A new recycling system for expanded polystyrene using a natural solvent. Part 1. A new recycling technique

A new recycling technique has been developed which uses a natural solvent, d limonene, to shrink expanded polystyrene (EPS). d-Limonene is a natural vegetable oil which is extracted from the rinds of citrus fruits and is a good solvent of EPS. Limonene has almost the same solubility as toluene at room temperature. This technique reduces the volume of EPS to about 1/20th of the original. Contracted EPS is recyclable with almost no molecular weight degradation because d-limonene acts as an antioxidant of polystyrene during the heating process. © 1998 John Wiley & Sons, Ltd.     

A new recycling system for expanded polystyrene using a natural solvent. Part 3. Life cycle assessment

A new system of recycling expanded polystyrene has been developed which uses limonene orange oil as a solvent to recycle high grade polystyrene. Life cycle assessment was applied to this system to simulate its effect on the environment. It is shown that the new system has a lower greenhouse effect (−30%), acidification (−58%) and energy consumption (−20%) than the conventional recycling system using thermal shrinking. © 1998 John Wiley & Sons, Ltd.     

Comparison of various loose fill cushioning materials based on protective and environmental performance

This paper compares various loose fill packaging materials based on the amount of material required for a given level of protection. A methodology developed to evaluate and compare package cushioning materials on the basis of environmental concerns relative to disposal and recycling is used to compare seven different loose fill materials. The materials compared include recycled expanded polystyrene (EPS), starch and paper based materials, wood shavings and popcorn. The shock level G was related to the amount of cushion material needed both by weight and by volume. The results show that starch-based loose fill materials (Naturpack and Eco-Foam) and Fiberflow showed the best protective performance and minimum material utilization by volume. 100% recycled EPS showed the best performance in terms of percent weight utilization. Other materials tested, like popcorn and wood shavings, showed poor material utilization.     

A Study of Nonlinear Effects in a Cushion‐Product System on its Vibration Transmissibility Estimates with the Reverse Multiple Input–Single Output Technique

The Reverse Multiple Input–Single Output (R‐MISO) identification technique was implemented to determine vibration transmissibility frequency response functions (FRFs) of a cushion‐product system that accounts for nonlinearities known to exist in such systems. The signed quadratic x|x| nonlinear term was used. The results were compared with the classical linear approximation FRFs calculated with the single input–single output identification method. Comparisons were made for five types of expanded polystyrene (EPS) cushions with varying density and two levels of band‐limited random excitation. It was shown that vibration transmissibility FRFs obtained with the R‐MISO method and with the inclusion of a signed quadratic x|x| nonlinear term significantly (up to ~70%) improved the total coherence of the nonlinear vibration transmissibility FRFs for the EPS cushions subjected to the static load selected to coincide with the optimum of their respective cushion curves. The R‐MISO technique was successful in accounting for some of the nonlinearities in the EPS cushion‐product system. However, its ability to deal with nonlinearities is not specific to the EPS but rather common to cushion‐product systems subjected to vertical vibrations. Copyright © 2012 John Wiley & Sons, Ltd.     

Millimeter wave electromagnetic interference shielding by coating expanded polystyrene particles with a copper film using magnetron sputtering

Expanded polystyrene (EPS) particles were coated with copper by magnetron sputtering in order to produce a material suitable for electromagnetic interference (EMI) shielding. Field emission scanning electron microscopy (FE-SEM) and energy dispersive X-ray analysis (EDS) results demonstrated the effectiveness of successful copper deposition. The EMI shielding effectiveness (SE) of the Cu-coated EPS particles was measured to be 14–39 dB over a frequency range of 80–110 GHz, suggesting that Cu-coated EPS particles can be used as an effective lightweight millimeter wave EMI shielding material.     

