Gate Location Research Articles

BLDC 모터 고정자의 인서트 사출 성형에 관한 연구

Insert injection molding is a process in which molten plastic is injected into a mold that contains a pre-placed insert. During the injection stage, the insert can be deformed by the pressure applied by the polymer melts. The deformation of the insert changes the width of the flow path around the insert, which can cause several defects such as short shots or warpages of the parts. In order to reduce the deformation of the insert, it is important to achieve successful design of gating system, insert geometry, and molding conditions. In the present study, the insert deformations that occured during the injection molding of the BLDC motor stator were investigated by numerical analyses. The gate location and the insert shape were modified to reduce the insert deformation. Finally, the injection molding with the modified designs was carried out, and it was confirmed that the insert deformation was reduced.

An MINLP Model for Scheduling and Placement of Quantum Circuits with a Heuristic Solution Approach

Recent works on quantum physical design have pushed the scheduling and placement of quantum circuit into their prominent positions. In this article, a mixed integer nonlinear programming model is proposed for the placement and scheduling of quantum circuits in such a way that latency is minimized. The proposed model determines locations of gates and the sequence of operations. The proposed model is proved reducible to a quadratic assignment problem which is a well-known NP-complete combinatorial optimization problem. Since it is impossible to find the optimal solution of this NP-complete problem for large quantum circuits within a reasonable amount of time, a metaheuristic solution method is developed for the proposed model. Some experiments are conducted to evaluate the performance of the developed solution approach. Experimental results show that the proposed approach improves average latency by about 24.09% for the attempted benchmarks.

자동차용 에어클리너 상부커버 사출성형에서 게이트의 위치 결정

플라스틱 제품의 사출금형을 위한 게이트 위치의 최적 설계는 다양한 설계에 대한 3차원 사출성형 분석으로 도출할 수 있다. 이 논문은 사출금형에서 게이트 위치의 영향에 관한 연구이다. 게이트 위치는 플라스틱 제품의 생산성과 품질에 결정적인 영향을 미친다. 논문의 목적은 사출기를 사용한 자동차 에어 클리너 상부커버의 제조과정 중에 수지충전, 웰드라인, 사출압력에 대한 게이트의 영향을 분석하기 위한 것이다. 따라서 이 논문에서 이러한 문제들을 분석하기 위한 게이트의 위치는 4가지 경우로 변화를 주었다. 논문에서 각각의 게이트 위치 변화를 고려한 CAE 시뮬레이션은 사출금형공정에서 제품에 나타나는 결함의 원인을 예견하기 위하여 수행되었다. 【The proper design of the gate location for injection molding of plastic goods is obtained from three-dimensional injection molding analysis for various design alternatives. This paper is study on effect of gate location in injection molding. It have a decisive impact on productivity and quality of plastic goods. This objectives of this paper is to analysis effect of hot runner gate location for resin filling, weld line, injection pressure to manufacture of automobile air cleaner upper case with injection molding machine. Thus, to analysis these problems in this paper, location of gate are gave variety in 4 CASEs. In this paper, the CAE simulation considering each variations in location of gate is performed to predict the cause of faulty which appears in the injection molding process.】

Sustainable injection moulding: The impact of materials selection and gate location on part warpage and injection pressure

