Mold Filling Research Articles

Numerical Simulation of Mold Filling of Polymeric Materials with Friction Effect during Hot Embossing Process at Micro Scale.

The filling efficiency during the hot embossing process at micro scale is essential for micro-component replication. The presence of the unfilled area is often due to the inadequate behavior law applied to the embossed materials. This research consists of the identification of viscoplastic law (two-layer viscoplastic model) of polymers and the optimization of processing parameters. Mechanical tests have been performed for two polymers at 20 °C and 30 °C above their glass transition temperature. The viscoplastic parameters are characterized based on stress-strain curves from the compression tests. The influences of imposed displacement, temperature, and friction on mold filling are investigated. The processing parameters are optimized to achieving the complete filling of micro cavities. The replication of a micro-structured cavity has been effectuated using this process and the experimental observations validate the results in the simulation, which confirms the efficiency of the proposed numerical approach.

Flow Front Monitoring in High-Pressure Resin Transfer Molding Using Phased Array Ultrasonic Testing to Optimize Mold Filling Simulations.

During the production of fiber-reinforced plastics using resin transfer molding (RTM), various characteristic defects and flaws can occur, such as fiber displacement and fiber waviness. Particularly in high-pressure RTM (HP-RTM), fiber misalignments are generated during infiltration by local peaks in the flow rate, leading to a significant reduction in the mechanical properties. To minimize or avoid this effect, the manufacturing process must be well controlled. Simulative approaches allow for a basic design of the mold filling process; however, due to the high number of influencing variables, the real behavior cannot be exactly reproduced. The focus of this work is on flow front monitoring in an HP-RTM mold using phased array ultrasonic testing. By using an established non-destructive testing instrument, the effort required for integration into the manufacturing process can be significantly reduced. For this purpose, investigations were carried out during the production of test specimens composed of glass fiber-reinforced polyurethane resin. Specifically, a phased array ultrasonic probe was used to record individual line scans over the form filling time. Taking into account the specifications of the probe used in these experiments, an area of 48.45 mm was inspected with a spatial resolution of 0.85 mm derived from the pitch. Due to the aperture that had to be applied to improve the signal-to-noise ratio, an averaging of the measured values similar to a moving average over a window of 6.8 mm had to be considered. By varying the orientation of the phased array probe and therefore the orientation of the line scans, it is possible to determine the local flow velocities of the matrix system during mold filling. Furthermore, process simulation studies with locally varying fiber volume contents were carried out. Despite the locally limited measuring range of the monitoring method presented, conclusions about the global flow behavior in a large mold can be drawn by comparing the experimentally determined results with the process simulation studies. The agreement between the measurement and simulation was thus improved by around 70%.

Study on Simulation of Mold Filling and Solidification Characteristics of Hypereutectic High-Chromium Cast Iron by Lost Foam Suspension Casting

In this paper, the finite element software ProCAST version 14.5 was used to simulate the temperature field, flow field and defect prediction in the filling and solidification process of hypereutectic high-chromium cast iron. The effects of pouring temperature, negative pressure and the amount of suspension agent added during the technological process were explored. The optimum process parameters were presented. It was found that the suspension agent has a certain hindrance to the filling process, but the filling process remains stable. In the solidification stage, 89.4% of the suspension agent melted, resulting in a relative supercooling degree of 50 °C, which had a certain chilling effect and improved the solidification rate.

Investigation of Mold Filling Simulation, Segregation, and Rheological Properties in Low Pressure Injection Molding of Alumina Parts

Investigation of Mold Filling Simulation, Segregation, and Rheological Properties in Low Pressure Injection Molding of Alumina Parts

Parametric Analysis and Quality Improvement of Mould Filling Process for the Manufacturing of a Car Side Mirror Cover: A Case Study

Parametric Analysis and Quality Improvement of Mould Filling Process for the Manufacturing of a Car Side Mirror Cover: A Case Study

Effect of Bottom Gating Filling System Design on the Initial Stage of Mold Filling: A Parametric Study

Effect of Bottom Gating Filling System Design on the Initial Stage of Mold Filling: A Parametric Study

Numerical simulation of mould filling process using ansys

ABSTRACT Filling of moulds with molten metal and solidifying it affects the cycle time, casting’s interior quality and the amount of material required throughout the process. Blow holes, slag inclusions, cold shut, shrinkage, and other casting faults are all linked to the mould filling process. Industry demands the simulation of filling and solidification process before the actual operation begins. The simulation helps to examine the molten metal’s free surface variations, temperature distribution, and gas pouring problems to reduce filling-related defects and benefited to the industrial sector by eliminating the wastage of raw resources, money, labour and time. CFD analysis was carried out to investigate the impact of VOF and air entrapment in the casting part at subjected velocities to uncover pouring flaws of the casting part generated in response to the applied velocities.

