scholarly journals The Improvement Effect and Mechanism of Longitudinal Ultrasonic Vibration on the Injection Molding Quality of a Polymeric Micro-Needle Array

Polymers ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 151 ◽  
Author(s):  
Shan Gao ◽  
Zhongjun Qiu ◽  
Junhao Ouyang
Keyword(s):  
Injection Molding ◽  
Ultrasonic Vibration ◽  
Material Properties ◽  
Amorphous Polymer ◽  
Crystalline Polymer ◽  
Enhancement Effect ◽  
Industrial Processing ◽  
Filling Time ◽  
Improvement Effect ◽  
Enhancement Method

A polymeric micro-needle array with high quality has been fabricated using a longitudinal ultrasonic-assisted micro-injection molding (LUμIM) method. To realize the practicability and stability in actual industrial processing, this paper is aimed at studying the improvement mechanism of ultrasonic vibration on the molding quality. The melt-filling process in the micro-needle array cavity is simulated, and the improvement effect of ultrasonic vibration is discussed. The enhancement effect of ultrasonic vibration on material properties of polypropylene and polymethylmethacrylate parts are experimentally investigated. The results show that in the manufacturing of the micro-needle array part using LUμIM, the mold-filling quality is improved by the enhanced melt filling capability and pressure compensation effect, which are caused by the increased corner viscosity gradient, reduced the filling time and melt viscosity under ultrasonic vibration. Material properties of both the semi-crystalline polymer and amorphous polymer could be enhanced by the transformation of micromorphology. It is proved that for a semi-crystalline polymer, this novel method could be employed as a material properties enhancement method, and an optimal excitation voltage of ultrasonic vibration is obtained to achieve the best material properties.

scholarly journals Reducing the Sink Marks of a Crystalline Polymer Using External Gas-Assisted Injection Molding

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Shaofei Jiang ◽  
Taidong Li ◽  
Xinxin Xia ◽  
Xiang Peng ◽  
Jiquan Li
Keyword(s):  
Injection Molding ◽  
Process Parameters ◽  
Amorphous Polymer ◽  
Uniform Design ◽  
Quantitative Relationship ◽  
Crystalline Polymer ◽  
Process Conditions ◽  
Data Processing Method ◽  
Optimal Value ◽  
Sink Marks

External gas-assisted injection molding (EGAIM) has been used to reduce the sink marks of amorphous polymer products, but that of crystalline polymer products has not yet been reported. EGAIM of a crystalline polymer product was investigated in this study, and the influences of process parameters on the sink marks were discussed based on experiments. An isotactic polypropylene (iPP) product was fabricated by EGAIM under different process conditions. A uniform design was applied as an experimental design to investigate the influences of the process parameters on the sink marks. A regression equation was established to describe the quantitative relationship between the important parameters and sink marks in which a data-processing method was applied to determine the optimal value of Fα at significant level α to reduce the possibility of omission of some important parameters. The results show that EGAIM was effective in reducing the sink marks in these iPP products, and the most important parameters were the cooling time, gas pressure, and gas time. This study also provides the quantitative relationship between the important parameters and sink marks as reference for the research of EGAIM on crystalline polymer.

The Effect of Heat Treatment on Mechanical Properties of Car Interior Fabric Used for Injection Molding

2012 ◽  
Vol 532-533 ◽  
pp. 234-237
Author(s):  
Wei Lai Chen ◽  
Ding Hong Yi ◽  
Jian Fu Zhang
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
High Temperature ◽  
Injection Molding ◽  
High Temperatures ◽  
Material Properties ◽  
Injection Molding Process ◽  
Molding Process ◽  
Composite Fabrics

The purpose of this paper is to study the effect of high temperature in injection molding process on mechanical properties of the warp-knitted and nonwoven composite fabrics (WNC)used in car interior. Tensile, tearing and peeling properties of WNC fabrics were tested after heat treatment under120, 140,160,180°C respectively. It was found that, after 140°C heat treatment, the breaking and tearing value of these WNC fabrics are lower than others. The results of this study show that this phenomenon is due to the material properties of fabrics. These high temperatures have no much effect on peeling properties of these WNC fabrics. It is concluded that in order to preserve the mechanical properties of these WNC fabrics, the temperature near 140°C should be avoided possibly during injection molding process.

scholarly journals Fiber orientation and material properties analysis in injection molding.

1991 ◽  
Vol 48 (3) ◽  
pp. 151-157 ◽  
Author(s):  
Takaaki MATSUOKA ◽  
Yoshinori INOUE ◽  
Jun-ichi TAKABATAKE
Keyword(s):  
Injection Molding ◽  
Material Properties ◽  
Fiber Orientation

Gate location optimization scheme for plastic injection molding

e-Polymers ◽  
2009 ◽  
Vol 9 (1) ◽  
Author(s):  
Ming Zhai ◽  
Yeecheong Lam ◽  
Chikit Au
Keyword(s):  
Injection Molding ◽  
Objective Function ◽  
Flow Path ◽  
Computationally Efficient ◽  
Gate Location ◽  
Adjacent Node ◽  
Filling Time ◽  
Efficient Scheme ◽  
Balanced Flow ◽  
Search Routine

AbstractGate location of injection molding is vital to achieve high quality plastic part. The determination of gate location is an important issue in mold design. A computationally efficient scheme based on flow path is proposed to locate the optimum gate for achieving balanced flow. The range of filling time is employed as objective function. Comparisons were made between the flow path search scheme and the existing adjacent node evaluation scheme, and between the objective function of the range of filling time and the existing standard deviation of filling time. The two examples investigated indicated that the search routine based on the concept of flow path is more efficient computationally and the range of filling time is a better objective function to reflect the uniformity of fill.

