Plastic Manufacturing Process Research Articles

Dual-Factor-Controlled Dynamic Precursors Enable On-Demand Thermoset Degradation and Recycling.

Thermosets are well known for their advantages such as high stability and chemical resistance. However, developing sustainable thermosets with degradability and recyclability faces several principal challenges, including reconciling the desired characteristics during service with the recycling and reprocessing properties required at the end of life, establishing efficient methods for large-scale synthesis, and aligning with current manufacturing process. Here a general strategy is presented for the on-demand degradation and recycling of thermosets under mild conditions utilizing dynamic precursors with dual-factor-controlled reversibility. Specifically, dynamic triazine crosslinkers are introduced through dynamic nucleophilic aromatic substitution (SNAr) into the precursor polyols used in polyurethane (PU) synthesis. Upon removal of the catalyst and alcohol, the reversibility of SNAr is deactivated, allowing for the use of standard PU polymerization techniques such as injection molding, casting, and foaming. The resulting cyanurate-crosslinked PUs maintain high stability and diverse mechanical properties of traditional crosslinked PUs, yet offer the advantage of easy on-demand depolymerization for recycling by activating the reversibility of SNAr under specific but mild conditions-a combination of base, alcohol, and mild heat. It is envisioned that this approach, involving the pre-installation of dual-factor-controlled dynamic crosslinkers, can be broadly applied to current thermosetting plastic manufacturing processes, introducing enhancedsustainability.

Optimizing Antimony Speciation Analysis via Frontal Chromatography-ICP-MS to Explore the Release of PET Additives.

Antimony (Sb) contamination poses significant environmental and health concerns due to its toxic nature and widespread presence, largely from anthropogenic activities. This study addresses the urgent need for an accurate speciation analysis of Sb, particularly in water sources, emphasizing its migration from polyethylene terephthalate (PET) plastic materials. Current methodologies primarily focus on total Sb content, leaving a critical knowledge gap for its speciation. Here, we present a novel analytical approach utilizing frontal chromatography coupled with inductively coupled plasma mass spectrometry (FC-ICP-MS) for the rapid speciation analysis of Sb(III) and Sb(V) in water. Systematic optimization of the FC-ICP-MS method was achieved through multivariate data analysis, resulting in a remarkably short analysis time of 150 s with a limit of detection below 1 ng kg-1. The optimized method was then applied to characterize PET leaching, revealing a marked effect of the plastic aging and manufacturing process not only on the total amount of Sb released but also on the nature of leached Sb species. This evidence demonstrates the effectiveness of the FC-ICP-MS approach in addressing such an environmental concern, benchmarking a new standard for Sb speciation analysis in consideration of its simplicity, cost effectiveness, greenness, and broad applicability in environmental and health monitoring.

Improving plastic manufacturing processes with the integration of Six Sigma and machine learning techniques: a case study

ABSTRACT This research integrates machine learning (ML) and Six Sigma’s Define, Measure, Analyze, Improve, and Control (DMAIC) methodology to address these issues. The study details the selection and utilization of ML techniques, including Linear Regression (LR), Artificial Neural Network (ANN), Decision Tree (DT), K-nearest neighbors (KNN), and Cluster Analysis (CA). Implemented at the Innovative Plastic Manufacturing Company in Egypt, this research enhances the consistency of plastic bottle production by addressing issues such as surface marks, flashes, bubbles, and variations in liter capacity. Integrating Six Sigma with ML techniques reduces the average defect rate from approximately 67.8%. It elevates the Sigma level from 3.14 to 4.30, reducing material over-consumption costs from 5% to 1.7% of total manufacturing expenses. Notably, the KNN model achieves the best results for defect testing, with an R-squared value of 98.8%. These methodologies lead to cost reduction, increased competitiveness, and improved product quality when implemented.