Technology of Production of Mold Filling Material for Specific Purposes in the Field of Metallic Foam Casting

Technology of Production of Mold Filling Material for Specific Purposes in the Field of Metallic Foam Casting

The Modelling of Mold Filling in Resin Transfer Molding

Abstract The resin transfer moulding process (RTM) allows the industrial production of large FRP parts. In this technique layers of reinforcements (mats, woven rovings) are inserted into the mold cavity and resin is injected to fill the closed mold applying external pressure. Due to the strong interdependence between mold design, filling behavior and part quality it is most important to control the cavity pressure as the major influencing process parameter. A simple model is proposed to represent the pressure distribution during mold filling. It is based on Darcy’s law for flow of liquids through a porous media and can be applied to single type or combinations of different reinforcements.

Mathematical Simulation of CCM Mold Filling with Liquid Metal during Its Feeding from Rotary Submerged Nozzle

Mathematical Simulation of CCM Mold Filling with Liquid Metal during Its Feeding from Rotary Submerged Nozzle

Influence of Bifilm Defects Generated during Mould Filling on the Tensile Properties of Al–Si–Mg Cast Alloys

Entrapped double oxide film defects are known to be the most detrimental defects during the casting of aluminium alloys. In addition, hydrogen dissolved in the aluminium melt was suggested to pass into the defects to expand them and cause hydrogen porosity. In this work, the effect of two important casting parameters (the filtration and hydrogen content) on the properties of Al–7 Si–0.3 Mg alloy castings was studied using a full factorial design of experiments approach. Casting properties such as the Weibull modulus and position parameter of the elongation and the tensile strength were considered as response parameters. The results suggested that adopting 10 PPI filters in the gating system resulted in a considerable boost of the Weibull moduli of the tensile strength and elongation due to the enhanced mould filling conditions that minimised the possibility of oxide film entrainment. In addition, the results showed that reducing the hydrogen content in the castings samples from 0.257 to 0.132 cm3/100 g Al was associated with a noticeable decrease in the size of bifilm defects with a corresponding improvement in the mechanical properties. Such significant effect of the process parameters studied on the casting properties suggests that the more careful and quiescent mould filling practice and the lower the hydrogen level of the casting, the higher the quality and reliability of the castings produced.

Mold Filling Dynamics of Thermoplastic Forming of Bulk Metallic Glass Mems Parts: Numerical Simulation and Comparisons with Experiment

Mold Filling Dynamics of Thermoplastic Forming of Bulk Metallic Glass Mems Parts: Numerical Simulation and Comparisons with Experiment

X-Ray Transmission Observation of Mold Filling Behavior Immediately After Pouring in Cast Iron Full-Mold

X-Ray Transmission Observation of Mold Filling Behavior Immediately After Pouring in Cast Iron Full-Mold

Influence of Gas Replacement in Foamed Pattern on Pattern Decomposition and Mold Filling Rate in Evaporative Pattern Casting Process of Iron Castings

Influence of Gas Replacement in Foamed Pattern on Pattern Decomposition and Mold Filling Rate in Evaporative Pattern Casting Process of Iron Castings

