Polystyrene Granules Research Articles

Experimental Study of the Heat Flux Effect on Combustion Characteristics of Commonly Exterior Thermal Insulation Materials

For the sake of examining the heat flux effect on combustion characteristics of commonly exterior thermal insulation materials, the six kinds of exterior thermal insulation materials were tested by the cone calorimeter in this paper included rock wool, adhesive polystyrene granule, phenolic resin, EPS, XPS and RPU. The experimental results showed that the fire risk of different thermoplastic insulation materials arrange in descending order was XPS>RPU>EPS> adhesive polystyrene granule> phenolic resin> rock wool; with the increase of radiation intensity, the heat release peak rate of PS increased and the ignition time and the peak time reduced, the heat release peak rate and the peak time points showed inverse proportion; the peak HRR value of B2 RPU is 2 times of B1 RPU and the efficiency of fire retardant of B1 RPU increases by 37.53% compared to B2 RPU.

Experimental Study of Porous Concrete Material Thermal Insulation Material Lightweight Polystyrene Particles

In this paper, through the test to determine the polystyrene granule as aggregate, the cement foaming slurry as cementitious material, with various additives for the performance adjustment material, optimum matching of polystyrene particles made of lightweight aggregate cellular concrete heat preservation material ratio, was the influence of raw materials on the performance and the thermal insulation of building production technology product form and key.

Optimization of Belt-Type Electrostatic Separation of Triboaerodynamically Charged Granular Plastic Mixtures

Electrostatic separation is frequently employed for the selective sorting of conducting and insulating materials for waste electric and electronic equipment. In a series of recent papers, the authors have presented several novel triboelectrostatic separation installations for the recycling of the main categories of plastics contained in information technology wastes. The aim of the present work is to optimize the design and the operation of such an installation, composed of a belt-type electrostatic separator associated to a propeller-type tribocharging device. The experimental design method is employed for modeling and optimizing the separation of a mixture of high-impact polystyrene and acrylonitrile butadiene styrene granules originating from shredded out-of-use computer cases. A distinct experiment is carried out on three synthetic mixtures of virgin plastic granules: 75% polyamide (PA)+ 25% polycarbonate (PC), 50% PA+ 50% PC, and 25% PA + 75% PC. The best results are obtained for the mixtures containing equal quantities of the two constituents.

Fabrication and compressive properties of expanded polystyrene foamed concrete: Experimental research and modeling

As the construction of high-rise building becomes popular, improvement and innovation are required to expand the product line of lightweight concrete. In this paper, two ways of fabricating lightweight concrete were combined to make a new kind of super lightweight concrete. Normal aggregate is replaced with expanded polystyrene (EPS) granule, while foam is introduced to facilitate fabrication process. As a result, super lightweight concrete denoted as EPS foamed concrete is fabricated, whose bulk density is less than 500 kg/m3. Compressive properties of EPS foamed concrete with bulk density 300–500 kg/m3 were investigated by stress-strain curve. It’s demonstrated that the compressive strength ranges from 0.7 to 2.5MPa, which is higher than that of similar products. Furthermore, low elastic module and high residual to ultimate strength ratio ensure its excellent deformation and energy absorption capacity. At last, numerical analysis was performed to interpret the inherent variation of elastic modulus and failure mechanism of this material. The results show that EPS foamed concrete is a kind of super lightweight, easy to fabricate material with excellent compressive property and profound utilization potential.

The Energy Saving Effect Evaluation for Outside Wall with Different Material in Island District

In order to evaluate the energy saving effect for building outside wall under the damp island environment, the heat insulation performance of brick wall, MU10 concrete brick wall and aerated concrete are tested. The testing method is combined of infrared photos and heat flow meter. The results showed that the insulation performance of clay brick is worst, its heat transfer coefficient is 60% more than that required by energy saving standard. Although the concrete brick has painted 25mm polystyrene granule outside, the heat transfer coefficient is still smaller than energy saving standard required. The economic thickness of polystyrene granule is 79mm , which makes the both heating cost and insulating layer minimum during the life cycle of heat insulating layer. Among the three types of outside wall, only the aerated concrete can satisfy the energy saving standard for hot summer and cold winter district, it constitutes the self-insulating system.

The Cause Detection and Analysis of the Surface Cracks on ETIRS

The cause detection and analysis have been made over the surface cracks of external thermal insulating rendering systems made of mortar with bonding powder and using expanded polystyrene granule as aggregate (ETIRS) by means of integrating the basic concept of the cracks and actual project practices, on the basis of structure design, materials performances and construction. The result shows that the major causes for surface cracks, the hazardous ones are caused by poor construction quality. In order to guarantee the quality of external thermal insulation wall, the structure design of the said thermal insulation system shall be underlined and building quality on the key parts, stressed.