Investigating Heat-Treatment Effects on Biodegradable Banana Peel Plastic Manufacturing Processes

Traditional petroleum-based plastic takes hundreds of years to degrade, and so it is accumulating at an alarming rate, while plastic consumption is also increasing exponentially. Global plastic contamination has been the most threatening environmental issue globally since it is a staple in everybody's lives. So, an urgent method must be created to minimize the usage of conventional non-biodegradable plastics. In this study, banana peel plastic models shaped as rods, beads, and films were created first and subjected to four different heat-treatment methods: two with a low-heat treatment of 80℃ and 65℃ 24 hours with a fanning function in a dehumidifier, while high-heat treatments of 120℃, 1 or 2 hours in an electric oven. The study's results suggested that the banana plastic created with the low-heat treatment 80℃ presents more favorable qualities in molding weight change, pressing hardness, tensile force, and water stability. The stability in the pH solution was more excellent in low-heat treated plastic than in high-heat treated plastic. More studies might be needed to clarify the causes of differences in the characteristics examined.

Bisphenol A (BPA) Content in Food and Beverage Plastic Packaging Perspective of Food Law and Consumer Protection

The packaging sector is an important industry. Packaging is used as a material to protect goods from external contamination. There are various kinds of packaging, one of which is often used is plastic packaging. In plastic packaging there is one of the BPA materials used in the plastic manufacturing process. This BPA content has the potential to be released and mixed with packaged food and drinks. While BPA is a content that can cause various diseases such as cancer. This study aims to determine the content of BPA in plastic packaging seen from the Law on Food and the Law on Consumer Protection. This study uses normative legal research that is descriptive analytical with a qualitative approach to primary data, secondary data and tertiary data which includes the content and structure of positive law. It is used as a reference in reviewing legal issues that are the object of study. The results of the study show that the BPA content in plastic packaging does not meet the packaging quality standards in accordance with the Law on Food. The Law on Food states that food packaging must use materials that do not endanger health. The Law on Consumer Protection also states that one of the rights of consumers is to have security and safety in consuming goods and services. The content of BPA which can cause various diseases is clearly not in accordance with the clauses in the Consumer Protection Act.

Production of Polyhydroxyalkanoates During Bokashi Composting

This study examines how the sustainability of the plastic industry can be improved through a concurrent method of polyhydroxyalkanoate production, specifically that of a bokashi compost media. In studying previous research on the plastic manufacturing processes, the researcher found a gap in knowledge in the affordability and accessibility of bioplastic production, limiting the expansion of the industry. By studying how Escherichia coli reacts to a feast famine cycle in a bokashi compost habitat, the study addresses the question: to what extent, if any, does the ability to modify phosphorus, nitrogen, carbon, and oxygen levels in compost bins allow for polyhydroxyalkanoates to be produced in order to determine and expand the accessibility of bioplastics? The researcher collected data of the bacterial body mass containing polyhydroxyalkanoate before and after a feast famine cycle. This data lead to the definitive conclusion that polyhydroxyalkanoates can be produced in a concurrent method of production in a bokashi compost bin. To see the complete thesis, please visit https://journals.colorado.edu/index.php/honorsjournal/article/view/1745.

Improvement of Plastic Manufacturing Processes by Six Sigma and DMAIC Methods

Improvements are required in any industry to maximize productivity by reducing faults in any method and removing overall waste produced within the manufacturing facility. This study examines the problems faced by some leading companies in the plastic manufacturing industry, such as Motorola, General Electric, and Zamil Plastic and how to solve them. In this study, the key difficulty in this plastic manufacturing industry was black dots, which can be seen in injection molding operations. When compared to other faults, the injection molding technique result shows that black dot defects are the main reason for rejects in May, making up almost 41% of all rejects. Because, Defectives Per Million Opportunities (DPMO) of products in Plastic Remote Controls (PRC) result in numerous wastes, statistical quality control (SQC) methods, such as the Pareto chart, cause-effect diagram, and control chart were utilized to examine the data. Also, this study shows that the time necessary for tool changeover was extremely long, resulting in a significant wait for manufacturing because multiple dies and molds were required for production (types of plastic fuel tanks). The novelty of this research is that it clarifies when the company uses six sigma and the DMAIC method to rapidly discover the problem in the products and find a suitable solution to save time, effort, and cost. Run charts and the layout of mold storage are used to solve the problem and ensure that the process is truly improved by reducing the time it takes to change over for tools and dies.