A new recycling method for expanded polystyrene

A new recycling method was investigated in this work, in which polystyrene (PS) sub‐µm fibres were electrospun from recycled expanded polystyrene (EPS). The experimental results in this work show that fibres with diameters of around 500 nm were produced by the electrospinning method. The fibres were produced to form a non‐woven mat. Non‐woven mats of electrospun fibres have large surface areas and small pore sizes compared to commercial textiles, making them excellent materials for use in filtration applications. Copyright © 2005 John Wiley & Sons, Ltd.     

聚苯乙烯泡沫不耦合装药爆破试验研究

基于EPS泡沫材料的吸能特性,建立实验混凝土模型,将聚苯乙烯(EPS)泡沫与空气作为不耦合介质,利用DH3820高速静态应变测试采集系统采集应变数据,采用G-G-S分布函数分析爆破块度。研究表明:与径向空气不耦合装药结构相比,聚苯乙烯(EPS)泡沫不耦合装药爆破应变峰值更大,破碎块度更为均匀。在区间1.66~1.80内,径向聚苯乙烯(EPS)泡沫不耦合装药存在最优不耦合系数,使得聚苯乙烯泡沫不耦合装药爆破效果最佳。聚苯乙烯(EPS)泡沫作为一种新型介质在现场不耦合装药中具有一定可行性。     

低成本、便携式的EPS快速成形系统

 针对目前聚苯乙烯泡沫塑料（EPS）加工的发展需要,研制了低成本、便携式的EPS快速成形系统.系统综合应用CAD/CAM技术、电机控制技术、计算机数控技术、先进制造技术等知识,确定系统的设计方案,开发了上位机软件系统,编程实现图形优化、图元排序、路径规划等一系列算法,将DXF文件中的图形信息转换为系统定制的加工指令并进行传输控制.最后测试了软件系统的功能并对样机进行加工试验,证明该系统易于使用,加工精度可以满足工程需要.     

Redesign of a recycling system for LPG-tanks

This paper presents a case study that is performed at Auto Recycling Nederland (ARN), the organization for end-of-life vehicle recycling in the Netherlands. End-of-life vehicle recycling starts with the removal of dangerous materials, such as oil, fuel and LPG-tanks (Liquefied Petrol Gas). We consider the problem of redesigning the recycling system for LPG-tanks. Like in many reverse logistics network design questions, uncertainty in system behavior and difficulty in gathering reliable data are important characteristics of our case. Especially while the total costs consist for almost 50% of transportation costs, reliable transportation costs estimations are crucial. We use a vehicle routing model to solve this data problem and feed the estimations into a mathematical programming model. The system uncertainty is tackled with sensitivity analysis.Correspondence to: H. M. le Blanc     

Effect of polystyrene aggregate size on strength and moisture migration characteristics of lightweight concrete

The aim of this study is to investigate the effect of polystyrene aggregate size on strength and moisture migration characteristics of lightweight concrete. The present study covers the use of expanded polystyrene (EPS) and un-expanded polystyrene (UEPS) beads as lightweight aggregate in concretes that contain fly ash as a supplementary cementitious material. Lightweight concrete with wide range of concrete densities (1000–1900 kg/m³) were studied mainly for compressive strength, split tensile strength, moisture migration and absorption. The results indicate that for comparable aggregate size and concrete density, concrete with UEPS aggregate exhibited 70% higher compressive strength than EPS aggregate. EPS aggregate concrete with small EPS aggregates showed higher compressive strength and the increase in compressive strength was more pronounced in low density concrete when compared with high density concrete. The UEPS aggregate concrete exhibited brittle failure similar to normal weight concrete (NWC), whereas, gradual failure was observed in EPS concrete. Moreover, the moisture migration and absorption results indicate that the EPS concrete containing bigger size and higher volumes of EPS aggregate show higher moisture migration and absorption.     

