scholarly journals Rheological characterization of polystyrene melts dissolved with supercritical nitrogen fluid during microcellular injection moulding

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Shia-Chung Chen ◽  
Ming-Hsiu Chung ◽  
Yu-Wan Lin ◽  
Ping-Shun Hsu ◽  
Shyh- Shin Hwang ◽  
...  
Keyword(s):  
Injection Moulding ◽  
Rheological Behaviour ◽  
Rheological Characterization ◽  
Melt Temperature ◽  
Moulding Process ◽  
Foaming Process ◽  
Lower Viscosity ◽  
Injection Moulding Process ◽  
Mould Cavity ◽  
Moulding Pressure

AbstractThere are several benefits of using the supercritical fluid microcellular injection moulding process. The part weight, melt temperature, viscosity, moulding pressure, shrink/warpage, and cooling/cycle time are all significantly reduced. The purpose of this study is to investigate the rheological behaviour of PS melt dissolved SCF of nitrogen during Microcellular Injection Moulding process applied with Gas Counter Pressure (GCP) technology. The application of gas into the mould cavity prior to the melt filling provides a counter force against the melt front advancement, restricting the foaming process during the melt filling stage. A slit cavity is designed to measure the pressure drop of polystyrene mixed with 0.4wt% supercritical nitrogen fluid under different mould temperatures (185°C, 195°C, and 205°C), injection speeds (5, 10, and 15 mm/s) as well as counter pressures (0, 150, 300 bars). It was found that melt viscosity is reduced by up to 30% when GCP is increased from 50 to 150 bar as compared to conventional injection moulding. The non-nucleation mixture melt obtained by using a GCP of 300 bar has 32~49% lower viscosity. In addition, the glass transition temperature, Tg, was found to be reduced from 96 °C to 50 °C when the applied GCP is 300 bar.

Investigating the Effects of Injection Moulding Process Parameters on Multiple Tensile Characteristics of Plastic Spur Gear via Experimental Approach

2013 ◽  
Vol 748 ◽  
pp. 544-548 ◽  
Author(s):  
Nik Mizamzul Mehat ◽  
Shahrul Kamaruddin ◽  
Abdul Rahim Othman
Keyword(s):  
Process Parameters ◽  
Injection Moulding ◽  
Experimental Approach ◽  
Low Cost ◽  
Spur Gear ◽  
Melt Temperature ◽  
Moulding Process ◽  
Packing Pressure ◽  
Injection Moulding Process ◽  
State Of Tension

This paper presents the original development of an experimental approach in studying the multiple tensile characterizations as key quality characteristics for several different plastic gear materials related to various parameters in injection moulding process. In this study, emphases are given on a new low-cost mechanism for the testing of the injection moulded plastic spur gear specimens with various teeth module. The testing fixture are developed and validated to provide uniform state of tension with series of plastic gear specimens produced in accordance with the systematically designed of experiment. The effects of changes in the process parameters including melt temperature, packing pressure, packing time and cooling time at three different levels on the elongation at break and ultimate strength of plastic gear is evaluated and studied through the proposed experimental approach.

scholarly journals Optimisation of Mould Design for Injection Moulding – Numerical Approach

2021 ◽  
Vol 15 (2) ◽  
pp. 258-266
Author(s):  
Damir Godec ◽  
Vladimir Brnadić ◽  
Tomislav Breški
Keyword(s):  
Computer Simulation ◽  
Injection Moulding ◽  
Numerical Approach ◽  
Processing Parameters ◽  
Simulation Software ◽  
Moulding Process ◽  
Part Geometry ◽  
Injection Moulding Process ◽  
Mould Cavity ◽  
Mould Design

Computer simulation of injection moulding process is a powerful tool for optimisation of moulded part geometry, mould design and processing parameters. One of the most frequent faults of the injection moulded parts is their warpage, which is a result of uneven cooling conditions in the mould cavity as well as after part ejection from the mould and cooling down to the environmental temperature. With computer simulation of the injection moulding process it is possible to predict potential areas of moulded part warpage and to apply the remedies to compensate/minimize the value of the moulded part warpage. The paper presents application of simulation software Moldex 3D in the process of optimising mould design for injection moulding of thermoplastic casing.

