PET (Polyethylene terephthalate)
Definition:
Polyethylene terephthalate which is commonly known as PET is a type of thermoplastics polymers resins. When PET is used in fabrics then it is also called as Polyester which is just like a clothing fabric. PET is lightweight, economical, non reactive and shatterproof that’s why it is highly valued packaging material. Despite its name it does not contain polyethylene. Polyethylene terephthalate (PET) consists of polymerized units of the ethylene terephthalate, with repeating units of C10H8O4
PET may exist both as invisible and also in semi colours.
Uses:
PET used in many different things such as
Food containers.
Beverage containers
Drinking water bottles
It is also used to cover bakery products
It is used to hold cosmetics products because it is easy to mold into desirable shape.
It is also used to store chemicals such as household cleaners, varnishes etc.
It is used thermal insulation such as Space blankets.
It is used as substrate in thin films and solar cells.
In synthetic fibres
Platic bottles
Juices bottles
Page # 2
Physical Properties:
It is colourless in its natural state. It is a good barrier to moisture, solvents and makes a good gas. It has impact resistance and very strong. It became white when exposed to other chemicals like chloroform and toluene. The most important property of PET is intrinsic viscosity which means it absorbs water from the surroundings and makes...
... middle of paper ...
...polyester are just about as differed as the assembling methodologies focused around essential pellets or melt. Contingent upon virtue of the reused materials, polyester could be utilized today within the greater part of the polyester assembling techniques as mix with virgin polymer or progressively as 100% reused polymer. A few exemptions like BOPET-film of low thickness, exceptional provisions like optical film or yarns through FDY-turning at > 6000 m/min, microfilaments, and micro-strands are processed from virgin polyester just.
Conclusion:
From all of the above information and research we conclude that PET is very useful plastic among all of them because it is very effective and safe that’s why it is used to cover food and beverages. PET is very long lasting plastic. Most of the PET plastic is used in bottles, juice bottles and food storage containers.
A group of polymer chains can be organised together in a fiber. How the polymer chains are put together is important, as it improves the properties of the material. The flexibility, strength and stiffness of Kevlar fiber, is dependent on the orientation of the polymer chains. Kevlar fiber is an arrangement of molecules, orientated parallel to each other. This orderly, untangled arrangement of molecules is described as a “Crystalline Structure”. A manufacturing process known as ‘Spinning’ is needed to achieve this Crystallinity structure. Spinning is a process that involves forcing the liquefied polymer solution through a ‘die’ (small holes).
The most common form of polyethylene is petroleum based or olefins based; as before mentioned polyethylene compounds have a wide commercial applicability and are made from non-renewable resources (Harding, Dennis, von Blottnitz, Harrison, & S.T.L., 2007). Its manufacturing processes are regarded as energy intensive and release significant amount of CO2 and heat into the atmosphere (Broderick, 2008). Next a little more detailed description of polyethylene’s production processes will be presented, with a focus on the way the material inputs are extracted and synthesized.
The plastic obtained from polyethylene can be pressed into varying shapes, ranging from the simplest to the most complicated. The ethylene market is indirectly driven by the increased polyethylene consumption for the production of several plastic components. In 2011, the global propylene market is valued at more than $ 90 billion and significant growth is anticipated in the coming years. Acrylic fibers and coatings, PVC plasticizers and coatings, polyurethane resins, epoxy resins and propylene polymers are applied on polycarbonates and solvents, that are used in the production of propylene. The automotive industry is the biggest end-user of polypropylene. The enormous expansion of ethylene and propylene production will contribute to the growth of the ethylene and propylene market, along with the rising demand for downstream products from India, China, and the Middle East. Tight environmental regulations, fluctuations in raw material prices and political uncertainties in crude oil producing regions are the main factors limiting the ethylene and propylene market [9].
Polyethylene (PE) is one of the most commonly used polymers which can be identified into two plastic identification codes: 2 for high-density polyethylene (HDPE) and 4 for low density polyethylene (LDPE). Polyethylene is sometimes called polyethene or polythene and is produced by an addition polymerisation reaction. The chemical formula for polyethylene is –(CH2-CH2)n– for both HDPE and LDPE. The formation of the polyethylene chain is created with the monomer ethylene (CH2=CH2).
