scholarly journals Characterization of Microchannel Replicability of Injection Molded Electrophoresis Microfluidic Chips

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 608 ◽  
Author(s):  
Bingyan Jiang ◽  
Laiyu Zhu ◽  
Liping Min ◽  
Xianglin Li ◽  
Zhanyu Zhai ◽  
...  
Keyword(s):  
Microfluidic Chip ◽  
Mold Temperature ◽  
Disease Diagnosis ◽  
Injection Rate ◽  
Holding Time ◽  
Critical Element ◽  
Profile Curve ◽  
Microfluidic Chips ◽  
Melt Temperature ◽  
Injection Molded

Microfluidic chips have been widely applied in biochemical analysis, DNA sequencing, and disease diagnosis due to their advantages of miniaturization, low consumption, rapid analysis, and automation. Injection molded microfluidic chips have attracted great attention because of their short processing time, low cost, and mass production. The microchannel is the critical element of a microfluidic chip, and thus the microchannel replicability directly affects the performance of the microfluidic chip. In the current paper, a new method is proposed to evaluate the replicability of the microchannel profile via the root mean square value of the actual profile curve and the ideal profile curve of the microchannel. To investigate the effects of injection molding parameters (i.e., mold temperature, melting temperature, holding pressure, holding time, and injection rate) on microchannel replicability, a series of single-factor experiments were carried out. The results showed that, within the investigated experimental range, the increase of mold temperature, melt temperature, holding pressure, holding time, and injection rate could improve microchannel replicability accuracy. Specifically, the microchannels along the flow direction of the polymer melt were significantly affected by the mold temperature and melt temperature. Moreover, the replicability of the microchannel was influenced by the distance from the injection gate. The effect of microchannel replication on electrophoresis was demonstrated by a protein electrophoresis experiment.

scholarly journals Magnesium Permanent Mold Castings Optimization

2011 ◽  
Vol 690 ◽  
pp. 65-68 ◽  
Author(s):  
Fady Refaat Elsayed ◽  
Norbert Hort ◽  
Mario Alberto Salgado Ordorica ◽  
Karl Ulrich Kainer
Keyword(s):  
Magnesium Alloys ◽  
Casting Process ◽  
Mold Temperature ◽  
Holding Time ◽  
Permanent Mold ◽  
Melt Temperature ◽  
Cast Part ◽  
Mold Casting ◽  
Permanent Mold Castings ◽  
Inhomogeneous Properties

Permanent mold casting is a well-established route for casting large magnesium alloys components. Casting parameters like superheat, mold temperature, and holding time can often result in inhomogeneous properties, porosity, and segregation problems in the cast part. In order to optimize the casting process, control of the casting parameters including mold temperatures and holding times is essential to promote directional solidification, and ensure defect free homogenous structure. Binary Mg-9wt.%Al and Mg-10wt.%Gd alloys were used to investigate the effect of casting parameters such as melt temperature and holding time on the part macro and microstructure.

Residual stresses determination in injection molded virgin and recycled HDPE blends: mechanical properties and morphology

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Mirigul Altan ◽  
Mehmet Emin Yurci ◽  
Nihan Nugay
Keyword(s):  
Elastic Modulus ◽  
Impact Strength ◽  
Residual Stresses ◽  
Thermal Stresses ◽  
Mold Temperature ◽  
Morphological Properties ◽  
Time Layer ◽  
Melt Temperature ◽  
Injection Molded ◽  
Recycled Hdpe

AbstractAn experimental study of residual thermal stresses has been carried out in injection molded virgin and recycled high density polyethylene (HDPE) blends. Effects of blend concentrations on residual stresses were investigated under different injection conditions such as melt temperature, mold temperature and cooling time. Layer removal technique was used for measuring residual stresses. In order to determine the relation between the residual stresses and material characteristic of HDPE blends, mechanical and morphological properties of the blends were also investigated. Elastic modulus and impact strength were important key factors for determining the blend characteristics. As a result, it was found that HDPE blends gave higher residual stresses but lower impact strength with higher elastic modulus when recycled concentration was increased. Furthermore, it was seen that shape and size of the crystallites were also effective on residual stresses. Small and spherulitic crystallite structured blends such as 30 % recycled HDPE induced reduction in residual stresses due to easier relaxation with lower elastic modulus and higher impact strength while lamellar crystallite structured blends such as 50 % recycled HDPE gave higher elastic modulus but lower impact strength with higher residual stresses.

scholarly journals Simulation and Optimization of Short Fiber Circumferential Orientation in Short-Fiber-Reinforced Composites Overflow Water-Assisted Injection Molded Tube

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Haiying Zhou ◽  
Hesheng Liu ◽  
Tangqing Kuang ◽  
Qingsong Jiang ◽  
Zhixin Chen ◽  
...  
Keyword(s):  
Delay Time ◽  
Water Pressure ◽  
Mold Temperature ◽  
Short Fiber ◽  
Range Analysis ◽  
Melt Temperature ◽  
Simulation And Optimization ◽  
Experimental Scheme ◽  
Filling Time ◽  
Injection Molded

