Properties Of Mold Research Articles

Development of Calculation Program for Thermophysical Properties of Artificial Sand Mold

Development of Calculation Program for Thermophysical Properties of Artificial Sand Mold

Impact of Runner Size, Gate Size, Polymer Viscosity, and Molding Process on Filling Imbalance in Geometrically Balanced Multi-Cavity Injection Molding.

The injection molding process is one of the most widely used methods for polymer processing in mass production. Three critical factors in this process include the type of polymer, injection molding machines, and processing molds. Polypropylene (PP) is a widely used semi-crystalline polymer due to its favorable flow characteristics, including a high melt flow index and the absence of a need for a mold temperature controller. Additionally, PP exhibits good elongation and toughness, making it suitable for applications such as box hinges. However, its tensile strength is a limitation; thus, glass fiber is added to enhance this property. It is important to note that the incorporation of glass fiber increases the viscosity of PP. Multi-cavity molds are commonly employed to achieve cost-effective and efficient mass production. The filling challenges associated with geometrically balanced layouts are well documented in the literature. These issues arise due to the varying shear rates of the melt in the runner. High shear rate melts lead to high melt temperatures, which decrease melt viscosity and facilitate easier flow. Consequently, this results in an imbalanced filling phenomenon. This study examines the impact of runner size, gate size, polymer viscosity, and molding process on the filling imbalanced problem in multi-cavity injection molds. Tensile bar injection molding was performed using conventional injection molding (CIM) and microcellular injection molding (MIM) techniques. The tensile properties of the imbalanced multi-cavity molds were analyzed. Flow length within the cavity served as an indicator of the filling imbalance. Additionally, computer simulations were conducted to assess the shear rate's effect on the runner's melt temperature. The results indicated that small runner and gate sizes exacerbate the filling imbalance. Conversely, glass fiber-filled polymer composites also contribute to increased filling imbalance. However, foamed polymers can mitigate the filling imbalance phenomenon.

Effects of printing parameters on the mechanical properties of sand molds produced by a novel binder jetting 3D printer

Effects of printing parameters on the mechanical properties of sand molds produced by a novel binder jetting 3D printer

Thermal Properties of 3D-Printed Molds for Light Metal Casting

AbstractBinder Jetting technology is well established for the production of sand molds and cores for foundry use, owing to its flexibility and expansive design capabilities. A wide array of sand, aggregate, and binder combinations is commercially available. Utilizing these types of refractory materials in the casting process presents both technical and economic benefits and drawbacks. For intricate cast components, foundry technologists must assess the thermophysical properties of the mold material systems. With this knowledge, specialized high-performance material combinations may be employed in specific areas of the mold, while more economically viable systems are used for shaping the external mold support. This study primarily focuses on determining the heat capacity and thermal diffusivity and consequently the thermal conductivity using a specially developed analytical method. It investigates three different fundamental aggregates: silica, cerabeads®, and chromite. The result’s range provides an overview of relevant characteristics for the selected material systems. Given that the properties of sand affect heat flow during casting and solidification, these newly determined values can be utilized in future simulations. Consequently, these findings aid in maintaining and enhancing the quality of critically stressed cast parts.

High-Performance 3D Sand Printing Process Using Interlayer Heating

Sand mold 3D printing technology has been recognized as a digital, high-quality, and promising sand mold forming method. However, sand mold 3D printing technology has drawbacks, such as single molding material and long curing time, which limit its further industrial application. Therefore, this study proposes a method for forming composite sand molds based on a layer-stacking structure and a strengthening method based on interlayer heating. The influence of the process parameters on the properties of traditional and composite sand molds was systematically studied. Experimental results demonstrated that when the heating temperature was 150 °C, the enhancement of the sand mold was obvious, with an increase of approximately 20% compared to untreated sand mold. When the composite sand mold with a laminated thickness of 1.5 mm was heated at this temperature, its tensile strength reached 1.53 MPa, and compressive strength reached 5.80 MPa, which met the casting requirements. The composite sand mold printed by interlayer heating has excellent casting performance and economic advantages, which provide theoretical guidance for the high-performance printing of sand molds.

