Drinking bottles

Soft-drink bottles made from poly(ethylene terephthalate) (PET) are usuady made by stretch-blow mol ding in a two-step process. Eirst, a test-tube-shaped preform is molded, which is then reheated to just above its glass-transition temperature, stretched, and blown. Stretching the PET produces biaxial orientation, which improves transparency, strength, and toughness of the botde (54,56). A one-step process is used for many custom containers that are injection stretch-blow molded. 

Labels for soft drink bottles, shampoo bottles, plastic food containers and the like, require high adhesion to materials like polyester and polyolefins. Once applied, the adhesive may have to withstand repeated flexing, freezing, water and other fluid spillage, while maintaining aesthetic appearance. 

Similarly, glass sample bottles should never be carried by hand. Workers have been injured when bottles they were carrying knocked against projections and broke. Bottles should be carried in baskets or other containers, such as those used for soft drinks. Bottles containing particularly hazardous chemicals, such as phenol, should be carried in closed containers. 

Benzene (80 ml) is placed in a suitable pressure vessel (soft drink bottle or hydrogenation bottle) and chilled to 5°. The bottle is weighed, and a gas dispersion tube connected to a cylinder of butadiene is immersed in the benzene. Butadiene is introduced into the flask with continued cooling until a total of 32 g has been transferred. Pulverized maleic anhydride (50 g) is added to the bottle, which is then capped or stoppered with a stopper wired in place. The bottle is allowed to stand at room temperature for 12 hours, then is heated (behind a safety shield) to 100° for 5 hours. The bottle is cooled, then opened, and the contents are transferred to an Erlenmeyer flask. The mixture is heated to boiling, and petroleum ether is added until there is a slight turbidity. After cooling, the product is collected, mp 101-103° (yield 90%). 

Problem 31.8 I Polyfethylene terephthalate), or PET, is a polyester used to make soft-drink bottles. 

Poly (ethylene terephlhalate) L—PET Soft-drink bottles... 

A two-liter plastic soft drink bottle can withstand a pressure of 5 atm. Half a cup (approximately 120 mL) of ethyl alcohol, C2H5OH (d = 0.789 g/mL), is poured into a soft drink bottle at room temperature. The bottle is then heated to 100°C (3 significant figures), changing the liquid alcohol to a gas. Will the soft drink bottle withstand the pressure, or will it explode ... 

The crystallinity in PET soft drink bottles is about 25%. Because a more crystalline state is normal for PET, the amorphous content is increased intentionally by copolymerization and rapid cooling for the molten PET from the melt to a temperature below the glass transition temperature. Companies which perform high-speed blow molding of PET prefer PET resins made with small amounts of glycol and diacid comonomers. 

Both thermosets and thermoplastics are used as food-contact materials, though thermoplastics predominate in this appfication. Examples of the former are phenol- and urea-formaldehyde, while probably the best known example of the latter is low-density poly(ethylene). Other linear polymers are used include high-density poly(ethylene), poly(propylene), and PVC, all of which find quite extensive use. Polymers for food packaging may be in the form of films and other flexible items, or in the form of rigid containers, such as clear drinks bottles or opaque cartons for dairy products. 

Poly(ethylene terephthalate) Drinks bottles, oven-ready tray meals ... 

In America there are promising signs for certain polymers. For example, poly(ethylene terephthalate) drinks bottles can be cleaned and recycled to give an acceptable grade of PET resin in a process that is economically viable. The recycled polymer is used as carpet fibre, furniture stuffing, or insulation. Waste nylon can also be recycled profitably. 

PETP flakes produced from used soft drinks bottles were subjected to alkaline hydrolysis in aqueous sodium hydroxide. A phase transfer catalyst (trioctylmethylammonium bromide) was used to enable the depolymerisation reaction to take place at room temperature and under mild conditions. The effects of temperature, alkali concentration, PETP particle size, PETP concentration and catalyst to PETP ratio on the reaction kinetics were studied. The disodium terephthalate produced was treated with sulphuric to give terephthalic acid of high purity. A simple theoretical model was developed to describe the hydrolysis rate. 17 refs. 

A description is given of a comparative study of the glycolysis of PETP waste soft drinks bottles by various mixtures of EG and DEG with subsequent polyesterification of the glycolysed products by maleic anhydride in order to obtain unsaturated polyesters suitable for the production of varnishes. The processing characteristics such as viscosity, exotherm temperatures of curing, compatibility of resins with monomers was investigated with respect to the type and amount of reactive monomers. The mechanical properties of varnishes produced were analysed. 13 refs. 

Both terephthalic acid (TPA) and dimethyl terephthalate (DMT) are used exclusively for the manufacture of polyesters for textile fibers (e.g,. Dacron ), films, soft-drink bottles, and engineering resins for automotive applications. The glycol used for most TPA-based polyesters is ethylene glycol. The polyester is then known as polyethylene terephthalate, or PET. 

Construct a LCA process flow sheet for a PET drinks bottle, indicating what data you would wish to collect. Compare this with a similar LCA for an aluminium can. Discuss the meaning of the term Functional Unit in this context. 

In a joint project between the Waste and Resources Action Programme (WRAP) and Coca Cola Enterprises in the UK it proved possible by redesigning bottle production to reduce the weight of 500 ml PET bottles by 8%. These lighter bottles meet all of the required performance standards, and when production reaches the full scale of 700 million p.a. will save 1400 tonnes of PET. This may seem to be a small improvement, but lightweighting of drinks bottles has been a continuous process for many years, and yet progress is still possible. 

Polyethylene terephthalate is injection blow molded to make water and carbonated drink bottles, and other liquid food packages. High stiffness, excellent clarity, and good resistance to carbon dioxide permeation are the principal attributes of these bottles. We carefully control molding conditions to promote transparency and surface gloss, which are prized for food... 

Polyesters, which are a class of engineering thermoplastics, are found in a wide variety of applications including carbonated drink bottles, fibers for synthetic fabrics, thin films for photographic films and food packaging, injection molded automotive parts, and housings for small appliances. In this chapter, we svill explore the synthesis of this class of polymers. We will also look at the typical properties and end uses for the most common of these resins, polyethylene terephthalate and polybutylene terephthalate, which are commonly known as PET and PBT, respectively. 

Because polyethylene terephthalate crystallizes slowly, it can readily be produced in its amorphous state. This is especially true when it is used in packaging materials, such as thin films and carbonated drink bottles. The final products exhibit high clarity and directionally balanced properties because they lack crystalline regions. 

A student mixed aluminium foil and drain cleaner in a soft drink bottle, which started emitting gas. Another student carried the bottle outside and was claimed to have been overcome by the toxic fumes [1]. Most drain cleaners are alkalis, so that aluminium will dissolve to produce hydrogen. The bleach that it is is suggested may have been present will produce no toxic fumes in alkali, and one would be surprised to find arsenic or antimony compounds present. If the collapse was not... 

On opening the drink bottle we hear a hissing sound, which occurs because the pressure of the escaping C02 gas above the liquid is greater than the atmospheric pressure. We saw in Chapter 4 that the molar change in Gibbs function for movement of a gas is given by... 

Carbonated soft drinks (CSDs), estimated maximum oxygen tolerance, 3 38 It Carbonated soft drink bottles, 20 45-46 world market for, 20 53-54 Carbonate leaching, of uranium ores,... 

Indeed, the increasing industrial significance of the SSP process can be directly related to the success of the PET bottle. PET was introduced for use in drinking bottle applications in the mid 1970s and the SSP process was required to reduce the AA level below that achievable in the melt phase while increasing... 

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