Mold Design Research Articles

Finite Element Simulation of Injection Mold Design Integrating Different Structures of Conformal Cooling Channels

Injection molding (IM) is a process in which completely melted plastic material is injected into the mold cavity under high pressure at a specific temperature, and the molded product is obtained after pressure holding, cooling, and demolding. During the mold cooling process, the conformal cooling channel system can improve the uniformity of mold temperature, reduce warping deformation, and significantly improve product accuracy. However, the cost consumption of conformal cooling channels for the cavity and core of injection molds is significant, which is a distinct disadvantage. This paper proposes an innovative conformal cooling channel. Compared with conventional cooling channels, the warpage of plastic parts has been reduced by 0.3401 mm. Moreover, the cooling time difference between C2 and C4 is relatively small, about 7.9 s. Among them, C4 takes the shortest time, C1 takes the longest, and C4 is 4.371 s shorter than C1. Compared with C1, the cooling efficiency of C4 has increased by 35.48%. In addition, from a commercial value perspective, many mold manufacturing companies’ real production applications are better suited for using conformal cooling channels alone on the injection mold core. This paper establishes injection molding models under different working conditions, simulates the cooling of dynamic mold temperature molds, and analyzes the effects of fluid media and various fluid rates on mold temperature changes. The results indicate that the cooling effect of cooling water is significantly better than that of cooling oil at the same fluid rate. When the fluid rate increases from 0.75 L/min to 6 L/min, the effect of cooling oil on the temperature change in the mold is significantly higher than that of cooling water. The influence of mold temperature on the cooling medium’s fluid rate tends to stabilize once the cooling medium’s flow rate reaches a specific value.

Interactive casting simulation assistant for conceptual design of permanent moulds

Interactive casting simulation assistant for conceptual design of permanent moulds

Freeze-Casting Mold-Based Scalable Synthesis of Directional Graphene Aerogels with Long-Range Pore Alignment for Energy Applications.

In various applications, the pore structure of a porous medium must be controlled to facilitate heat and mass transfer, which considerably influence the system performance. Freeze-casting is a versatile technique for creating aligned pores; However, because of the complexity of the associated equipment and the energy inefficiency of liquid-nitrogen-based cooling in a room-temperature environment, limits scalability for industrial applications. This study is aimed at establishing a novel freeze-casting strategy with a simple mold design combining heat-conductive and insulating materials for long-range pore alignment via directional ice growth under deep-freezing conditions, rendering it feasible for large-scale production. Using this technique, axially aligned (Axial-GA) is developed, radially aligned (Radial-GA), and randomly distributed (Random-GA) pore structures within NaBr-impregnated graphene aerogel (GA-NaBr) configurations, demonstrating enhanced ammonia adsorption for thermal energy management. The pore structure exerted notable effects on the ammonia adsorption behavior, with Radial-GA exhibiting a higher adsorption rate due to reduced ammonia transit distance. The Radial-GA-NaBr structure demonstrated unique adsorption characteristics, retaining ≈85% of the adsorption capacity and achieving a ≈270% adsorption rate gain compared with pure NaBr powder. Overall, this research demonstrates the fabrication of aerogels with various configurations and orientations using facile and scalable methods, thereby expanding their industrial applications.

A springback minimization study using the experimental design methods for 15-5 PH stainless steel material in the hydroforming process

Purpose This study aims to examine the springback behavior of 15-5 PH stainless steel, which is widely used in the aviation industry. Design/methodology/approach The shaping sheet metal with a diaphragm is a widely used shaping method in aviation. In this process, the sheet metal is attached to the mold, placed in the form machine and pressure is applied. The diaphragm, which swells under the influence of gas, transmits pressure to the sheet metal surface and allows the mold to take its shape. One of the behaviors that occurs in the part after processing is springback. The mold design is shaped according to this springing amount. Some prominent parameters in the amount of springback are bending radius, bending angle, material thickness and material type. Material thickness is taken as 0.813, 1.27, 1.6 and 2 mm for experimental studies. This study compares the general full factorial design with the 2k factorial design. Then, the authors get analysis of variance (ANOVA) tables for the experiments and finite element analysis results, respectively. Findings At the end of the study, a mathematical expression was obtained that gives the springback rate with an accuracy of over 90%, depending on the process parameters, in 15-5 PH material. In addition, the main effects of the working parameters on the springback behavior were revealed by ANOVA method. Originality/value To the best of the authors’ knowledge, this is a new application that provides robust results to the springback minimization for the sheet metal bending process.