Numerically Detection Fluid Characteristic Effects in Porous Media for Plastic Manufacturing Process Reconstruction

Research work aimed to prove the cooling effectiveness and efficiency of heating numerically. It was carried out by reconstructing the mold to reduce condensation while keeping the production cycle time. The simulation was done using CFD Fluent, Finite Volume Method (FVM) with a solution method of pressure-velocity, SIMPLE coupling, and second-order upwind discretization scheme. The model's boundary condition represents plastic packaging's production process. The simulation was done to optimize performance during production. Reconstruction and simulation were undertaken. The initial investigation was to produce data for cooling time versus the whole production time. The research result indicated that the average cooling time was 3/5 of the total production time. There were 15.5706 of 26.4206 sec and 15.641 of 26.491 sec, respectively. Further investigation was focused on investigating heat absorption and transfer through cells in the matrix. The porous effect showed temperature gradient reduction between cooled and cooler temperatures by simulation in color. The phenomenon predicted that the Ra contributed to the rate of temperature decrease revealed. There is also an apparent increase in temperature interfaces is evidence. The porous media application with The Rayleigh Number ≥ 105 retained the potential cooling effectivity and heating efficiency. By simulation, a series of discussions of the result of research, the potential may apply in the plastic mold to reconstruct the space and its methods using filling-porous. It is relevant because the heating ability in the phase change of fluid that creates particular characteristics has the potential to make effective cooling.

Multi response optimization of injection moulding process to reduce sink marks and cycle time

In the rapidly growing field of technology, there is a demand for consumer goods made of plastic. To meet needs of customer, plastic products are made in different ways. There are different plastic manufacturing process. Numerous plastic manufacturing process are thereInjection molding is involves injecting molten material into a mold and allowing it to take on the shape of the mold.There are wide ranges of products such as plastic chairs, Computer cabinet etc. are manufactured with the help of smaller and more complex profiles. Due to lack of dimensional accuracy these complex profile produces defects inside the mold. Current study provides insights into transparent thermoplastic Polypropylene products. Five plastic injection molding variable criteria are considered for reducing the depth of sink mark in injection molding for commercial grade transparent thermoplastic (Polypropylene). Melting temperature (8C), mold temperature (8C), packing time (seconds), ratio of ribs to walls (%) and rib to gate distance (mm). According to Taguchi's design L27 experiments are performed and factors are optimized using the Taguchi based utility concept for multi criteria problems. The sink mark's depth on the part's surfaceis considered as quality of product and cycle time is considered as the productivity of product. It is the one of the best techniques, which can maintain the equilibrium between two.

Multi-omics profiling and biochemical assays reveal the acute toxicity of environmental related concentrations of Di-(2-ethylhexyl) phthalate (DEHP) on the gill of crucian carp (Carassius auratus)

Di-(2-ethylhexyl) phthalate (DEHP) is one of the most extensively utilized plasticizers in the plastic manufacturing process. It is widely used in various fields due to its low cost and excellent effect. Although there is evidence that DEHP is harmful to animal and human health, DEHP-induced gill toxicity in aquatic organisms is inconclusive, and its mechanism has not been fully elucidated. Here, we investigated the effects of DEHP acute exposure on crucian carp gills at environmentally relevant concentrations of 20, 100, and 500 μg/L. Multi-omics profiling and biochemical assays were employed to characterize the potential toxicological mechanisms. The results showed that acute exposure to 100 and 500 μg/L of DEHP leads to oxidative stress in gills, as evidenced by overproduction of reactive oxygen species (ROS), increased antioxidant enzyme activity, and the transformation of glutathione from reduced to oxidized form, resulting in lipid peroxidation. Integrative analysis of transcriptomics and metabolomics indicated that increased purine metabolism was the potential source of increased ROS. Moreover, lipid metabolism disorder, including arachidonic acid metabolism, induces inflammation. Further, DEHP causes the imbalance of the CYP enzyme system in the gill, and DEHP-induced gill toxicity in crucian carp was associated with interference with CYP450 homeostasis. Taken together, this study broadens the molecular understanding of the DEHP-induced gill toxicity in aquatic organisms and provides novel perspectives for assessing the effects of DEHP on target and non-target aquatic organisms in the environment.

