Investigation of Mold Temperature Affecting on Shrinkage of Rapid Heat Cycle Molding Plastic Part

2011 ◽  
Vol 189-193 ◽  
pp. 2477-2481 ◽  
Author(s):  
Dong Lei Liu ◽  
Chang Yu Shen ◽  
Chun Tai Liu ◽  
Yong Xin ◽  
Ling Sun
Keyword(s):  
Deformation Temperature ◽  
Thermal Deformation ◽  
Injection Pressure ◽  
Mold Temperature ◽  
Cooling Time ◽  
Melt Temperature ◽  
Heat Cycle ◽  
Temperature Conditions ◽  
Packing Pressure ◽  
Packing Time

In order to further investigate the influence of mold temperature in rapid heat cycle molding on shrinkage of plastic past, a self-developed vehicle-used blue-tooth front shell high-gloss mold and an auxiliary device for controlling the mold temperature were employed in experiments. And the effect of the other parameters on shrinkage of part with fixed or changed mold temperature conditions was also studied. Results reveal that the shrinkage of RHCM part is reduced obviously compared with a conventional one, decreasing as quasi-linear with mold temperature increased gradually. At same mold temperature conditions, packing pressure, followed by packing time, is the most significant parameter on shrinkage of part, while cooling time has almost no impact on it. Melt temperature and injection pressure effecting on shrinkage of part exists a critical value, near the thermal deformation temperature of plastic. When mold temperature is set below this temperature, injection pressure has more significant than melt temperature, but it is the opposite. With being elevated gradually of mold temperature, shrinkage of part shows a slight decrease trend under same melt temperature and injecting pressure. While it fluctuates as a “V” shape with a narrow range under same packing pressure, packing time and cooling time presumed conditions, and reaches the minimum near the thermal deformation temperature of plastic.

Shrinkage and Warpage in the Permanent Shape of Sape-Memory Polyurethane Parts

2022 ◽  
Vol 58 (4) ◽  
pp. 102-113
Author(s):  
Sukran Katmer ◽  
Cetin Karatas
Keyword(s):  
Shape Memory ◽  
Injection Moulding ◽  
Flow Direction ◽  
Injection Pressure ◽  
Cooling Time ◽  
Mould Temperature ◽  
Melt Temperature ◽  
Packing Pressure ◽  
Permanent Shape ◽  
Packing Time

The shape memory effect, as the most important ability of shape memory polymers, is a working property and provides the design ability to shape memory polymer features. Shrinkage and warpage are important parameters to control the dimensional accuracy of permanent and temporary shapes of an injection moulded shape memory polyurethane (SMPU) part. In this study, the effects of injection moulding parameters on the shrinkage and warpage of the permanent shape of moulded SMPU parts were experimentally investigated. The parameters of injection pressure, melt temperature, mould temperature, packing pressure, packing time, and cooling time, were chosen as the injection moulding control factors. Taguchi�s L27 orthogonal array design table was used with six injection moulding parameters and their three levels. The results showed that the part has different shrinkage ratios in three main directions, namely, the flow direction, perpendicular to the flow direction, and the direction through the thickness. The results of the analysis of variance showed that the cooling time is the most influential parameter on both the shrinkage (except in thickness) and warpage. The shrinkage in the flow direction as well as in perpendicular to the flow direction decreased with increasing the cooling time. Warpage also decreased with increasing the cooling time. Injection pressure and melt temperature were found to be effective on shrinkage in thickness. Effects of mould temperature, packing pressure, and packing time were found to be limited. A statistically significant relationship has been noticed among shrinkage, warpage, and residual stresses during the study.

Influence of Processing Conditions on the Morphological Structure and Ductility of Water-Foamed Injection Molded PP/LDPE Blended Parts

2017 ◽  
Vol 36 (2) ◽  
pp. 51-74 ◽  
Author(s):  
Ying-Guo Zhou ◽  
Bei Su ◽  
Lih-Sheng Turng
Keyword(s):  
Injection Molding ◽  
Morphological Structure ◽  
Injection Pressure ◽  
Mold Temperature ◽  
Processing Conditions ◽  
Injection Time ◽  
Melt Temperature ◽  
Packing Pressure ◽  
Packing Time ◽  
Number Of Cells