Predicting Curing Distortion in Composite Manufacturing-A Fast and Cost-Efficient Numerical Simulation Method.

The curing distortion is a critical determinant of the quality of integrally manufactured composite structures, playing a pivotal role in the design and fabrication of composite. This paper presents two simplified methods in predicting the curing distortion for large-scale composite aircraft structures manufactured through the autoclave process. Firstly, the refined finite element models of the two simplified methods were developed. Then, it was utilized to predict the curing distortion of Ω-shaped composite laminates. The comparative study between the experimental data and numerical results shows that the proposed second simplified method balanced the prediction accuracy and efficiency, which is urgently needed in practice. Finally, using the second simplified method, predictions were conducted for the curing distortion of practical large-scale composite skin structures. The results were in good agreement with the corresponding experiments. This study provides a new solution for the rapid iterative design of large-scale composite structures, as well as the efficient design of frame molds for their manufacturing.

Pottery complex of the Alakul Culture from kurgans 1 and 14 of the Alakul cemetery: results of technical and technological analysis

Presented are the results of the analysis of pottery skills of a group of the Bronze Age Alakul Culture, who made burials under mounds 1 and 14 of the Alakul burial ground (forest-steppe Trans-Urals). The study was car-ried out within the framework of the historical and cultural approach and following the methodology developed by A.A. Bobrinsky. The traditional methods of making vessels that existed among potters of the analysed population have been determined, the heterogeneity of potters' views on the initial plastic raw materials has been detected, as well as some differences in the manufacture of vessels from different burial mounds at the stages of compiling moulding compounds and design. As a result of the study, the earlier assumption, based on the analysis of shape and ornamentation of the products, about the increased complexity of the composition of the analysed population at the stage of construction of mound 1 and the processes of mixing, in all likelihood, of related groups of the population who had their own traditions in the manufacture of pottery, manifested in the materials of kurgan 14, has been confirmed.

Numerical evaluation of the transverse permeability determination experiment

Polymeric composites produced by liquid molding are becoming more and more common in nowadays applications. Quality control of the produced parts relies on precise evaluation of the manufacture parameters and physical properties. Permeability is one of these important properties and the subject of present work where mold design for transverse permeability (out-of-plane) determination is investigated. The most used mold design is based on a resin rectilinear (one dimensional) flow which is forced through the fibers. To assemble it inside the mold cavity, two perforated plates are used. The geometry of these plates, as well as the distance between them, directly influences the calculated permeability, however quantification of this influence is not well documented in literature. Furthermore, the anisotropy ( K xx/ Kzz ratio) of the material is evaluated as a factor that intensifies the influence of flow distortions that vary with the plates used. A numerical study has been performed to quantitatively evaluate how much these parameters may affect the calculated permeability. Results have shown that errors up to 40% may occur if a wrong setup was used in materials with low permeability ratios. Better accuracy is obtained for materials with higher ratios regardless of the used perforated plate.

