Influence of Injection and Cavity Pressure on the Demoulding Force in Micro-Injection Moulding

2014 ◽  
Vol 136 (3) ◽  
Author(s):  
C. A. Griffiths ◽  
S. S. Dimov ◽  
S. G. Scholz ◽  
G. Tosello ◽  
A. Rees
Keyword(s):  
Experimental Study ◽  
Process Parameters ◽  
Design Of Experiment ◽  
Injection Moulding ◽  
Processing Conditions ◽  
Cavity Pressure ◽  
Mould Temperature ◽  
Melt Temperature ◽  
Injection Speed ◽  
Micro Injection Moulding

The paper reports an experimental study that investigates part demoulding behavior in micro-injection moulding with a focus on the effects of pressure and temperature on the demoulding forces. In particular, the demoulding performance of a representative microfluidics part was studied as a function of four process parameters, melt temperature, mould temperature, holding pressure, and injection speed, employing the design of experiment approach. In addition, the results obtained using different combinations of process parameters were analyzed to identify the best processing conditions in regards to demoulding behavior of microparts when utilizing a COC polymer to mould them.

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.

Rejection Rate Reduction of the Automotive Thermoplastic Parts in Injection Moulding Using Response Surface Methodology

2020 ◽  
Vol 841 ◽  
pp. 225-231
Author(s):  
Huei Ruey Ong ◽  
Ifwat Mohd Shah ◽  
Wan Mohd Eqhwan Iskandar ◽  
Md. Maksudur Rahman Khan ◽  
Chi Shein Hong ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Process Parameters ◽  
Injection Moulding ◽  
Injection Pressure ◽  
Acrylonitrile Butadiene Styrene ◽  
Rejection Rate ◽  
Mould Temperature ◽  
Melt Temperature ◽  
Rsm Model

Plastic injection moulding is widely used for manufacturing due to variety of plastic product. In this study, plastic part defects such as air bubble and gas mark defect are commonly occurs in thermoplastic part, specifically acrylonitrile butadiene styrene (ABS). In order to optimize the process parameters of injection moulding, design of experiment (DOE) with Response Surface Methodology (RSM) model was used. Process parameters such as melt temperature, mould temperature and injection pressure were selected for the DOE development. The experiments were conducted with melt temperature range from 200 °C to 240 °C, mould temperature from 60 °C to 80 °C and injection pressure from 90 to 99%. The result indicates that, all the selected parameters were significantly influence the rejection rate of the automotive ABS part. The optimum melt temperature, mould temperature and injection pressure were 220 °C, 70 °C and 98% respectively, in obtaining minimum rejection rate.

Experimental Study on the Crystallinity and Mechanical Properties of the Injection Molded Polypropylene

2011 ◽  
Vol 239-242 ◽  
pp. 2809-2812 ◽  
Author(s):  
Xiao Xun Zhang ◽  
Luo Wang ◽  
Qiu Hui Liao
Keyword(s):  
Mechanical Properties ◽  
Injection Molding ◽  
Diffraction Method ◽  
Processing Conditions ◽  
Mould Temperature ◽  
X Ray Diffraction ◽  
Melt Temperature ◽  
X Ray ◽  
Injection Speed ◽  
Injection Molded

Polypropylene specimens were made by the injection molding experiments under different processing conditions. The crystallinity of each polypropylene specimen was obtained using the X-ray diffraction method. The effects of the injection molding processes on the crystallinity of polypropylene were revealed: (1) the crystallinity decreases as the melt temperature increases, and the higher the melt temperature, the slower the crystallinity decreases, (2) the crystallinity decreases as the mould temperature increases, and the higher the mould temperature, the faster the crystallinity decreases, (3) the crystallinity increases as the injection speed increases, and the larger the injection speed, the faster the crystallinity increases. By the tensile experiments of the injection molded specimens, it is also found that the crystallinity has a major impact on the mechanical properties of polypropylene. The yield strength and tensile strength of polypropylene specimens increase as the crystallinity increases.

Process Factors Influence on Cavity Pressure Behavior in Microinjection Moulding

2011 ◽  
Vol 133 (3) ◽  
Author(s):  
C. A. Griffiths ◽  
S. S. Dimov ◽  
S. Scholz ◽  
H. Hirshy ◽  
G. Tosello
Keyword(s):  
Polymer Materials ◽  
Similar Process ◽  
Cavity Pressure ◽  
Mould Temperature ◽  
Quality Factors ◽  
Melt Temperature ◽  
Pressure Work ◽  
Injection Speed ◽  
Process Factors ◽  
Microinjection Moulding

Process monitoring of microinjection moulding (μIM) is of crucial importance when analysing the effect of different parameter settings on the process and then in assessing its quality. Quality factors related to cavity pressure can provide valuable information about the process dynamics and also about the filling behavior of different polymer melts. In this paper, a pressure sensor mounted inside a tool cavity was employed to analyse maximum cavity pressure, pressure increase rate during filling and pressure work. The influence of four μIM parameters, melt temperature, mould temperature, injection speed, and packing pressure on these three pressure-related process parameters was investigated. A design of experiment study was conducted by moulding a test part, a microfluidic component, in three different polymer materials, PP, ABS, and PC. The results show a similar process behavior for all three polymers, in particular a higher injection speed led to a reduction of the pressure work while a lower mould temperature reduces the pressure rate.

scholarly journals Multiobjective Optimization of Injection Moulding Process Parameters on Mechanical Properties Using Taguchi Method and Grey Relational Analysis

