Polycarbonate/acrylonitrile-butadiene-styrene Research Articles

Development of a Zr-Based Metal-Organic Framework (UiO-66) for a Cooperative Flame Retardant in the PC/ABS.

Polycarbonate/acrylonitrile butadiene styrene (PC/ABS) blends are widely used as engineering plastic alloys; however, they have a low fire safety level. To improve the flame-retardant property of PC/ABS, a zirconium-based metal-organic framework material (UiO-66) was synthesized with zirconium chloride and terephthalic acid and used as a flame-retardant cooperative agent. Its flame-retardant performance and mode of action in the PC/ABS blends were carefully investigated. The results showed that UiO-66 had good thermal stability and delayed the pyrolysis of the materials, thus significantly enhancing the efficiency of intumescent flame retardants. By compounding 7.0 wt% hexaphenyloxy-cyclotri-phosphazene (HPCTP) with 3.0 wt% UiO-66, the PC/ABS blends reached a limiting oxygen index value of 27.0% and V0 rating in the UL-94 test, showing significantly improved resistance to combustion dripping. In addition, UiO-66 enhanced the smoke and heat suppression characteristics of the intumescent flame-retardant materials. Finally, the flame-retardant mode of action in the blends was indicative of UiO-66 having a cooperative effect on the flame-retardant performance of PC/ABS/HPCTP materials. This work provides good ideas for further development of the flame-retardant ABS/PC.

Experimental Investigation of Processing Temperature Effect on Adhesive Bond Strength Between Engineering Thermoplastics in the Plastic Injection Molding Process

Abstract Multicomponent injection molding industry is experiencing a growth due to its ability to reduce production costs and streamline processes. However, compared to single injection, multicomponent injection molding introduces interface regions where multiple engineering polymers meet. Consequently, it is essential to comprehend and enhance the adhesive bonding strength properties of these polymers. This study investigates the adhesive bond strength of polymer–polymer multimaterial molding using two-shot bi-injection and overmolding techniques. The research also emphasizes the influence of injection molding process parameters of mold temperature and melt temperature on the adhesive bond strength of polycarbonate (PC), polycarbonate–acrylonitrile butadiene styrene (PC–ABS), acrylonitrile butadiene styrene (ABS), and styrene ethylene butadiene styrene (SEBS). Tensile strength results revealed that the bi-injection method yields the highest interface strength, approximately 10 MPa lower than the reference value for single-material hard–hard plastics. Results from overmolded samples for both injection sequences are presented, indicating that material with low melting temperature was found to be the first injected part for better adhesion strength. Empirical equations for estimating adhesion strength were derived as a function of interface temperature obtained from CAE numerical simulations and polymer glass transition temperatures. The proposed equation achieved R2 values greater than 0.96. This empirically derived equation will serve as a guide for multi-injection manufacturing processes.

Copper oxide decorated one-dimensional mineral nanorods: Construction of strengthened gas-phase and condensed-phase coupled intumescent flame retardant

Polycarbonate/acrylonitrile–butadiene–styrene (PC/ABS) features superior mechanical properties but suffers from high flammability, presenting a grand challenge in enhancing its flame retardancy with halogen-free additives. Herein, we developed an efficient flame-retardant system (BH/CuATP) by incorporating phosphazene additive (HP), copper oxide modified attapulgite (CuATP) and bisphenol A bis (diphenyl phosphate) (BDP). This system achieves a UL-94V-0 rating without melt-dripping and leads to reductions in the peak heat release rate (43.1 %), total heat release (29.8 %) and total smoke production (5.7 %). The strength effect of CuATP in both gas-phase and condensed-phase significantly contributes to its enhanced fire safety. Additionally, the mechanical properties of PC/ABS/B1H1/CuATP1 are improved due to the rod-like CuATP, showing enhanced comprehensive properties superior to other reported systems. This work presents valuable insights into the effectiveness of mineral-strength intumescent flame retardancy for PC/ABS, offering practical guidance for the development of high-performance PC/ABS composites.