Effect of polymer donor aggregation on the active layer morphology of amorphous polymer acceptor-based all-polymer solar cells

2020 ◽  
Vol 8 (16) ◽  
pp. 5613-5619 ◽  
Author(s):  
Lu Zhang ◽  
Zicheng Ding ◽  
Ruyan Zhao ◽  
Feng Jirui ◽  
Wei Ma ◽  
...  
Keyword(s):  
Solar Cells ◽  
Phase Separation ◽  
Active Layer ◽  
Amorphous Polymer ◽  
Polymer Solar Cells ◽  
Crystalline Polymer ◽  
Dominant Factor ◽  
Polymer Acceptor ◽  
Aggregation Tendency

The aggregation tendency in solution of polymer donors is the dominant factor in the phase separation of semi-crystalline polymer donor/amorphous polymer acceptor blends in all-PSCs.

Kinetic immiscibility of crystalline polymer/amorphous polymer blends

Polymer ◽  
1997 ◽  
Vol 38 (9) ◽  
pp. 2171-2174 ◽  
Author(s):  
Arun K. Nandi ◽  
Pralay Maiti
Keyword(s):  
Polymer Blends ◽  
Amorphous Polymer ◽  
Crystalline Polymer

Effects of Molding Parameters on MIM’s Material Distribution using Numerical Simulation Method

2012 ◽  
Vol 59 (2) ◽  
Author(s):  
Mohd Fazuri Abdullah ◽  
Abu Bakar Sulong ◽  
Norhamidi Muhamad ◽  
Muhamad Afkar Husin
Keyword(s):  
Injection Molding ◽  
Flow Rate ◽  
Computer Aided Design ◽  
Manufacturing Industry ◽  
Injection Pressure ◽  
Global Market ◽  
Element Analysis ◽  
Percentage Difference ◽  
Filling Time ◽  
Injection Temperature

In the competitive world in the global market, manufacturing industry is striving to produce products at high quality, shorter time and low cost. This can be achieved through proper design activities, with assist of finite element analysis (FEA) and computer aided design (CAD). The objective of this project is to study the effect of the molding parameters on the physical characteristics of surgery tool via MIM based on design of experiment (Taguchi method). This numerical results show the behavior of feedstock entering the mould during injection process and the possibility defects that might occur. The quality of the injected product depends on the selection of the feedstock as well as the parameters for injection molding such as injection temperature (A), mold temperature (B), flow rate (C) and injection pressure (D). From the analysis of Taguchi, the optimal levels of process parameters for the shortest filling time is [A3(200ºC), B1(80ºC), C3(20 cm3/s), D3(260 MPa)]. Set of optimal parameters for the smallest shrinkage percentage difference is [A1(180ºC), B3(100ºC), C3(20 cm3/s), D2(255 MPa)]. The most influence injection molding parameters are injection temperature and injection pressure. Follow by the flow rate.

scholarly journals Experimental Validation of Injection Molding Simulations of 3D Microparts and Microstructured Components Using Virtual Design of Experiments and Multi-Scale Modeling

Micromachines ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 614 ◽  
Author(s):  
Dario Loaldi ◽  
Francesco Regi ◽  
Federico Baruffi ◽  
Matteo Calaon ◽  
Danilo Quagliotti ◽  
...  
Keyword(s):  
Injection Molding ◽  
Process Simulation ◽  
Current Work ◽  
Injection Molding Process ◽  
Process Conditions ◽  
Virtual Design ◽  
Molding Process ◽  
Micro Injection Molding ◽  
Multi Scale ◽  
Filling Time

The increasing demand for micro-injection molding process technology and the corresponding micro-molded products have materialized in the need for models and simulation capabilities for the establishment of a digital twin of the manufacturing process. The opportunities enabled by the correct process simulation include the possibility of forecasting the part quality and finding optimal process conditions for a given product. The present work displays further use of micro-injection molding process simulation for the prediction of feature dimensions and its optimization and microfeature replication behavior due to geometrical boundary effects. The current work focused on the micro-injection molding of three-dimensional microparts and of single components featuring microstructures. First, two virtual a studies were performed to predict the outer diameter of a micro-ring within an accuracy of 10 µm and the flash formation on a micro-component with mass a 0.1 mg. In the second part of the study, the influence of microstructure orientation on the filling time of a microcavity design section was investigated for a component featuring micro grooves with a 15 µm nominal height. Multiscale meshing was employed to model the replication of microfeatures in a range of 17–346 µm in a Fresnel lens product, allowing the prediction of the replication behavior of a microfeature at 91% accuracy. The simulations were performed using 3D modeling and generalized Navier–Stokes equations using a single multi-scale simulation approach. The current work shows the current potential and limitations in the use of micro-injection molding process simulations for the optimization of micro 3D-part and microstructured components.

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