Process Parameters and Tool Design in Friction Stir Extrusion: A Sustainable Recycling Technique

ABSTRACTFriction stir extrusion (FSE) is a versatile technique that plays a dual role in sustainable recycling and shaping of materials. This method involves a rotating mandrel and a fixed matrix within a mold, where compressed waste metal chips or primary bulk materials are introduced. The rotating mandrel exerts continuous axial pressure, generating frictional heat that softens and bonds the materials together. As the mandrel advances, the materials are reshaped and extruded through the cavity inside the mandrel or the space between the mandrel and the matrix, resulting in the desired product, such as wires or pipes. FSE finds applications in recycling machining wastes, improving powder metallurgy products, producing wire raw materials, creating structures with fine microstructures, and developing new alloys and composites. The resulting materials exhibit refined grains, leading to enhanced mechanical and metallurgical properties. This review article compiles experimental studies exploring the mechanical and microstructural characteristics of samples manufactured using FSE for recycling, reshaping, alloying, or bilayer production. Additionally, it discusses various tool, mold, and machine designs proposed by researchers. Beyond its unique properties, FSE is highlighted as an energy‐efficient, sustainable, and eco‐friendly process.

Geometric Optimization of the Five-Point Double-Toggle System for the Clamping Unit of an Injection Molding Machine with the Response Surface Method

Injection molding is one of the most used processes for the manufacture of plastic products with high-volume capacity. The five-point double toggle mechanism is frequently employed in the clamping unit to augment the force generated by a linear actuator, thereby achieving the requisite clamping force. This is a crucial aspect that determines the productivity and quality of the finished product in the injection molding process. Nevertheless, the geometrical synthesis of this type of mechanism has not been sufficiently addressed with regard to its integration into the mold design and the opening/closing stroke. This paper presents a novel approach for analyzing and evaluating the impact of parameters pertaining to mechanism posture on its force amplification, employing the Taguchi method. The relationship between force amplification ratio and the most influential parameters is simplified with the Face-Centered Central Composite Design (FCCCD) method, thereby allowing the optimal posture of the mechanism at the mold-closing stage to be determined. With these optimal parameters, once the mold height and desired opening/closing stroke have been selected, the dimensions of the links in the mechanism can be calculated. The results demonstrate that there are numerous combinations of these parameters that can yield a high force amplification ratio, thus providing the designer with a range of options for the design of a clamping unit. The proposed method can be employed at the initial stage of the design process to obtain a preliminary design, thus preparing for the dynamic analysis or further optimization problems of the mechanism.

Adaptable Manufacturing and Biofabrication of Milliscale Organ Chips With Perfusable Vascular Beds.

Microphysiological systems (MPS) containing perfusable vascular beds unlock the ability to model tissue-scale elements of vascular physiology and disease in vitro. Access to inexpensive stereolithography (SLA) 3D printers now enables benchtop fabrication of polydimethylsiloxane (PDMS) organ chips, eliminating the need for cleanroom access and microfabrication expertise, and can facilitate broader adoption of MPS approaches in preclinical research. Rapid prototyping of organ chip mold designs accelerates the processes of design, testing, and iteration, but geometric distortion and surface roughness of SLA resin prints can impede the development of standardizable manufacturing workflows. This study reports postprocessing procedures for manufacturing SLA-printed molds that produce fully cured, flat, patently bonded, and optically clear polydimethyl siloxane (PDMS) organ chips. Injection loading tests were conducted to identify milliscale membrane-free organ chip (MFOC) designs that allowed reproducible device loading by target end-users, a key requirement for broad nonexpert adoption in preclinical research. The optimized milliscale MFOC design was used to develop tissue engineering protocols for (i) driving bulk tissue vasculogenesis in MFOC, and (ii) seeding the bulk tissue interfaces with a confluent endothelium to stimulate self-assembly of perfusable anastomoses with the internal vasculature. Comparison of rocker- and pump-based protocols for flow-conditioning of anastomosed vascular beds revealed that continuous pump-driven flow is required for reproducible barrier maturation throughout the 3D tissue bulk. Demonstrated applications include nanoparticle perfusion and engineering perfusable tumor vasculature. These easily adaptable methods for designing and fabricating vascularized microphysiological systems can accelerate their adoption in a diverse range of preclinical laboratory settings.