Effect and mechanism study of mixed‐dimensional palygorskite clay on thermo‐stability, flame‐retardant and smoke‐suppression for PC/ABS composites

AbstractThis investigation investigates the effects and mechanisms of mixed‐dimensional palygorskite clay (MDPal) on the thermal stability, flame retardancy and smoke suppression of polycarbonate/acrylonitrile‐butadiene‐styrene (PC/ABS) composites. MDPal, comprising palygorskite and illite as its main mineral components, is characterized by its interwoven morphology and the presence of Fe ions in its octahedral framework, making it highly promising for enhancing the fire safety of flammable composites. The incorporation of MDPal at a 10 wt% dosage leads to significant improvements in the fire safety of PC/ABS composites, including the reduction of 29.8% in peak heat release rate, 9.9% in total heat release, 34.5% in peak smoke production rate and 15.7% in total smoke production compared to pure PC/ABS. Besides, there is a notable increase of 31.5% in tensile strength and 80.4% in elongation at break when the content is 5 wt%. This research offers valuable insights into the application of MDPal for enhancing the thermal stability, flame retardancy and smoke suppression of flammable polymers.Highlights MDPal plays dual functions in gas and condensed phases as a flame retardant. MDPal effectively reduces the heat and smoke release of PC/ABS composites. MDPal improves the thermo‐stability and tensile strength of PC/ABS composites. The flame‐retardant and smoke‐suppression mechanisms of PALC are elucidated.

Effects of Gamma Irradiation on the Tensile Properties of 3D-Printed Polycarbonate Acrylonitrile Butadiene Styrene

3D printing is now being applied in various research areas due to its ability to produce highly complex parts whenever needed. This is highly helpful in the fields of robotics; radiation environment monitoring and space applications where stand-alone equipment are usually required. In this work, FDM 3D-printed polycarbonate acrylonitrile butadiene styrene (PCABS) samples were subjected to 1 kGy to 9 kGy of gamma irradiation from a Cobalt-60 irradiator. Parameters such as infill density and dose rate were modified to determine the best setting to improve the mechanical characteristics of the 3D-printed thermoplastic. Results show that samples with lower infill density obtain higher ultimate strength when exposed to higher doses of radiation.

A low pollution surface pretreatment of PC‐ABS under acidic conditions

AbstractIn the present study, the low pollution acidic potassium permanganate system has been used in the study of its micro‐etching effect on polycarbonate‐acrylonitrile butadiene styrene (PC‐ABS). Prior to micro‐etching using a N methyl pyrrolidone (NMP)‐glycol butyl ether solution was used as the swelling system of PC‐ABS. Reasonable swelling conditions were determined, a 2‐min expansion period at a temperature of 35°C with an NMP concentration of 80%. After the swelling processes, the effects of the volume ratio of :, micro‐etching temperature, and micro‐etching duration on the PC‐ABS surface morphology, surface roughness, surface hydrophilicity, and peel strength, have been investigated. It was finally determined that the best micro‐etching effect could be obtained by reacting at : = 1:2 and a temperature of 60°C for 25 min. The surface of the PC‐ABS copolymers was characterized by x‐ray photoelectron spectroscopy, atomic force microscopy, and Fourier‐transform infrared spectroscopy. The results showed that the micro‐etching process changed the morphology of the PC‐ABS surface and generated cavities. In addition, the surface roughness increased from the initial Ra = 9.69 to Ra = 197 nm. Also, the water contact angle on the PC‐ABS surface decreased from 92.2° to 28.6°, and the peel strength increased to 0.98 kN/m.

Multi-material 4D printing to realize two-phase morphing in self-actuating structures

4D printing has garnered significant attention within the field of engineering due to its capacity to introduce novel functionalities in printed structures through shape-morphing. Nevertheless, there persist challenges in the design and fabrication of intricate structures, primarily stemming from the intricate task of controlling variables that impact morphing characteristics. In order to surmount these hurdles, the approach of multi-material 4D printing is employed, underpinned by parametric studies, to actualize complex structures through a two-phase morphing process. This study specifically investigates the utilization of acrylonitrile butadiene styrene (ABS) and polycarbonate/ABS. The distinction in glass transition temperatures within these materials enables the realization of two distinct morphing phases. The research delves into the impact of structural parameters on morphing properties. Finite element analyses are subsequently conducted, leveraging the insights gained from parametric studies, to facilitate the accurate prediction of a diverse array of shape alterations in response to temperature fluctuations. Several structural models are both simulated and fabricated to experimentally validate the precise forecasting of desired morphing phases. The culmination of this study manifests in the design and fabrication of multiple multi-material structures, exemplifying both their functionality and intricate geometric complexity.

