PLASTIC
MATERIALS


  • Acetal Resins

    The first commercial acetal resins were made in 1959. They are some of the most resistant rigid thermoplastic materials known and offer many excellent properties such as high elasticity, tenacity, resistance to stress and a white translucency similar to Nylon. They are used to make technical parts in varied sectors, from videocassettes to carburettors, to zips.


  • Cellulose Acetate

    This material belongs to the cellulosic resin family. Like Celluloid it is obtained from the chemical modification of a natural polymer: cellulose, which is one of the most diffuse organic substances in nature. Cellulose acetate was the first plastic to be injection moulded. It is a white powder and because of its attractive appearance is used for transparent, translucent and opaque objects such as typewriter keys, calculators, switches, car wheel coverings, knife-handles, shoe-heels, lamp shades, pens, umbrella handles toys and so on.


  • ABS

    ABS resins are one of the most valued mixtures of a resin and elastomer and owe their extraordinary success to the excellent properties deriving from this marriage. The initials ABS stand for three base substances in their preparation: acrylonitryl, butadiene and styrene. The first ABS resins were produced in the fifties. Their properties are tenacity, crash resistance and a hard surface. They are therefore mainly used for furniture, car parts, television sets, radios etc.


  • Alkyd Resins

    The most important starting materials to produce alkyd resins are today still glycerol and phthalate anhydride. The first alkyd resins were obtained by W. J.Smith in 1901, but as a moulding material were only developed from 1948 onwards. Apart from being used in the paint industry; alkyds are used to make car parts, electric switches, engine insulators, electronic components and television parts.


  • Amber

    This is a fossil resin from extinct coniferous plants which existed especially on the coasts of the Baltic sea during the Eocenic period. It was used by the most ancient civilisations to produce ornamental objects which incision techniques or pressure moulding. One the first uses of Bakelite was to imitate amber.


  • Asphalt

    A natural organic material with a hydrocarbon base which softens with heat. It is a blackish plastic material. It has been used for thousands of years. It was used to make artificial basins and water ways impermeable as early as 3000 BC.


  • Ivory

    It is obtained from animal tusks and is essentially composed of dentine, that is, calcium salts and other organic substances. It was used before plastics were invented to make piano keys, knife handles, combs and billiard balls. Hyatt made his Celluloid discovery while looking to replace the ivory in billiard balls. In 1970 25,000 tons of ivory were still consumed.


  • Bitumen

    It is compound of different types of hydrocarbons known in ancient times for its cementing and insulating properties. It is a plastic material which can also be moulded with the addition of mineral charges.


  • Casein formaldehyde

    Casein formaldehyde is a plastic of natural protein origin made from organic substances such as milk, horn or vegetable products such as soy beans, wheat and the like. It was obtained in 1897 by Adolph Spitteler and W.Kirsche who started out with whey and formaldehyde and tested the action of an enzyme on them. The patent was registered in Baviera and then extended to the USA, Great Britain and Italy. It should be noted that with its commercial name, Galalith (Galalite in Italy and Erinoid in Great Britain) it sometimes looked like celluloid, sometimes ivory and sometimes artificial horn. The first factory to manufacture it was in Great Britain in 1913. In 1930 world-wide production had reached 10,000 tons. Casein formaldehyde was used to make buttons, pins, cigarette-cases, fountain pens, umbrella handles and radio cabinets.


  • Celluloid

    It was the first of the artificial plastic materials, invented by J.W.Hyatt starting from cellulose nitrate and camphor. It has infinite applications thanks to easy manufacture, colouring, resistance and resilience. All the objects made with Celluloid are made starting from semimanufactureds, such as plates, sheets, sticks, tubes strips and film. Celluloid can be sawn, cut, laminated, folded, punched, stretched, twisted, pressure moulded, sewn, nailed and seamed. It can be modelled simply by heating it with hot water or air, it can be glued and superficially decorated. It cannot be injected or compressed or extruded as it is decomposed at the temperature necessary for such processes.


  • Compounds

    Composite materials or reinforced plastics are obtained from the combination of a thermosetting resin like polyester or epoxy resins, with a reinforced base of fibre glass, carbon fibre, fabric or similar. This combination gives a certain mechanical resistance to the manufactured goods; they are thus used for car bodies, boat fairing, aircraft and bicycle frames.