Modeling Electrical Conductivity of Injection-Molded Polymer Composite Bipolar Plates

Bipolar plates can be responsible for up to 40% of the total stack cost and 80% of the weight of a polymer electrolyte membrane fuel cell [1]. To reduce these cost and weight limitations, this work explores injection molding of polymer composites. Injection molding is well-suited for mass production and polymeric materials can significantly reduce the weight of traditional metallic bipolar plates. While polymers lack electrical conductivity, fillers can be added to fabricate conductive polymer composites. The main objective of this research is to model and injection mold polymer composites that will meet the United States Department of Energy technical target for bipolar plate electrical conductivity (> 100 S/cm).A fiber contact model was developed to predict electrical conductivity based upon direction in the material, fiber alignment, fiber length and diameter, fiber concentration, and fiber conductivity [2]. Fiber alignment was measured experimentally by imaging cross sections of injection-molded nylon/carbon fiber composites. Imaging was performed on samples with different weight percentages of carbon fiber and from different mold designs to compare how fiber angles change based on mold geometry. To reduce the significant time required to measure fiber angles experimentally, computer recognition and processing of fiber alignment was developed. Nylon composites were injection molded with carbon fiber loadings ranging from 5 to 40 wt%. Modeling predictions show good correlation within 20% of experimental conductivity measurements. Samples with at least 20 wt% carbon fiber exceeded the US DOE technical target for bipolar plate conductivity, reaching 250 S/cm. In addition to modeling electrical conductivity, the Halpin-Tsai equations are used to model the elastic modulus and ultimate strain of the polymer composite. Tensile testing showed that the modulus of elasticity increases with carbon fiber loadings up to 30 wt%, reaching 7.3 GPa. At loadings above 30 wt%, the higher filler content can create voids which decrease the modulus of elasticity. De Las Heras, A.; Vivas, F. J.; Segura, F.; Andujar, J. M., From the cell to the stack. A chronological walk through the techniques to manufacture the PEFCs core. Renewable & Sustainable Energy Reviews 2018, 96, 29-45.Weber, M.; Kamal, M. R., Estimation of the volume resistivity of electrically conductive composites. Polymer Composites 1997, 18 (6), 711-725. Figure 1

A Single-Cell Interrogation System from Scratch: Microfluidics and Deep Learning.

Live-cell imaging using fluorescence microscopy enables researchers to study cellular processes in unprecedented detail. These techniques are becoming increasingly popular among microbiologists. The emergence of microfluidics and deep learning has significantly increased the amount of quantitative data that can be extracted from such experiments. However, these techniques require highly specialized expertise and equipment, making them inaccessible to many biologists. Here we present a guide for microbiologists, with a basic understanding of microfluidics, to construct a custom-made live-cell interrogation system that is capable of recording and analyzing thousands of bacterial cell-cycles per experiment. The requirements for different microbiological applications are varied, and experiments often demand a high level of versatility and custom-designed capabilities. This work is intended as a guide for the design and engineering of microfluidic master molds and how to build polydimethylsiloxane chips. Furthermore, we show how state-of-the-art deep-learning techniques can be used to design image processing algorithms that allow for the rapid extraction of highly quantitative information from large populations of individual bacterial cells.

Towards dynamic multiscale feedback during the injection moulding cycle of plastics

Injection moulding is a very popular technology for shaping plastics. Its history stretches back to the nineteenth century, and, as a consequence, it has developed outside the framework of digitisation. In order to fully implement the concepts of Industry 4.0, we need to update these legacy technologies so that they can fully benefit from the developments inherent in the “Internet of Things” and allow the process of injection moulding to take full advantage of digital optimisation so that it can fit effectively in the digital factory. In this work, we explore the quantitative use of X-ray scattering as a technology that can provide dynamic and multiscale feedback during the injection moulding cycle to be able to exploit digital twin technology as a means to optimise the operational parameters involved in injection moulding and to enable digital design of moulds in the fullest sense. This manuscript provides a way to mark future work and draw these possibilities to a wider audience.

