PIM moulding of post consumer mixed plastics

Post consumer plastics from household are highly mixed and contaminated and are thus particularly difficult to recycle. Although advances in sorting and cleaning technologies for waste plastics have enable the relatively pure and clean streams such as bottles to be recycled, there is a increasing need for processing technologies that can utilise the low grade and mixed plastic residues from the plastics recovery facilities (PRF). In this work, potentials of utilisation of such feedstock in Powder Impression Moulding (PIM), a process capable of fabricating lightweight sandwich structures, are investigated in terms effects of loading and size of flakes from PE-rich mixed plastics in the formulations of the core on flexural properties of the sandwich panels. It was demonstrated that sandwich panels can be made by incorporating about 75 wt% of coarse flakes of a low-grade mixed plastics material directly obtained from a PRF

Improving the mechanical recycling and reuse of mixed plastics and polymer composites

This is a post-print version of the chapter.In this chapter we will explore the possibilities and viability of commercially recycling and reusing of composites and mixed polymer based waste that is difficult and expensive to separate into individual generic polymers for subsequent recycling. The chapter will also attempt to cover legislations that hinder and drive this technology and give sources of information for further examples of polymer recycling in action

The environmental and financial benefits of recovering plastics From residual municipal waste before energy recovery

A life cycle assessment was carried out to investigate the environmental benefits of removing dense plastics from household waste before burning the waste in an energy from waste (EfW) facility. Such a process was found to improve the climate change and non-renewable resource depletion impacts of the waste management system. A preliminary financial assessment suggests that the value of the plastics recovered in this way would be less than the reduction in electricity income for the EfW. However, if the plastics were separated by the householders and collected in a kerbside recycling scheme, the greater price commanded by the higher-quality reclaimed plastics means that the operation would financially viable Further work is required to assess the effectiveness of using both kerbside collections and mechanical recovery to reduce the plastics content and carbon intensity of EfW feeds

Relevance of the composition of municipal plastic wastes for metallurgical coke production

This study is concerned with the effects of the composition of mixed plastic wastes on the thermoplastic properties of coal, the generation of coking pressure and the quality of the resulting cokes in a movable wall oven at semipilot scale. The mixed plastic wastes were selected to cover a wide spectrum in the relative proportions of high- and low-density polyethylenes (HDPE and LDPE), polypropylene (PP), polystyrene (PS) and polyethylene terephthalate (PET). From the results it was deduced that the reduction in Gieseler fluidity in the coal blend is linked to the total amount of polyolefins in the waste. It was also found that these thermoplastics increase the pressure exerted against the wall in the course of the coking process and that coke quality is maintained or even improved. However, when the level of aromatic polymers such PS and PET are increased at the expense of polyolefins, the coking pressure decreases. Thus, the amount of aromatic polymers such as PS and PET in the waste is critical, not only for controlling Gieseler fluidity and coking pressure, but also for avoiding deterioration in coke quality (reactivity towards CO CRI and mechanical strength of the partially-gasified coke CSR). An amount of polyolefins in the waste lower than 65 wt.% for a secure coking pressure is established

Influences of impurities in recycled plastics on properties of PIM sandwich panels

Powder impression moulding (PIM) is a novel technology for manufacturing lightweight sandwich panels from plastics in powder form. The process is featured by its high tolerant to impurities or contaminants in the feedstock and thus requires much less materials segregation and cleaning operations when use recycled plastics. This paper investigate the influences of polymer impurities and soil contamination on structure and properties of PIM sandwich panels using compositions that simulate a PE-rich recycled plastic feedstock. It is demonstrated that the PIM process can accommodate considerable impurities (rPET residues or soil contamination) in a core dominated by LDPE/HDPE blendes. The variation of flexural properties can be predicted or controlled through monitoring of impurities. There exist significant scopes for reduction of the degree of sorting and cleaning in recycling systems by using lower grades of recyclates and for reduction of the associated costs and energy consumption