Decay of the electric potential at the surface of coronacharged uniform layers of HIPS granules

The aim of the present paper is to evaluate the factors that affect the discharge of mm-sized High-Impact Polystyrene (HIPS) granules forming uniform layers at the surface of grounded plate electrodes. The samples were charged using a triode-type electrode arrangement, consisting in: (i) a metallic plate connected to the ground; (ii) a wire-type corona electrode parallel to the grounded plate and energized from an adjustable dc power supply; (iii) a metallic grid of well-defined potential. The decay of the potential at the surface of the samples was measured with the capacitive probe of an electrostatic voltmeter (TREK, model 370). The experimental design methodology was employed for quantifying the effects of three variables that influence the process of potential decay at the surface of a corona-charged layer of insulating granules: (i) the initial potential, imposed by that of the grid electrode (range ±1000 to ±2800 V); (ii) the granule size (range 0.3 to 1.5 mm); (iii) the number of compact granular layers (1 to 3 layers). It was found that the surface potential decay is accelerated by the grid potential, but is slower for coarser, multi-layered granular samples. These results are useful for the design of the electrostatic separation processes involving this class of insulating materials.

Weatherability studies on external insulation thermal system of expanded polystyrene board, polystyrene granule and polyurethane foam

Atmospheric exposure tests including two experimental stages of high temperature-spraying water cycle and heating-refrigeration cycle were carried out on three currently used ETIS of expanded polystyrene (EPS) board, polystyrene granule mortar and polyurethane foam in order to study the weatherablility of external thermal insulation system (ETIS). The change rules of adhesive strength were hereby studied at different time period of atmospheric exposure tests. The experimental results show that the adhesive strength of three kinds of ETIS changes a little during high temperature-spraying water cycle, but the adhesive strength of ETIS with EPS board decreases significantly after heating-refrigeration cycle. The lowering rate of adhesive strength with painting finishes is obviously faster than that of tile finishes for ETIS of EPS board during heating-refrigeration cycle. The weatherability of ETIS with EPS board is worse than the other two, and ETIS of polystyrene granule mortar and polyurethane foam are more suitable than ETIS of EPS board in cold area.

Conversion of Waste Polystyrene into Porous and Functionalized Adsorbent and Its Application in Humic Acid Removal

Disposal of plastic waste has become an ever-increasing concern throughout the world. There has been considerable interest or demand for recycling plastic waste into higher-value products. In this study, an attempt has been made to convert waste polystyrene (PS) into porous and functionalized granular adsorbent for a potential application in humic acid removal. Porous PS granules were prepared via a dissolution/precipitation and etching/oxidation method, and their surfaces were modified with cross-linked polyethylenimine (PEI). The surface morphologies of PS granules, oxidized PS granules, and PEI-immobilized PS granules were examined with a scanning electron microscope (SEM), and the surface properties of these granules were investigated through Fourier transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC). The prepared PS granules had a more-or-less spherical shape with sizes in the range of 1.3−2.4 mm, depending on the polymer concentrations used. The etching/oxidation process resulted in highly porous granules, and their surfaces were activated with polar chemical groups, which facilitated the immobilization of PEI on the external and internal surfaces of the granules in a simple solution reaction process. The PEI-functionalized PS granules were demonstrated to be an effective adsorbent for humic acid removal.

Particle size effect on EPS lightweight concrete compressive strength: Experimental investigation and modelling

It had been observed [Parant, E., Le Roy, R., 1999. Optimisation des bétons de densité inférieure à 1. Tech. rep., Laboratoire Central des Ponts et Chaussées, Paris, France; Le Roy, R., Parant, E., Boulay, C., 2005. Taking into account the inclusions’ size in lightweight concrete compressive strength prediction. Cem. Concr. Res. 35 (4), 770–775; Ganesh Babu, K., Saradhi Babu, D., 2002. Behaviour of lightweight expanded polystyrene concrete containing silica fume. Cem. Concr. Res. 2249, 1–8; Laukaitis, A., Zurauskas, R., Keriene, J., 2005. The effect of foam polystyrene granules on cement composite properties. Cem. Concr. Compos. 27 (1), 41–47] that the compressive strength of expanded polystyrene (EPS) lightweight concrete increases significantly with a decrease in EPS bead size ( ϕ), for the same concrete (macro) porosity ( p) (EPS volume fraction). To confirm that this scaling phenomenon is an intrinsic particle size effect which is related to the EPS bead size ( ϕ) and not affected by a volume size effect related to the specimen size ( D), compressive tests have been carried out on homothetic EPS concrete specimens containing homothetic EPS beads. Moreover, five concrete (macro) porosities ranging from 10% to 50% have been investigated. Compressive tests results have confirmed the presence of a particle size effect on the EPS concrete compressive strength. Further, it is observed that this size effect is very pronounced for low porosity concretes and becomes negligible for very high porosity concretes. Based on EPS concrete failure modes analysis, a phenomenological model has been proposed with a view to explaining the EPS concrete particle size effect and predicting its normalized compressive strength according to the concrete (macro) porosity ( p) and to the ratio ϕ l c , where ( l c) is the width of the EPS concrete matrix fracture process zone (FPZ). The model predictions have been then compared with experimental results, showing a good agreement.

