Recycled plastics testing

Laboratory tests indicated that gamma radiation treatment and cross-linking using triaHylcyanurate or acetylene produced a flexible recycled plastic from mixtures of polyethylene, polypropylene, general-purpose polystyrene, and high impact grade PS (62). 

In this study, Raman spectroscopy and pattern-recognition techniques were used to develop a potential method to differentiate common household plastics by type [87-89], which is crucial to ensure the economic viability of recycling. The test data consisted of 188 Raman spectra of six common household plastics high-density polyethylene (HDPE), low-density polyethylene (LDPE), polyethylene terephthalate (PET), polypropylene (PP), polystyrene (PS), and polyvinylchloride... 

Franz R, Huber M and Piringer O G, 1994, Testing and evaluation of recycled plastics for food packaging use - possible migration through a functional barrier. Food Additives and Contaminants 1994, 11 (4), 479-496. 

Laoubi S. Feigenbaum A and Vergnaud J M, 1995, Safety of Recycled Plastics for Food Contact Materials Testing to Define a Functional Barrier. Packaging Technology and Science 8,17-27. 

It is generally known that only a very limited number of packaging materials such as glass or metal provide absolute protection properties concerning the penetration of chemical compounds from layers behind or from the environment. In the case of multi-layers with plastics materials as functional barriers there occurs, in most cases to a certain extent, an unavoidable mass transfer from the plastics layers into the product. This must be understood as a functional quantity which, however, must comply with food regulations. Therefore it is necessary firstly to understand functional barrier characteristics and mechanisms and, secondly, to define the functional barrier efficiency in relation to food safety and to establish appropriate test methods. This is especially important with those food packaging applications where recycled plastics are covered by plastics functional barriers. 

Finally, the current available elaborated knowledge and the proposed test methodologies are suitable to serve for national or federal authorities and industry as a basis for safety evaluation, establishing criteria and guidelines for the appropriate functional barrier protection design of recycled plastics for food packaging. 

Keyword paving material, asphalt mixture, waste plastics, recycling, Marshall test, wheel tracking test, dynamic stability, bending test. 

One of the products to be tested was made of recycled plasticized PVC material with granular texture and had an apparent density of 900 kg/m3 it would be produced and delivered in rolls having a surface area ranging from 12 m2 (for 5 mm mat thickness) to 8 m2 (for 8 mm thickness). The other material consisted of recycled rubber which was bonded with a Polyurethane Polymer it had a density of 820 kg/m3. The material of geotexile fleece was Polyester. 

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