Influence of Sintering Temperature and Holding Time on the Properties of DLP-Fabricated Si3N4/SiAlON Ceramics

Si3N4/SiAlON ceramics are extensively utilized in aerospace, mechanical, and biomedical fields. Traditional synthesis methods, such as direct synthesis, are well-established but limited in producing complex shapes and structures due to mold design constraints and high hardness. Additive manufacturing (AM), particularly digital light processing (DLP), offers greater design freedom and reduced costs without the need for molds. This study investigates the use of DLP to fabricate Si3N4/SiAlON ceramic green bodies and optimizes their sintering process. The results indicate that the sintering regime greatly affects the phase composition, microstructure and overall properties of composite ceramics. Holding the ceramics at 1800 °C for 2 h during gas pressure sintering produces β-Si3N4/β-SiAlON composites with optimal properties, including a high density of 91.96 ± 3.45%, flexural strength of 374.59 ± 9.50 MPa, Vickers hardness of 20.66 ± 1.39 GPa, and fracture toughness of 6.57 ± 0.24 . These findings provide valuable insights for future research and industrial applications of Si3N4/SiAlON ceramics via DLP.

Cost and Time Reduction of Industrial Mold Design and Manufacturing by Implementing Additive Manufacturing for Premature Neonatal Prong.

For a long time, molding was one of the most important methods of producing metal, ceramic, and polymer materials. The two essential factors in this method were always cost and time. Technology advancements have made it possible to design in 3D using a computer and additive manufacturing. This article covers methods for using 3D printers to save time and money in the process of creating the final product. The "Prong" molds for premature neonatal respiratory aid were designed and produced based on neonatologists' considerations. The study was conducted on fifteen very low birth neonates at Alzahra Hospital in Tabriz University from September 2017 to September 2019. In the first section, we described dental plaster material for molding. When using this material, the printing material must be selected and the parameters, like melting temperature and printer speed, must be controlled to achieve acceptable quality for the final sample. CAD software can be used to print various objects if the final 3D design is appropriate. We used additive manufacturing technology to create a new design and successfully resolved bubble issues at a low cost through a combination of creativity and experimentation. The new mold has cavities that allow the silicon to occupy the entire space and escape any bubbles. The use of 3D printers allows us to achieve the best design for the prong mold while reducing both production costs and time. The ultimate mold made of aluminum was finally produced by the CNC machine. The final product was tested at Al-Zahra Hospital in Tabriz, Iran, and the results were satisfactory, with no reports of necrosis on the babies' noses.

Improving parameters for achieving uniform cylindrical cup wall thickness in two-step deep drawing processes with SPCC sheet material

Deep drawing processes are essential in modern manufacturing for creating intricate components with deep hollows, particularly cylindrical forms. These processes are widely used in industries such as household appliances, automotive manufacturing, aerospace engineering, and fire safety equipment. This study focuses on the two-step deep drawing of cylindrical cups, utilizing both simulation and experimental methods. The primary goal is to determine optimal geometric and technological parameters for mold design and to address issues like wrinkling and tearing. Key parameters, including punch nose radius (Rpf), die nose radius (Rdf), punch-die clearance (Wf), and blank holder force (BHF), are systematically analyzed. Results show that proper parameters lead to a uniform wall thickness, with deviations reduced to 4.77%. Conversely, improper parameters result in a 12.03% deviation. Improved parameters in the second-step deep drawing yield cylindrical cups that closely match experimental outcomes, free from wrinkling or rim cracking. This research highlights the importance of selecting appropriate parameters to avoid defects.

Monitoring the thermal state of an ingot with beveled and rounded corners in a slab crystallizer of a CCM