The Effect of Mould Filling on the Mechanical Properties of Wall Tile Production

This study is focused on the development of properties of ceramic wall tile bodies by changing the degree of mould filling under industrial conditions (Usak Seramik A.S., Usak, Turkey). The effects of spray dryer operating conditions and granule size distribution on the degree of mould filling have been investigated. The study measured the ceramic wall tile bodies water absorption, fired shrinkage, fired and dried strength, and porosity. The granule size and distribution were changed by adjusting the pressure and the nozzles’ diameter of the spray dryer. This study aimed to reduce grain size and quantity over 500 microns and to increase quantity between 500 microns and 75 microns by increasing the spray dryer pressure and reducing the nozzle disc diameter. It was also aimed to increase the degree of mould filling by decreasing granule size. 200 tone wall tile slips were prepared and 11,000 m2 of wall tile products were produced. The phase and microstructure analysis were investigated using an X-ray diffractometer (XRD) and scanning electron microscope (SEM). As a result of this study, it was found that a lower granule size of above 500 µm improved the technical characteristics of the tiles. Ceramic wall tiles produced with lower granule grain size have high strength values, mainly due to the higher degree of mold filling. The ceramic tile production parameters in the Usak Seramik Company have been rearranged according to the data obtained from this study. This granule size and distribution set is now an industrial production standard in Usak Seramik.

Experimental and Numerical Analysis of Mold Filling in Rotational Molding

This work focuses on the development of a numerical mold filling simulation for the rotational molding process. In the rotational molding process, a dry fiber preform is placed in a mold and impregnated with a thermoset matrix under rotation. Additionally, metallic load introduction elements can be inserted into the mold and joined with co-curing or form-fit, resulting in hybrid drive shafts or tie rods. The numerical model can be used to simulate the impregnation of the preform. Based on the resin transfer molding process, an OpenFOAM solver is extended for the rotational molding process. Permeability, kinetic and curing models are selected and adapted to the materials used. A wireless measurement solution with a capacitive sensor is developed to validate the model. Comparisons between measurements and numerically calculated impregnation times to reach the capacitive sensor with the matrix show good quality of the developed model. The average deviation between calculated result and measured mean values in the experiment is 43.8% the maximum deviation is 65.8% . The model can therefore be used to predict the impregnation progress and the curing state.

Effects of Reduced Pressure and Casting Design on Mold Filling in Expendable Pattern Casting Process of Thin Wall Aluminum Alloy Castings

Effects of Reduced Pressure and Casting Design on Mold Filling in Expendable Pattern Casting Process of Thin Wall Aluminum Alloy Castings

Effects of Reduced Pressure and Casting Design on Mold Filling in Expendable Pattern Casting Process of Thin Wall Aluminum Alloy Castings

Effects of Reduced Pressure and Casting Design on Mold Filling in Expendable Pattern Casting Process of Thin Wall Aluminum Alloy Castings

Inlet Condition for Mold Filling Simulation in Gravity Casting of Aluminum Alloy

The casting CAE is useful tool for casting design in order to obtain the sound castings without defects. It is very important to know the influence of casting conditions on the mold filling. In the present study, the inlet condition for the mold filling simulation in gravity casting of aluminum alloy is investigated to simulate the real phenomena changing with the difference in the casting shape. The direct observation experiment is carried out with six types of sprue designs using an aluminum alloy and sand mold. There are three types of sprues: the elbow, bend and stair-step shapes. The molten metal of Al–7%Si alloy is poured using the stopper ladle. The velocity change in accordance with the different casting condition is analyzed using images observed by the video camera. The velocity of flow front in the early stage of the mold filling is changed intensely. Then, the velocity after the middle stage of the mold filling is decreased calmly. It is difficult to simulate the present phenomena by the mold filling simulation using the velocity inlet boundary. In order to reproduce the difference of each filling behavior, new inlet condition, which is named to “OverFlow pouring Basin” (OFB), is proposed in this study. The mold filling behavior and filled-up time simulated using the inlet condition of OFB are more or less agreed with six real phenomena according with three sprue shapes and two sprue heights.

Investigating the Effect of Counter Gravity Mold Filling on Microstructure and Mechanical Properties of Cast Aluminium

In present study an effort has been made to investigate the effect of changing the mode of mold cavity filling on mechanical properties and microstructure of cast aluminium. The pouring of the melt in mold cavity is avoided so as to check defects associated with it and instead of pouring, counter gravity filling of mold technique is utilized. The obtained properties and microstructure are compared with gravity poured (traditionally cast) aluminium. Characterization techniques like optical microscopy, scanning electron microscopy, X-Ray diffraction and mechanical testing like tensile and hardness of the cast samples is carried out. Hardness and tensile strength reported an increment of 22.37% and 26.71% respectively as compared to traditionally cast specimens. This enhancement in mechanical properties was attributed to improved microstructure obtained.