Water-foamed injection molding (WFIM) uses conventional injection molding (CIM) with water as a physical foaming agent. Compared to CIM, WFIM is a much more complicated process. As such, it is critical to determine the processing conditions for fabricating quality parts using WFIM. We used the design of experiment (DOE) method based on the Taguchi method to determine the influence of the processing conditions on the morphological structure and ductility of PP/LDPE WFIM parts, which were investigated by tensile testing and scanning electron microscopy (SEM). Our research suggests that fabricating PP/LDPE super-ductile parts using WFIM is indeed feasible. Our research also indicates that there is a close relationship between the ductility and the foamed structures, both of which are deeply influenced by the processing conditions. The analysis of variance results shows further that the water content had the greatest influence on the ductility, followed by the melt temperature, packing time, packing pressure, and PP/LDPE ratio. However, the ductility was only slightly influenced by the mold temperature, injection pressure, and injection time in WFIM. As to the number of cells, the order of influence was melt temperature, water content, packing time, packing pressure, mold temperature, injection pressure, PP/LDPE ratio, and injection time, in that order. In addition, applying DOE is a quite effective method for deducing the optimal set of effective factors in WFIM to produce super-ductile parts with a maximum number of cells. To our knowledge, this is the first time that the relationship among the processing conditions, ductility, and foamed structure of PP/LDPE WFIM super-ductile parts has been investigated and reported.

Using Taguchi Method to Optimize Molding Process Parameters of Chair Base

2012 ◽  
Vol 271-272 ◽  
pp. 1190-1194
Author(s):  
Hsueh Lin Wu ◽  
Ya Hui Wang
Keyword(s):  
Taguchi Method ◽  
Process Parameters ◽  
Simulation Analysis ◽  
Mold Temperature ◽  
Cooling Time ◽  
Injection Time ◽  
Molding Process ◽  
Melt Temperature ◽  
Packing Pressure ◽  
Moldflow Simulation

In this study, volumetric shrinkage at ejection of the chair base in the injection process, application of the 3D CAD software pro/e to design the shape of the product, and then combines moldflow simulation analysis and Taguchi method with L25 Orthogonal Array to determine the optimal injection molding parameters combination. In the Taguchi L25 experimental design, the six controlling factors used are melt temperature, mold temperature, injection time, packing time, packing pressure and cooling time, the result of experiment revealed that the optimum combination of parameters was the A2 (melting temperature 265°C), B3 (mold temperature 40°C), C2 (injection time 1.7sec), D4 (packing pressure 95%), E5 (packing time20sec), F5 (cooling time 20sec). The results show that the combination of Taguchi method and Moldflow can not only improve the molding process parameters effectively, but also optimize the quality of the products.

The simulation of the warpage rule of the thin-walled part of polypropylene composite based on the coupling effect of mold deformation and injection molding process

2018 ◽  
Vol 25 (3) ◽  
pp. 593-601 ◽  
Author(s):  
Jixiang Zhang ◽  
Xiaoyi Yin ◽  
Fengzhi Liu ◽  
Pan Yang
Keyword(s):  
Injection Molding ◽  
Coupling Effect ◽  
Mold Temperature ◽  
Injection Molding Process ◽  
Plastic Part ◽  
Molding Process ◽  
Melt Temperature ◽  
Packing Pressure ◽  
Thin Walled ◽  
Packing Time

Abstract Aiming at the problem that a thin-walled plastic part easily produces warpage, an orthogonal experimental method was used for multiparameter coupling analysis, with mold structure parameters and injection molding process parameters considered synthetically. The plastic part deformation under different experiment schemes was comparatively studied, and the key factors affecting the plastic part warpage were analyzed. Then the injection molding process was optimized. The results showed that the important order of the influence factors for the plastic part warpage was packing pressure, packing time, cooling plan, mold temperature, and melt temperature. Among them, packing pressure was the most significant factor. The optimal injection molding process schemes reducing the plastic part warpage were melt temperature (260°C), mold temperature (60°C), packing pressure (150 MPa), packing time (2 s), and cooling plan 3. In this situation, the forming plate flatness was better.

Warpage Measurement of a Micro Electrical Fan on Micro-Injection Molding

2012 ◽  
Vol 184-185 ◽  
pp. 1651-1654
Author(s):  
Jeou Long Lee ◽  
Y. Lin ◽  
Y.K. Shen
Keyword(s):  
Injection Molding ◽  
Injection Pressure ◽  
Acrylonitrile Butadiene Styrene ◽  
Mold Temperature ◽  
Micro Injection Molding ◽  
Optimum Result ◽  
Suitable Material ◽  
Packing Pressure ◽  
Injection Molded ◽  
Packing Time

This study characterizes warpage of a micro-injection molded micro electrical fan using the Michelson interference method. This study conducts experiments to analyze different polymers-polypropylene (PP), polyamide (PA), acrylonitrile-butadiene styrene (ABS), ABS+ polycarbonate (PC), and polyoxymethylene (POM)-process parameters, such as mold temperature, injection temperature, injection pressure, injection time, packing time, and packing pressure, for a micro electrical fan. To obtain the optimum result (minimum warpage), this study assesses the effect (warpage) of each material on micro-injection molding. PA plastic is the very suitable material for micro electrical fan with Michelson interference analysis on micro-injection molding.

