scholarly journals Cavity Air Flow Behavior During Filling in Microinjection Molding

2011 ◽  
Vol 133 (1) ◽  
Author(s):  
C. A. Griffiths ◽  
S. S. Dimov ◽  
S. Scholz ◽  
G. Tosello
Keyword(s):  
Flow Behavior ◽  
Air Flow ◽  
Polymer Melt ◽  
Mold Temperature ◽  
Quality Factors ◽  
Melt Temperature ◽  
Injection Speed ◽  
Microinjection Molding ◽  
Process Dynamics ◽  
Flow Length

Process monitoring of microinjection molding (μ-IM) is of crucial importance in understanding the effects of different parameter settings on the process, especially on its performance and consistency with regard to parts’ quality. Quality factors related to mold cavity air evacuation can provide valuable information about the process dynamics and also about the filling of a cavity by a polymer melt. In this paper, a novel experimental setup is proposed to monitor maximum air flow and air flow work as an integral of the air flow over time by employing a microelectromechanical system gas sensor mounted inside the mold. The influence of four μIM parameters, melt temperature, mold temperature, injection speed, and resistance to air evacuation, on two air flow-related output parameters is investigated by carrying out a design of experiment study. The results provide empirical evidences about the effects of process parameters on cavity air evacuation, and the influence of air evacuation on the part flow length.

Analysis of Influences of Processing Parameters on Filling Behavior in Microinjection Molding with a Hot Runner Nozzle

2012 ◽  
Vol 501 ◽  
pp. 117-121
Author(s):  
Gang Gou ◽  
Peng Cheng Xie ◽  
Wei Min Yang ◽  
Yu Mei Ding
Keyword(s):  
Injection Pressure ◽  
Polymer Melt ◽  
Mold Temperature ◽  
Processing Parameters ◽  
Simulation Software ◽  
Processing Parameter ◽  
Melt Temperature ◽  
Injection Speed ◽  
Microinjection Molding ◽  
Packing Pressure

The ability for polymer melt to flow into the microstructure is a crucial factor for successful molding in the microinjection molding of plastic parts. In this study, a simplified analytical model with a direct hot runner nozzle and was constructed to estimate the filling percentage of mold’s cavity. The filling behavior of polymer melt was observed by 3D simulation software Moldflow. The effects of the mold temperature, melt temperature, injection pressure, injection rate, and packing pressure on the filling behavior of polymer melt were investigated. Results revealed that the filling percentage increased with respect to the increase of mold temperature and melt temperature which didn’t exceed its degradation temperature. The injection pressure and packing pressure dramatically influence the filling percentage, and it made no sense to lift the injection speed to fill the cavity when the injection speed reached the relatively high values, and only processing parameter combined available could guarantee the perfect flow and filling for the microstructure.

Molding and Optical Performance Simulations of a New Plastic Grating Lens for an Asymmetric LED Fog Lamp

2012 ◽  
Vol 253-255 ◽  
pp. 2223-2226 ◽  
Author(s):  
Yi Cheng Chen ◽  
Yen Chao Wang ◽  
Shi Chang Tseng
Keyword(s):  
Central Zone ◽  
Injection Pressure ◽  
Mold Temperature ◽  
Stray Light ◽  
Optical Simulation ◽  
Melt Temperature ◽  
Injection Speed ◽  
3D Cad ◽  
Multi Stage ◽  
Test Distance

This research focuses on the effect manufacture factors about the brightness and uniformity of multi-stage reflector. Trace-pro and 3D CAD model were used for optical simulations. The optical simulation results of grating lens and reflector were done as well as successfully developed the LED fog lamp. The results meet the regulations, R19 CLASS F3, of Economic Commission for Europe (ECE) at the test distance of 25 meters, and central zone under line6 achieves average over 3200cd. The optimal design of reflector is of third-order paraboloidal one to improve the brightness and uniformity. The acuter the microstructure’s tip is(R below 0.1mm), the better the apparent improving of eliminating stray light. In accordance with microstructure of grating lens, Moldex-3D is used to help the mold flow filling simulation and mold design. The mold cavity with microstructure was manufactured by the wire cutting and polishing processing. And the molding plastic was optics level PC (Polycarbonate). Both Taguchi’s method applied in Moldex-3D and real injection molding experiments showed that high melt temperature, low injection speed and suitable holding time can reduce warpage; in addition, using higher melt temperature, mold temperature and injection pressure can achieve higher degree of replication of micro features.