The Influence of Graphite Filler on the Viscoelastic and Mechanical Characteristics of PC/ABS Hybrid Composite for Automotive Applications

This work aims to enhance the viscoelastic and mechanical properties of the neat Polycarbonate/Acrylonitrile Butadiene Styrene (PC/ABS) blend by incorporating graphite filler. Thermoplastic composites were prepared with PC/ABS as the matrix and graphite powder as fillers of 3, 6, and 9 wt% by injection molding. The influence of graphite particulate on the mechanical properties of PC/ABS/graphite composite was studied through tensile strength, tensile modulus, percentage elongation, impact strength, flexural strength, and modulus. The results show a 20% improvement in the tensile and flexural modulus of the PC/ABS/graphite composite compared to the neat PC/ABS blend. However, the tensile strength and percentage elongation were reduced by 11.64% and 29.63%, respectively. The storage modulus with 9 wt% of graphite in the PC/ABS blend has the highest modulus over the entire temperature range compared to the neat PC/ABS blend. The addition of graphite filler to the PC/ABS blend increased the tensile, flexural, and storage modulus, even though some mechanical attributes were compromised. The viscoelastic, mechanical, and thermal properties were enhanced by adding graphite as a filler to help plastic product designers design plastic products for automobile applications.

The Effect of Size on the Mechanical Properties of 3D-Printed Polymers

Most of the experiments on additively manufactured polymers are on a small scale, and it remains uncertain whether findings at a small scale can be extrapolated to their larger-scale counterparts. This uncertainty mainly arises due to the limited studies on the effect of size on three-dimensional (3D)-printed polymers, among many others. Given this background, this preliminary study aims to investigate the effect of geometric dimensions (i.e., the size effect) on the mechanical performance of four representative types of 3D-printable polymers, namely, (1) polycarbonate acrylonitrile butadiene styrene (PC/ABS), (2) acrylonitrile-styrene-acrylate (ASA), (3) polylactic acid (PLA) as a bio biodegradable and sustainable material, and (4) polyamide (PA, nylon), based on compression, modulus of elasticity, tension, and flexural tests. Eight different sizes were investigated for compression, modulus of elasticity, and tension tests, while seven different sizes were tested under flexure as per relevant test standards. A material extrusion technique was used to 3D-print the polymers in a flat build orientation and at an infill orientation angle of 45°. The results have shown that the mechanical properties of the 3D-printed polymers were size-dependent, regardless of the material type, with the most significant being flexure, followed by tension, compression, and modulus of elasticity; however, no clear general trend could be identified in this regard. All the materials except for nylon showed a brittle failure pattern, characterized by interfacial failure rather than filament failure. PLA outperformed the other three polymer specimens in terms of strength, irrespective of the type of loading.

Recycling of Metallized Plastic as a Case Study for a Continuous Sustainability Improvement Process