2018 ◽  
Vol 7 (3.7) ◽  
pp. 14 ◽  
Author(s):  
Mohd Amran Md Ali ◽  
Noorfa Idayu ◽  
Raja Izamshah ◽  
Mohd Shahir Kasim ◽  
Mohd Shukor Salleh ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Taguchi Method ◽  
Grey Relational Analysis ◽  
Injection Moulding ◽  
Cooling Time ◽  
Mould Temperature ◽  
Plastic Part ◽  
Melt Temperature ◽  
Relational Analysis ◽  
Grey Relational

This study presents an optimization of injection moulding parameters on mechanical properties of plastic part using Taguchi method and Grey Relational Analysis (GRA) approach. The orthogonal array with L9 was used as the experimental design. Grey relational analysis for ultimate tensile strength, modulus and percentage of elongation from the Taguchi method can convert optimization of the multiple performance characteristics into optimization of a single performance characteristic called the grey relational grade (GRG). It is found that mould temperature of 62oC, melt temperature of 280oC, injection time of 0.70s and cooling time 15.4s are found as the optimum process setting. Furthermore, ANOVA result shows that the cooling time is the most influenced factor that affects the mechanical properties of plastic part followed by mould temperature and melt temperature.  

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.

Polymeric Micro-Filter Fabrication Using a Micro Injection Moulding Process

2015 ◽  
Author(s):  
Rossella Surace ◽  
Vincenzo Bellantone ◽  
Irene Fassi
Keyword(s):  
Injection Moulding ◽  
Electrical Discharge Machining ◽  
Polymeric Materials ◽  
Machining Process ◽  
Injection Velocity ◽  
Mould Temperature ◽  
Moulding Process ◽  
Micro Injection Moulding ◽  
Injection Moulding Process ◽  
Incomplete Filling

This paper reports on fabrication and characterization of a micro-filter for hearing aid, dialysis media and inhaler. The micro-feature specifications consist in a diameter of 2.3 mm, a thickness of 0.2 mm and it is composed by a mesh with grid of 80 μm and ribs with width of 70 μm. The proposed micro-filter is fabricated by micro injection moulding process adopting a steel mould manufactured by micro Electrical Discharge Machining process (micro EDM). Different polymeric materials (POM, HDPE, LCP), particularly indicated for the injection moulding applications due to their flowability and stability, are tested and evaluated in relation to the process replication capability. Since the polymer micro-filter is made of a complex grid of micro-ribs, the injection moulding process must ensure complete filling of the micro-parts, preventing any defects (i.e. premature solidification, incomplete filling, flash and air traps). To this aim, different system parameters configurations (melt and mould temperature, injection velocity, holding time and pressure, cooling time, pressure limit) are tested for obtaining acceptable part in all polymers grade. Finally, the component is dimensionally characterized by confocal microscopy and its filtration capacity is then verified. Although the feature complexity was high, the results showed that the object could be successfully replicated by filling completely the micro cavities with two of them: POM and HDPE. The most significant parameters influencing the part filling were the mould temperature and the injection velocity. These findings allow to further optimize the micro-injection process parameters to obtain a high quality product.

Influence of the injection moulding parameters on the microstructure and thermal properties of microcellular polyethylene terephthalate glycol foams

2012 ◽  
Vol 49 (1) ◽  
pp. 47-63 ◽  
Author(s):  
Francisco Jaime Gómez-Gómez ◽  
David Arencón ◽  
Miguel Ángel Sánchez-Soto ◽  
Antonio B Martínez
Keyword(s):  
Mechanical Properties ◽  
Injection Moulding ◽  
Ethylene Terephthalate ◽  
Flow Direction ◽  
Skin Layer ◽  
Mould Temperature ◽  
Strong Variation ◽  
Injection Speed ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene

Microcellular injection moulding is capable of producing lightweight polymeric products. The present study analyses the influence of several representative injection moulding parameters on the foam’s morphology, apparent density and thermo-mechanical properties of PETG, poly(ethylene terephthalate-co-1,4-cyclohexylene-dimethylene terephthalate) specimens. A strong variation of the cell morphology along the melt flow direction has been found, as well as a dependence on the shot volume. The most homogeneous microcellular structure is achieved when low shot volume, intermediate injection speed and low mould temperature are employed. The skin–core structure of the injected parts, determined the thermo-mechanical features of the specimen, which are ruled by the skin layer.

scholarly journals Effect of the Injection Moulding Processing Conditions on Biopolymers Final Properties

2012 ◽  
Vol 730-732 ◽  
pp. 20-25
Author(s):  
Pedro Teixeira ◽  
António Pontes ◽  
Elsa Henriques
Keyword(s):  
Lactic Acid ◽  
Injection Moulding ◽  
Research Work ◽  
Poly Lactic Acid ◽  
Processing Conditions ◽  
Mould Temperature ◽  
Experimental Procedure ◽  
Main Injection ◽  
Plasticized Starch ◽  
Injection Temperature

This research work intended to study the effect of the main injection moulding parameters in the final properties of biopolymers mouldings. An experimental procedure was carried out in which four biopolymers containing different composition percentages of poly-lactic acid (PLA) and plasticized starch (PLS) were compared with polypropylene (PP). For each material the effect of the processing conditions (mould temperature, injection temperature and holding pressure) on the final properties was discussed and the possibility of using biopolymers as a substitute of PP in household utility products was evaluated.

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