Plastic solid waste (PSW) of polymers (like: high density polyethylene (HDPE), low density polyethylene (LDPE), Nylon etc.) is creating new challenges, which in today's scenario are major research ...concerns. A sharp rise has been observed in production of different products based on different plastic material. This huge increase in plastic commodities also increases the waste generation thus creating new challenges. Some researchers have reported work in the field of PSW management with different recycling methods. This paper compiles the different research work done by researchers in this field of recycling and progress in recovery and management of PSW by different methods (i.e. Primary, secondary, tertiary and quaternary) along with the various identification/separation techniques. Further, this paper reviews the effect on properties of virgin and recycled HDPE/LDPE/Nylon PSW with different reinforcements like sand, natural fibre, hemp fibre, metal powder etc.
Polymer composites have certain advantages over metals in terms of mechanical as well as metallurgical properties. These can be joined with similar as well as dissimilar polymer composites (subject ...to certain conditions like glass transition temperature, rheological properties etc.). In last 20-25 years number of techniques and concepts has been developed to offer the possibility of joining of polymeric materials which have similar or dissimilar characteristics. In present scenario mechanical fastening and adhesive bonding is replaced by applying welding concepts like: laser transmission welding, friction stir welding (FSW), ultrasonic welding, hot fusion resistance welding etc. The FSW is one of the most acceptable welding techniques for production of structural/industrial components. In this present work, requirements of FSW and its process capability has been highlighted for joining of similar/dissimilar polymeric materials for future prospective.
In the present work, 3D-printed cylindrical discs of dissimilar thermoplastics polyamide (PA6) reinforced with Al powder and acrylonitrile butadiene styrene (ABS) reinforced with Al powder have been ...successfully joined by friction welding (FW) for structural applications such as joining of pavement sheets and assembly of pipe lines. The melt flow index of PA6 + Al and ABS + Al matrix was maintained in a suitable range by varying the proportions of Al in PA6 and ABS matrix. After fixing proportions of Al powder in PA6 and ABS matrix, these matrix proportions were used for preparation of feed stock filament of fused deposition modelling (FDM) filament by a twin-screw extrusion process. Finally, two FDM filaments of PA6 + Al and ABS + Al were fed into FDM machine independently. The cylindrical discs were printed on commercial FDM (one with filament of PA6 + Al and second with ABS + Al powder). These cylindrical discs of two dissimilar thermoplastic composite materials were processed on FW set-up (on central lathe machine). Finally, under the best parametric conditions of feed, rpm, etc., these polymer matrixes were successfully joined. This study provides a response surface methodology-based mathematical model for enhancing the weldability of dissimilar thermoplastic composites with improved mechanical/morphological properties.
The friction stir welding (FSW) or friction stir spot welding (FSSW) with non-consumable tool is one of the established processes for joining of thermoplastics/low melting point metals/alloys. But ...hitherto little has been reported on joining of similar/dissimilar thermoplastics with FSSW especially with use of semi-consumable/consumable tool. The present study deals with thermo-mechanical investigations for FSSW of thermoplastics with fully/semi-consumable tool as a novel method. The FSSW was performed on 3D printed functional prototypes of acrylonitrile butadiene styrene (ABS) reinforced with 15% Al powder (by weight) as ABS-15Al, with polyamide (PA)6 reinforced with 50%Al powder (by weight) as PA6-50Al. The online monitoring by thermal imaging camera and axial force measurements was performed to investigate variations in tensile, thermal and morphological properties. The influence of input process variables (namely: rotational speed, plunge depth and stirring time) of FSSW joints has been explored. The results of study suggest that for joining of ABS-15Al substrates with PA6-50Al, rotational speed 1400 rpm, plunge depth 2 mm and stirring time 15 s are the best settings from multifactor optimization view point. Further the tensile properties of ABS-15Al joints prepared by FSSW are comparable to virgin ABS thus made it suitable for maintenance and repair applications.
Fused Deposition modelling (FDM) is one of the additive manufacturing (AM) technologies used extensively for modelling and prototyping applications. In commercial FDM setup, filament wire is uncoiled ...from wire spools and plastic based material is supplied to produce the part. The application area of FDM is limited presently due to selective material availability in market. Some researchers have highlighted the use of reinforced composite wires as FDM filament. But hitherto no work has been reported on the effect of Single particle size (SPS), Dual particle size (DPS), Triple particle size (TPS) of Al2O3 (as reinforcement) in Nylon-6 matrix to be used as feed stock filament for FDM. In this paper, effect of SPS, DPS, and TPS of Al2O3 (as reinforcement) in Nylon-6 matrix on mechanical properties (like: percent age elongation, tensile strength, yield strength, Young's modulus) has been studied. Further, empirical relations have been developed for above mentioned properties and a surface characteristic of developed wires has been observed with SEM image.
