Experimental and Numerical Modeling the Effect of the Residual Stress in the Case of the Molding of a Plastic Part

2021 ◽  
Vol 58 (2) ◽  
pp. 60-70
Author(s):  
Sana Ben Khlifa ◽  
Ltaief Lammari ◽  
Hassen Kharroubi
Keyword(s):  
Mold Temperature ◽  
Thermomechanical Properties ◽  
Food Storage ◽  
Second Step ◽  
Practical Case ◽  
Plastic Part ◽  
Injection Process ◽  
Industrial Performance ◽  
Minimum Residence Time ◽  
Time And Energy

There is always time and energy optimization and reduction of faults the aim of research and in this context our article presents a study of a practical case of the deformation of a plastic part placed in a refrigerator for food storage, and that the use increases in number of these types of metals, are found in several sectors, and because of their industrial performance, a minimum residence time of the part in the mold is sought in order to reduce the cycle time of the process at the same time that the injection process is quite complex and requires a certain number of recurring questions to succeed. In the desired model. These are linked to residual stresses and deformations, pressure, mold temperature, filling threshold, shape of the part, but also to other mechanical and optical properties. Several investigations have been carried out and according to the authors the causes of these failures vary according to the manufacturing technique used. In this article, we try to find the origin of a deformation detected on a part at the end of the mold. Our work consists first of all in presenting, according to different studies, the thermomechanical properties of the material injected at different stages of the injection process. In a second step, compare the theoretical and analytical results. At the end of our study, we propose an optimization of the parameters necessary for the success of the molding and of the geometry of the assembly (mold and part).

scholarly journals Impact of Alternative Stabilization Strategies for the Production of PAN-Based Carbon Fibers with High Performance

Fibers ◽  
2020 ◽  
Vol 8 (6) ◽  
pp. 33 ◽  
Author(s):  
Spyridon Soulis ◽  
George Konstantopoulos ◽  
Elias P. Koumoulos ◽  
Costas A. Charitidis
Keyword(s):  
Mechanical Properties ◽  
Carbon Fibers ◽  
Thermal Processing ◽  
High Performance ◽  
Relevant Literature ◽  
Thermomechanical Properties ◽  
Composition Effect ◽  
Ladder Polymer ◽  
Fiber Manufacturing ◽  
Time And Energy

The aim of this work is to review a possible correlation of composition, thermal processing, and recent alternative stabilization technologies to the mechanical properties. The chemical microstructure of polyacrylonitrile (PAN) is discussed in detail to understand the influence in thermomechanical properties during stabilization by observing transformation from thermoplastic to ladder polymer. In addition, relevant literature data are used to understand the comonomer composition effect on mechanical properties. Technologies of direct fiber heating by irradiation have been recently involved and hold promise to enhance performance, reduce processing time and energy consumption. Carbon fiber manufacturing can provide benefits by using higher comonomer ratios, similar to textile grade or melt-spun PAN, in order to cut costs derived from an acrylonitrile precursor, without suffering in regard to mechanical properties. Energy intensive processes of stabilization and carbonization remain a challenging field of research in order to reduce both environmental impact and cost of the wide commercialization of carbon fibers (CFs) to enable their broad application.

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.

Technology and Mechanical Properties of Samples Obtained by Injection From Arboform L, V3 Nature Reinforced With Aramid Fibers

2014 ◽  
Author(s):  
Dumitru Nedelcu ◽  
Constantin Carausu ◽  
Ciprian Ciofu
Keyword(s):  
Mechanical Properties ◽  
Injection Pressure ◽  
Mold Temperature ◽  
Xrd Analysis ◽  
Sem Analysis ◽  
Aramid Fibers ◽  
Injection Process ◽  
Plastic Materials ◽  
Important Trend ◽  
Manufacturing Technologies