Study on the Effect of Recycled Brass-Filled Epoxy Mould Inserts for Rapid Tooling

Rapid Tooling able to produce complex prototypes directly from three-dimensional CAD software using materials such as polymer, wax, and paper, but it is typically used for low-volume production. The current technology uses epoxy filled with metal fillers such as aluminum or copper to enhance the mechanical properties of rapid tooling molds. This study aims to investigate the effect of using recycled brass filler mixed with epoxy resin as mold inserts for Rapid Tooling in injection molding applications. An optimal ratio of brass filler particles will be evaluated to determine the best physical and thermal properties for the mold inserts. Significantly, this study will encourage the use of recycled materials such as metal waste from machining to offer great help in environmental sustainability.

Effect of Wall Thickness on Properties of Multilayer Composite Plaster Mold for Investment Casting

Effect of Wall Thickness on Properties of Multilayer Composite Plaster Mold for Investment Casting

Analysis of Cooling a Printed 3D Mold Using a Casting and Solidification Simulation of a CuSn20 Bronze Bell Casting

The work done in this study is a preliminary investigation into the possibility of modelling the filling and solidification process of castings in molds made with the additive method. The work originated from an experiment to produce a bronze casting with a high tin content in an additive mold. The mold filling and solidification simulation was carried out in the MAGMASO FT program, and the lambda thermal conductivity coefficient used in the program’s material database was corrected based on the actual temperature values of the printed form. The results were compared with the modeling results for the physical properties of furan molds based on the program database. The microstructure of the castings obtained in the compared forms was assessed.

Addition of Modifying Agents vs Basic Functional Properties of Moldings Made of ABS

Unconventional injection methods include i.e. blowing injection that allows for production of moldings with a lower weight while maintaining mechanical properties of detail. Due to the fact that most polymers are dyed at the processing stage, it is important to examine the simultaneous effect of blowing and colorbatch, as well as variable processing conditions, on the functional properties of moldings made of the most popular construction material, i.e. ABS. Samples were made of ABS polymer without and with the addition of a colorbatch containing brown pigment on ABS matrix, and blowing agent. Variable processing conditions were: mold and injection temperature, holding pressure and time. Other parameters were constant. Samples were tested for basic functional properties such as color, gloss, mass, density and thickness. Moldings produced with a higher blowing agent content and a higher injection temperature were characterized by lower mass. No significant influence of processing parameters and content of colorbatch on mass of samples was found. Blowing agent has no significant impact on thickness of moldings, regardless of processing conditions. Addition of a colorbatch influenced samples’ gloss. Increase in colorbatch and blowing agent content and mold temperature allow to obtain moldings with a higher surface gloss. Colorbatch also changed color of samples – a decrease in luminance L even by about 40% and great changes in parameters “a” and slight changes in parameter “b”. It was found that blowing agent content had the greatest influence on density of moldings. Injection temperature and colorbatch, do not significantly affect density of moldings.

Optimization and empirical studies of riser design in sand casting process using different mould properties

Optimization and empirical studies of riser design in sand casting process using different mould properties

Additive manufacturing of high-performance Ni-Co coatings for micro/nanomold applications using an advanced gradient ultrasonic electrochemical deposition process

The mass production of polymeric microdevices using microinjection molding or nanoimprinting necessitates high-performance micro/nano Ni-Co molds. However, the achievement of a synergistic enhancement of the mechanical and lubricating properties of Ni-Co mold through general electrodeposition process remains challenging. This study for the first time proposes a gradient ultrasonic-assisted electrodeposition process to investigate its impact on the microstructural, mechanical, and tribological properties of Ni-Co coatings. Meanwhile, wear simulations are also conducted to elucidate the deterministic relationship of microstructure-process-properties by integrating surface topography and dynamically changing the coefficient of friction (COF) in the wear model. Our findings show that a high Co content (Ni:Co = 5:5) along with gradient-increased ultrasonic power (30–100 W) achieves maximum hardness (approximately 489 HV) and minimum COF (approximately 0.17), indicating a 1.73-fold hardness increase and 72% COF decrease relative to Ni coating. Such improvements result from grain refinement, reduced lattice distortion, and increased hydrophobicity, driven by the synergistic enhancement of high Co content and gradient ultrasonic power. Wear simulations highlight the undeniable impact of surface roughness and dynamic COF, which is vitally important for micro/nanomolds applications. This study realizes the integration of wear model–ultrasonic-process–microstructure–properties of Ni-Co coatings, offering valuable insights into the development of high-performance micro/nano Ni-Co molds based on gradient ultrasonic-assisted electrodeposition process.