Emerging technological processes should be designed and operated according to the highest technological performance and sustainability standards. For this reason, assessments should be included during the design stage to track technological, environmental, economic, and social sustainability impacts. This study presents the concept of a Continuous Sustainability Improvement Process (CSIP) with the case study of project ReComp (Development of an Economically and Ecologically Sensible Recycling Method for Metal/Plastic Composites). In this project, metallized plastic production waste from the automotive industry was recycled to produce high-purity copper (Cu), chromium (Cr), and plastic, i.e., Polycarbonate/Acrylonitrile Butadiene Styrene (PC/ABS). Through CSIP, two stages of ReComp were developed, ReComp I and ReComp II. ReComp I was found to provide a significant environmental improvement compared to the primary production for Cu, Cr, and PC/ABS (>90% improvement for all environmental indicators). However, it was calculated as making 17,000 EUR/annum loss, with a unit processing cost of 103 EUR/kg of waste input and therefore was deemed as not economically sustainable. From this outcome, ReComp II was developed with the purpose of improving the economic outcome by increasing the process’s throughput without the need for significant additional costs. Therefore, the mechanical treatment at the first process step was modified in such a way that the metallized plastics were separated into two fractions, metal flakes and plastic particles. Using these fractions in two parallel process streams, the cycle time was reduced from 15 to 5 days, and throughput of the process-limiting step (electrochemical treatment) increased. Although still not profitable, ReComp II was shown to reduce the process cost per kg of waste input by 93% compared to ReComp I, whilst maintaining the same revenue per kg of waste input. Additionally, ReComp II was shown to provide an improved environmental outcome compared to ReComp I. Therefore, this study proves an important result that a more ecologically sustainable solution can correlate with a more economically sustainable process, due to lower waste formation as well as less material and energy use.

Assessment of the mechanical properties of PC/ABS blends for functional prototyping by FFF 3D printing

PurposeThis paper aims to evaluate the mechanical behaviour of polycarbonate/acrylonitrile butadiene styrene (PC/ABS) filaments for fusion filament fabrication (FFF). PC/ABS have emerged as a promising material for FFF due to their excellent mechanical properties. However, the optimal processing conditions and the effect of the blending ratio on the mechanical properties of the resulting workpieces are still unclear.Design/methodology/approachA statistical factorial matrix was designed, including infill pattern, printing speed, nozzle size, layer height and printing temperature as factors (with three levels). A total of 810 workpieces were printed using PC/ABS blends filament with the FFF. The workpieces’ finishing and mass were evaluated. Tensile tests were performed. Analysis of variance was performed to determine the main effects of the processing conditions on the mechanical properties.FindingsThe results showed that the PC/ABS (70/30) exhibited higher tensile. Tensile rupture corresponded to 30% of the tensile strength. The infill pattern showed the highest contribution to the responses. The concentric pattern showed higher tensile strength. Tensile strength and mass ratio demonstrated the influence of mass on tensile strength. The influence of printing parameters on deformation depended on the blend proportions. Higher printing speed and lower layer height provided better quality workpieces.Originality/valueThis study has implications for the design and manufacturing of three-dimensional printed parts using PC/ABS filaments. An extensive experimental matrix was applied, aiming at a complete understanding of mechanical behavior, considering the main printing parameters and combinations not explored by literature.

Advancing Urban Wastewater Management: Optimizing Sewer Performance through Innovative Material Selection for the Armlet with a Wet Circuit Measurement System

Rainwater infiltration presents substantial challenges for urban wastewater management systems. This article delves into enhancing the quality of wastewater systems by proposing a novel device designed to tackle this issue comprehensively. The focal point of our research revolves around the conceptualization, construction, rigorous testing, and the potential multifaceted applications of this innovative wastewater device. Our study is dedicated to assessing the viability of a cutting-edge apparatus that empowers municipal entities in swiftly identifying rainwater ingress points within channels during precipitation events. Our findings vividly showcase the device’s remarkable capability to directly measure moisture levels along the channel’s path, eliminating the arduous need for manual data input, extensive data collection, and intricate water analysis procedures. To ensure the seamless flow of both sewage and water within the sewer channel, the use of a relatively slender strap is conventionally favored. However, factoring in the requisite structural robustness, we recommend a minimum thickness of 4 mm for 3D printing applications. For instances where maintaining the channel’s cross-sectional area integrity is paramount, opting for an armlet with a wet circuit measurement thickness of up to 7 mm is vital. In the realm of material selection, our investigation advocates for the utilization of PC/ABS (polycarbonate/Acrylonitrile Butadiene Styrene), ABS, ASA (Acrylonitrile Styrene Acrylate), or HIPS (High Impact Polystyrene) for strap housing. For sewer diameters surpassing 315 mm, the application of thin-walled PVC (Poly Vinyl Chloride) emerges as a practical recommendation. Notably, the incorporation of PVC flat bars is discouraged, as their presence might potentially hinder the fluidity of sewage flow, thereby compromising the precision of wet circuit measurements. The pivotal innovation lies in the armlet with a wet circuit measurement system, harboring immense potential for broad-scale integration across municipal facilities. This solution emerges as a streamlined and efficient strategy, offering a comprehensive avenue for continuously monitoring, fine-tuning, and optimizing the structural soundness and operational efficacy of sewer systems.