This paper presents an approach of how warpage (i.e. part deflection) and injection pressure of an intricate geometry could be minimised by selecting an optimal thermoplastic material and injection gate location (through which the molten plastic flows into the cavity). The numerical analyses for mould filling considered four gate locations along with a PP (polypropylene), PS (polystyrene) and a fibre-filled PP material (each had different shrinkage characteristics, mechanical property and viscosity). Results of the cavity filling simulations indicated that (on average) the largest and smallest warpage was predicted with the PP and PS respectively. The warpage of the fibre-filled PP showed the most gate location dependent behaviour. In addition, the lowest injection pressure was associated with the fibre-filled PP. For reduced pressure, the best and second best solutions for gate location were the top and middle ones. In addition, specific attention was paid to differential fibre orientation, as one of the most important factors responsible for part warpage. In an attempt to maximise the part stiffness, the fibre-filled PP was selected. It became clear that the gate location affected the melt flow evolution and therefore the fibre orientation. Simulation results showed that bidirectional flow and asymmetrical fibre distribution was achieved with the gate positioned at the mid-section of the part. Unidirectional flow and therefore symmetrical fibre distribution could be achieved by placing the gate at the top section of the part. The injection moulding experimental utilised the fibre-filled PP along with the two aforementioned gate locations. It was discovered that warpage was present when the middle gate was applied, but it was successfully eliminated using the top gate location. It can be stated that differential fibre orientation did not cause warpage, but the asymmetrical distribution of fibre orientation did. The information discussed in the paper may be particularly useful in the early mould/part design stages when any modification can still be easily and cost-effectively implemented. An important finding is that the final gate location should only be chosen after the thermoplastic material properties and melt flow direction have been taken into account. The successful reduction of warpage and injection pressure may help to reduce the amount of production waste and energy consumption, ensuring defect-free sustainable manufacturing.

Spatial Transition of Existing Old Settlements in Downtown Cheongju, Korea

The purpose of this study is to clarify the spatial structure and its transitional process by focusing on 22 existing old settlements established before 1913 in downtown Cheongju, Korea. The results are as follows: First, the old settlements are classified into four types relating to their topographic features: the Sanrok and Gogae Types are located on hills and the Daegok and Sogok Types are located in valleys. Second, in traditional Korean villages, a road system is composed of outer roads, approach roads, inner roads, and side roads having different functions. An inner road among them is the most important element in spatial structure as the basic framework of the road system inside villages. Third, the preservation or division of settlements has been influenced by the transformation of inner roads during the urbanization process. When spatial structures of inner roads have been maintained, old settlements have tended to be preserved. In addition, when new roads have been built to pass near communal spaces, old settlements have been preserved in spite of the lack of connection to old inner roads. Fourth, the functions of communal spaces have been influenced by the changing of society over time. Some functions have been changed, lost, or have suffered reduction in importance due to changes in modern lifestyles, but the personality of communal space is lasting. Finally, when the characteristics of the old settlement and functions of old roads have been preserved, housing layout has had a tendency to follow the original orientation, courtyard location, gate location, and access route as can be seen in Topdong Yangdalmal.

Warpage control of headlight lampshades fabricated using external gas-assisted injection molding

Headlight lampshades with an uneven part thickness and large-area complicated geometry often exhibit uneven shrinkage and considerable deformation when fabricated using injection molding. Conventional strategies for controlling shrinkage and warpage involve optimizing the gate number and location, cooling system, and mold conditions and performing annealing in a secondary process; however, conventional strategies are limited in improving the quality of injection molding. This study involved employing conventional approaches and external gas-assisted injection molding (eGAIM) to control part shrinkage and warpage effectively. The research consisted of three stages: (1) using computer simulations to optimize the mold design and molding conditions and, thus, reduce the shrinkage and warpage of headlight lampshades; (2) verifying the performance experimentally using a miniaturized geometry of the one use in (1); (3) applying eGAIM to show the potential of further improving part warpage. Simulation and experimental results indicated that optimizing the gate location facilitates improving the flow balance and reducing the filling pressure, leading to a reduction in part deformation. An optimal layout of cooling channels combined with two-stage holding conditions contributed to a superior cooling effect and low volumetric shrinkage. Parts fabricated using eGAIM exhibited less volumetric shrinkage than did parts fabricated using conventional injection molding. Moreover, annealing treatment can further reduce the deformation of molded parts. This case study investigated headlight lampshade deformation and was systematically conducted; the experimental results showed the feasibility of using eGAIM to minimize part warpage.

