Products

Plastic Polymers.

Chemically, plastics are generally the result of the polymerization of a quantity of basic molecules (monomers) to form even very long chains. We speak of homopolymers if the monomer is unique, copolymers if the polymer is obtained from two or more different monomers, and of polymer alloys if the material is the result of the mixing of two monomers that polymerize without chemically combining. Various substances (called "fillers") are then added to this polymeric base depending on the application to which the plastic material is intended. These substances can be plasticizers, dyes, antioxidants, lubricants and other special components capable of giving the finished plastic material the desired properties of workability, appearance and resistance. The advantageous characteristics of plastics compared to metallic and non-metallic materials are the great ease of processing, cost-effectiveness, colorability, acoustic, thermal, electrical, mechanical (vibration) insulation, resistance to corrosion and chemical inertia. , as well as water repellency and resistance to attack by molds, fungi and bacteria. THERMOPLASTICS Thermoplastics are those plastic materials that acquire malleability, that is, soften, under the action of heat. In this phase they can be modeled or formed into finished objects and therefore, upon cooling, they become rigid again. This process, theoretically, can be repeated several times according to the qualities of the different plastics. ACRYLONITRILE-BUTADIENE-STYRENE - ABS Obtained by copolymerization of acrylonitrile, butadiene and styrene. Used for the production of particularly impact-resistant products such as suitcases, small and large household appliances, chassis for electrical / electronic equipment, telephones, accessories in the automotive sector. It is also mixed with PVC POLYACETALS - POM Obtained by polymerization of formic aldehyde. Mainly used in the production of fine mechanics. POLYAMIDES - PA Obtained from the reaction between diamines and dibasic acids or between lactams and amino acids. Used for the production of synthetic fibers (nylon), for molding masses in the mechanical industry, in the production of films for flexible packaging of food products. POLYBUTYLENTEREPHTHALATE - PBT Obtained by condensation of terephthalic acid with butylene glycol. It is used in mechanical and electrotechnical constructions, reinforced with glass fibers. POLYCARBONATE - PC Obtained by the reaction of bisphenol and phosgene. Used for transparent artifacts, protective helmets, car components. POLYPHENYLENOXIDE - PPO It is an aromatic polyether polycondensation polymer of 2,6 methylphenol. Withstands an operating temperature of 175 ° C and retains its mechanical characteristics between –40 and + 120 ° C. Used in a series of technical sectors where high mechanical characteristics at high temperatures are required: electrical, electronic, medical, transport, household appliances, industrial. POLYETHYLENE or POLYTHENE - PE Discovered by Gibson and Fawcett in 1935 and obtained by polymerization of ethylene. By differentiating the polymerization process it is possible to obtain: LDPE (low density PE) for the production of films, household goods, toys, containers, pipes; LLDPE (linear low density PE) for film production; HDPE (high density PE) for the production of industrial crates and caissons, bottles, containers for liquids, fuel tanks and pipes for the transport of gas and water under pressure. POLYPHENYLENESULFIDE - PPS Obtained by treating paradichloro- benzene with sodium sulphide in the presence of solvents. Withstands temperatures of 190 ° C continuously, with peaks of 230/260 ° C. It is characterized by high chemical inertness and stiffness. Used in numerous technical applications in the electrical, electronic, photographic, aeronautical, mechanical fields and in the manufacture of particular household appliances. POLYETHYLENTEREPHTHALATE - PET Obtained by condensation of terephthalic acid with ethylene glycol. Used for the production of containers for liquids, supports for photographic films, carpets, multilayer bags for precooked foods, tapes for audio and video cassettes. POLYISOBUTYLENE - PIB Polyisobutylene is a saturated thermoplastic polymer. It is characterized by excellent dielectric properties. It is resistant to acids, bases and is insoluble in alcohols, ketones and ethers. Oily grades are used in the adhesives industry, as capacitor and transformer oil and as a viscosity regulator in motor oils. Semi-solid types are used as waterproofing of fabric substrates. PIB plates serve as tank linings. POLYVINYLIDENCLORIDE - PVDC Obtained by polymerization of polyvinylidene chloride (vinylidene polychloride). It is mainly used in the form of a solution and an aqueous emulsion for the vapor barrier coating of water, gas and aromas, of packaging films of various compositions. POLYMETHYL METHACRYLATE - PMMA Obtained by polymerization of methacrylic acid. It