They are amorphous or solely moderately crystalline once injection shaped, but the degree of crystallinity will be abundant redoubled for fiber and film applications by orientation via mechanical stretching. The two most vital polyamides poly(hexamethylene adipamide) Nylon 6,6 and polycaprolactam Nylon 6. Both have wonderful mechanical properties together with high impact strength, high flexibility, high tensile strength, good resilience and low creep. They are straightforward to dye and exhibit wonderful resistance to wear due to a low constant of friction. Both amides have a high melting temperature (500 - 540 K) and glass transition temperature reports in excellent mechanical properties at elevated temperatures. For example, the heat rebound temperature of PA-6, 6 is usually between 180- 240°C that exceeds those of polycarbonate and polyester. They also have excellent resistance to fungi, oils, bases, etc. The main limitation is that the strong wet sensitivity water acts as a plasticizer and therefore the ensuring changes in mechanical properties. For example, the tensile strength of moist polyamide is 50% below that of dry polyamide. Another important polyamide is Nylon 6,12. It is less hydrophilic than Nylons 6,6 and 6 due to the larger range of chemical group of methylene within the compound backbone. For this reason, it has better dimensional
This is a polymer which is, if, treated with strong heat, turns into a fire-resistant polymer. On burning no smoke is formed, which makes it convenient as a plastic for aeroplane interiors. When PHA is intensely heated, it loses water and re-arranges to form PBO. PHA is used as a plastic as it is easier to mould so it is used instead of PBO.
Polyurethanes are used for the manufacturing of non-flexible, high-resilience foam seating; microcellular foam seals and gaskets; durable elastomeric wheels and tires ; automotive suspension bushings; rigid foam insulation panels; electrical potting compounds; high performance adhesives; surface coatings and surface sealants; synthetic fiber carpet underlay; hard-plastic parts; condoms; and
The food we consume everyday touches plastic infinitely, whether it is during the preparation stages, packaging, storage or even just eating the food from a plastic plate. There is no escaping the fact that the food we eat has a huge contact with plastics. However, what does this mean for our food? There is an adverse effect to plastics and their contact with foods, particularly acidic, fatty or salty foods. The chemicals in plastics go through a process called “leaching” or “migration” which leads to transfer of polymer additives, impurities and polymerisation solvents into packaged goods with a consequent risk of toxic hazard to the consumer (Crompton, T. (1979). [book]). In this
Polypropylene is one of those most versatile polymers available with applications, both as a plastic and as a fiber, in virtually all of the plastics end-use markets.[3]
Waxes are used in the rubber industry for the production of rubber hoses, conveyor belts, rubber toys, fitting gloves, tires, gaskets and many other similar rubber applications.
Polymers are made from relatively small molecular fragments known as monomers that are joined together. Synthetic polymers which include the large group known as plastics are divided into three groups: commodity thermoplastic, engineering thermoplastics (ETP), and advanced engineering thermoplastics (AETP). The engineering thermoplastics (ETP) have heat resistance, strong mechanical properties, lightness, self-lubrication, and easy manufacturing. This plastic category has been lately used to replace wood and metal applications.
Polymers popularly coined as “plastics” have proved their importance in different areas like FMCG, pharma, automobiles, etc. Plastics are versatile materials with unique properties like high strength to weight ratio, good aesthetics; good Processability, balanced engineering properties and optimum cost led its entry into medical
There are two popular ways of creating nylon for fiber applications. One, ¡°molecules with an acid (COOH) group on each end are reacted with molecules containing amine (NH©ü) groups on each end.¡± The nylon 6,6 is made in this fashion. The other common way of making nylon fibers is by polymerizing a compound containing an amine at one end and an acid at the other, to form a chain with reoccurring groups of (-NH-[CH©ü]n-CO-)x. If the x=5, the fiber is named nylon 6 (Nylon Fiber).
used to make products such as plastic lumber, toys, containers, carpet, fiber fill for jackets
Most products made with the rotational molding method are from the polyethylene family. Other materials include nylons, polypropylene and PVC plastics. Some manufacturers have developed formulas that integrate the use of natural materials such as sand and chips of stone to make