Origin Materials forms partnerships to bring 100% bio-content carbon black to plastics and rubber compounding

On July 27, 2022, Origin Materials announced that ATC Plastics has agreed to purchase sustainable carbon-negative carbon black from Origin Materials for use in various plastic manufacturing processes.

The Influence of anisotropy on the vibration behaviour of S600Mc sheet metal

Sheet metal anisotropy is the directional dependence of mechanical properties. It is a critical factor that must be considered when using numerical simulation to predict any plastic deformation manufacturing process. Sheet metals prove anisotropic plastic behaves due to crystallographic texture caused by progressive rolling steps, Banabic D. et al. (2000). Cold bending of steel sheets is a widely used manufacturing process in the automotive industry due to its cost efficiency. By avoiding line heating, the oxidative process of steel is thus avoided. The automotive industry's primary application of sheet metal includes doors, fenders, bumpers, roof panels, and seat frames. In this paper, test specimens were laser cut at orientations θ = 0°, 45°, and 90° to the rolling direction. The specimens were subjected to forced vibration on an electromechanical shaker, and the frequency response amplitude was measured using accelerometers. Natural frequency and Q-factors were discussed. Experimental data are used for viscous damping coefficients (alpha and beta) for each direction of the specimen. The measured coefficients are then used to validate each type's finite element, numerical models. The results show the level of dependency between the structural damping and anisotropy of the laminated sheet metal and the influence on the high cycle fatigue performance.

To Explore the Effect of Injection Molding Processing Parameters on Crazing in Acrylic Polymers

Plastic manufacturing industry is the fastest growing industry as the demand for plastic products is exponentially growing worldwide. Poly (methyl methacrylate) (PMMA), also known as acrylic glass, is a transparent and rigid thermoplastic. PMMA is highly resistant to UV light. Weathering has an excellent light transmission and unlimited coloring options compared to other transparent plastic and has been used in wide applications such as architecture, automotive and transportation, lighting (LED lights), medical and healthcare, and furniture. Injection molding is the widely used plastic manufacturing process to produce plastic products for various applications. The quality of the plastic products depends on the injection molding parameters, viz. melting temperature, injection speed, and pressure, holding and cooling time, and holding pressure. Therefore, it is important to control injection molding parameters to reduce injection molding defects or parts. Hence, the main objective of this research is to optimize the injection molding parameters, including the amount of mold releasing agent, to avoid the crazing marks in PMMA which is a long-standing problem in the production of PMMA products or parts such as motorbike headlight lenses. Three different holding pressures (65, 75, and 85 kg/cm2) were varied against three different injection pressures (70, 80, and 90 kg/cm2). The injection speed (60 %), cooling time (4 s), and barrel zones temperature (185-205: 185-205: 190-210: 195-215) were kept constant not to disturb the production cycle, a constraint from the production industry. The minimum criteria required for the motorbike headlight lens selection was based on the LUX intensity test, density, and crazing demanded by the Japanese standard throughout this research. The optimized injection molding parameters and amount of mold releasing agent (Nabakem mold release R2) were 70 kg/cm2 (injection pressure), 65 kg/cm2 (holding pressure), and 1.18 g, respectively. The motorbike headlight lens produced with optimized injection molding parameters showed no crazing. In addition to the desired LUX intensity, density, and no crazing criteria, the motorbike headlight lens also showed improved impact properties and no substantial changes in mechanical properties when compared to virgin PMMA or literature. Hence, it is concluded that the optimized injection molding parameters (thermo-mechanical history) did not much affect the molecular weight and morphology of the PMMA.

Phthalate hydrolase: distribution, diversity and molecular evolution.

The alpha/beta-fold superfamily of hydrolases is rapidly becoming one of the largest groups of structurally related enzymes with diverse catalytic functions. In this superfamily of enzymes, esterase deserves special attention because of their wide distribution in biological systems and importance towards environmental and industrial applications. Among various esterases, phthalate hydrolases are the key alpha/beta enzymes involved in the metabolism of structurally diverse estrogenic phthalic acid esters, ubiquitously distributed synthetic chemicals, used as plasticizer in plastic manufacturing processes. Although they vary both at the sequence and functional levels, these hydrolases use a similar acid-base-nucleophile catalytic mechanism to catalyse reactions on structurally different substrates. The current review attempts to present insights on phthalate hydrolases, describing their sources, structural diversities, phylogenetic affiliations and catalytically different types or classes of enzymes, categorized as diesterase, monoesterase and diesterase-monoesterase, capable of hydrolysing phthalate diester, phthalate monoester and both respectively. Furthermore, available information on in silico analyses and site-directed mutagenesis studies revealing structure-function integrity and altered enzyme kinetics have been highlighted along with the possible scenario of their evolution at the molecular level.

