suited to collection specific, for example at major events where only PLA bottles and cups are used. It is a chemical recycling process. Economy
World production in 2008 reached about 200 billion PET bottles, 75% are not recycled 2 . However, countries like Switzerland are hovering around 100% recycled plastic bottles. France is around 45%, the rate rose steadily. Recycling “PET bottle” PET allows the manufacture of fiber (the “polyester”) for duvets and anoraks. Since 2009, some processes are approved by EU to re-beverage bottles from used bottles. Alternatives to plastic bottles
Glass bottles The jug water filters and the tap water References
↑ The antimony, a toxic old still unknown [ archive ] , atctoxicologie ↑ Bottled Water: Pouring Resources Down the Drain [ archive ] , Earth Policy Institute Appendices
Comparison Bottled water Reuse of water bottles Baby bottle Waste Eco-Packaging Composting Recycling Drinking water in France Regional Observatory waste Ile-de-France
Plastic granulate Jump to: navigation , search
Plastic granules
Compounding: Example of pellet production from formulat ( polymer formulated) homogeneous, using a mixer-extruder, a single screw extruder and a cutter 1
The injection molding uses granules (in polypropylene 2 for this simplified example) placed in the hopper feed. A material made of plastic granules contain at least one product thermoplastic and is in the form of small grains . It is a semifinished often used in plastics , especially for processes of extrusion and to injection , this form is very convenient to store, manipulate, and well suited to process (easy filling machines and mixing facility). The implementation of a plastic material often used granulated plastic 3 . It involves several steps, described below. Production of pellets: synthesis of the resin , usually by polymerizing 4 and formulation (addition of substances such as loading , plasticizer and additive in proportions defined); Compounding 5 : Formatting formulat (appearing eg in the form of tubes at output of mixer) by extrusion through a die with circular holes, then cut the cords cooling and drying to produce granules of a few millimeters in diameter . Use of pellets by the processor: delivery: the granules may be packaged in bulk in plastic bags of 25 kg, in big bags or containers into cardboard hex (with lid) over one cubic meter of capacity, placed on pallet . For large quantities, automatic feeding machine is from a silo ; pellets hygroscopic [ PA , ABS , polybutylene terephthalate (PBT), PMMA , etc..] undergo a pre- drying before formatting to prevent defects related to the moisture on the plastic parts; hot forming (the material is melted again) and under pressure to get the finished product (the object). A plastic recyclable can undergo a crushing and then be remelted and reused. Summary [ hide ] 1 Environment 2 Notes 3 Annexes 3.1 Related Environment
A significant amount, but unknown, granules is found dumped in the environment, and forms small plastic pellets called mermaid tears . Indestructible, these residues are present plastic on the beaches of all the seven seas. Taken up by fish and sea birds, they are a threat to the environment. The origin of these granules is not well known: spills or industrial plastic granules ultimate state of fragmentation of plastic products released into the marine environment. Notes
↑ The connection between the mixer-extruder and cna certification the extruder is actually discontinuous (the formulat from the mixer is stored until a future use). The granules are dried after harvest, before storage. ↑ For this polymer, the injection pressure is between 1000 and 1500 bar . ↑ According to the process of transformation, of powders , pellets , preforms , preforms, sheets, pastes , liquid or prepreg can be used. ↑ For chemical modification in the case of a synthetic resin, eg cellulose acetate . ↑ In English, compounding . The compound is produced by the polymer or by the compounder.