Determination of residual styrene monomer in polystyrene granules by gas chromatography–mass spectrometry

Polystyrene is widely used in formulations intended for children use. The main problem with this plastic is the residual styrene, which can migrate from the product, and therefore, be in contact with children. The acute toxicity of styrene is well known, raising the need of an efficient and fast method of analysis for this compound. Several extraction methods have been evaluated and compared for the determination of residual styrene monomer in polystyrene granules used in toys: supercritical fluid extraction (SFE), microwave-assisted extraction (MAE), Soxhlet extraction, headspace emission and dissolution-precipitation. The analyte was subsequently detected by gas chromatography (GC) with MS detection. The results indicated that the most efficient method was dissolution-precipitation giving even higher extraction efficiency than SFE. For validating the method, PS samples spiked with known quantities of styrene at three concentration levels were prepared to calculate the extraction recovery. The founded validation data proved the suitability of the proposed method.

The effect of foam polystyrene granules on cement composite properties

Abstract Crumbled recycled foam polystyrene waste as well as spherical large and fine blown polystyrene waste is used to produce the filler for a light thermo-insulating composite, the matrix of which is light foam cement. For better cohesion, fillers are hydrophilizated with foam cement surfactant solution. Polystyrene granules and foam cement concrete interaction schemes are discussed. The investigation of foam cement concrete and polystyrene granule contact zone showed that the contact of these two materials is very close, without any fractures or microcracks. Adherence of the two components depends on the size and shape of granules used. When a polystyrene granule is ripped out of foam cement concrete, the emerged “hole” closely repeats the structure of the granule and there is some polystyrene residue left in it. This proves the fact that foam cement concrete contact zone is stronger than the polystyrene granule material. When fine polystyrene granules are used, it disintegrates along the contact zone. Such composite has the lowest adhesion strength, however, it is stronger in comparison with a composite, made with different foam polystyrene granules, provided by better macrostructure. Strength and thermal conductivity of the composite depend on its density, the filler, its sort and amount used, and is defined by regression equations.

A Quasi-stationary Approach to Drying Kinetics of Fluidized Particulate Materials

A modified quasi-stationary method has been proposed to describe drying kinetics of particulate materials dried in convective dryers with active hydrodynamic regimes. Both our own results and literature data were used. These include sliced celery, cranberry, diced carrot, wheat and polystyrene granules dried in four types of dryers: pulsed fluid bed dryer, fluid bed dryer with a mixer, spouted bed dryer with a draft tube, and vortex dryer. The method was validated by comparing experimental data with results of modeling in terms of a reduced moisture content and material temperature. A new form of the generalized drying curve has been proposed with the reduced time and the index of hydrodynamic intensity as parameters. The equations developed can be used to calculate the total drying time and determine the temporal variation of the moisture content and material temperature.

An Investigation of the Possibility of Diameter Reduction for Polystyrene and Styrene-Divinylbenzene Copolymer Granules Obtained by Suspension Polymerization

The reduction in the mean diameter of polystyrene and styrene-divinylbenzene copolymer granules, brought about by suspension polymerization, has been investigated. For this purpose, emulsifiers containing hydrophilic polyethylene glycol fragments were added to a stabilizer [starch, poly(vinyl alcohol) or polymethacrylic acid with 10 mol% methylmethacrylate units]. The emulsifiers investigated such as ‘Stearox’ (20s-oxyethylated stearic acid), ‘Phenoxol’ (15s-oxyethylated phenol) and ‘APhO’ (10s-oxyethylated alkylphenol) were found to reduce the mean diameters of granules by a factor of 10 or more. The same tendency was observed when benzoyl peroxide was replaced by the surface-active oligomeric peroxide of sebacinic acid whose surface activity is due to the polymeric chain ends.

Macroreticular Hydrogel Effects on Dissolution Rate of Controlled-Release Fertilizers

The effects of cross-linked sulfonated polystyrene granules (soil conditioner) with three different absorptions of deionized water were investigated on the dissolution of three different K2SO4 fertilizers. One of the fertilizers used was water soluble, whereas the other two were controlled-release fertilizers with differing nutrient release rates. Soil columns regularly rinsed with water for a period of 3 months were used for testing. It was found for water-soluble fertilizer that the quantities of K leached from the columns increased with the absorption capacity of the polymers. In the case of application of the polymer with the highest absorption capacity (100 g of water g-1 dry polymer), the water-soluble K leached was 188% more than that leached from controlled-release formulations. It was found also that the presence of hydrogels in soil increased dissolution of controlled-release fertilizers. Yet, this increase was relatively small and did not depend significantly on absorption. Keywords: Controlled...