scholarly journals Characterization of the Fluidity of the Ultrasonic Plasticized Polymer Melt by Spiral Flow Testing under Micro-Scale

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 357 ◽  
Author(s):  
Bingyan Jiang ◽  
Yang Zou ◽  
Tao Liu ◽  
Wangqing Wu
Keyword(s):  
Size Effect ◽  
Amorphous Polymer ◽  
Polymer Melt ◽  
Mold Temperature ◽  
Polyamide 66 ◽  
Spiral Flow ◽  
Crystalline Polymers ◽  
Micro Scale ◽  
Flow Length ◽  
And Control

The fluidity of a molten polymer plasticized by ultrasonic vibration was characterized by spiral flow testing based on an Archimedes spiral mold with microchannels. Mold inserts with various channel depths from 250 to 750 µm were designed and fabricated to represent the size effect under micro-scale. The effect of ultrasonic plasticizing parameters and the mold temperature on the flow length was studied to determine the rheological nature of polymers and control parameters. The results showed that the flow length decreased with reduced channel depth due to the size effect. By increasing ultrasonic amplitude, ultrasonic action time, plasticizing pressure, and mold temperature, the flow length could be significantly increased for both the amorphous polymer polymethyl methacrylate (PMMA) and the semi-crystalline polymers polypropylene (PP) and polyamide 66 (PA66). The enhanced fluidity of the ultrasonic plasticized polymer melt could be attributed to the significantly reduced shear viscosity.

Optimization and Design for Parameter in Injection Molding Technology of Cell Shell of Polypropylene

2011 ◽  
Vol 189-193 ◽  
pp. 537-540
Author(s):  
Jia Min Zhang ◽  
Ming Yi Zhu ◽  
Zhao Xun Lian ◽  
Rong Zhu
Keyword(s):  
Injection Molding ◽  
Injection Pressure ◽  
Mold Temperature ◽  
Injection Molding Process ◽  
Technological Parameters ◽  
Molding Process ◽  
Melt Temperature ◽  
Injection Speed ◽  
Technical Parameters ◽  
High Degree

The use of L27 (35) orthogonal to the battery shell injection molding process is optimized. The main factors of technical parameters were determined mould temperature, melt temperature, the speed of injection, injection pressure, cooling time.On the basis of actual production, to determine the factors values of different process parameters.Combination of scrapped products in key (reduction and a high degree of tolerance deflated) tests were selected in the process parameters within the scope of the assessment. Various factors impact on the product of the total height followed by cooling time, mold temperature, melt temperature, injection pressure, injection speed from strong to weak .The best products technological parameters were determined.Good results were obtained for production.

scholarly journals Effects of Injection Molding Process Parameters on the Chemical Foaming Behavior of Polypropylene and Polystyrene

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2331
Author(s):  
Chen-Yuan Chung ◽  
Shyh-Shin Hwang ◽  
Shia-Chung Chen ◽  
Ming-Chien Lai
Keyword(s):  
Injection Molding ◽  
Process Parameters ◽  
Mold Temperature ◽  
Expansion Ratio ◽  
Injection Molding Process ◽  
Molding Process ◽  
Melt Temperature ◽  
Foaming Agent ◽  
Experimental Database ◽  
Injection Speed