MOLD PROPERTIES OF INDONESIA NATURE SAND AS GREEN SAND


 The mould properties of Juwono sand, were investigated. The samples were subjected to various physical and mechanical test. These include permeability, green compression strength, and chemical composition by XRF/ XRD analysis. Green shear strength, grain shape, water content, and clay content were also carried out on the samples. Juwono sand casting containing 32.76% clay and category in grade 212/75 of fine sub grades were found to posses adequate permeability, good strength and refractoriness suitable for casting of both ferrous and non ferrous alloys.

Effective Utilization of Industrial and Constructional Solid Waste Materials in Foundry Mould Making to Prevent Environment Pollution and Conserve Natural Silica Sand

<p>Green sand moulding uses silica sand for metal casting. Silica sand mining and delivery to foundries destroy the ecosystem, making metal casting unsustainable. Due to increased sand-casting output and massive civil buildings in India, the silica sand supply is declining. The depletion and shortage of silica sand necessitate the search for viable replacements. Industrial solid waste from large-scale industrialization pollutes land, air, and water. In order to use industrial waste in large amounts, an attempt is made to use it as a replacement for natural resources. The main objective of this research is to reduce the consumption of silica sand in the foundry mould-making process. Silica sand is replaced with industrial solid waste, cupola slag, and construction solid waste sources like spent fire bricks and quarry dust, up to a considerable amount, to save the natural resources. Utilization of solid waste material in the mould-making process will reduce production costs and environmental pollution, like dumping solid waste materials on land. Sand tests like permeability, green compression strength, dry compression strength, and compactability were conducted to assess the moulding properties of these alternative moulding materials. The process parameters considered for this investigation were the percentage of bentonite binder and the percentage addition of alternative mould materials with silica sand. The various sand tests showed that 40%, 30%, and 20% of quarry dust, spent fire bricks, and cupola slag, respectively, will adequately replace silica sand for mould making. A bentonite binder of 8% is suitable for quarry dust mould, and a 10% bentonite binder is required for spent fire brick particles and cupola slag to yield better results. Aluminium castings were produced at the optimal mixture of these solid waste particles and silica sand. The results of mechanical tests such as hardness, tensile, and impact tests are comparable to those of silica sand castings.</p>

Mechanical integrity and erosion resistance of 3D sand printing materials

3D sand printing, a binder jetting-based additive manufacturing process, can directly produce sand molds with complex geometries for high-quality and lightweight metal parts. However, there is still a lack of information on how to degrade and erode the mechanical integrity of 3D sand molds. Here, correlations have been investigated between 3D printing materials and various properties of 3D-printed molds: microstructure, flexural strength, reliability, and erosion resistance. As a result, given the mechanical strength and the formation of the binder necks, the most appropriate flexural strength of 4.2 MPa, reliability of 7.8, and high erosion resistance of 86% are achieved from the 3D-printed sand molds prepared with a binder of 2 wt% and an activator of 0.25 wt%. The exhaust manifold casted using a 3D-printed sand mold with optimum conditions, it shows the same or better performance than the genuine part.

