Polycarbonate/acrylonitrile-butadiene-styrene Research Articles

Electrostatic separation of HIPS/ABS and HIPS/ABS-PC plastic mixtures from IT equipment using fluidized bed tribocharging

The paper presents an experimental study of the triboelectrostatic separation feasibility of two plastic mixtures, high-impact polystyrene (HIPS)/acrylonitrile butadiene styrene (ABS) and high-impact polystyrene (HIPS)/acrylonitrile butadiene styrene-polycarbonate (ABS-PC). To mirror real-world material recovery situations, the mixtures of 1-2 mm granular samples were sourced from Information Technology (IT) waste. In addition to balanced composition mixtures of 50% component A and 50% component B, heavily unbalanced compositions such as 10% A/90% B and 90% A/10% B were used in this study. The laboratory set-up consists in a free fall electrostatic separator equipped with a fluidized bed tribocharging device, characterized by interchangeable tribocharging chambers. Preliminary tests established the optimal material for the tribocharging chamber and the duration of the charging process. Samples of granular mixture were tribocharged, then introduced into the free-fall electrostatic separator. The analysis of the seven collecting boxes contents shows a recovery rate of approximately 90% and a purity of about 99% for both components. These results demonstrate the feasibility and the high efficiency of the triboelectrostatic separation of balanced and as well as heavily unbalanced composition mixtures of HIPS/ABS and HIPS/ABS-PC, using the fluidized bed for the tribocharging device.

Thermo-mechanical variability of post-industrial and post-consumer recyclate PC-ABS

The aim of this work is to investigate the performance variability of post-industrial (PIR) and post-consumer recycled (PCR) polycarbonate acrylonitrile-butadiene-styrene (PC-ABS). In addition, necessary testing methodology for understanding polymer variation in recycled polymers are established. The thermal expansion behaviour of all tested material were found to be similar and FT-IR testing revealed no conclusive evidence of oxidative degradation. Both PIR and PCR exhibited similar levels of variation in mechanical properties compared with prime samples, with the exception of elongation at break and quasi-static impact behaviour. In these two tests, prime polymers showed lower variation and superior performance to both recycled polymers. The presence of defects and changes in molecular weight were determined to be leading causes of the reduced deformability. Our work contributes by identifying key areas where recycled PC-ABS show good potential as replacements for neat PC-ABS. Furthermore, the work demonstrates methods for material testing against performance criteria to pave way for effective replacement of neat PC-ABS with its recycled counterparts.

Effects of blend composition on the morphologies and physical properties of polycarbonate/acrylonitrile‐butadiene‐styrene blends

AbstractThe morphologies and physical properties of twin‐screw‐extruded polycarbonate/acrylonitrile‐butadiene‐styrene (PC/ABS) blends with various blend ratios are studied. The needle‐like co‐continuous phase in PC‐rich blends changes to the sea‐island phase for blend ratios of more than 50 wt% ABS. While pure PC exhibits an almost‐Newtonian flow behavior, PC/ABS blends exhibit the interesting rheological transition. The viscosities of the ABS‐rich blends at low shear rates are almost equal to those of the pure ABS polymer. The yield stress for the PC/ABS blend ratio of 3:7 is the highest in composition. At the frequency of 10 rad/s, the PC‐rich blends exhibit highly viscous properties, whereas the ABS‐rich blends present highly elastic properties as the temperature increases. Moreover, the ABS polymer in the PC/ABS polymer blend induces significant change at the fracture surface of PC, transitioning from brittle to ductile nature.