The Effect of TiH2 Particle on Rheological Behaviour of NiTi for Metal Injection Moulding

2017 ◽  
Vol 882 ◽  
pp. 23-27
Author(s):  
Ros Atikah Abdul Kadir ◽  
Nor Hafiez Mohamad Nor ◽  
Istikamah Subuki ◽  
Muhammad Hussain Ismail
Keyword(s):  
Shear Rate ◽  
Titanium Hydride ◽  
Injection Moulding ◽  
Rheological Behaviour ◽  
Nickel Titanium ◽  
Elastic Behaviour ◽  
Capillary Rheometer ◽  
Moulding Process ◽  
Injection Process ◽  
Injection Moulding Process

This paper highlights the influence of titanium hydride particle on the rheological behaviour of nickel-titanium feedstock used in the metal injection process. The ratio of 50at% nickel and 50at% titanium hydride with 2 different powder loadings (65.5vol% and 67.5vol%) were investigated. A Rosand RH2000 capillary rheometer was used to determine the flow behaviour of feedstocks. The feedstocks were characterized at different temperature ranging from 150°C and 170°C and shear rate ranging from 50/s and 4442.63/s. The results showed on pseudo-elastic behaviour flow of NiTi feedstock which is suitable for injection moulding process.

Warpage Analysis of Different Number Cooling Channels for Dumbbell Plastic Part in Injection Moulding

2015 ◽  
Vol 761 ◽  
pp. 8-11 ◽  
Author(s):  
Mohd Amran ◽  
Siti Salmah ◽  
Raja Izamshah ◽  
Mohd Shahir ◽  
Mohd Amri ◽  
...  
Keyword(s):  
Injection Moulding ◽  
Simulation Analysis ◽  
Cooling System ◽  
Cooling Channel ◽  
Mould Temperature ◽  
Plastic Part ◽  
Melt Temperature ◽  
Moulding Process ◽  
Cooling Channels ◽  
Injection Moulding Process

Warpage deflection is one of the common pitfalls in plastic injection moulding which is always affected the quality and accuracy of the plastic products. It occurs due to the influences of mould temperature during injection moulding process and it is related to the number of cooling system existed in the mould. Therefore, this paper studies the effect of cooling channels on warpage of dumbbell plastic part having different number of cooling channel using Moldflow software. Warpage analysis was run using four and eight cooling channels. Parameters involved in this study are injection time, packing time, melt temperature and mould temperature. The result of warpage from simulation analysis was projected on the graphic having different colour which is presented the actual value of warpage. It is found from warpage simulation result that the maximum warpage for four cooling channels is 1.283mm and the maximum warpage for eight cooling channels is 1.280mm. It shows that the increasing of the number of cooling channel from four to eight channels in the injection mould reduces the warpage deflection about 0.2%. Thus, the result shows that the number of cooling system in the mould plays an important role on the quality of plastic part during injection moulding process.

Optimization of Injection Moulding Process from the View of Cavity Filling Time and Product Cooling Time

2014 ◽  
Vol 621 ◽  
pp. 208-213
Author(s):  
Katarina Monkova ◽  
Slavomir Hric
Keyword(s):  
Injection Moulding ◽  
3D Model ◽  
Cooling System ◽  
Moulding Process ◽  
Mould Filling ◽  
Injection Moulding Process ◽  
Filling Time ◽  
Moulding Machine ◽  
Mould Cavity ◽  
Cavity Filling

The article deals with the mould cooling system design. The goal of design presented in the article was to propose the mould form so to be achieved the shortest time for both mould filling and product cooling. Studied product is intended to serve as a stopper in the automotive spotlight. After filling of mould cavity, the melt has to cool at 100 ° C, only then it is possible to accede to the next phase, which is final pressure. So the cooling and filling time is directly proportional to the reduction of production cost. 3D model of the mould was created in Autodesk Inventor Proffesional software and then solidification of material was simulated in Autodesk Moldflow Insight software. There were considered four types of cooling system in the article and the best one from the view of time was manufactured and placed into the injection moulding machine Arburg Allrounder 320 C.

A Review of the Effect of Process Parameters on the Performance of Plastic Injection Molding Process to Control the Warpage in Plastics

2015 ◽  
Vol 830-831 ◽  
pp. 116-119 ◽  
Author(s):  
Gurjeet Singh ◽  
Mohan Kumar Pradhan ◽  
Ajay Verma
Keyword(s):  
Process Parameters ◽  
Injection Moulding ◽  
Process Parameter ◽  
Coolant Temperature ◽  
Injection Molding Process ◽  
Melt Temperature ◽  
Influence Of Process Parameters ◽  
Moulding Process ◽  
Injection Moulding Process ◽  
Plastic Injection