Community Waste Plastic Recycling System Through Plastic Injection Molding

High demand for plastic worldwide has resulted in increasing environmental pollution. To make the plastic manufacturing process more environmentally friendly, recycling of waste plastic must be considered. In view of this a social enterprise called Me.reka Makerspace aims to use waste plastic to produce recycled plastic products using injection molding. However, injection molding is a complex process. In the past Me.reka experienced numerous failures resulting in defective plastic products and cost wastage. To assist with Me.reka’s objective, this study aimed to recommend a process capable of producing good quality recycled plastic products that meet dimensional accuracy and surface roughness requirements. Literature review done on plastic waste separation techniques, plastic properties testing for injection molding, and ventilation systems. Manual plastic sorting was found to be the best for Me.reka, where it can separate all 7 types of plastics collected by Me.reka with the highest accuracy and efficiency and the lowest cost. The melt flow rate of specific plastic type can determine its compatibility for use in the injection molding machine. Furthermore this study found that the best ventilation system for Me.reka Makerspace’s plastic injection molding facility was the displacement ventilation. It is expected that with the installation of an efficient ventilation system, the hazardous gasses produced during the process will be efficiently expelled thus protecting the health of workers. With regards to injection molding, a mold design was made for a book cover mold by applying the applicable mold design principles. However, this mold was later sent for testing at another facility. A flowerpot mold that had arrived at Me.reka which required immediate testing was tested instead. Through testing, improvements were made to the mold and the molding process by finding out the optimum injection molding temperature for the waste plastic used and the mold sprue diameter required to produce a well formed molding.

Rheology of Crystallizing LLDPE.

Polymer crystallization occurs in many plastic manufacturing processes, from injection molding to film blowing. Linear low-density polyethylene (LLDPE) is one of the most commonly processed polymers, wherein the type and extent of short-chain branching (SCB) may be varied to influence crystallization. In this work, we report simultaneous measurements of the rheology and Raman spectra, using a Rheo-Raman microscope, for two industrial-grade LLDPEs undergoing crystallization. These polymers are characterized by broad polydispersity, SCB and the presence of polymer chain entanglements. The rheological behavior of these entangled LLDPE melts is modeled as a function of crystallinity using a slip-link model. The partially crystallized melt is represented by a blend of linear chains with either free or crosslinked ends, wherein the crosslinks represent attachment to growing crystallites, and a modulus shift factor that increases with degree of crystallinity. In contrast to our previous application of the slip-link model to isotactic polypropylene (iPP), in which the introduction of only bridging segments with crosslinks at both ends was sufficient to describe the available data, for these LLDPEs we find it necessary to introduce dangling segments, with crosslinks at only one end. The model captures quantitatively the evolution of viscosity and elasticity with crystallization over the whole range of frequencies in the linear regime for two LLDPE grades.

Experimental investigation of linear low density polyethylene composites based on coir for rotational molding process

Rotational Molding is a plastic manufacturing process mainly implemented to produce stress free hollow products. Linear Low Density Polyethylene (LLDPE) is widely preferred as base resin for molding roto molded product, but it displays moderate value in some critical applications where strength is the major criteria. Additives can fill the gap in sustaining the necessary strength needed. In the present work, an attempt has been made to analyze the optimum percentage of coir reinforced with LLDPE for rotational molding technique to provide requisite processability for rotational molding process. Coir in its powder form is mixed at concentrations varying in the range of 3% to 20% with respect to LLDPE. In order to justify the prerequisite of processability for rotational molding, various experiments namely FTIR, MFI, rheology and thermal analysis were conducted. FTIR suggested the range of 5% to 15% wherein the significance of LLDPE and coir peaks can be observed. MFI test supported FTIR result which ended in considering 3% to 12% by weight ratio suitable in terms of flow ability. Rheological and thermal analysis subjecting to shear and heat parameter respectively, confirmed the range of 10 weight percentage of coir or below is suitable in terms of material processability. From the experimental results, it is concluded that 10% or less concentration of coir fiber in LLDPE as an optimum range of blend yielding better processability for rotational molding process.