Recycled polycarbonate and polycarbonate/acrylonitrile butadiene styrene feedstocks for circular economy product applications with fused granular fabrication-based additive manufacturing

Distributed recycling and additive manufacturing (DRAM) holds enormous promise for enabling a circular economy. Most DRAM studies have focused on single thermoplastic waste stream. This study takes three paths forward from the previous literature: 1) expanding DRAM into high-performance polycarbonate/ acrylonitrile butadiene styrene (PC/ABS) blends, 2) extending PC/ABS blend research into both recycled materials and into direct fused granular fabrication (FGF) 3-D printing and 3) demonstrating the potential of using recycled PC/ABS feedstocks for new applications in circular economy contexts. A commercial open source large-format FGF 3-D printer was modified and used to assess the different printability and accuracy of recycled PC and PC/ABS. The mechanical properties (tensile and impact) following the ASTM D638 and D6110–18 standards were quantified. A weather simulation test (ASTM D5071–06) was performed to assess outdoor performance. Finally, two applications in sporting goods and furniture were demonstrated. In general, better printability was achieved with recycled PC/ABS compared to recycled PC, as well as good dimensional accuracy at printing speeds of 30 and 40 mm/s. Minimal qualitative differences and discoloration were visible on the samples after accelerated weather exposure, with results in accordance with the state-of-the-art. The rPC/ABS results from tensile tests show similar values to those of rPC for elastic modulus (2.1 ± 0.1 GPa), tensile strength (41.6 ± 6.3 MPA), and elongation at break (2.8 ± 0.9%), which are also comparable with previous studied virgin 3-D printed filaments. Similarly, impact energy (115.78 ± 24.40 kJ/m2) and resistance values (810.36 ± 165.77 J/m) are comparable in the two tested formulations, reaching similar results compared to FFF 3-D printed filaments, as well as virgin materials for injection molding. Finally, the two demonstration products in the sporting goods and furniture sectors were successfully fabricated with rPC/ABS, achieving complex patterns and good printing speeds for recycled feedstocks. It is concluded rPC/ABS blends represent a potential high-performance feedstock for DRAM, validating its use in direct FGF 3-D printing systems and potential applications for a circular economy.

Prediction of the mechanical properties of heat-treated fused filament fabrication thermoplastics using adaptive neuro-fuzzy inference system

The requirement for post-processing methods in 3D printing has increased due to its major limitations such as poor mechanical and surface properties. Thermal annealing, a heat-treatment procedure, has proven to be an excellent approach for increasing the mechanical strength of additive manufactured thermoplastics. The optimized thermal annealing parameters for maximum tensile strength are identified. The Adaptive Neuro-fuzzy Inference System (ANFIS) methodology is employed in this study to forecast the tensile strength of thermal annealed fused filament fabricated polylactic acid (PLA), carbon fiber filled polylactic acid (PLA-CF), and polycarbonate acrylonitrile butadiene styrene (PC-ABS). The root mean square error (RMSE) of the predicted tensile strength of PLA, PLA-CF, and PC-ABS are obtained as 1.012, 0.5, and 0.835 respectively. The coefficient of determination for the predicted model of thermoplastics PLA, PLA-CF, and PC-ABS is determined as 0.98, 0.99, and 0.89 respectively. The ANFIS model developed is successful in determining the tensile strength of annealed 3D printed thermoplastics at various annealing conditions of temperature and duration. Further, the study investigates the effect of heat treatment on the compressive, impact, and flexural properties of PLA prints.