Quality control is important aspect of manufacturing process. The quality of product in injection moulding is influenced by injection moulding process parameter. A study of the influence of process parameters on the injection moulding process is presented. Statistically based model approach were studied. In this the process parameter that affect the injection moulding process are like injection time, injection pressure, packing pressure, packing time, cooling time, coolant temperature mold temperature, melt temperature are studied and compared. This paper deals with design of experiment approach to fine out optimal parameter setting. The comparison shows effect of parameters on injection moulding process.Key words: Plastic injection moulding, Orthogonal array, Cycle time

The Simulation as a Tool for Technical Devices Design and Optimization

2014 ◽  
Vol 718 ◽  
pp. 122-127
Author(s):  
Slavomir Hric ◽  
Dominika Lehocka ◽  
Jan Carach ◽  
Filip Murgas ◽  
Peter Pastucha
Keyword(s):  
Injection Moulding ◽  
3D Model ◽  
Cooling System ◽  
Moulding Process ◽  
Design And Optimization ◽  
Running System ◽  
Injection Moulding Process ◽  
Moulding Machine ◽  
Mould Cavity

The article deals with the research of the pressures originated inside the cooling system and also in the mould cavity during the injection moulding process. The simulations were realized for three designed types of running system and for four versions of cooling system. 3D model of the mould was created in Autodesk Inventor Proffesional software and then solidification of material was simulated in Autodesk Moldflow Insight software. The results were compared and the best version from the view of pressure was manufactured and placed into the injection moulding machine Arburg Allrounder 320 C.

Thermal Degradation of the Thermoplastic Elastomers during the Injection Moulding Process

2016 ◽  
Vol 862 ◽  
pp. 148-155 ◽  
Author(s):  
Luboš Bĕhálek ◽  
Jiří Habr ◽  
Martin Seidl ◽  
Petr Lenfeld ◽  
Martin Boruvka
Keyword(s):  
Thermal Degradation ◽  
Injection Moulding ◽  
Physical And Mechanical Properties ◽  
Degradation Process ◽  
Thermoplastic Elastomers ◽  
Chemical Compositions ◽  
Oxidation Induction Time ◽  
Melt Temperature ◽  
Moulding Process ◽  
Injection Moulding Process

The thermal degradation of the thermoplastic elastomers (TPEs) during the injection moulding process – depending on the melt temperature and residence time of the processed material within the barrel of the injection unit, was studied on the basis of oxidation induction time evaluation (isothermal OIT) of the moulded parts (according to ISO 11357-6) and their physical and mechanical properties, according to ISO 1183-1, ISO 37 and ISO 7619-1. TPEs with different chemical compositions intended for automotive, industrial and medical applications were analysed during the study of the thermal degradation process.

Micro Injection Moulding Process and Product Characterization

2011 ◽  
Author(s):  
Rossella Surace ◽  
Gianluca Trotta ◽  
Alessandro Bongiorno ◽  
Vincenzo Bellantone ◽  
Claudia Pagano ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Injection Moulding ◽  
Process Conditions ◽  
Scale Production ◽  
Mould Temperature ◽  
Melt Temperature ◽  
Injection Speed ◽  
Moulding Process ◽  
Micro Injection Moulding ◽  
Injection Moulding Process

Due to its high efficiency for the large scale production of polymeric parts, micro injection moulding is one of the key technologies of the new millennium. Although a lot of researches have been conducted to identify the most effective processing conditions for micro injection moulding, the comprehension of the influence of all parameters on the quality, the properties and the reliability of the moulded parts is still an issue. In this context, this study aims to evaluate the effects of the micro injection moulding process conditions on the tensile properties of micro parts, investigating the influence of three main process parameters: the injection speed, the mould temperature and the melt temperature. A full factorial plan has been applied to study the contributions of these parameters and a second study has been performed to understand the synergic interaction between the two temperatures on the tensile strength. Due to its high level of potential crystallinity, a typical semi-crystalline thermoplastic resin was used in the experiments. The results of the analysis showed a great influence of the mould temperature (Tmould) on the ultimate tensile strength and of the melt temperature (Tmelt) on the deformation at the point of breaking; whereas the injection speed was significant on the overall mechanical performance. A new studied factor (Tmelt-Tmould) could affect the resulting molecular structure and consequently the mechanical behaviour, but itself is not sufficient to thoroughly explain the observed behaviour. Moreover, the visual inspection of the deformation mechanism at break shows three distinctive trends demonstrating the great variability of the mechanical properties of micro-injected specimens due to process conditions.

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