Processing waste printed circuit boards for material recovery

PURPOSE We have investigated the use of pyrolysis for the processing of waste printed circuit boards (PCBs). The aim was to make the process of separating the organic, metallic, and glass fibre fractions of PCBs much easier and therefore make recycling of each PCB fraction more viable. DESIGN / METHODOLOGY / APPROACH The PCBs were pyrolysed in a fixed bed reactor at 850°C. The organic fraction released by the boards was analysed by a variety of gas chromatography techniques. The residue that remained after pyrolysis was analysed by ICP-MS to determine the type of metals that were present. FINDINGS When PCBs were heated to 800°C in an oxygen free atmosphere, the organic fraction decomposed to form volatile oils and gases leaving behind the metal and glass fibre fraction of the boards. The pyrolysed boards were very friable and the different fractions (metal components, copper power boards, glass fibre, etc) could be easily separated. The recovered metals could then be recycled by traditional routes with particular emphasis being placed on the recovery and recycling of rare and precious metals. The organic oils and gases which are produced during pyrolysis of PCBs can either be used as a chemical feedstock or as a fuel. RESEARCH LIMITATIONS/IMPLICATIONS The research was only carried out on a very small scale so an investigation into scale-up must be performed. PRACTICAL IMPLICATIONS By using pyrolysis, the organic and metallic fraction of printed circuit boards can be separated and recycled. ORIGINALITY/VALUE This paper presents a novel method for resource recovery from PCBs

Assessment of element-specific recycling efficiency in WEEE pre-processing

Pre-processing is a crucial step to ensure the efficiency of subsequent processes and the quality of recyclates. The efficiency of pre-processing can be affected by high losses to undesignated output fractions. Standard batch tests usually provide mass balances and are a good proxy for bulk materials balances (iron/steel, aluminum, plastics). This article aims at harmonizing methodologies and recommends a strategy for further study in pre-processing on a plant scale. We have developed an “extended batch test” method, which should help to • describe the fates of materials and elements, • assess the quality of output fractions, • identify access points for critical metals and other valuable elements to enable their recovery. A methodical approach was compiled with common material flow analysis methods and an extended set of methods, which improve the reliability via the assessment of uncertainties. This applies to systematic effects and random effects. This extended batch test was performed with a 40 Mg Waste Electrical & Electronic Equipment (WEEE) batch to trace the flows of industrial base metals, precious metals and critical metals in a WEEE pre-processing plant. Results show that one-third of the input was separated and sorted manually, while the remaining material was subsequently crushed and automatically sorted. Copper and precious metals are distributed to various output fractions but are most concentrated in the sorting residues. Critical metals like cobalt and rare earth elements are mainly concentrated in the manually sorted materials but also appear in the ferrous metals scrap and the shredder light fraction

State of the art of plastic sorting and recycling : Feedback to vehicle design

Today car manufacturers are beginning to integrate recycling constraints in the first stages of the design of a new car due to their concern regarding the effects of car design on the recovery of material after End-of-Life Vehicle treatment. Improved understanding of the recycling process can help designers to avoid contaminants in the recycled product and improve the efficiency of current and new sorting methods. The main goal of this paper is to describe the state of the art of the technical efficiency of recovery channels for plastics in Europe in order to define requirements for automotive plastic part design. This paper will first present the results of a survey on industrial and innovative recycling technologies mainly originating from the mining sector, and secondly a simplified methodology for car design integrating plastic recycling constraints. This methodology concerns material association and compatibility, the type of assemblies favourable to better recycling, and better reuse of recycled products in cars.Renault Research Direction FR TCR LAB 1 13, Service 641000-Recycling Engineering, 1 avenue du Golf, 78288 Guyancourt Cedex, Franc

Thermal degradation of real-world waste plastics and simulated mixed plastics in a two-stage pyrolysis-catalysis reactor for fuel production

Real-world postconsumer mixed plastics and a simulated mixture of plastics were processed in a two-stage pyrolysis-catalysis fixed bed reactor in the presence of a zeolite HZSM-5 catalyst. In addition, single plastic polyethylene, polypropylene, polystyrene, and polyethylene terephthalate were also processed in the two-stage reactor. The product yield, composition, and hydrocarbon distribution of the product oil was obtained in relation to plastic type. Noncatalytic pyrolysis of the plastics produced a high yield of an oil/wax product in the 81-97 wt % range. Addition of the catalyst reduced the yield of oil to between 44 and 51 wt %, with an increase in gas yield from cracking of the oil volatiles. However, the condensed oils produced from pyrolysis-catalysis were enriched with lower molecular weight (C5-C15) hydrocarbons and were markedly more aromatic in composition with a high proportion of single-ring aromatic hydrocarbons. Comparison of the results from pyrolysis and pyrolysis-catalysis of the simulated mixture of plastics with the data obtained for the individual plastics showed that significant interaction between the plastics occurred in the mixture with higher C2-C4 gas yield and higher aromatic content in the oils than expected from the proportions of the individual plastics in the mixture