A Study on the Physical Properties of Polycarbonate/Acrylonitrile-Butadiene-Styrene Blends with Various Thermal Stabilizers to Secure the Safety of Automobile Passengers

Deterioration of polymer materials can cause breakdown of various automobile parts during their life cycles, which is a threat to the safety of occupants. In the research described here various thermal stabilizers were incorporated into polycarbonate/acrylonitrile-butadiene-styrene (PC/ABS) blends, often used in automotive parts, to investigate the thermal degradation of PC/ABS as a function of mixing rate and mixing time and as a function of stabilizer type and content. A phenolic stabilizer, octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate (S1) and two kinds of phosphite stabilizers, tris-(2,4-di-tert-butyl-phenyl phosphite) (S2) and bis(2,4-dicumylphenyl) pentaerythritol diphosphite (S3) were used. Thermogravimetric analysis (TGA) and differential scanning calorimeter (DSC) results showed that high mixing rates, over 2000 rpm, caused high shear heating, which brought about thermal degradation of the polymer blends. The S3 better prevented thermal degradation of the PC/ABS blends during high speed processing compared to the other stabilizers. Characterization of the mechanical properties of the blends prepared at a screw speed of 1000 rpm for 20 sec indicated decreases in elongation at break from 148% prior to processing to 63% for S1, 108% for S2 and 131% for S3, whereas the tensile strengths showed only slight changes. Scanning electron microscope (SEM) images indicated that the size distribution of the dispersed phase was decreased with increasing screw speed and mixing time. The interfacial tension of the blends decreased with increasing mixing rate, whereas it did not exhibit significant change with increasing mixing time.

Double percolation and segregated structures formed in polymer alloy with excellent electrical conductivity

AbstractIt can efficiently enhance electrical conductivity and electromagnetic interference (EMI) shielding performance to construct segregated structures in conductive polymer composites (CPCs). However, it can also deteriorate mechanical properties due to weak interfacial interaction between matrixes and fillers. So segregated structures CPCs that polycarbonate/acrylonitrile‐butadiene‐styrene (PC/ABS) was coated by ABS/multi‐walled carbon nanotubes (ABS/MWCNTs) were prepared by solution‐mechanical mixing method. The surface resistivity of the segregated composites achieved 105 Ω/sq with only 0.05 wt% of MWCNTs and was lower than composites prepared by melt and solution mixing methods. Tensile strength of the segregated composites was nearly 40 MPa. The EMI shielding values of the segregated composites with 7 wt% of MWCNTs were 50 to 80 dB as high as the uniform structure composites with 10 wt% of MWCNTs between 30 MHz and 1 GHz electromagnetic frequency. All the results displayed that this work provided a novel and efficient method to produce segregated conductive composites for antistatic and EMI shielding applications.

Laser-Induced Selective Electroless Plating on PC/ABS Polymer: Minimisation of Thermal Effects for Supreme Processing Speed.

The selective surface activation induced by laser (SSAIL) for electroless copper deposition on Polycarbonate/Acrylonitrile Butadiene Styrene (PC/ABS) blend is one of the promising techniques of electric circuit formation on free-shape dielectric surfaces, which broadens capabilities of 3D microscopic integrated devices (3D-MIDs). The process consists of laser excitation, chemical activation of laser-excited areas by dipping in a liquid and electroless copper deposition of the laser-treated areas. The limiting factor in increasing throughput of the technology is a laser activation step. Laser writing is performed by modern galvanometric scanners which reach the scanning speed of several meters per second. However, adverse thermal effects on PC/ABS polymer surface abridge the high-speed laser writing. In this work, an investigation was conducted on how these thermal effects limit surface activation for selective metal deposition from the view of physics and chemistry. An advanced laser beam scanning technique of interlacing with precise accuracy and the pulse-on-demand technique was applied to overcome mentioned problems for fast laser writing. Initially, the modelling of transient heat conduction was performed. The results revealed a significant reduction in heat accumulation. Applied methods of laser writing allowed the overall processing rate to increase by up to 2.4 times. Surface morphology was investigated by a scanning electron microscope. Energy-dispersive X-ray spectroscopy was used to investigate the modification of atomic concentration on the surface after laser treatment. Experiments did not show a correlation between surface morphology and electroless plating on laser-treated areas. However, significant variation in the composition of the material was revealed depending on the surface activity for electroless plating.

Rheological Investigation of Relaxation Behavior of Polycarbonate/Acrylonitrile-Butadiene-Styrene Blends.