Effect of recycling flux on performance and characteristics of activated sludge hydrolytic–aerobic recycling process in degradation of 2,4-dichlorophenol

The degradation of a model molecule, 2,4-dichlorophenol (2,4-DCP), was studied using an activated sludge hydrolytic–aerobic recycling process (HARP). 2,4-DCP and chemical oxygen demand (COD) total removal efficiency in the recycling process was 98% and 96% at the recycling flux of 15 mL/min after 24 h degradation, respectively. With the recycling flux increasing, the peak values of the concentration of volatile fatty acid (VFA) declined. Polysaccharide and protein contents in EPS were dramatically increased as recycling flux increasing from 5 to 15 mL/min in the HARP. There is obviously fit to the linear correlation between the PN/PS ratios and recycling flux. The zeta potentials decreased with recycling flux increasing. As the recycling flux increasing at a certain degree, the increase in polysaccharide and protein contents of EPS could more favor the stability of the HARP.     

Assessment of Edible Fungi and Films Bio-Based Material Simulating Expanded Polystyrene

Expanded polystyrene (EPS) contains benzene and styrene, posing a risk to human health. Research objective was to create and evaluate a bio-based material that mimics EPS physical and mechanical properties; this material was developed from crop residues (Triticum sp.), fungi (Pleurotus sp.), and edible films (carrageenan, chitosan, and xanthan gum). Treatments differed in the type of film applied over the bio-based material, and physical and mechanical properties were evaluated. Compressive and flexural strength ranged from 20 to 60 kPa and 4.6 to 17.9 kPa, respectively; dimensional stability and relative density ranged from 5.1 to 7.3% and 178.7 to 198.9 kg m^?3, respectively. The bio-based material does not pose to be an alternative to EPS yet, and further researches must assess water absorption and biodegradability.     

A system tradeoff model for processing options for household plastic waste

With the "Containers and Packaging Recycling Law", Japan has shown a firm conviction towards the promotion of recycling. Waste can be "recycled", i.e. resource value of waste material can be recovered, in many ways, from material recycling to energy recycling. Alternatively, waste can be reduced or disposed of in landfills. A system tradeoff model is developed from component process technology models of six different recycling and disposal options for household plastic waste processing: plastic pellet production, refuse derived fuel production, oil production, waste incineration to produce electricity, use of waste plastic as a coke substitute, and incineration for volume reduction. These technologies are compared with the case where all waste plastic is land filled. Models based on plant data, laboratory experiments, and theoretical considerations of scale effects and mass balances are developed to calculate the cost, energy consumption, CO₂ emission, and land fill occupancy. The models also calculate the valued products of each technology and convert them into cost, energy, CO₂, and landfill occupancy using life cycle inventory data. These values are subtracted from the outputs of the waste processing models to obtain overall performances for each technology. The overall tradeoff system model is then used to evaluate several scenarios of plastic recycling and disposal technologies in Tokyo. Electronic Publication     

Study of Polyurethane Foaming Dynamics Using a Heat Flow Meter

This work presents the results of the study concerning the effects of fillers addition on the heat flux density \(\dot{q}\left( t \right) \) of foaming of polyurethane–polystyrene porous composite (PSUR) and describes the dynamics of this process during the first 600 s. This foaming process resulted in obtaining porous materials that were based on HFC 365/225 blown rigid polyurethane foam (PUR) matrix, which contained thermoplastic expandable polystyrene (EPS) beads as the filler. In PSUR composites, the EPS beads were expanded after being heated to a temperature above the glass transition temperature of EPS and vaporing gas incorporated inside, by using the heat of exothermic reaction of polyol with isocyanate. From the start \((t=0)\) to the end of the PSUR composite foaming process (\(t=t_{k}), \dot{q}\left( t \right) \) was measured with the use of the heat flow meter. For the purpose of the study two PUR systems were selected: one with high and one with low heat density of foaming process q. EPS beads were selected from the same manufacturer with large and small diameter. The mass fraction of EPS in PSUR foam varied during the measurements. Additionally, a study of volume fractions of expanded EPS phase in PSUR foams as a function of mass fractions of EPS was conducted. In order to verify effects of the EPS addition on the heat flux density during PSUR foaming process, the thermal conductivity measurements were taken.     