Formation mechanism and structural characteristics of unfoamed skin layer in microcellular injection-molded parts

The microcellular injection-molded part usually consists of a foamed core region and two unfoamed skin layers on the cross section. This paper investigated the formation process, formation mechanism and structural characteristics of the unfoamed skin layers in microcellular injection-molded part. It is found that the unfoamed skin layers are formed in two processes namely “during filling” process and “after filling” process. The shear flow and the fountain flow behaviors of the melt in the filling stage are the main controlling factors on the formation of the unfoamed skin layer in “during filling” process, and the cooling solidification of the melt in cooling stage is the fundamental reason for the formation of the unfoamed skin layer in “after filling” process. Further studies found that the unfoamed skin layer in microcellular injection-molded part has two distinct regions, the outer region is a thin frozen layer which contains deformed and broken cells, and the inner region is a relatively thick solid-like layer which has no visible cells in. The unfoamed skin layer has a minimum thickness in the gate location. The whole thickness of the unfoamed skin layer is decreased with the increase of injection speed and mold temperature, but is slightly affected by melt temperature.

Optimal Design of Runner for Shell of Mobile Telephone Based on Moldflow Software

The runner balance of upper cover and back cover of mobile telephone was optimized in view of the runner imbalance of different mould multi-cavity in the design of plastic injection mold by means of Moldflow software. The results that the fill time of the back cover of mobile telephone is 0.8858s, that of the upper cover of mobile telephone is 0.8588s, the imbalance rate is 3.1%. The optimized runner size is φ3.739mma and φ1.666mm while the runner size is φ3mm before optimization. The gate location of V/P switch point is 29.85Mpa and is close to the target pressure 30Mpa, the pressure in the distribution is uniform.

두 특성의 가치함수를 이용한 사출성형의 최적 설계

Optimizing multiple design characteristics which are usually in conflict with each other in the injection molding process is frequently becoming a critical problem for designers who work in this area. The purpose of this work is to develop an automated design methodology for optimizing two such design characteristics found in injection-molded parts. A value function based on decision-making theory is used as a means of evaluating the performance of a two-characteristic design alternative. Also, a design space reduction algorithm based on Taguchi's orthogonal arrays is utilized to discover an optimal design alternative. Verification of the developed design methodology is carried out for an actual model with two design characteristics, the weld line and the gate location, to be optimized in computer simulation experiments.

자동차 대시보드의 사출압력 최소화를 위한 게이트 위치와 공정조건의 강건설계

ABSTRACT In this paper, multiple gate locations and process conditions under concern are automatically optimized by considering robustness to minimize the injection pressure required to mold an automotive dashboard. Computer simulation-based experiments using orthogonal arrays(OA) and a design-range reduction algorithm are consolidated into an iterative search scheme, which is then used as a tool for the optimization process. The robustness of a design is evaluated using an OA-based simulation of process fluctuations due to noise as well as the signal-to-noise ratio. The optimal design solution for the automotive dashboard shows that the robustness of the injection pressure is significantly improved when compared to the initial design. As a result, both the die clamping force and the pressure distribution in the part cavity are also much improved in terms of their robustness. Key Words : Robust Design(강건설계), Injection Pressure(사출압력), Gate Location(게이트위치), Design-Range Reduction Algorithm(설계영역축소알고리듬), Orthogonal Array(직교배열)

Moldflow-Based Optimization Design of Gating System in Injection Mold for Automobile Bumper

The gating system of an injection mold for car bumper was studied. A design optimization scheme is proposed to optimize both the number and locations of the gates by analyzing the filling process, in order to reduce the part war page and weld line, numerical simulation of injection mold filling process is combined with the design optimization method to find the optimum number of gates and their locations to achieve balanced f low and less weld lines while satisfying the limit of injection pressure. Moldflow software was applied to make analysis and comparison of various gating system in terms of their filling time, injection pressure and clamp force, weld line and distribution of air traps, and an optimized gating system was obtained. The result shows that this method can effectively reduce costs, shorten development cycle and improve the efficiency of molding design.

사출성형 해석을 이용한 게이트 위치 최적화

게이트 위치는 제품 품질 및 생산성 등에 큰 영향을 미치기 때문에 사출성형에 있어서 게이트 위치를 결정하는 것은 대단히 중요하며 이를 위하여 사출성형 CAE가 적용되고 있다. 사출성형 해석의 증가와 3차원 유한요소의 사용은 더 많은 계산 시간을 필요로 하게 되면서, 컴퓨터 자원을 적게 사용하면서도 빠른 시간 내에 게이트 위치 최적화를 수행하는 것은 중요한 이슈가 되었다. 본 논문에서는 유동 균형과 웰드라인을 고려하기 위하여 유동 거리에 기반한 최적화 기법을 제시하였 다. 그리고 원판 형상의 모델에 적용하여 웰드라인이 응력집중이 예상되는 슬릿홀을 피하면서도 유동 균형을 유지하는 결과 를 도출하였다.