Reduction in Defect Rate by Taguchi Method in Plastic Injection Molded Components

2012 ◽  
Vol 488-489 ◽  
pp. 269-273 ◽  
Author(s):  
G.S. Dangayach ◽  
Deepak Kumar
Keyword(s):  
Injection Molding ◽  
Injection Pressure ◽  
Processing Parameters ◽  
Process Conditions ◽  
Melt Temperature ◽  
Defect Rate ◽  
Packing Pressure ◽  
Optimal Injection ◽  
Packing Time ◽  
Plastic Injection

In the present era, competition gets tougher; there is more pressure on manufacturing sectors to improve quality and customer satisfaction while decreasing cost and increasing productivity. These can be achieved by using modern quality management systems and process improvement techniques to reduce the process variability and driven waste within manufacturing process using effective application of statistical tools. Taguchi technique is well known technique to solve industrial problems. This technique is fast and can pinpoint the chief causes and variations. Plastic injection molding is suitable for mass production articles since complex geometries can be obtained in a single production step. The difficulty in setting optimal process conditions may cause defects in parts, such as shrinkage and warpage. In this paper, optimal injection molding conditions for minimum shrinkage were determined by the Taguchi design of experiment (DOE) approach. Polypropylene (PP) was injected in circular shaped specimens under various processing parameters: melt temperature, injection pressure, packing pressure and packing time. S/N ratios were utilized for determining the optimal set of parameters. According to the results, 2400 C of melt temperature, 75 MPa of injection pressure, 50 MPa of packing pressure and 15 sec. of packing time gave minimum shrinkage of 0.951% for PP. Statically the most significant parameter was melt temperature for the PP. Injection pressure had the least effect on the shrinkage. The defect rate was reduced from 14% to 3%.

Effects of Process Parameters on Surface Gloss in Rapid Heat Cycle Molding Process

2012 ◽  
Vol 497 ◽  
pp. 132-136
Author(s):  
Ji Quan Li ◽  
Chuan Chen ◽  
Shao Fei Jiang ◽  
Guo Zhong Chai ◽  
Zhi Biao Lian
Keyword(s):  
Process Parameters ◽  
Heating Temperature ◽  
Injection Pressure ◽  
Injection Rate ◽  
Molding Process ◽  
Melt Temperature ◽  
Heat Cycle ◽  
Packing Pressure ◽  
Product Surface ◽  
Surface Gloss

process parameters; surface gloss; Rapid Heat Cycle Molding Abstract: Rapid Heat Cycle Molding is a novel injection molding, which may improve product surface quality effectively. In this paper, one-factor experimental design and Taguchi method were used and the influence of different process parameters (mold heating temperature, melt temperature, injection rate, injection pressure, and packing pressure) on surface gloss of injection product was studied. The results showed that temperature is the significant factor to the surface gloss. Mold heating temperature is principal factor in mold process parameters, while the melt temperature is the secondary factor and injection pressure is the least. The surface gloss increases with increasing mold heating temperature, melt temperature, injection rate through whole processing, while it increases to top then decreases with increasing injecting and packing pressure

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.

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.

Study on Influencing Factors of High-Temperature Rapid Molding Product on the Rehabilitation of Mold Cavity

2011 ◽  
Vol 383-390 ◽  
pp. 6337-6342
Author(s):  
Ling Sun ◽  
Dong Lei Liu
Keyword(s):  
High Temperature ◽  
Injection Pressure ◽  
Mold Temperature ◽  
Mold Cavity ◽  
Cavity Surface ◽  
Reproduction Rate ◽  
Molding Process ◽  
Melt Temperature ◽  
Heat Distortion Temperature ◽  
Packing Pressure

Impact of product on the replication performance of mold cavity was tested and studied in the high-temperature rapid molding process based on high-fitness mold for in-vehicle Bluetooth module compartment cover. The results indicated that the main difference between high-temperature rapid molding and common molding is that when the mold temperature rises to around the plastic heat distortion temperature, the product’s reproduction rate of the mold cavity surface is improved significantly. In the area lower or higher than the plastic heat distortion temperature, the changes on mold temperature hardly influence the reproduction rate of product and the impacts of other parameters are similar to those of common molding; the impacts of major molding parameters on the product mass from large to small are “packing pressure- dwell time- injection time- mold temperature- injection pressure- melt temperature”.

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