  • Horn

    It is an organic material containing 80% keratin. It is thermoplastic and can be worked after dry heating or immersion in boiling water or alkaline solutions. After softening it can be pressed obtaining objects and various laminas, such as tobacco containers, boxes, buttons, pens and combs. It was great success, especially in England, before the advent of plastics.


  • Hard Rubber

    Hard rubber was obtained by Charles Goodyear last century, subjecting rubber to prolonged vulcanization. Certain goods made from hard rubber were on show in the 1851 exhibition at Crystal Palace, London. This compound is half way between true plastic materials and natural rubber. During the prolonged vulcanization process 30-40% sulphur is added to the mass, giving a compound with high dielectric power, high resistance to chemical products, a certain hardness and rigidity up to 50C. and a bright and shiny appearance. For many years hard rubber contended with Celluloid and phenolic resins in many applications. It was used in semi-manufactured extruders, subsequently worked on machines or compression moulds with two moulds. Hard rubber was very successful in the growing pen industry. It was also used for battery separators, telephone receivers, frames for photographic plates, cigarette holders and dental material.


  • Epoxy Resins

    They are thermosetting resins of great technical and commercial importance, on the market since 1946, just after the Second World War. There are numerous producers all over the world, especially in recent years with the development of so called composites which are the base of thermosetting resins (like polyesters or epoxy resins) with addition of fibrose reinforcement which increases their mechanical strength. Apart from composites, epoxy resins are used for the electronic, chemical and mechanical industries.


  • Phenol Resins

    These are the oldest and today the most widely used of all the thermosetting resins. They were developed by L.H.Baekeland in 1909 and had great success in the inter-war period. Phenolic moulding masses are made into industrial electrical components radio and televisions parts, telephones, automobile parts, electrical appliances, goods for the defense and space industries.


  • Fluorocarbon Resins

    These are thermoplastics which have been produced in the U.S.A. since 1950 and which have been very successful due to their special characteristics. The most famous is polytetrafluoroethylene which is usually delivered in a semimanufactured state and then worked with machines. Fluorocarbon resins have many uses which go from laboratory equipment to fibres and special film. Polytetrafluoroethylene has self-lubricating and anti-friction characteristics, which make it ideal for industrial gearing, surgical prosthestes and cooking utensil coating. It is also used for pumps, valves, filters and space vehicle components.


  • LAC

    A resinous substance produced by certain insects which live on certain plants in the East Indies. Lac is thermoplastic, soluble in alcohol and is a good electrical insulator and is also used for paints. It can be manufactured with extruders or by injection, to make buttons, boxes, frames, dentures and technical articles.


  • Melamine Resins

    Melamine resins, like urea resins belong to that group of thermosetting resins compounds which are called aminoplasts. They have been industrially produced since the 1930’s. They are important in making laminates and for cooking utensils, electrical appliances, decorative articles and insulators.


  • Homopolymers

    The name homopolymer signifies a polymer whose molecular chain is composed of units of the same molecule. A copolymer is instead composed of units of the same molecule, but with different molecules inserted at random at points along the chain. This difference makes for great compactness in homopolymer chains. This results in a higher fusion point, greater resistance, greater rigidity and a harder surface than the copolymers. The characteristic of homopolymers compared with copolymers can be found in polyolefin, polyamide and acetal resins.


  • Polyamides

    Perhaps none of the synthetic products have become so popular, so quickly, as polyamides are today. They are known of under the name they were first commercially produced in the U.S.A. in 1935: Nylon. Polyamides are processed in all the ways used for thermoplastics and it would be impossible to list all their uses, which include those in the car, electrical, electronic, radio and television industries, precision gearing, protective film for foods, surgical instruments, prostheses, clothing.


  • Polyethylene

    It was developed industrially in England fifty years ago. It is one of the most diffuse and well-known plastics. There are various ways of obtaining polyethylene which mainly vary according to pressure. Different polyethylenes have different characteristics, low, medium or high density; recently linear low density polyethylene has been developed which is better than the traditional low density product. Polyethylene’s characteristics are: low cost, easy manufacture, tenacity and flexibility at low temperatures, it is odourless and untoxic, transparent. It is also a good insulator. It uses are varied: household goods, toys, cable, bottles, protective film, greenhouses, tubing.