In the present study, semi-crystalline polypropylene (PP) and amorphous polystyrene (PS) were adopted as matrix materials. After the exothermic foaming agent azodicarbonamide was added, injection molding was implemented to create samples. The mold flow analysis program Moldex3D was then applied to verify the short-shot results. Three process parameters were adopted, namely injection speed, melt temperature, and mold temperature; three levels were set for each factor in the one-factor-at-a-time experimental design. The macroscopic effects of the factors on the weight, specific weight, and expansion ratios of the samples were investigated to determine foaming efficiency, and their microscopic effects on cell density and diameter were examined using a scanning electron microscope. The process parameters for the exothermic foaming agent were optimized accordingly. Finally, the expansion ratios of the two matrix materials in the optimal process parameter settings were compared. After the experimental database was created, the foaming module of the chemical blowing agents was established by Moldex3D Company. The results indicated that semi-crystalline materials foamed less due to their crystallinity. PP exhibits the highest expansion ratio at low injection speed, a high melt temperature, and a low mold temperature, whereas PS exhibits the highest expansion ratio at high injection speed, a moderate melt temperature, and a low mold temperature.

scholarly journals Correlation of mechanical and electrical properties with processing variables in MWCNT reinforced thermoplastic nanocomposites

2018 ◽  
Vol 52 (26) ◽  
pp. 3681-3697 ◽  
Author(s):  
Saeed Doagou-Rad ◽  
Aminul Islam ◽  
Jakob Søndergaard Jensen
Keyword(s):  
Electrical Properties ◽  
Mold Temperature ◽  
Processing Parameters ◽  
Industrial Applications ◽  
Micromechanical Modeling ◽  
Melt Temperature ◽  
Injection Speed ◽  
Mechanical And Electrical Properties ◽  
Processing Variables ◽  
Underlying Mechanisms

The influence of the processing variables and nanotube content on the mechanical and electrical properties of polyamide 6,6-based nanocomposites reinforced with multi-walled carbon nanotubes is investigated. Results show that variation in the processing variables such as compounding method, injection melt temperature, injection speed, mold temperature, and holding pressure varies the properties significantly. In fact, composites containing similar contents of the nanofillers show variations in mechanical properties up to 30.0% and in the electrical properties up to three orders of magnitude. Different processing parameters required for achieving optimal mechanical and electrical performances are also found. Correlation between processing parameters and microstructure within the nanocomposites is studied. Results show that variation of the processing parameters defines the existence or absence of a nanotube network in the nanocomposite structure. Experimental and micromechanical modeling results show that less control over the nanocomposite morphology and nanotube alignment is achievable in higher nanofiller contents. The underlying mechanisms responsible for the modulation in the properties are also discussed using scanning and transmission electron microscopy, rheological and crystallization investigations. The research provides a recipe to manufacture the tailored nanocomposite with the specified properties for various industrial applications.

The Study of Micro-Injection Molding of Thin-Wall Light Guide Plate with Hemispherical Micro Structures

2012 ◽  
Vol 562-564 ◽  
pp. 611-614 ◽  
Author(s):  
Peng Wei Dong ◽  
Heng Zhi Cai ◽  
Ya Jun Zhang ◽  
Zhong Li Zhao ◽  
Xin Liang Wang
Keyword(s):  
Light Guide ◽  
Injection Pressure ◽  
Mold Temperature ◽  
Thin Wall ◽  
Filling Process ◽  
Melt Temperature ◽  
Injection Speed ◽  
Light Guide Plate ◽  
Guide Plate ◽  
Micro Structures

Micro injection molding is widely used due to it’s high accuracy, high production efficiency, low cost and the ability to fabricate products with complex structures. For thin-wall and large area parts, it is difficult to fill the cavity with micro structure. The light guide plate is a typical product. In this paper, the filling process of the light guide plate (LGP) with micro structures on the surface is studied. And the warpage of the LGP is analyzed, which affects the optical performance remarkably. Orthogonal method is used to analyze the filling process and the wrapage. The most important factor that affects the filling process and the wrapage is the injection pressure. The levels of the different process parameters on filling process are injection pressure, melt temperature, mold temperature, injection speed and packing pressure. For warpage, the sequence of the effect is injection pressure, mold temperature, packing pressure, melt temperature and injection speed.

scholarly journals The Study of Optimal Molding of a LED Lens with Grey Relational Analysis and Molding Simulation

2019 ◽  
Vol 63 (4) ◽  
pp. 278-294 ◽  
Author(s):  
Min-Wen Wang ◽  
Fatahul Arifin ◽  
Van-Hanh Vu
Keyword(s):  
Injection Molding ◽  
Mold Temperature ◽  
Injection Molding Process ◽  
Molding Process ◽  
Melt Temperature ◽  
Injection Speed ◽  
Relational Analysis ◽  
Total Displacement ◽  
Packing Pressure ◽  
Grey Relational