A moderate physiological dose of benzyl butyl phthalate exacerbates the high fat diet-induced diabesity in male mice.

Exposure to endocrine disrupting chemicals (EDCs) used in plastic manufacturing processes may be contributing to the current increase in metabolic disorders. Here, we determined that benzyl butyl phthalate (BBP), a common EDC and food packaging plasticizer, mixed into chow diet (CD) and high fat diets (HFD) at varying concentrations (4μg/kg body weight (bw)/day, 169μg/kg bw/day, 3mg/kg bw/day, 50mg/kg bw/day) produced a number of detrimental and sex-specific metabolic effects in C57BL/6 male and female mice after 16weeks. Male mice exposed to moderate (3mg/kg bw/day) concentrations of BBP in an HFD were especially affected, with significant increases in body weight due to significant increases in weight of liver and adipose tissue. Other doses did not show any significant changes when compared to only CD or HFD alone. HFD in the presence of 3mg/kg bw/day BBP showed significant increases in fasting blood glucose, glucose intolerance, and insulin intolerance when compared to HFD alone. Furthermore, this group significantly alters transcriptional regulators involved in hepatic lipid synthesis and its downstream pathway. Interestingly, most of the BBP doses had no phenotypic effect when mixed with CD and compared to CD alone. The female mice did not show a similar response as the male population even though they consumed a similar amount of food. Overall, these data establish a dose which can be used for a BBP-induced metabolic research model and suggest that a moderate dosage level of EDC exposure can contribute to widely ranging metabolic effects.

Investigation of tensile properties of polymeric nanocomposite samples in the rotational molding process

Rotational molding is a plastic manufacturing process that is used to produce seamless, one-piece, and hollow parts by rotating a mold subjected to heat and then cooling it. The aim of this study is to investigate the tensile properties of produced polymeric nanocomposite samples by rotational molding. Linear low-density polyethylene was considered as the polymeric matrix, and nanoclay was added at various weight percentages of 0, 1, and 2 as reinforcement. The effects of weight percentages of nanoclay and processing conditions including rotational speed and processing temperature are investigated on the tensile properties of nanocomposite samples based on the design of experiments according to the L9 orthogonal array of Taguchi approach. Scanning electron microscopy tests were performed on the nanocomposite samples in order to study the possible agglomeration regions of the nanoclays in the polymeric matrix. The results indicate that the processing temperature is the most effective parameter on the tensile strength and Young’s modulus of nanocomposite samples. Tensile strength and Young’s modulus were increased by 21% and 33%, respectively, by increasing the processing temperature. Also, the rotational speed is found to be the second effective parameter on the tensile properties.

IoT-based Production Output Monitoring System for Plastic Packaging Manufacturing Process

This paper discusses about the development of an IoT-based production output monitoring system in the production line of Chiga Light Industries Sdn. Bhd. which is a plastic packaging manufacturing company. Although the existing company Enterprise Resource Planning (ERP) system provides a platform for production manager and officers to monitor as well as collect the length of plastic film produced on a printing machine, only the total amount of finished goods in kilograms (kg) is recorded. However, the total length of plastic produced, and time taken to finish one tubing are needed for machine analysis and production planning. Therefore, a length encoder is used to detect the length of plastic film produced and connected to a counter meter to display the present value of plastic produced as well as the setting value for one roll of plastic. Besides, an Arduino board is used to read data from the counter meter while an ESP8266-01 Wi-Fi module is used to send the data to ThingSpeakTM cloud for storing. ThingSpeakTM analysed and visualised the collected present and setting values of the counter meter on a private channel. The duration for uploading a data is set to one hour. From the developed monitoring system, production manager and officers could monitor machine performance, operators working performance and collect the length of plastic produced on a printing machine. Besides, the total length of plastic in a roll could also be detected to ensure customer requirement is achieved.