The mechanical properties of the water-assisted injection molded tube can be enhanced by the increase in the short fiber circumferential orientation (SFCO). Thus, the numerical method verified by experiments is used to simulate the SFCO distribution in the overflow water-assisted injection molding (OWAIM), with the mechanism of short fiber orientation analyzed as well. The effect of parameters (filling time, melt temperature, mold temperature, delay time, water pressure, and water temperature) on the SFCO is explored by range analysis and variance analysis of the orthogonal experimental scheme. Moreover, both of artificial neural network (ANN) and genetic algorithm (GA) are used to model and optimize process parameters. Results show that the melt temperature, delay time, and water pressure are predominant parameters. The evolution of SFCO increases with the increase of melt temperature and water pressure, whereas the changes in delay time reverse. The value of the maximum SFCO tensor obtained by GA optimization is found to be 0.234.

Influence of Process Conditions on the Local Shrinkage and on the Pressure Evolution inside the Mold Cavity of the Injection Molded Polypropylene in Two Modifications - PP Homopolymer; 40 % Talc Filled PP

2015 ◽  
Vol 669 ◽  
pp. 11-18
Author(s):  
Robert Záboj
Keyword(s):  
Rectangular Plate ◽  
Wall Thickness ◽  
Injection Rate ◽  
Semicrystalline Polymer ◽  
Mutual Interaction ◽  
Mold Cavity ◽  
Process Conditions ◽  
Melt Temperature ◽  
Injection Molded ◽  
Pressure Evolution

This work is focusing on optimization of the chosen process conditions (melt temperature, injection rate and holding pressure) and their mutual interaction on the local shrinkage of wall thickness carried out on rectangular plate. The test was applied on semicrystalline polymer in following modifications - polypropylene homopolymer and 40 % talc filled polypropylene. For better understanding of processes influencing shrinkage the pressure evolution inside cavity was captured by transducers placed near the gate and at the end of flow.

Influence of Process Parameters on Plastic Injection Molding of Automobile Interior Trim

2011 ◽  
Vol 189-193 ◽  
pp. 1675-1680
Author(s):  
Qing Qing Liu ◽  
Lin Hua ◽  
Wei Guo
Keyword(s):  
Mold Temperature ◽  
Process Conditions ◽  
Injection Time ◽  
Molding Process ◽  
Melt Temperature ◽  
Influence Of Process Parameters ◽  
Packing Pressure ◽  
Optimal Setting ◽  
Injection Molded ◽  
Packing Time

The influence of process conditions on the formability of injection-molded PX0034 (9% talc-filled PP) automobile B column mounting trim applied as a model has been studied in current work. This study has been focused on the interactive influence of melt temperature and mold temperature, the interactive influences of injection time and packing time and the influences of packing pressure. Weighting the effect of optimization is by formability including the values of pressure at V/P switchover, volumetric shrinkage differential at ejection, and maximum warpage. Aforementioned values were obtained by numerical simulation of the whole molding process using commercial dedicated code Moldflow. Results indicate that the combination of mold temperature at 25 °C, melt temperature at 220 °C, injection time at 2.2 s, packing time at 16 s and packing pressure at 90% of the filling pressure is the optimal setting for formability of this trim. The simulation results obtained under the optimized parameters are that the pressure at V/P switchover is 27.29 Mpa, the shrinkage differential at ejection is 6.55 %, and maximum warpage is 3.072 mm. Good correlation is highlighted between the experiments and the simulations by comparing effects of the global optimization in formability, which verifies the validity of the optimal combination.

scholarly journals Thermoplastic Overmolding onto Injection-Molded and In Situ Polymerization-Based Polyamides

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2140 ◽  
Author(s):  
Róbert Boros ◽  
Praveen Rajamani ◽  
József Kovács
Keyword(s):  
In Situ Polymerization ◽  
Mold Temperature ◽  
Technological Parameters ◽  
Temperature Dependent ◽  
Welding Zone ◽  
Melt Temperature ◽  
Injection Molded ◽  
The Individual ◽  
Dependent Mass

We investigated products manufactured by in situ polymerization, which were reinforced with overmolded ribs. We developed our own mold and prototype product for the project. We used three different materials as preform: a material with a magnesium catalyst, manufactured by in situ polymerization, a Brüggemann AP-NYLON-based in situ polymerization material and an injection-molded PA6 (Durethan B30S, Lanxess GmbH) material. The ribs were formed from the same PA6 material (Durethan B30S, Lanxess GmbH). We examined the effect of the different technological parameters through the pull-off of the overmolded ribs. We measured the effect of melt temperature, holding pressure and holding time, and mold temperature. Considering the individual preforms, we pointed out that monomer migration and binding strength are related, which we concluded from the temperature-dependent mass loss of the materials, measured by thermogravimetric analysis (TGA). Finally, we designed a mold suitable for manufacturing overmolded parts. We designed and built pressure and temperature sensors into the mold to examine and analyze pressures and temperatures around the welding zone of the materials.