Experience with nutrient removal in a fixed-film system at full-scale wastewater treatment plants

In the upgrade of wastewater treatment plants to include biological nutrient removal the space available is often a limiting facor. It may be difficult to use conventional suspended growth processes (i.e. activated sludge) owing to the relatively large surface area required for these processes. Recent years have therefore seen a revived interest in treatment technologies using various types of attached growth processes. The “new” attached growth processes, like the Biostyr process, utilise various kinds of manufactured media, e.g. polystyrene granules, which offer a high specific surface area, and are therefore very compact. The Biostyr plants allow a combination of nitrification-denitrification and filtration in one and the same unit. The results obtained are 8 mg total N/l and an SS content normally below 10 mg/l. The plants in Denmark which have been extended with a Biostyr unit have various levels of PLC control and on-line instrumentation.

The Design of the Ballistic Furnace and Initial Microshells Formation Experiments

The design and operation of a new “Ballistic Furnace” facility at the Lebedev Physical Institute for producing large plastic shells from solid polystyrene granules is presented, along with the results of the first experimental trials. Good quality shells with diameters up to 1.7 mm have been produced, though surface debris is a serious problem. AFM surface characterization of these shells is presented. The formation of several shells from a single initial granule has been experimentally observed. Based on our initial experimental results, the problems, possible routes to their solution, and other upgrade possibilities for the Ballistic Furnace that will result in improved shell quality will be discussed.

Experience with nutrient removal in a fixed-film system at full-scale wastewater treatment plants

In the upgrade of wastewater treatment plants to include biological nutrient removal the space available is often a limiting facor. It may be difficult to use conventional suspended growth processes (i.e. activated sludge) owing to the relatively large surface area required for these processes. Recent years have therefore seen a revived interest in treatment technologies using various types of attached growth processes. The “new” attached growth processes, like the Biostyr process, utilise various kinds of manufactured media, e.g. polystyrene granules, which offer a high specific surface area, and are therefore very compact. The Biostyr plants allow a combination of nitrification-denitrification and filtration in one and the same unit. The results obtained are 8 mg total N/l and an SS content normally below 10 mg/l. The plants in Denmark which have been extended with a Biostyr unit have various levels of PLC control and on-line instrumentation.

New Technology for Waste Water from Water-Washed Paint Spray Booths

A new procedure for treatment of waste water from water-washed paint spray booths was developed. This technology has been established on a modular basis. All process units have a new design and were developed in our previous projects. The treatment included chemical coagulation in a special fixed-bed reactor, suspended solids separation in deep-bed filter with floating media, and adsorption. Experiments were realized both on the bench and pilot-plant scale. Some commercial coagulants and flocculants were used in chemical treatment. Jar-tests were performed to select reactants and determine optimum doses. Pilot-plant tests were conducted with aluminium sulphate as coagulant (optimum dose 160–180 mgl−1) and polyacrylamide as flocculant (optimum 1–1.5 mgl−1). Domestic bauxite, perlite, zeolite and activated carbon were used as adsorbents in laboratory tests. Expanded polystyrene granules were used as packing material in the multipurpose reactor and deep-bed filter. The following characteristics of expanded polystyrene and adsorbents were measured: main diameter, effective diameter, uniformity, bulk density, density, bed porosity (on the basis of sieve analysis), permeability, zeta-potential, microstructure, and surface morphology. The efficiency of each step was estimated on the basis of COD values and suspended solid content in the influent and effluent. The efficiency of chemical coagulation step after deep-bed filtration was from 30 to 72%, whereas total efficiency, including adsorption, was from 66 to 86%, all estimated on the basis of COD values.

Two-Stage Coalescer for Oil/Water Separation

Many different types of coalescers are used for separation of oil-in-water dispersion. The investigated results of a newly developed two stage coalescer are given in this work. The proposed designofthis coalescer includes two independent stages which are set in the same coalescer body. Expanded polystyrene granules are being used in the first stage. By using this coalescent material, gravity separation and the large oil droplets, coalescence processes are at the same time being insured. The second stage of this new type of coalescer uses polyurethane foam. The surface of this layer has been previously oiled. the proposed two stage coalescer has been tested for different type of oily wastewaters. A high loaded oilywastewater has been treatedby the new coalescer separator in the field In a one year working period, a mean oil separation efficiency has been higher than 98 %. The proposed coalescer can be use for suspended solids separation at the same time. Mean separation efficiency has been 85% duringthe field test.