Injection molding technology is known as the most widely used method in mass production of plastic products. To meet the quality requirements, a lot of methods were applied in optimization of injection molding process parameter. In this study the optimization based on Taguchi orthogonal array and Grey relational analysis (GRA) is used to optimize the injection molding process parameters on a LED lens. The four process parameters are: packing pressure, injection speed, melt temperature and mold temperature. The multi-response quality characteristics are total displacement, volumetric shrinkage, and thermal residual stress. The optimal molding parameters are packing pressure (90 MPa), injection speed (300 mm/sec), melt temperature (270 °C) and mold temperature (90 °C). The luminous uniformity of the LED is 92.61 % and the viewing angle of the LED is 124.76°. Among the four factors, packing pressure plays the key role in reducing total displacement, volumetric shrinkage, and thermal residual stress.

scholarly journals Effect of Process Parameters on Repeatability Precision of Weight for Microinjection Molding Products

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Quan Wang ◽  
Jinrong Wang ◽  
Chongying Yang ◽  
Kaihui Du ◽  
Wenli Zhu ◽  
...  
Keyword(s):  
Orthogonal Experiment ◽  
Mold Temperature ◽  
Tensile Specimen ◽  
Cavity Pressure ◽  
Melt Temperature ◽  
Microinjection Molding ◽  
Packing Pressure ◽  
Impact Specimen ◽  
Injection Molded ◽  
The Impact

The repeatability precision of weight for injection molded products is important technical parameter to measure the quality and accuracy of injection molded products and evaluate the performance of injection molding machine. The influence of mold temperature, melt temperature, packing pressure, and packing time on the weight of microinjection molding products was studied by Taguchi orthogonal experiment. The influence of peak cavity pressure on the weight of products also was analysed. The experimental results show that the packing pressure is the most important process parameter affecting both the weight of the tensile and the impact specimens. With the increase of the packing pressure, the weight of the tensile and the impact specimens increases. When the peak cavity pressure reaches a certain value, the pressure value of the tensile specimen is 65 MPa, and the pressure value of the impact specimen is 68 MPa, the weight of the product increases quickly. The packing pressure increased from 85 MPa to 100 MPa, the weight of the tensile specimen increased from 0.544g to 0.559g, an increase of 2.7%, and the weight of the impact specimen increased from 0.418g to 0.425g, an increase of 1.7%.

Numerical Simulation of Shrinkage in the Microinjection Molding of Multi-Microparts Produced in one Mold

2011 ◽  
Vol 221 ◽  
pp. 649-656 ◽  
Author(s):  
Jian Wang ◽  
Wei Min Yang
Keyword(s):  
Numerical Simulation ◽  
Injection Molding ◽  
Plastic Material ◽  
Control Volume ◽  
Injection Pressure ◽  
Mold Temperature ◽  
Processing Parameters ◽  
Injection Molding Process ◽  
Melt Temperature ◽  
Microinjection Molding

The aim of this paper is to verify the reliability of numerical results obtained by using MPI (Moldflow Plastic Insight) for predicting the shrinkage of multi-microparts produced in one mold in microinjection molding. 3D numerical simulation (control volume finite element method) was employed. Pure and 10-20 % GRF (glass fiber reinforced) POM materials were used for the plastic material. The injection molding process was used for different parameters (mold temperature, melt temperature and injection pressure). A DOE (Design of Experiments) technique was then used to plan the numerical simulation activity of the injection molding phase. Among injection processing parameters (mold temperature, melt temperature and injection pressure), the results showed that the mold temperature is the most important factor to affect the shrinkage of multi-microparts significantly for processing parameters. The results also indicated that the processing is very well for micro-injection molding by numerical simulation. In addition, properties of polymer composites with added fillers were systematically studied. Numerical simulation results showed that the numerical resulting composites with 10–20 wt% glass particles exhibited significant improvement in shrinkage, and showed good agreement with experimental results.

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