The rheological properties of polycarbonate/acrylonitrile-butadiene-styrene (PC/ABS) blends with various blend ratios are investigated at different temperatures to determine the shear dependent chain motions in a heterogeneous blend system. At low frequency levels under 0.1 rad/s, the viscosity of the material with a blend ratio of 3:7 (PC:ABS) is higher than that of pure ABS polymer. As the temperature increases, the viscosities of ABS-rich blends increase rather than decrease, whereas PC-rich blends exhibit decrease in viscosity. Results from the time sweep measurements indicate that ordered structures of PC and the formation and breakdown of internal network structures of ABS polymer occur simultaneously in the blend systems. Newly designed sequence test results show that the internal structures formed between PC and ABS polymers are dominant at low shear conditions for the blend ratio of 3:7 and effects of structural change and the presence of polybutadiene (PBD) become dominant at high shear conditions for pure ABS. The results of yield stress and relaxation time for PC/ABS blends support this phenomenon. The specimen with a blend ratio of 3:7 exhibited the highest value of yield stress at high temperature among others, which implies that the internal structure become stronger at higher temperature. The heterogeneity of ABS-rich blends increases whereas that of PC-rich blends decreases as temperature increases.

Mobilisation kinetics of Br, Cd, Cr, Hg, Pb and Sb in microplastics exposed to simulated, dietary-adapted digestive conditions of seabirds

Samples of beached plastics and historical and contemporary consumer plastics containing hazardous elements derived from reaction residues or functional additives have been micronised and subject to extraction conditions representative of the digestive environment of seabirds. Mobilisation of Br, Cd, Cr, Hg, Pb and Sb into NaCl solution, an avian physiologically-based extraction test (PBET) and a dietary-adapted PBET (DA-PBET) incorporating fish oil as part of the avian diet was monitored by ICP-MS over a 168-h period. Kinetic data were subsequently fitted using pseudo-first-order and parabolic diffusion models in order to derive rate constants for the release of hazardous elements during avian digestion of microplastics. Rate constants were variable and dependent on the nature and origin of plastic, type of residue or additive, extractant solution employed and model applied. Resulting estimates of bioaccessibility, defined as the equilibrium or maximum concentration of an element mobilised over the time course relative to its total concentration, were variable but considerable in many cases. Specifically, maximum values of about 65% of Cd and 100% of Pb were observed in consumer polycarbonate-acrylonitrile butadiene styrene exposed to the avian PBET and beached polyurethane exposed to the DA-PBET, respectively. The potential health risks of hazardous elements in microplastics are addressed and criteria for classification based on the European Toy Safety Directive migration (mobilisation) limits are proposed.

Process Development: Burr and Film Formation during High Speed Punching of Extruded PC Based Polymers

First investigations focus on the usage, processing and material properties of polycarbonate (PC) based materials used in cable duct production. Test coupons were taken from in-situ cable ducts including further additives generally used in industry. Different mechanical and optical analytical methods were performed. Significant differences in tensile properties of polycarbonate/ acrylonitrile butadiene styrene (PC/ABS) compared to mineral reinforced PC were observed. The hardness of mineral reinforced PC is significantly dependent on the geometry of the cable ducts. The fracture behavior and morphology of the PC/ABS fracture surface is directly related to the coupon temperature during Charpy impact testing. The process temperature influences the failure behavior during high impact processing such as high speed punching. Due to the lower impact strength of mineral reinforced PC less film and burr formation compared to PC/ABS are likely. However, the mineral distribution is not homogeneous and therefore subject to further investigation. This study aims at a better understanding of process properties of PC/ABS products, parameter selection, quality improvement and general understanding of underlying microstructural and surface properties.