is used for the production of transparent sheets, roofing sheets, luminous signs and for optical equipment. POLYVINYLIDENCLORIDE CHLORINATED - CPVDC Obtained by chlorination of polyvinyl chloride. It is characterized by a heat resistance higher than that of PVC by about 30 ° C. Used in the production of plates, pipes, fittings, pump parts and other technical items. It is also used in the textile and adhesive sectors. POLYPROPYLENE - PP Obtained by polymerization of propylene. Used for the production of car components, pipes, furniture, housewares, packaging films, thermo- hydraulic pipes for heating systems. POLYVINYLIDENFLUORIDE - PVDF Obtained by polymerization of vinylidene fluoride, it is characterized by a high chemical inertness accompanied by excellent qualities of rigidity and heat resistance. It is used in the chemical industry with operating temperatures up to 120 ° C. Due to its piezoelectric characteristics it finds application in the electrical and electronic sectors. POLYSULPHONES - PSU Obtained by reaction between diphenyl ethers and diphenyl sulfones. Used for equipment that must undergo treatments at temperatures above 150/180 ° C, up to 250 ° C for a particular type. POLYSTYRENE or POLYSTYRENE - PS Obtained from the polymerization of styrene. In the crystal or shockproof versions it is widely used in the production of packaging, items for domestic use, large and small appliances, toys, consumer electronics. EXPANDED POLYSTYRENE - EPS Obtained from the polymerization of styrene in the presence of a blowing agent. Once expanded, it appears as a very light material, mainly used in packaging, in the insulation and lightening of structures in construction, in the production of inner shells for protective helmets. ACRYLONITRILE TERPOLYMER - STYRENE - ACRYLIC ESTER - ASA Obtained by polymerization and grafting: an acrylic elastomer dissolved in styrene and acrylonitrile is polymerized in the presence of peroxides. Used for the production of street lamps, signs, license plates, garden furniture, bicycle and motorcycle parts and small household appliances. POLYVINYL ACETATES - PVA Obtained by polymerization of vinyl acetate. Used for the production of adhesives, water paints and inks. TERPOLYMER METHYL METHACRYLATE BUTADIENE STYRENE - MBS Obtained by polymerization and grafting of methyl methacrylate, on the butadiene styrene copolymer or polybutadiene and styrene in the presence of catalysts. Used in the production of toys, refrigerator parts, pens, batteries, technical and decorative items, sports items. Polyvinyl chloride - PVC Obtained by polymerization of vinyl chloride. Produced industrially since 1930, PVC, thanks to its versatility, its resistance to wear, to chemical and atmospheric agents and to fire, lends itself to the most varied applications in the building and construction sectors (pipes, window profiles), packaging. food and pharmaceutical (food trays, blister packs, etc.) cables, transport, sports and leisure, furniture, clothing, household items and medical products (blood plasma bags, oxygen tents, etc.) CELLULOSE ACETATE - CA Obtained by reaction of cellulose with acetic anhydride in the presence of solvents and catalysts. Characterized by a shiny appearance, high transparency and pleasant touch. It is used in a variety of products for many consumer sectors: from combs to spectacle frames, from faceplates for helmets to keys for typewriters, from transparent boxes to toothbrushes. STYRENE-ACRYLONITRILE COPOLYMER - SAN Obtained by copolymerization of styrene and acrylonitrile. It is used in numerous technical applications in various sectors, from housewares to road transport, from packaging to plates, from small appliances to cosmetics, from stationery to electronics. ETHYLENVINYL ACETATE - EVA Obtained by co-polymerization of ethylene with vinyl acetate. The characteristics vary according to the vinyl acetate content. It is generally used in the production of coextruded films, in the electrical and medical fields, in the footwear and toy sectors. THERMOSETS They are a group of plastic materials which, after an initial softening phase due to heating, harden due to the three- dimensional cross-linking effect; in the softening phase due to the combined effect of heat and pressure they are formable. If these materials are heated after hardening they no longer soften, but they decompose and carbonize. The heat, therefore, irreversibly changes their chemical structure and therefore they can no longer be softened. UNSATURATED POLYESTERS - UP Unsaturated polyester resins are obtained by esterification of a mixture of a saturated dibasic acid and an aliphatic acid with aliphatic glycols. They are implemented using various application technologies. Buttons, buckles, electrical parts, tiles, fake marble slabs are produced by casting. By molding prepolymerized resin with fillers and fiberglass products are obtained for the electrical, electronic and chemical industries. Corrugated flat