Low-Energy Injection Molding Process by a Mold with Permeability Fabricated by Additive Manufacturing

2016 ◽  
Vol 10 (1) ◽  
pp. 101-105 ◽  
Author(s):  
Hiroshi Koresawa ◽  
◽  
Kohei Tanaka ◽  
Hiroyuki Narahara
Keyword(s):  
Additive Manufacturing ◽  
Injection Molding ◽  
Electric Energy ◽  
Mold Insert ◽  
Low Energy ◽  
Injection Molding Process ◽  
Molding Machine ◽  
Molding Process ◽  
Injection Process ◽  
Flow Length

This paper describes the improvement of flow length and realization of low-energy molding in the injection molding process, by focusing on the injection mold with permeability fabricated by additive manufacturing. The mold is equipped with a sintered body with permeability, which is used as a mold insert. The inside of the sintered mold insert is structured so that the permeability should not be degraded, even if the thickness is increased. With respect to the effect of the sintered mold insert with permeability, the flow length and low-energy molding are evaluated by the filling rate of a thin section of moldings, and the electric energy of the injection molding machine that drives the screw in the injection process. Through fundamental experiments, the mold using the sintered mold insert with permeability was found to improve the flow length. The electric energy of the injection molding machine in the injection process is reduced by 6%--13% compared with the sintered mold insert without permeability.

scholarly journals Study on External Gas-Assisted Mold Temperature Control with the Assistance of a Flow Focusing Device in the Injection Molding Process

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 965 ◽  
Author(s):  
Nguyen Truong Giang ◽  
Pham Son Minh ◽  
Tran Anh Son ◽  
Tran Minh The Uyen ◽  
Thanh-Hai Nguyen ◽  
...  
Keyword(s):  
Injection Molding ◽  
Temperature Control ◽  
Mold Temperature ◽  
Injection Molding Process ◽  
Melt Flow ◽  
Flow Focusing ◽  
Molding Process ◽  
Heating Efficiency ◽  
Flow Length ◽  
Insert Plate

In the injection molding field, the flow of plastic material is one of the most important issues, especially regarding the ability of melted plastic to fill the thin walls of products. To improve the melt flow length, a high mold temperature was applied with pre-heating of the cavity surface. In this paper, we present our research on the injection molding process with pre-heating by external gas-assisted mold temperature control. After this, we observed an improvement in the melt flow length into thin-walled products due to the high mold temperature during the filling step. In addition, to develop the heating efficiency, a flow focusing device (FFD) was applied and verified. The simulations and experiments were carried out within an air temperature of 400 °C and heating time of 20 s to investigate a flow focusing device to assist with external gas-assisted mold temperature control (Ex-GMTC), with the application of various FFD types for the temperature distribution of the insert plate. The heating process was applied for a simple insert model with dimensions of 50 mm × 50 mm × 2 mm, in order to verify the influence of the FFD geometry on the heating result. After that, Ex-GMTC with the assistance of FFD was carried out for a mold-reading process, and the FFD influence was estimated by the mold heating result and the improvement of the melt flow length using acrylonitrile butadiene styrene (ABS). The results show that the air sprue gap (h) significantly affects the temperature of the insert and an air sprue gap of 3 mm gives the best heating rate, with the highest temperature being 321.2 °C. Likewise, the actual results show that the height of the flow focusing device (V) also influences the temperature of the insert plate and that a 5 mm high FFD gives the best results with a maximum temperature of 332.3 °C. Moreover, the heating efficiency when using FFD is always higher than without FFD. After examining the effect of FFD, its application was considered, in order to improve the melt flow length in injection molding, which increased from 38.6 to 170 mm, while the balance of the melt filling was also clearly improved.