Multi Objective Optimization of Fused Deposition Modeling Parameters for PC/ABS Blend Material Parts using GRA

In this research, multi objective optimization is done on Fused Deposition Modeling (FDM) printing machine for Polycarbonate/Acrylonitrile Butadiene Styrene (PC/ABS) blend material parts. Reductions in part build time and material consumption without compromising its dimensional accuracy and mechanical properties are the major goals of many industries, because there is need to fulfil one part with multiple qualities. So that in this research, part printed without support structure by controlling five FDM process parameters at three levels such as layer thickness, raster width, extrusion temperature, bed temperature and printing speed by using Taguchi’s design of experiments method (L27 Orthogonal Array). This research can saves part build time, post processing time on support removal and damages occurred due to removal of support structure in part. For that, in this research effects of parameters are studied on surface roughness, build time, and flatness error of overhang structure of parts. Then Grey Relational Analysis (GRA) methodology is used for multi-objective optimization of FDM parameters to find best set of parameters for three responses. Analysis of Variance (ANOVA) is also used to find out significant parameters for multi responses and then confirmation test of experimental results also performed to verify the optimal settings of FDM parameters. The experimental result showed, layer thickness, raster width and part printing speed have the more significant effects on multiple performance characteristics.

Mechanical characterization and experimental modal analysis of 3D Printed ABS, PC and PC-ABS materials

Additive manufacturing (AM) process builds the parts, layer by layer precisely from Computer-Aided Design (CAD) models, whereas traditional subtractive manufacturing process removes layers from materials to attain the desired shape. Of late Rapid prototyped (RP) parts are used for the direct production of components for manufacturing and testing in the industries. Understanding material, machine used along with the process variables that affect the strength of the final part gains importance as the parts can be printed directly from CAD data and effectively integrated into structures. The main aim of this investigation is to present the mechanical characterization and free vibration analysis of various 3D printed Engineering Plastic Materials. Acrylonitrile Butadiene Styrene (ABS), Polycarbonate (PC), and Polycarbonate–Acrylonitrile Butadiene Styrene (PC-ABS) materials are used in this study. Spools are prepared from plastic pellets using wire extruder. Tensile tests have been performed on dog bone specimens to evaluate strength, fractured specimen’s surfaces which are further evaluated using Field Emission Scanning Electron Microscope (FESEM) to explore fracture of the raster and bonding between layers. From the experimental results it’s noticed that the PC-ABS material exhibits improved elastic limit and load-carrying capacity compared with ABS and PC. Three types of beams are fabricated using different materials and modal analysis has been conducted to predict the stiffness of beams in terms of natural frequencies under clamped free (CF) and clamped clamped (CC) end conditions. Higher natural frequencies observed with PC-ABS is compared with the rest of the materials.

Adjusting the Punching Process of Poly Vinyl Chloride (PVC) and Polycarbonate/ Acrylonitrile Butadiene Styrene (PC/ABS) Cable Ducts Using High-Speed Video Recordings

Adjusting the Punching Process of Poly Vinyl Chloride (PVC) and Polycarbonate/ Acrylonitrile Butadiene Styrene (PC/ABS) Cable Ducts Using High-Speed Video Recordings

High-speed tensile testing of extruded PC based polymers for cable ducts

Previous tensile tests at 50, 100 and 400 mm/min using standard polycarbonate/acrylonitrile butadiene styrene (PC/ABS) material qualities have led to the suspicion that strain at break decreases with increasing test speed. Here, the plastic deformation component is regarded as the main burr cause. Thus, higher process speeds during punching would lead to less burr formation. This thesis was proven by high-speed tensile tests with a self-developed test rig operating at a test speed of 36.000 mm/min. Both, pure standard materials, provided by a polymer granules supplier, and customized materials were investigated. The customized materials contain unknown additives generally used in industry, e.g. fillers. All samples were taken laterally from in-situ cable ducts. The remaining plastic strain was introduced as material parameter to compare the results of high-speed and conventional tensile tests. The investigations show that the remaining plastic strain which is understood as the major burr cause decreases with increasing test speed. Furthermore, the mean values of the remaining plastic strain of the individual materials converge when exposed to higher test speeds. This leads to the thesis that one tool configuration can be used for different polycarbonate (PC) based materials presumed the process speed is adjusted correctly.