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%.

The influence of level of interfacial healing on the weld-line strengths of injection molded parts

2012 ◽  
Vol 32 (6-7) ◽  
pp. 365-378
Author(s):  
Chung-Ching Huang ◽  
Yu-Yi Wu ◽  
Hui-Tang Chang ◽  
Yi-Jen Yang
Keyword(s):  
Weld Line ◽  
Mold Temperature ◽  
Cross Sectional Area ◽  
Sectional Area ◽  
Cross Sectional ◽  
Melt Temperature ◽  
Molded Parts ◽  
Injection Molded ◽  
Structural Loading ◽  
Plastic Components

Abstract Weld lines are commonly present within injection-molded plastic components and generally reduce strength. In designing a plastic part, the designer can often vary the wall thicknesses, or move the gate locations to position the weld line, so that its structural loading is minimized. By altering such variables as melt temperature, mold temperature, and packing pressure, slight increases in weld-line integrity can be achieved. These approaches often do not increase the part strength or performance to an acceptable level, resulting in the exclusion of numerous applications for plastic conversion. This study investigated a hot runner system, sequential valve gates, and heat degree, to achieve economical methods for predicting weld-line properties. By calculating melt front temperatures with MoldFlow analysis, we can predict the strength of the weld line according to the definition of “heat degree”, which is the effective cross-sectional area of the melt front multiplied by the temperature gradient. An effective cross-sectional area of the melt front is defined as the area of the temperature above the melting point. In contrast to the test result, when the “sum of heat degree” is lower than 1150 mm2 °C for PA6 (Mitsubishi 1030J) and 500 mm2 °C for polypropylene (PP) (FCFC K1012), the molecules cannot bond adequately at the interface of the melt fronts. Therefore, the mechanical property declines significantly.

The Correlation Between the Residual Stresses of ABS Terpolymers and Injection Molding Conditions

1987 ◽  
Vol 109 (2) ◽  
pp. 171-175 ◽  
Author(s):  
Cheng Ping Chiu ◽  
Min Chin Hsieh
Keyword(s):  
Surface Layer ◽  
Residual Stresses ◽  
Measurement Techniques ◽  
Injection Pressure ◽  
Mold Temperature ◽  
Processing Parameters ◽  
Injection Rate ◽  
Holding Time ◽  
Microscopic Measurement ◽  
Injection Rates

Residual stresses (R.S.) in a microcomputer-controlled injection molded ABS terpolymers have been determined. The layer-removal method and the microscopic measurement techniques were used to evaluate the stresses in these molded articles. The relationship between the R.S. and the processing parameters such as injection pressure, holding pressure, holding time, injection rate, and mold temperature was studied. Experimental results indicated that, at the higher injection rates (>10g/s), the R.S. are compressive in the surface layer and tensile in the interior; however, at the lower injection rates (<10g/s), the residual stresses are tensile in the surface layer and compressive in the interior. The results also indicated that the higher the injection rate, the lower the residual stresses; the compressive residual stresses increased in proportion to the increase of holding pressure; the residual stresses could be decreased by keeping a higher mold temperature; the longer the holding time, the higher the compressive R.S. and the lower the tensile R.S.

Experimental Study of Injection Conditions for a Thin-Walled Wax Pattern Using Response Surface Methodology

2014 ◽  
Vol 607 ◽  
pp. 185-192 ◽  
Author(s):  
Chang Hui Liu ◽  
Sun Jin ◽  
Xin Min Lai ◽  
Dong Hong Wang ◽  
Yu Lian Wang
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Process Parameters ◽  
Mold Temperature ◽  
Holding Time ◽  
Melt Temperature ◽  
Packing Pressure ◽  
Wax Pattern ◽  
Thin Walled ◽  
The Relationship

In this paper, the relationship between the shrinkage of the thin-walled wax part in the investment casting process (ICP) and the process parameters including mold temperature, melt temperature, packing pressure and holding time are investigated through a series of experiments. The relationship is successfully described by a mathematical regression model which is based on the response surface methodology (RSM). The rationality and adequacy of the mathematical model are checked via analysis of variation (ANOVA) and a sensitivity analysis for process parameters on the dimensional shrinkage variation are conducted which shows that the contribution percentages of mold temperature, melt temperature, packing pressure and holding time are 23.77%, 43.67%, 11.85% and 16.99%, respectively. Additionally, the optimal setting of the process parameters is also obtained by calculating the desirability function. The optimal combination of the mold temperature, melt temperature, packing pressure, and holding time is 74°C, 30°C 25bar, and 5 sec, respectively.

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