Finite Element in Designing of the Gate Location, Shape and Moulding Injection Path

800x600 Like all industrial processes, injection molding can produce flawed parts. In the field of injection molding, troubleshooting is often performed by examining defective parts for specific defects and addressing these defects with the design of the mold or the characteristics of the process itself. Trials are often performed before full production runs in an effort to predict defects and determine the appropriate specifications to use in the injection process [1]. Gate solidification time is important, as it determines cycle time and the quality and consistency of the product, which itself is an important issue in the economics of the production process. Holding pressure is increased until the parts are free of sinks and part weight has been achieved. [2] The number of triangle in the mesh has an impact on calculation times. Each triangle has three nodes and the calculations done by the SolidWorks Plastics solvers are performed at each of those nodes. So, a higher number of elements mean a higher number of nodes and as the number of nodes increases, compute time increases. That said, element counts up to 100,000 should solve in a reasonable time, while element counts over 100,000 may take longer to solve. Gates vary in size and shape depending upon the type of plastic being molded and the size of the part. Small gates have a better appearance but take longer time to mold or may need to have higher pressure to fill correctly. Large parts will require larger gates to provide a bigger flow of resin to shorten the mold time. In this paper we will study the influence of the gate shape and location over the specimen. We will study in particular the fiber orientation for a material reinforced with fiberglass.

Resin infusion under flexible tooling process and structural design optimization of the complex composite part

Employing optimum structural design strategies and accompanying optimal production processing while employing efficient and cost effective methods is a key for the expansion of composite structures in various industrial applications. Within this context, Resin Infusion under Flexible Tooling (RIFT) process has become a rapidly growing manufacturing approach for large scale and complex parts. In this study, replacement of automotive body parts with glass woven fabric/epoxy composite manufactured by RIFT Type I (RIFT I) process is investigated both experimentally and numerically to improve the mechanical characteristics with weight saving. The optimization of the laminate stacking sequence is the first step taken. Then the simulation of resin infusion for the optimum location of gates and vents in order to shorten the filling time, decrease dry spots and voids, and avoid costly and time consuming trial-and-error procedures. Numerical results of the filling time and fluid front position over time are assessed by comparison with the experimental data and good accuracy was obtained. Based on the results of the optimization, an automotive part with a complex geometry is fabricated with 50% weight saving relative to steel.

Improvement on Die-Casting Efficiency and Property of Aluminum Alloy Casing.

Die-casting process is significantly used in the industry for its high productivity and less post-machining requirement. For high pressure die-casting, it needs well-design of gating and runner system; therefore, die cavity design and technology parameter calculations are essential. In the current paper of die-casting for automobile starter motor casing, the following issues are focused: filling simulation, defect analysis, and finally the use of the Taguchi multi-quality analysis method to find the optimal parameters and factors to increase the aluminum ADC10 die-casting quality and efficiency. When the casting speed is increased, the volume shortage detects due to solidification procedure can be reduced. However, if the casting speed exceeds a permissible level, the defects of gas volume and porosity will occur. After Taguchi method analysis, the results of the optimum parameters are: for the gate area of 40mm2, group 2 of the gate location, the speed of the liquid metal at the gate 50 m/s, the temperature of molten aluminum 670° C.

A prototype silicon double quantum dot with dispersive microwave readout

We present a unique design and fabrication process for a lateral, gate-confined double quantum dot in an accumulation mode metal-oxide-semiconductor (MOS) structure coupled to an integrated microwave resonator. All electrostatic gates for the double quantum dot are contained in a single metal layer, and use of the MOS structure allows for control of the location of the two-dimensional electron gas via the location of the accumulation gates. Numerical simulations of the electrostatic confinement potential are performed along with an estimate of the coupling of the double quantum dot to the microwave resonator. Prototype devices are fabricated and characterized by transport measurements of electron confinement and reflectometry measurements of the microwave resonator.