The organization of ingot cooling in the continuous caster mold affects the reliability, productivity and quality of the resulting ingots. Insufficient heat exchange between the solidifying metal and the wall of the mold leads to a decrease in the thickness of the solid shell of the ingot, which causes the formation of surface defects, and when the ingot is pulled out of the mold, emergency breakthroughs occur. Excessive heat transfer leads to an increase in the thickness of the solid shell, which entails excessive shrinkage of the ingot surface with the formation of a gap between the solid shell of the ingot and the walls of the mold. The appearance of an air gap leads to increased wear of the copper walls of the mold. There is a design of copper walls that makes it possible to reduce the normal component of forces that occurs during wear, reduce the temperature gradient and stress concentration in the corner of the ingot, and also bring the thickness of the hard crust stocking in the corner closer to the perimeter of the mold. However, the thermal state of the formed ingot with such a crystallizer design remains poorly understood. The goal of the work is to create a virtual tool for monitoring the operation of the mold of a slab continuous caster based on the development of a mathematical and computer model of the thermal state of an ingot with beveled and rounded corners. The temperature distribution in the ingot was calculated using the quasi-equilibrium theory of solidification. The numerical implementation of the mathematical model and obtaining an approximate solution using a computer were carried out using the finite dif-ference method and an implicit difference scheme. A computer program was developed in the Matlab development environment. Using computer modeling, the temperature distribution over the volume of the slab at the outlet of the mold with beveled and rounded corners was obtained. The program for the selected mold design allows you to analyze the solidification of the ingot skin and monitor this process for the selected steel grade and specified casting technological parameters

Effect of Mold Design on Microstructure and Macrosegregation in a 5.5-Ton Steel Ingot Using a Three-Phase Mixed Columnar-Equiaxed Model

Effect of Mold Design on Microstructure and Macrosegregation in a 5.5-Ton Steel Ingot Using a Three-Phase Mixed Columnar-Equiaxed Model

Research on preparation of micron-scale orthogonally aligned HMS patterns based on soft lithography

The soft lithography enables the fabrication of microfluidic honeycombs, which are micron-scale, orthogonally aligned hexagonal mesoporous silica (HMS) patterns with channels embedded within them, on silicon substrates. The process entails meticulous cleaning, precise master mold design (including features for channel alignment) using electron-beam lithography, generation of polydimethylsiloxane (PDMS) mold creation, ink formulation, and pattern transfer. Subsequent steps include the sol-gel transition, hardening, alignment verification, characterization, and optional functionalization. It is of the utmost importance to optimize these steps and the master design in order to achieve success. Therefore, the paper examines the creation of micron-scale HMS patterns with orthogonal alignment through the innovative application of soft lithography. The technique encompasses the strategic design of hexagonal motifs, precision master mold crafting, the PDMS stamps, and a meticulous sol-gel procedure, resulting in HMS structures that exhibit remarkable precision and adaptability. This paper underscores the transformative potential of soft lithography in the realm of advanced materials, which offers a controlled and uniform approach to size and uniformity. The refined soft lithography process not only achieves the precise orthogonal alignment of HMS patterns but also highlights its adaptability and economic viability in nanotechnology ventures.

An Application of Computer-aided Engineering on Heat Transfer in a Mold for Natural Rubber Boot Production

The production of natural rubber boots refers to the process of manufacturing boots using natural rubber as the primary material. The manufacturing process involves injecting natural rubber into a mold to shape and size the boot. The molded boots are then cured and finished with other materials, such as fabric linings, soles, and straps. Natural rubber boots are popular for outdoor activities, work, and fashion. The purpose of this research is to develop a computer-aided engineering analysis simulation tool for heat transfer in the injection mold of rubber boot products. In this study, a finite element model was created to reduce the preheating time of the mold during the injection molding process, thus increasing production capacity. The first step was to design the mold used in the current factory, followed by an analysis of the heat transfer in the rubber mold. Finally, the position of the heater cartridges was fixed based on the analysis results. FEA was performed to improve the rubber mold, and experiments were conducted to validate the FEA. The results showed that the FEA was in good agreement with the experimental results, specifically with the temperature analysis.The time required for the heater cartridge to preheat the rubber boot mold is 35 minutes, down from 120 minutes, representing a percentage improvement of 70.8. The heat transfer values obtained at each location have an error of less than 10%, which is a good result for the calculated model. We propose an optimal design method for arranging cartridge heaters in rubber boot injection mold to improve the mold design, specifically on the mold outer surface.