Identification of plastics materials

Anon., Solar Hot Water Heating Systems Identification of Plastic Materials for Low Cost Glazings, PolyNEW, Inc., Subcontract TAR-9-29449-02 Report, National Renewable Energy Laboratory, Golden, CO, 2002. 

N. Eisenreich, J. Herz, H. Kull, and W. Mayer, Fast On-Line Identification of Plastics Materials by Near Infrared Sprectoscopy in proceedings of R 95, Geneva, Switzerland, 3, pp. 230-235 (1995). 

A classifying materials standard for plastics that can serve many of the industry s needs has been issued for ASTM. This standard, designated D 4000, or ISO 1043, is entitled Standard Guide for Identification of Plastic Materials. It provides for an easy means of identifying plastic materials used in fabricating parts. 

The following advanced methods are used for the positive identification of plastics materials. 

Brazihan Association of Technical Standards. NBR 13230 Symbology indicative of recyclabihty and identification of plastic materials. Rio de Janeiro (2008). 

Analysis of realistic aspects of fabrication and performance of plastic materials involves the combination of complex geometrical, material and physical factors. The identification of the material mechanisms responsible for a specific phenomenon requires the development of relatively complex numerical models which accommodate the critical factors. Once the model is in place, it is possible to simulate different material mechanisms and verify their predictions through a comparison with experimental results. 

Identification of the materials of construction (i.e., plastics, paper, metal, glass, elastomers, coatings, adhesives, and other such materials) should be identified by a specific product designation (code name and/or code number) and the source (name of the manufacturer) alternate materials of construction should be indicated postconsumer recycled plastic should not be used in the manufacture of a primary packaging component, and if it is used for a secondary or associated component, then the safety and compatibility of the material for its intended use should be addressed appropriately... 

Identification of Polymers, it is a fact of commercial life that there Is a frequent call for the rapid Identification of synthetic polymers, usually by industrial scientists and technologists Interested In a rival product. The growing possibility that recycling of plastic material may become economically attractive compared with disposal would also require Identification of different synthetic polymers for sorting purposes. Luminescence spectroscopy could provide a convenient method of rapid identification. 

Identification of plastics [34] is carried out by a systematic procedure preliminary test, detection of elements, determination of characteristic values, and, finally, specific tests. For an exact identification, however, the test sample should first be purified so that it contains no additives (plasticizers, fillers, pigments, etc.) that may affect the results of an analysis. Purification is achieved by solvent extraction either the material is dissolved out and polymer is obtained by reprecipitation or evaporation of the solvent, or the pure polymer remains as the insoluble residue. The solvent varies, and a general method cannot be given. However, for many materials particularly for those in which additives do not interfere, the unpurified material can be investigated and qualitative preliminary tests used. 

It is not possible to discuss here the special properties of all the different types of plastic materials that can occur within these three groups. The plastics industry today, by employing copolymerization or chemical modification, is capable of producing an extraordinary number of combinations of properties, making the identification of corresponding plastics more complicated. Its physical appearance and its classification as a thermoplastic, thermoset, or elastomer therefore permit us to draw conclusions about the chemical nature of the plastic only in simple cases. But they often provide a useful additional way of characterizing the material. 

Polyethylene and polypropylene are the polyolefins most commonly used as plastics. Polybutene-1 and poly-4-methylpentene-l are less common. Also important are certain copolymers of ethylene and also polyisobutylene, which is used for gaskets. The simplest method of identification of these materials is by infrared spectroscopy (see Section 8.2). However, some information can also be obtained from the melting range (see also Section 3.3.3) ... 

Plastics analysis is not only concerned with the identification of polymeric materials but also with the qualitative and quantitative determination of the additives and chemical aids that have been added to the plastic before or during processing. In a wider sense, plastics analysis also encompasses the determination of the properties of the end product. These properties depend not only on the starting materials, but also to a considerable extent on the processing conditions. As the focus of plastics analysis widens, it is also constantly gaining in importance for quality control and quality assurance purposes. 

For more recent synthetic polymers, interviews with the artist can provide information about materiak and technique used, although they do not always replace analysis. The date of manufacture or, if unavailable, the date of collection, can provide a starting point in the identification of plastics. If a plastic was manufactured before around 1905, it is likely to be a semi-synthetic or natural material, rather than a fully synthetic plastic. The period between 1939 and 1960 saw a dramatic increase in production of polystyrene, poly (vinyl chloride), nylon, acrylics and polyethylene and the phasing out of semi-synthetics. If a plastic was manufactured before the 1940s, it could not have been shaped by injection moulding, recognized by a small imperfection due to the filling hole. 

Coxon, H. C. (1993). Practical pitfalls in the identification of plastics. In Postprints of Saving the Twentieth Century The Conservation of Modem Materials Ottawa, 15—20 September 1991 (D. Grattan, ed.) pp. 395-406. Canadian Conservation Institute. 

A set of agreed symbols, to be molded into the plastic, or stamped or printed on it, to indicate the type of material, has been introduced in the USA and is being adopted in Europe. A German DIN specification has been published, for identification of plastics parts with particular reference to their material content (DIN 54840 Kunststoffe Kennzeichnung von Kunststoffteilen). 

Contents i.i Classification and Identification of Polymeric Materials (Plastics and Elastomers)... 

The ehallenge in this analysis lies in the efficient extraction and analysis of the complex matrices in which PBDEs are found. The compounds are used in a variety of plastic materials found in consumer products, and samples are prepared typically using either Soxhlet extraction or microwave digestion, followed by few or no clean-up steps. MS/MS can be used to isolate M + and [M-2Br] + isotopic cluster ions for accurate identification and quantitation. Three stages of the MS/ MS analysis of a PBDE are shown in Eigure 15.43. Eigure 15.44 shows a TIC of the common PBDE isomers that are tested for under the RoHS regulations these common PBDE isomers are listed in Table 15.2. Excellent quantitative results... 

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