Discrimination between virgin and recycled polystyrene containers by Fourier transform infrared spectroscopy and principal component analysis

A rapid and reliable method for discriminating virgin and recycled expanded polystyrene (EPS) containers was developed using Fourier transform infrared spectroscopy combined with principal component analysis. Standard normal variate, first and second‐order derivative spectra were compared for the discrimination results. The results show that carbonyl region (1780‐1620 cm^?1) spectra using first derivative transformation give the optimum classification results. In addition, the carbonyl compounds in EPS containers were detected to clarify the chemical difference between virgin and recycled containers, with a higher concentration of carbonyl compounds observed in recycled EPS containers. The combination of carbonyl region of Fourier transform infrared spectroscopy with chemometrics proved to be a promising method to discriminate virgin and recycled EPS containers, which could function as an additional tool for quality control of plastics.     

Associativity modelling of a mould assembly for expandable polystyrene foam

The design and fabrication of a mould for expandable polystyrene (EPS) buffers involves an approach which is radically different from that associated with conventional plastic injection moulding. This is because the EPS mould design encompasses both the classical tooling specifications and considerations of the actual moulding process itself. This paper discusses the notion of associativity modelling in the CAD design of a mould assembly for the manufacture of EPS buffers. This modelling paradigm aims to integrate 5 mould design factors with 25 process (moulding) parameters. Through a better understanding of the interactions between design factors and process parameters, and among the process parameters themselves, a harmonious decision table can be derived which compromises the competing demands of factors and parameters. Because of the visibility of the interactions among parameters, the notion of associativity modelling offers the designer a better insight into mould assembly design, leading to practical mould design solutions that harmonize the functions of the different sub-assemblies.     

Investigation of the electromagnetic characteristics of cement based composites filled with EPS

Due to the electromagnetic transparency of expanded polystyrene (EPS), the cement-based composites filled with EPS beads can be regarded as a type of “porous” material. The electromagnetic reflection loss of this porous composite material in the frequency range from 8 to 18 GHz was studied experimentally in this paper. Findings show that the filling of EPS beads can improve the reflection loss of plain cement material greatly and the EPS filling ratio, EPS bead size and sample thickness all have remarkable effects on the electromagnetic wave reflection loss of this porous composite material. With a EPS filling volume concentration of 60% and EPS size of 1 mm, the reflection loss is all higher than −8 dB in 8–18 GHz and the bandwidth for −10 dB reaches 6.2 GHz for a sample with the thickness of 20 mm. This composite material still has a relatively low bulk density and can be handled easily.     

EPS在汽车KD件出口包装中的应用

聚苯乙烯泡沫(EPS)材料在包装质量、作业效率、集装箱利用率等方面有明显优势,但在汽车KD件出口包装中,未得到全面推广应用.针对此现象,分析EPS材料在KD件出口包装中存在的问题,并从降低投资风险、优化EPS包装设计、完善质量控制体系、建立专业的EPS废弃物回收渠道、提高材料阻燃性能等方面提出解决方案.EPS材料的推广应用过程中,还要对具体的包装方案进行分析、验证,避免出现新的问题,影响被包装件质量.     

A method to measure the fusion strength between expanded polystyrene (EPS) beads

Cellular polystyrene (EPS) is the most commonly used cellular thermoplast whose main applications are insulation and packages. One of its new applications is core material in building elements, and this poses higher requirements for strength. This is particularly evident in self-supporting roof elements. This study presents a method for determining the fusion strength between beads in cellular polystyrene and the dependence of this strength on processing. This method has also enabled us to determine the adhesion of cellular polystyrene beads to other materials, such as glass fibre, and it allows measurement of the fusion strength between EPS beads without the influence of porosity. Fusion strength was found to have a characteristic behaviour. It has an absolute upper limit, and fusion forces approximate this limit asymptotically as heating time is prolonged (this increase is dependent on the energy content of the steam).