Utilizing of the Statistical Analysis for Evaluation of the Properties of Green Sand Mould

Utilizing of the Statistical Analysis for Evaluation of the Properties of Green Sand Mould

Study on mechanical and tribological properties of electroformed nickel composite mould co-deposited with nano-sized PTFE particles

To improve the lubrication and wear resistance of nickel composite moulds, nano-sized polytetrafluoroethylene (PTFE) particles were co-deposited with nickel. This work reports the effect of using micro-sized and nano-sized PTFE particles on the surface, mechanical and tribological properties of Ni composite moulds. The experimental results indicate that using nano-sized PTFE particles is significantly more effective than micro-sized PTFE particles in improving the lubrication, mechanical and tribological properties of the composite moulds. The microhardness of the composite mould increases by 2.5 times to 483 Hv for a Ni-PTFE nanocomposite mould, along with the COF against polymethyl methacrylate (PMMA) decreasing by 52.2% to 0.22. Using micro-sized PTFE particles serves to roughen the mould surface, which results in faster adhesive wear. In comparison, the Ni-PTFE nanocomposite mould has a low surface roughness and enhanced wear resistance against PMMA, while the tool lifetime increases by 11.5 times. Finally, a Ni/PTFE nanocomposite mould was successfully fabricated via UV-LIGA, and its lubricating properties were validated by producing high-quality PMMA replicas via micro hot embossing.

REGULATION OF THE PROPERTIES OF SAND-CLAY MOLDING MIXTURES BY SODIUM PHOSPHATE ADDITIONS

Purpose. Study of the effect of sodium phosphate additives on the properties of a reversible sand-clay mixture in the green and dry state to improve the quality of castings from iron-carbon and aluminum alloys.
 Research methods. A reversible molding mixture based on quartz sand and kaolin clay was used. The effect of three additives (sodium tripolyphosphate, sodium hexametaphosphate, sodium pyrophosphate) in amounts from 0.5 to 2.0% was studied. Properties of mixture were determined using standard methods: clay component content, strength, gas permeability, crumbleness, flowability, formability, packing.
 Results. Effective additives have been studied to ensure the possibility of multiple use of reversible molding sand-clay mixtures. Special attention is paid to the regulation of the properties of the mixture in the dry state, since this issue has been much less researched today. For this purpose, sodium phosphates, which are produced by the chemical industry in sufficient quantities, were used for the first time. As materials that affect the properties of the mixture as a whole, they have not been considered before.
 Scientific novelty. For the first time, the positive effect of sodium phosphate additives on the physical and mechanical properties such as strength and crumbleness of reversible sand-clay mixtures was established. This effect is manifested in the fact that additives contribute to a slight improvement of properties of the green mixture and a very significant improvement of these properties of the dry mixture. There is practically no effect on important technological properties (flowability, formability, packing).
 Practical value. Based on the results of the experiments, it is recommended to use sodium tripolyphosphate or hexametaphosphate additives in the amount of 0.5 to 1.0 % to significantly improve the properties of dry sand-clay foundry molds. The use of these additives eliminates the appearance of surface defects in cast parts from aluminum and iron-carbon alloys.

Surface properties of molds for powder injection molding and their effect on feedstock moldability and mold adhesion

The surface energy of various mold materials for low-pressure powder injection molding was evaluated using values of contact angles (Owens–Wendt method), and correlated with the feedstock moldability and mold adhesion. The surface tension of the binder used to formulate a metallic-based feedstock was also measured in the molten state at a typical injection temperature using the pendant drop technique. Real-scale injection tests were performed into metallic and polymeric mold cavities to assess the feedstock moldability and its adhesion with the mold surfaces that were compared with theoretical predictions obtained from the surface energies values. The results confirmed that the adhesion was significantly affected by the interfacial energy between the mold and the binder—in this case, the metallic mold exhibited low adhesion as compared to the polymeric mold. It was finally demonstrated that the adhesion phenomenon is only related to the surface properties of the mold (i.e., they are not related to the solidification rate)—in this case, a gold-coated polymeric mold produced the moldability of a polymeric mold and the adhesion properties of a metallic mold, which translated into a high moldability potential, with no resulting adhesion of the feedstock with the mold.

Prediction of Penetration Defects for Iron Castings Based on Thermophysical Properties of Several Sand Molds Using Casting CAE

Prediction of Penetration Defects for Iron Castings Based on Thermophysical Properties of Several Sand Molds Using Casting CAE

Effect of Vacuum-impregnated Sodium Silicate on the Properties of Sand Mold Formed by Binder Jetting Process

Effect of Vacuum-impregnated Sodium Silicate on the Properties of Sand Mold Formed by Binder Jetting Process