Modeling of post-filling stage in vacuum infusion using compaction characterization

Two-dimensional finite-element method solution of the post-filling stage of vacuum infusion was studied based on mass conservation in an infinitesimal control volume. First, resin pressure distribution at the instant of mold filling was calculated and then used as the initial condition for the transient post-filling stage. Explicit time-marching algorithm was used for the evolution of resin pressure and part thickness, and its stability was ensured by selecting the time step adaptively. Finite-element method solution was verified analytically for one-dimensional case and numerically for two-dimensional cases using global mass conservation. The time that it took for the settlement of pressure and thickness was investigated to compare the effectiveness of different resin-bleeding scenarios where different number and locations of gates were used. It was shown that the settlement time increased exponentially as the dimensions of the mold increased, which proved that process simulation fed with correctly designed material characterization can replace tedious trial-and-error search of control actions to reduce the settlement time and variation in part thickness.

INTEGRATING FLOW SIMULATION FOR INJECTION MOULDING COMPONENT BASETTA TU BASE

Injection moulding is one of the manufacturing techniques to produce mass production of engineering components made of typical polymer materials. The mould and part design of plastic parts for injection moulding is a complicated process, considerations for producing a part ranging from cost and speed of production to structural, ergonomics and aesthetic requirements. One of the routines problem faced by a designer while designing the tool for good quality parts is the process of cavity balancing. This entails controlling the plastic flow in the filling phase such that the melt front reaches the boundaries of the mould at the same time. The Plastic flow analysis is done using Mould Flow analysis software. It is necessary to provide a flow-way in injection moulding to connect the nozzle to the each impression; this flow-way is termed as feed system, normally feed system consisting of sprue, runner and gate. Gate location can have a drastic effect on a part that could result in incorrect parts. The analysis was carried out to study the location of gate which reduces filling time and flow visualization improves the part quality considering bezel part as an example, this case study is done by mouldflow analysis tool, to ensure the concepts mentioned above.

ANALYSIS AND DESIGN OF MOLD FOR PLASTIC SIDE RELEASE BUCKLE USING MOLDFLOW SOFTWARE

Injection Molding is a crucial segment of the plastics industry mainly due to its ability and flexibility to manufacture intricate components at high production rates and also with easy process flow. Injection molding has laid its hands over right from small parts to big machine parts. Plastic side release buckles, commonly employed in standard bags, suitcases and pouches, and are manufactured exclusively by the injection molding process all around the world. The process involved should be perfect enough to produce parts without defects and low quality. Gate location is one of the important in this process which is necessary for the filling purposes. In view of the significance of a perfect gate location for the plastic injection mold for the side release buckle, this paper focusses on the complete analysis of the buckle using a moldflow software and the determination of optimum gate locations for it. The analysis is complete look into the various quality features important for the mold, it considers identification and improvement of parameters such as fill time, quality, extent of packing and reduced defects and warpage. Utilization of the optimized gate locations for the mold lead to reduced production costs, higher quality and enhanced competitive power of mold enterprises.

하천 수리구조물에 의한 제내지 침수모의

A local rain that is concentrated in specific area in a short time frequently occurs due to recent abnormal weather. To prevent potential flood disasters, therefore, it is necessary to be established to the flood control system. Checking the river design standard, however, hydrologic design frequency of water gate is only marked as over 20 years, so this fact shows that the standard is unclear. The inland inundation modeling considering the stage in a river and quantitative assessment are required to reduce flood damage. The simulation for internal inundation is very complex and is time-consuming due to considering hydraulic hydrology characteristics at the same time. Using the already established river master plan, consequently, this study proposed the simple and convenient method for assessment of the internal inundation simulation. Using the proposed method in the upper and middle regions of a river, influences for design frequency or water gate location were assessed by applying the nine probability precipitation with design frequency and by targeting the water gates which are installed in five inlands.