Estimation of Maximum Flow Length for CF-PEEK Overmolded Grid Structures Using the Finite Element Method

2021 ◽  
Author(s):  
Carlos Rodríguez-Mondéjar ◽  
Álvaro Rodríguez-Prieto ◽  
Ana María Camacho
Keyword(s):  
Aspect Ratio ◽  
Injection Molding ◽  
Cross Section ◽  
Maximum Flow ◽  
Thermoplastic Composites ◽  
Injection Molding Process ◽  
Geometrical Parameters ◽  
Molding Process ◽  
Support Tool ◽  
Flow Length

Abstract Injection overmolding process is a high versatile process that permits, when used in combination with fiber reinforced thermoplastic composites, the obtaining of high mechanical properties structures with complex geometries in short time cycles. The maximum flow length is a parameter that reflects the success of filling in a polymer injection molding process. Geometry of the part, rheological properties of the polymer and process parameters, such as injection pressure and temperature, are involved on the value of this parameter and therefore on the viability of a certain configuration. For injection molding manufacturing, the understanding of the relation between maximum flow length and main geometrical parameters of the molded part is fundamental to approach the product design, which is conditioned severely by processing capabilities. In this work, the maximum flow length is obtained for different geometries of an overmolded rectangular stiffener grid of carbon fiber filled polyether eter ketone (CF-PEEK) using the software Moldflow© Adviser© for calculations. Value of maximum flow length is provided as a function of cross section aspect ratio for gate diameters between 0.8 mm and 1.4 mm and cross section areas from 10 to 50 mm2. An exponential decrement of maximum flow length has been observed with the increment of aspect ratio of the cross section as well as a linear increment with the increment of cross section area. Gate diameter variation is slightly related with maximum flow length for the simulated values. These results provide a support tool for geometry sizing in overmolded rectangular grid parts at preliminary design stages.

scholarly journals Prediction of the maximum flow length of a thin injection molded part

2020 ◽  
Vol 40 (9) ◽  
pp. 783-795
Author(s):  
Sara Liparoti ◽  
Vito Speranza ◽  
Annarita De Meo ◽  
Felice De Santis ◽  
Roberto Pantani
Keyword(s):  
Injection Molding ◽  
Maximum Flow ◽  
Mold Temperature ◽  
Complete Characterization ◽  
Rheological Parameters ◽  
Injection Molding Process ◽  
Spiral Flow ◽  
Molding Process ◽  
Molded Part ◽  
Flow Length

AbstractOne of the most significant issues, when thin parts have to be obtained by injection molding (i.e. in micro-injection molding), is the determination of the conditions of pressure, mold temperature, and injection temperature to adopt to completely fill the cavity. Obviously, modern computational methods allow the simulation of the injection molding process for any material and any cavity geometry. However, this simulation requires a complete characterization of the material for what concerns the rheological and thermal parameters, and also a suitable criterion for solidification. These parameters are not always easily reachable. A simple test aimed at obtaining the required parameters is then highly advantageous. The so-called spiral flow test, consisting of measuring the length reached by a polymer in a long cavity under different molding conditions, is a method of this kind. In this work, with reference to an isotactic polypropylene, some spiral flow tests obtained with different mold temperatures and injection pressures are analyzed with a twofold goal: on one side, to obtain from a few simple tests the basic rheological parameters of the material; on the other side, to suggest a method for a quick prediction of the final flow length.

scholarly journals Injection Molding Process Control of Servo–Hydraulic System

2019 ◽  
Vol 10 (1) ◽  
pp. 71
Author(s):  
Chun-Ying Lin ◽  
Fang-Cheng Shen ◽  
Kuo-Tsai Wu ◽  
Huei-Huang Lee ◽  
Sheng-Jye Hwang
Keyword(s):  
Injection Molding ◽  
Hydraulic System ◽  
Pid Controller ◽  
Position Control ◽  
Performance Standards ◽  
Pressure Control ◽  
Injection Molding Process ◽  
Proportional Integral Derivative ◽  
Molding Machine ◽  
Molding Process

The present study constructs a servo–hydraulic system to simulate the filling and packing processes of an injection molding machine. Experiments are performed to evaluate the velocity and position control of the system in the filling stage and the pressure control in the packing stage. The results demonstrate that the proposed system meets the required performance standards when operated with the proportional-integral–derivative (PID) controller under a sampling frequency of 1000 Hz.