In this research article, a novel method of additive manufacturing (AM) assisted investment casting (IC) has been demonstrated (by using the patterns prepared from waste materials reinforced with ...ceramic particles) for development of a metal matrix composite (MMC). In first stage, recycled low density polyethylene (LDPE) has been selected as matrix material, while ceramic reinforcement of SiC and Al2O3 has been blended in LDPE by screw extrusion. Initially, the recycled LDPE has been collected in granules form from the local market and processed on single screw extruder to prepare pallets. The ceramic particles and LDPE were blended together to prepared the final blend in different proportions on twin screw extruder. After that Taguchi L9 orthogonal array has been employed to ascertain the affect of different input parameters of FDM machine to prepare the functional prototypes in the form of cubical patterns. Instead of using conventional IC, a rapid method has been employed to prepare sacrificial pattern by using siladent powder (which is being used for preparing cast in clinical dentistry for dentures). Further this method has been explored as an alternate route of rapid IC, which requires very less time as compared to the traditional methods. At final stage cast were prepared with aluminium (Al) alloy as matrix material reinforced with SiC and Al2O3 (which were present in the mould cavity after removal of LDPE). The properties of MMC prepared via this novel route were subjected to hardness and grain size testing supported by photomicrographs and EDAX analysis.
•The traditional Quality Management System (QMS) has been digitalized using Quality 4.0.•Developed autonomous QMS system has been validated and implemented successfully.•Process yield has been ...significantly increased using the autonomous system.•The machining process get improved from 1.5 sigma to 5.5 sigma.
The goal of this research is to use the Quality 4.0 (Q4.0) concept to digitalize the traditional Quality Management System (QMS) and demonstrate the efficiency of the Autonomous Quality Management System (AQMS) in the case organization.
The Internet of Things (IoT) concept was used to develop AQMS. The Q4.0 technique was used to digitalize the developed system. Gage repeatability and reproducibility (gage R&R) of traditional and autonomous QMS systems have been evaluated. Both the QMS systems were examined using six-sigma quality indicators, as well as machining and inspection cost analysis.
In traditional and autonomous QMS, the gage R&R was found to be 91.60 percent and 0.67 percent, respectively. The special purpose machine (SPM), computer numerical control (CNC), and hydraulic machine production rates were increased by 44.42 percent, 65.60 percent, and 65.76 percent, respectively. The effective deployment of AQMS has reduced the production and inspection costs by 52.16 percent and 78.35 percent. The AQMS process yield has increased from 86.80 percent to 99.99 percent, and the component rejection rate has decreased by 93.70 percent. Overall machining process improved significantly as the sigma level increased from 1.5 to 5.5.
The current study's findings are limited to hub bolt products only. In future investigations, the application of AQMS to other types of products will be considered.
This study was carried out practically to reflect the effectiveness of the implemented Q4.0 concept in the actual industry scenario.
In the present work PA6 matrix reinforced with metal powder (Fe) has been joined by friction welding with ABS matrix reinforced with Fe powder for structural applications (like: joining of pavement ...sheets, assembly of pipe lines etc.). The melt flow index (MFI) of PA6+Fe powder was put approximately equivalent to MFI of ABS + Fe powder by varying the proportion of Fe powder in PA6 and ABS matrix. After fixing proportion of Fe powder in PA6 and ABS material, these materials were used for preparation of feed stock filament of fused deposition modelling filament (FDM) by screw extrusion process. Finally two FDM filaments of PA6+Fe powder and ABS + Fe powder were fed into FDM machine independently. The functional prototypes of circular cross-section were prepared on FDM machine (one with filament of PA6+ Fe powder and second with ABS + Fe powder). These geometrical shapes of two dissimilar plastic/polymer materials were used on friction welding setup. Finally under best parametric conditions of feed, rpm etc. these reinforced polymer materials were successfully joined. This study provides a response surface methodology (RSM) based statistical model for enhancing the weldability of dissimilar polymer materials (as an alternative method) with improved mechanical/metallurgical properties.
In this article, detailed procedure for the development of polylactic acid (PLA), hydroxyapatite (HAp) and chitosan (CS)-based biocompatible functional prototype has been outlined by using ...three-dimensional (3D) printing as a case study. The biocompatible composite-based feedstock filament (comprising of PLA-HAp-CS) has been prepared through twin-screw extruder (TSE) for open-source fused deposition modelling (FDM)-based 3D printer. This case study provides two-stage multifactor optimization: (a) for preparation of feedstock filament on TSE and (b) 3D printing on FDM based upon tensile and flexural samples. The results of study suggest that the best settings of input parameters for TSE are barrel temperature of 190°C, screw speed of 140 r/min and dead weight of 12 kg. Further, the optimized settings for FDM are layer thickness of 0.2 mm, deposition angle of 30/45° and infill density of 100%. The results have been supported by scanning electron microscopic analysis.
Friction welding is one of the solid state welding techniques, for which the two pieces of thermoplastic materials must be compatible to each other. Friction welding of the two similar thermoplastic ...is an easy exercise but joining two dissimilar thermoplastic is difficult because of large differences in viscosity, specific density, molecular weight, melting point, crystalline vs. amorphous nature, surface behavior and dynamic-mechanical properties. In last three decades, studies have been reported to perform the friction and friction stir welding of thermoplastics but still the reason for compatibility of thermoplastic is not understood properly. In the present study attempts have been made to perform the compatibility analysis of two dissimilar polymers namely; acrylonitrile butadiene styrene (ABS) and polyamide 6 (PA6) by establishing their melt flow properties after Aluminum (Al) metal powder reinforcement. Twin screw extrusion (TSE) and fused deposition modeling (FDM) technologies were used to fabricate the welding specimen for potential application in maintenance engineering.