Designing of reactive micro-crosslinked PBAT as the efficient biodegradable toughener for PLLA

Melt blending with biodegradable poly (butylene adipate-co-terephthalate) (PBAT) represents a facile strategy to toughen poly (l-lactide) (PLLA). Unfortunately, the toughening efficiency of PBAT is far from the practical requirements regardless of significant efforts to strengthen interface between PLLA and PBAT phases. Herein, two reactive micro-crosslinked PBAT tougheners (RMBTs) via simple reactive processing of PBAT/glycidyl methacrylate (GMA)/dicumyl peroxide (DCP) with or without PLLA-inclusions have been designed to break the toughening restriction of PBAT for PLLA. The results indicate that the RMBT without PLLA increases the toughness of the final PLLA blends in comparison to pristine PBAT. Intriguingly, further enhancements can be achieved by using the RMBT incorporating PLLA moieties. The notched impact strength of the PLLA-incorporated RMBT toughed PLLA is as high as 52.3 kJ/m2 at 30% PBAT content, which is 600% higher than the pristine PBAT toughed PLLA, while the tensile strength keeps almost the same value of about 44.4 MPa. The collaborative enhancement is not only attributed to the micro-crosslinking and reactive group grafting modification, but also ascribed to sub-inclusion of rigid PLLA chains in the PBAT phase. The comprehensive mechanical properties of the fully biodegradable PLLA blends are even higher than those of the commercially available polycarbonate/acrylonitrile-butadiene-styrene (PC/ABS) blends. The high toughening efficiency of the reactive micro-crosslinked PBAT would evoke new inspiration in the field of industrial manufacture of fully degradable PLLA blends with high stiffness-toughness balance.

Polymer Composites Based on Polycarbonate/Acrylonitrile-Butadiene-Styrene Used in Rapid Prototyping Technology.

As part of this work, polymer composites based on polycarbonate/acrylonitrile-butadiene-styrene (PC/ABS) were obtained and used in 3D printing technology, particularly Melted Extrusion Modeling (MEM) technology. The influence of selected fillers on the properties of the obtained composites was investigated. For this purpose, modified fillers such as silica modified with alumina, bentonite modified with a quaternary ammonium salt, and hybrid lignin/silicon dioxide filler were introduced into the PC/ABS matrix. In the first part of this work, polymer blends and their composites containing 1.5-3 wt. of the filler were used to obtain the filament using the proprietary technological line. Moldings for testing the performance properties were obtained using additive manufacturing techniques and injection molding. In the subsequent part of this work, rheological properties (mass flow rate (MFR) and viscosity curves) and mechanical properties (Rockwell hardness and static tensile strength with Young's modulus) were examined. The structures of the obtained composites were also determined by scanning electron microscopy (SEM/EDS). The obtained results confirmed the results obtained from a wide-angle X-ray scattering analysis (WAXS). In turn, the physicochemical properties were characterized on the basis of the results of tests using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Based on the obtained results, it was found that the introduced modified additives had a significant impact on the processing and functional properties of the tested composites.

Dimensioning of the Clearance as a Means of Avoiding Burr and Film Formation during the Punching of PC/ABS Cable Ducts

The production of staple articles such as cable ducts offers reductions in resource and production energy consumption if the process is optimized. Side recesses made of polyvinyl chloride (PVC) have already been punched successfully as one of the process steps during the production of cable ducts. However, punching cable ducts made of flame-retardant polycarbonate/acrylonitrile–butadiene–styrene (PC/ABS) is challenging because increased burr and film formation occurs. This study introduces the correct dimensioning of the clearance as a means of reducing the burr and film formation and presents the ideal clearance dimensions. This new process design approach comprises the dimensioning of the clearance and its subsequent successful application. Tools with clearances in the relevant size range were purchased and examined by means of punching tests. The punch-outs were evaluated regarding the quality characteristics, such as the burr, film, cut surface quality, shear droop, and plastic flow characteristics. Excerpts from high-speed recordings were used to assess the punch-outs qualitatively. The burr formation is significantly decreased by the use of a correctly dimensioned clearance, allowing for the crack initiated at the punch side and the crack initiated at the die side to meet perfectly. It is assumed that film formation can be avoided via a significant reduction in the friction or heat input during the punching process.