Torsional fretting wear experimental analysis of a R3 offshore steel against a PC/ABS blend

Abstract The mooring lines of offshore vessels are composed of metallic chains coupled with polyester cables. In this setting, failure of a single chain link can result in severe financial losses, environmental disaster and deadly hazard to personnel. It is known that fretting wear due to torsional reciprocating movement is one of the main causes of early failure of a R3 offshore steel chain link. In this study, a possible option to increase the lifespan and reliability of mooring chains is presented. The torsional fretting wear behavior of a Polycarbonate/Acrylonitrile-Butadiene-Styrene (PC/ABS) 60:40 blend is compared to the reference configuration. Wear scars are investigated using confocal microscopy analysis. The PC/ABS, despite having a much weaker structure and higher wear rate, shows a considerably more predictable wear behavior. It is concluded that, a PC/ABS coating can lead to a significant increase in reliability of operation and lifespan of a mooring system.

Auto-sorting commonly recovered plastics from waste household appliances and electronics using near-infrared spectroscopy

Abstract The recycling of plastics from Waste electrical and electronic equipment (WEEE) was constrained by the mix of types. Near-infrared (NIR) spectroscopy is suitable for polymer detection, and it is a rapid, non-destructive analysis method that can be applied to automatic on-line sorting system. The NIR spectra of four commonly recovered WEEE plastics, which are polypropylene (PP), polystyrene (PS), acrylonitrile butadiene styrene (ABS), and acrylonitrile butadiene styrene/polycarbonate (ABS/PC) blend, was collected. The flame-retardant ABS showed difference from ABS in NIR spectra. Three classification methods, which are spectral angle mapper (SAM), partial least squares discriminant analysis (PLS-DA) and linear discriminant analysis combined with principal component analysis (PCA-LDA), was tested. And the classification models trained on the virgin plastics have been compared with the models trained on the WEEE plastic to evaluate how these methods perform under limited training data. PLS-DA is one of the most widely used classification method in spectral data analysis, but it had unsuccessful prediction when the training set only included virgin plastics. But the overall prediction accuracy over 99% could be achieved by the other two whether the training set was the spectra of virgin plastics or WEEE plastics. In general, NIR spectroscopy has the competency of separating WEEE plastics. Finally, an automatic on-line sorting system was designed specifically for the large plastic segments from household appliances and electronics.

Internal Reconfigurable Dipole–Loop Antenna Array for High Reception Rate of Wideband UHD-TV Applications

An internal reconfigurable Dipole–Loop antenna array, covering the entire ultra-high frequency (UHF) band for ultra-high definition television (UHD-TV) applications is presented. The internal antenna array is used to overcome the influence of electromagnetic interference when integrating the antenna element inside the TV model and to increase the gain and reception rate of receiving signals for television broadcasting. The antenna array is designed based on the Dipole–Loop antenna elements, placing on substrate material PC-ABS (polycarbonate-acrylonitrile butadiene styrene: er = 3.5, tan δ = 0.005) of the bezel frame in the TV model. By simultaneously switching PIN diodes with two ON/OFF states, the antenna array can be frequency reconfigured to achieve a wide operating bandwidth for UHF (470–771 MHz) band. The spacing between the antenna elements in the array at each mode is chosen as 0.5λ0 (λ0 represents the free space wavelength of the highest frequency in the operating band). The proposed antenna array is designed, fabricated, and tested for experimental verification. Measurement results show that the antenna array is good for high reception rate of UHD-TV applications, with a − 6 dB impedance bandwidth of 51.6% (460‒780 MHz), covering the whole UHF band. The 3 dB gain bandwidths of 42.5% and 54.6% are obtained with peak realized gains of 9.6 dBi and 8.5 dBi for the horizontal and vertical polarizations, respectively. In addition, the diversity performance parameters are obtained and evaluated using the mean effective gains of the elements, and the diversity gain using both simulation and measurement results. It shows that the proposed antenna array can receive multi-side signals, applied in diversity and MIMO systems.