Effect of Powder Loading and Binder Materials on Mechanical Properties in Iron-ABS Injection Molding Process

2013 ◽  
Vol 315 ◽  
pp. 582-586 ◽  
Author(s):  
Nasuha Sa'ude ◽  
M. Ibrahim ◽  
Wahab Saidin
Keyword(s):  
Mechanical Properties ◽  
Injection Molding ◽  
Iron Powder ◽  
Acrylonitrile Butadiene Styrene ◽  
Injection Molding Process ◽  
Molding Machine ◽  
Molding Process ◽  
Injection Molding Machine ◽  
Feedstock Material ◽  
Butadiene Styrene

This paper presents the development of a new polymer matrix composite (PMC) feedstock material by the injection molding machine. The material consists of iron powder filled in an acrylonitrile butadiene styrene (ABS) and surfactant powder (binder) material. In this study, the effect of powder loading and binder content on the mechanical properties was investigated experimentally. The detailed formulations of compounding ratio by Brabender Mixer and injection molding machine of the sample specimen was used with various combinations of the new PMC material. Based on the result obtained, it was found that, higher powder loading of iron filler affected the hardness, tensile and flexural strength of PMC material. With 32% iron powder loading in ABS composites increase the flexural force, maximum stress and force of PMC material through an injection molding process.

Numerical Study on the Melt Flow Length of the Composite Materials in the Injection Molding Process

2019 ◽  
Vol 971 ◽  
pp. 15-20
Author(s):  
The Nhan Phan ◽  
Trung Do Thanh ◽  
Son Minh Pham
Keyword(s):  
Composite Materials ◽  
Injection Molding ◽  
Numerical Study ◽  
Mold Temperature ◽  
Injection Molding Process ◽  
Melt Flow ◽  
Molding Process ◽  
Flow Length ◽  
Part Thickness ◽  
Good Agreement

Improving the melt flow length by increasing the mold temperature has been an issue encountered in the injection molding processes for composite products. In this study, an injection molding process was applied to a melt flow length model having a part thickness of 1.0 mm. The mold temperature varied from 30 °C to 110 °C. Six types of composite materials of polycaprolactam 6 (PA6) and glass fiber (GF) were selected to study the influence of mold temperature on the material filling in the injection molding process. The simulation results denoted that the mold temperature considerably influenced the flowability during the injection molding process, especially using 30% GF; further, the melt flow length was increased by 25.5% when the mold temperature was increased from 30 °C to 110 °C. In accordance with the simulation, our experiments demonstrated that we could achieve a mold temperature of 110 °C using all types of composite materials. Therefore, in this study, we denoted that both the simulation and experimental results of the melt flow length were comparable, thereby indicating a good agreement.

Experimental Study on Mold Separations of Plastic Injection Molding Machines with Different Clamping Units

2009 ◽  
Vol 87-88 ◽  
pp. 64-68 ◽  
Author(s):  
Pan Pan Zhang ◽  
Peng Cheng Xie ◽  
Dai Hua ◽  
Wei Min Yang
Keyword(s):  
Injection Molding ◽  
Value Added ◽  
Plastic Injection Molding ◽  
Injection Molding Process ◽  
Hydraulic Pressure ◽  
Molding Machine ◽  
Molding Process ◽  
Injection Molding Machine ◽  
Plastic Injection ◽  
Value Added Products

The plastic injection molding is widely used for the manufacturing of complicated-shaped and high value-added products. The plastic injection molding machine is the most important equipment for the industry. This paper focuses on the mold separation (MS) of the injection molding machines. The characteristics of the MS of injection molding machine with different clamping units are systemically analyzed, the five-hinge joint-double toggle clamping unit and the direct hydraulic pressure clamping unit included. The study points out there are several typical differences between the different clamping units. Meanwhile, it shows there is a linear relation between the MS value and the product weight, and explains why the MS signal can be used to control the injection molding process.

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