Polyethylene terephthalate processing data

Figure 7.4 Classification and image processing results of a typical situation in polymer waste recycling (a) digital image (b) initial classification result (c) calculation of separation data based on the initial classification result (d) classification result after real-time image processing. A, B Polyethylene terephthalate (PET) bottles with paper labels, C PE bottle with paper label, D PE bottle with PE film label, E PP cup, F PS cup. Classification colour code red high-density PE green PS dark blue PET yellow PP light blue paper.

Table VI compares the key properties of these two types of thermotropic polymers category by category. The samples compared had the same melting ranges, but were very different in reduced viscosities and solubility characteristics. The data compared were those processed under the most favorable conditions. Interestingly enough, the as-spun fibers from the polyester-carbonate can be heat-treated more efficiently than those fibers (of same tenacity) spun from the polyester. Both of them gave fiber properties far superior to those of nylons and polyethylene terephthalate. These two classes of polymers also had comparative properties (such as tensile strength, tensile modulus, flex modulus, notched Izod impact strength) as plastics and their properties were far superior to most plastics without any reinforcement.

Tables 14.22.1 and 14.22.2 provide data on releases and transfers from both polymer manufaeturing and man-made fiber produetion in flie USA. Carbon disulfide, methanol, xylene, and ethylene glycol are used in the largest quantities. Carbon disulfide is used in manufacture of regenerated cellulose and rayon. Efliylene glycol is used in the manufacture of polyethylene terephthalate, the manufacture of aUcyd resins, and as cosolvent for cellulose ethers and esters. Methanol is used in several processes, the largest being in the production of polyester. This industry is the 10th largest contributor of VOC and 7th largest in releases and transfers.

Pig. 1. Typical microhardness values of pol3maers compared with data for metals. LDPE, low density polyethylene HDPE, high density polyethylene iPP, isotactic polypropylene CEPE, chain-extended polyethylene POM, polyoxymethylene aPS, atactic polystyrene PET, poly(ethylene terephthalate) PEN, pol3Kethylene naphthalene-2,6-dicarboxylate) CF composite, carbon-fiber composite. Hardness data of metals and alloys markedly depend on composition, degree of work-hardening, processing conditions, etc. For this reason, the values in Figure 1 should be considered as typical values rather than as absolute values. Most of the data for metals are taken from Ref 1. 

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