sheets used in construction are also manufactured. An important sector is that of the nautical sector, where polyester resins are used in the manufacture of hulls and entire boats. They also find application in the transport sector, large containers and in a variety of applications ranging from aircraft and helicopter parts to radar displays, sporting goods, etc. POLYURETHANES - PU Obtained by reaction between divisocyanates and polyols. There are different compositions depending on the final application. Used in the manufacture of imitation leather, shoe soles and heels, films for electrical insulation, articles for sports, for technical use and in the medical sector. ALCOHID RESINS Obtained by esterification of triols (glycerin) and saturated and unsaturated dicarboxy acids. They may also contain vinyl monomers. Used in the paints and varnishes sector, as molding resins, and also where electrical characteristics, mechanical resistance, heat and flame resistance are required. The fields of application are RTV equipment, electrical parts of internal combustion engines and electric motors. ALLYL RESINS - DAP Obtained by esterification of unsaturated allyl alcohol with phthalic acids. Used as molding compounds for the impregnation of fabrics or glass fibers. Electrical insulators, technical items for computers, printed circuits, parts for avionics and aerospace, reinforced plates, pipes, missile parts are manufactured. EPOXY RESINS - EP Obtained by condensation of bisphenol and epichlorohydrin. Used in the production of paints, adhesives, laminates, electronic insulators. It is also used reinforced with glass, carbon and aramid fibers. PHENOLIC RESINS - PHENOPLASTS - PF Obtained by condensation of phenol and formaldehyde. Used in the production of laminates, adhesives, electrical and motor components. FURANIC RESINS Obtained by condensation of furfuryl aldehyde (furfural) and furfuryl alcohol with phenol. They are characterized by good resistance to heat, acids and bases and, some of them, solvents. Used as anticorrosive coatings in the chemical industry also in the form of impregnated laminates, for the preparation of mastics and putties, in foundries as sand binders in the preparation of molds, and in the adhesives sector. MELAMINE RESINS - MF Obtained by condensation of melamine and aldehyde. Due to its good mechanical resistance it is used for the production of laminates, dishes and electrical insulators. UREIC RESINS - UR Obtained by condensation of urea and formaldehyde. Used for the production of chipboard panels. POLYTETRAFLUOROETHYLENE - PTFE (Teflon) Obtained by polymerization of tetrafluoroethylene. Used for non-stick coatings resistant to high temperatures, for electrical insulation, for protection against acid agents. The transformation processes Polymers can be in powder, granules, liquids or solutions.The main processes that transform them into final products, using pressure and heat, are: CALENDERING It consists in spreading and compressing with a machine, made up of heated cylinders, the heated and plasticized polymer, obtaining sheets of desired thickness. EXTRUSION It consists in the continuous transformation of plastic material heated and pushed by an endless screw, through a nozzle which gives the material the required shape and which upon cooling assumes its stable shape. It is the most common procedure in the processing of plastic materials. BLOW The molten polymer is blown with air or steam, so as to assume the shape of the mold in which it is fed. PRINTING Technique that sees the molten polymer feed into a mold of which, by compression and cooling, it assumes the desired shape. The molding can be of four types: 1) by compression, to obtain products with better and homogeneous mechanical characteristics (as for objects with a complex shape, such as electrical sockets and plugs); 2) by stratification, to create even large products, such as boat hulls; 3) injection, to make for example containers, shoes, toothed wheels; rotational, which is used for artifacts such as tanks, drums. In the transformation process, plastics can be integrated with aramidic, carbon or glass fibers, to allow particular performances: this is how composites are born, used for boats, helmets, cars, etc. The temperature of use of plastic materials, for the production of products, varies according to the raw material used: it is between 150 ° and 170 ° C for the most used thermoplastics (PE, PET, PP, PS, PVC); temperatures above 220 ° C are necessary for the processing of some special polymers. Sectors of application PACKAGING They absorb 47% of all plastics production in Italy (43% in Europe). In Europe, around 50% of all food packaging is made of plastic: 60% of this type of packaging weighs less than 10 grams. In 20 years, the packaging has lightened by 80%, improving performance. The characteristics that make plastic preferable are versatility, lightness, strength, chemical inertness, reliability, economy.