Optimization of the injection molding process for the PC/ABS parts by integrating Taguchi approach and CAE simulation

This study was an application of the Taguchi method to optimize injection molding (IM) process parameters of the polycarbonate/acrylonitrile-butadiene styrene (PC/ABS) blends. A 4-factor, 3-level injection experiment was conducted using Taguchi L9 orthogonal array through the statistical design method. The parameters considered were material temperature, injection pressure, holding time, and mold temperature. The signal-to-noise (S/N) ratio was performed to obtain higher shear stress by defining the optimum injection parameters. The Taguchi method showed that injection pressure was the most influential parameter on the shear stress for the PC/ABS blends. The optimal injection parameter levels tested via Taguchi were verified via CAE simulation. SW plastics software was used to predict if the injected part contained injection defects through computation of key parameters such as the easy filling, the flow front central temperature, and the residual stress. The numerical simulation showed no injection defects observed on the injected PC/ABS parts. Therefore, the optimal combination parameters provided injected PC/ABS parts with a better shear stress and no injection defects. Such conditions would enhance the metallization process.

Improving the filament weld-strength of fused filament fabrication products through improved interdiffusion

Fused Filament Fabrication (FFF) is a popular additive manufacturing technique where molten polymer filament is applied in a raster pattern, layer by layer, to obtain the work piece. A necessary consequence of this method is a pronounced mechanical anisotropy of the product; the interface between the filaments is weaker compared to the filament itself. The strength of this interface is governed by the reptation theory which postulates a more efficient interpenetration of polymeric surfaces with decreasing polymer viscosity. This relationship was utilized in this work to modify a polycarbonate-acrylonitrile butadiene styrene polymer blend to produce FFF work pieces with less mechanical anisotropy, independent of printer settings. The tensile strength ratio of the printed interface to bulk tensile strength could be increased from 41% to 95%. Though the absolute bulk tensile strength decreases slightly, this method presents an easy and effective way to address the mechanical problems inherent in the FFF-method.

Compact broadband internal monopole antenna with parasitic strips and sleeve feed for UHD‐TV applications

In this study, an internal antenna integrated into a 49-inch TV model is presented, operating in the ultra-high frequency (UHF: 470‒771 MHz) band for signal reception in ultra-high definition television (UHD-TV) applications. The design of the proposed antenna has encountered major challenges such as relatively narrow impedance bandwidth, limited space, the effect of material properties, and the electromagnetic interference from the other components inside the TV that deteriorate the performance of the antenna considerably. The antenna is positioned directly on the bezel frame (made of polycarbonate-acrylonitrile butadiene styrene: ԑ r = 3.5, tan δ = 0.005) of the TV model as the substrate for the antenna. A monopole-type antenna is chosen to easily implement along the long side of the bezel frame in a very narrow spacing between the display and the casing of a TV (∼2.5 mm). Combined with a sleeve feed, tapered line, and parasitic strips, the proposed internal antenna exhibits a wideband impedance characteristics. The measured results show that a radiation efficiency of higher than 70% and a peak gain of 4.8 dBi are obtained over the operating frequency range of 430‒940 MHz (relative bandwidth of 75%), which cover the entire UHF band. These results indicate that the proposed antenna is very suitable for UHD-TV applications.

Bandwidth and directivity enhancement of an internal folded monopole antenna loaded by interdigital capacitor for ultra‐high‐definition television applications

AbstractAn internal antenna with bandwidth and directivity enhancement was developed for operation in ultra‐high‐frequency bands (UHF: 470‐771 MHz, bandwidth: 48.5%) for ultra‐high‐definition television (UHD‐TV) applications. The antenna is integrated into a 49‐in. TV model, which is surrounded by a bezel frame made of polycarbonate‐acrylonitrile butadiene styrene (PC‐ABS) plastic. This material was also used as a substrate in fabricating the antenna. The antenna has a compact size of 0.387λL × 0.023λL × 0.0093λL (where λL is the wavelength at the lowest operating frequency) and is fed by a 50 Ω coplanar waveguide (CPW) feedline. To achieve wideband operation and directional radiation, the proposed internal antenna was designed on the basis of a folded monopole antenna loaded with parasitic strips and an interdigital capacitor. The experimental results showed that the antenna exhibits a wide impedance bandwidth of 86% (400‐1000 MHz) under the criterion |S11| ≤ −6 dB (Voltage Standing Wave Ratio (VSWR) ≤ 3), a directional radiation pattern with a maximum realized gain of 5.2 dBi, and a radiation efficiency of more than 68%. These findings indicate that the antenna is suitable for UHD‐TV applications.