Design simulation of nonlinear static 2D and steady state thermal for sustainability downlight casing base

This paper explains the design and simulation of nonlinear static 2D and steady state thermal for sustainability downlight casing base. The main problem in designing of downlight casing base is to ensure the heat transferred to the surrounding while maintaining the quality of light. This study simulates of 6-in casing base downlight and Polycarbonate/acrylonitrile butadiene styrene (PC-ABS) based material. New product design methodology was presented using SolidWorks simulation to represent the phenomena of heat transfer in the downlight casing base at the design stage. The result shows the nonlinear static 2D for main base was achieved. The parameters of materials, dimension, and thickness was contributed in the seamless of heat transferred form casing base to the surrounding at ambient temperature. This practice prevents the quality of light while heat flux as applied to be further study. In addition, the steady state thermal simulation shows significant heat flux and convection changes to every face of casing base parts. Thus, this study is proposed to manage the development of new design relates with nonlinear static 2D and steady state thermal analysis for sustainability downlight casing base.

Development and Validation of a Computational Fluid Dynamics Model for the Optimization of a Sink-Float Separator for Plastics Recycling

The Circular Economy Action Plan, in the context of the European Green deal, introduces new policies which promote a more sustainable use of plastics. These policies also prioritize the optimization of plastics recycling processes by increasing both the amount and quality of plastic recyclates produced, which is to a large extend defined by the purity and yield achieved by state-of-the-art plastic sorting processes. Therefore, the presented research focuses on developing a Computational Fluid Dynamics (CFD) based model to predict and obtain better insights in the separation performance of sink float separators, more specifically Dense Medium Drum (DMD) separators. The flow inside the drum is simulated by adopting an Euler-Lagrangian approach, a widely employed model for the numerical simulation of multi-phase flows including solid particles. To validate the simulations, a transparent lab-scale sink float separator, using the principle of a rotating drum, is constructed. In all experiments, water is used as medium. The separation objects represent a single polymer type which is fed to the drum. For the present work these are Polypropylene (PP), Polystyrene (PS), High Density Polyethylene (HDPE) Acrylonitrilic Butadiene Styrene (ABS), Polycarbonate Acrylonitrile Butadiene Styrene (PC/ABS) grains with a length scale of 3 mm and High Density Polyethylene grains of 4 mm. The separation number is easily expressed as the ratio of objects leaving the sink or float outlet depending on the type of the polymer density to the total amount of separation objects. It was found that the separation numbers computed by the numerical model for all separated objects agree with the measured ones within a maximum error of 7%. When comparing the hydrophilic ABS to the hydrophobic PS, which have similar densities, it is shown that air bubbles have a large influence on the separation efficiency. With the validated CFD model, essential insights are gained on the physics of the flow field inside the separator which help in further optimizing these devices to achieve higher separation efficiencies.

Mechanical Properties of PC-ABS-Based Graphene-Reinforced Polymer Nanocomposites Fabricated by FDM Process.

This experimental study investigates the mechanical properties of polymer matrix composites containing nanofiller developed by fused deposition modelling (FDM). A novel polymer nanocomposite was developed by amalgamating polycarbonate-acrylonitrile butadiene styrene (PC-ABS) by blending with graphene nanoparticles in the following proportions: 0.2, 0.4, 0.6, and 0.8 wt %. The composite filaments were developed using a twin-screw extrusion method. The mechanical properties such as tensile strength, low-velocity impact strength, and surface roughness of pure PC-ABS and PC-ABS + graphene were compared. It was observed that with the addition of graphene, tensile strength and impact strength improved, and a reduction in surface roughness was observed along the build direction. These properties were analyzed to understand the dispersion of graphene in the PC-ABS matrix and its effects on the parameters of the study. With the 0.8 wt % addition of graphene to PC-ABS, the tensile strength increased by 57%, and the impact resistance increased by 87%. A reduction in surface roughness was noted for every incremental addition of graphene to PC-ABS. The highest decrement was seen for the 0.8 wt % addition of graphene reinforcement that amounted to 40% compared to PC-ABS.