  • Polymethyl Methacrylate

    It is the most important product derived from acrylic acid, made in the thirties, but industrially from The Second World War onwards. Moholy-Nagy and Pevsner made the first “object” sculptures in plastic. It is a rigid, transparent material and better at transmitting light than inorganic glass. These optical qualities are the basis for its principal applications: from building to furniture, road signs, the car industry, navy, electrical appliances, laboratory equipment.


  • Polycarbonates

    Three firms, two American and one German, almost simultaneously announced in 1957, that they had perfected polycarbonate production. The first was obtained in Germany. Polycarbonates maintain their characteristics unaltered from 140C to -100C. They have a very hard surface, are good insulators and resist atmospheric agents. They are particularly appreciated for their aesthetic and transparent qualities. They are used to make parts for mechanical and electronic industries, for helmets (the astronauts stepped onto the moon in polycarbonate helmets), windows, bank screens, police shields.


  • Polyesters

    Polyesters resins are varied and complex family of synthetic resins which can be obtained from many different starting materials. Unsaturated polyesters are quite viscous liquids of a yellowy colour which sets with catalyzer addition. Their strength, flexibility and rigidity can be modified with additives or reinforcements which are usually carbon or glass fibre. They are used in building, in the nautical field where over 90% of pleasure boats are made with reinforced polyester and today also for war purposes, minesweepers and surveillance vessels. In the transport industry; buses, trains, caravans. There are many other uses and even artists use a lot of polyester resins.


  • Polypropylene

    It is the youngest of the plastics and in just a few years has reached an unprecedented production level and variety of applications. It was obtained by G.Natta in 1954, in collaboration with research assistants at Montecatini, the first firm to develop industrial production. It is like polyethylene in density, but has a slightly lower density, and greater rigidity and is harder. It is the rigidest of the polyolefine polymers and maintains its rigidity up to 100C. It is very resistant to abrasion and heat, has excellent dielectric and insulating properties, has a special resistance to being repeatedly folded (10 million flexions). There are several types of propylene on the market. There are many applications for it: sanitary articles, electrical appliances, toys, cars, sports, food wrapping, agriculture, road signs, furniture and components for the chemical industry.


  • Polystyrene

    Erethylene and benzine are the starting material for this thermoplastic which became diffuse in the 1930’s and has been very successful in that it can be injected, extruded and blow moulded. It is impossible to describe all its uses. It is mainly used in packing. Also in toys, building, household, goods, electrical appliances and switches.


  • Polyurethanes

    These polymers are made with the polyaddition of isocyanates and polyhydric alcohol. They made their commercial appearance in 1941, in Germany, and today they are produced internationally. They can be rigid or flexible and therefore have many applications. In their flexible form they are used for cushions, mattresses, furniture, and when rigid, in cars, building, furniture. They can replace wood and leather. They are good thermal and electrical insulators.


  • PVC

    Polyvinyl chloride along with polystyrene and polypropylene is the most diffuse plastic. Although P.V.C. patents already existed, the P.V.C. industry began a little before 1939, simultaneously in the U.S.A. and Germany. It can be manufactured with all the techniques for plastics and it is impossible to describe all its applications, which include rigid, elastic and spongy goods. Fuses for plugs and sockets, slide valves, valves, pumps, stoppers, sewage pipes, wall papers, car seats, shoes, raincoats, toys and agricultural film.


  • Thermoplastics and Thermosetting Resins

    Plastics can be divided into two main categories: thermoplastics and thermosetting resins. The distinction in based on their molecular structures and their behaviour on heating during manufacture. During the dieing of a thermoplastic no chemical reaction occurs and moulding is not irreversible because thermoplastics can be returned to their plastic state and back to a solid state without really loosing their characteristic. Thermosetting resins are obtained with polycondensation. A polycondensed material is a thermosetting material because during manufacture when it is heated and subjected to pressure, a chemical reaction occurs provoking a restructuring which is molecularly irreversible; once formed, a thermosetting resin is unchangeable. Examples of thermosetting resins are phenolic, melamine, urea and polyester resins.


  • Urea Resins

    These are thermosetting resins which are obtained from the reaction of urea with formaldehyde. Around 1929 these resins had reached a substantial point in their commercial development, thanks to their properties and low cost. Like melamine resins, they are fine wide powders which are usually used in compression moulding in a die with the action of heat. The main use of urea resins is in the field of adhesives and glue, as a moulding material they are used for pans, electrical appliances, telephones, radios and furniture.


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