The use of recyclable materials has become an important trend in all activity areas, reason why material based on liquid wood called Arbofill, Arboblend and Arboform will replace plastic in different applications in the near future. The new materials are the main substances that have an important effect on company development and require some simple or complex manufacturing technologies. In case of Arboform L, V3 Nature the injected parts can be obtained using the same injection machines used for the injection of plastic materials. The technological injection parameters, such as: injection pressure, injection time, cooling time, mold temperature, etc., are different. The experimental research focused on tensile strength, friction coefficients, SEM analysis, XRD analysis and EDAX analysis. Considering all of these experimental results the Arboform L, V3 Nature reinforced with aramid fibers could replace the following plastic materials PA12, PVDF, ECTFE, PA66, PA12, PC, PP, PP GF 30, etc. Also taking into account all the results obtained, this material can replace plastic materials in many applications, such as: ornaments, including for cars, connectors, switches etc., electrical industry, different mobile accessories, computers, televisions, mobile phone cases, etc. The material obtained from Arboform reinforced with aramid fibers (5% percent) improved the injection process despite of easy decreasing of mechanical properties.

Effect of Injection Parameters on Warpage and Sink Index of High-Gloss Injection Parts

2014 ◽  
Vol 621 ◽  
pp. 88-93
Author(s):  
Yi Ning Song ◽  
Xi Ping Li ◽  
Ning Ning Gong
Keyword(s):  
Injection Molding ◽  
Mold Temperature ◽  
Rapid Cool ◽  
Orthogonal Experimental Design ◽  
Melt Temperature ◽  
Injection Process ◽  
Element Simulation ◽  
Injection Technology ◽  
Plastic Parts ◽  
Heat Injection

High-gloss injection molding technology is also called rapid cool and heat injection technology which can be used to eliminate weldmark on the surface of plastic parts, and improve the surface glossiness. However, the warpage, sink index and volume shrinkage of the parts are considered difficult to solve by using this technology. Reasons that cause the warpage and sink index of the parts were discussed in this paper firstly. Then, by using a LCD panel produced in practical injection process as an example, through orthogonal experimental design and finite element simulation, this paper discusses the effects of the injection molding parameters such as mold temperature, melt temperature etc. on warpage and sink index of the parts. The results are of great significance to help to set practical process parameters and assure the part quality in injection process.

Demolding Moment Calculation for Injected Parts with Internal Trapezoidal Thread

2016 ◽  
Vol 699 ◽  
pp. 104-109
Author(s):  
Simion Haragâş ◽  
Iuliu Negrean ◽  
Dumitru Pop ◽  
Ovidiu Buiga ◽  
Florina Rusu
Keyword(s):  
Significant Influence ◽  
Design Solution ◽  
Mold Design ◽  
Plastic Part ◽  
The Core ◽  
Whole Process ◽  
Injection Process ◽  
Ejector System ◽  
The Right ◽  
Adhesion Effect

At the final step of the injection process (of a plastic product with cavities) when the part is on the point to be ejected the adhesion phenomena occurs between the core and the plastic part. The mold adhesion effect has a significant influence on the mold design ejection system and over the whole process. This paper presents a computation methodology of the demolding moment for two cases of plastic injected parts with internal trapezoidal thread. Knowing the value of this moment offer us the possibility to adopt the right design solution of the ejector system and of the entire mold. As further work the author will try to validate this method through a set of practical experiments.

scholarly journals Welding lines formation in holes obtained by low pressure injection molding of ceramic parts

Cerâmica ◽  
2018 ◽  
Vol 64 (369) ◽  
pp. 97-103 ◽  
Author(s):  
C. A. Costa ◽  
A. F. Michels ◽  
M. E. Kipper
Keyword(s):  
Injection Molding ◽  
Injection Pressure ◽  
Mold Temperature ◽  
Low Pressure ◽  
Process Conditions ◽  
Injection Mold ◽  
Extraction Temperature ◽  
Post Injection ◽  
Injection Process ◽  
Pressure Injection

Abstract This work presents a study to evaluate the process of producing internal holes in ceramic disks produced by low pressure injection molding (LPIM) process. Two process conditions defined as pre-injection and post-injection were used to test the proposition. In the first one the pin cores that produce the holes were positioned in the cavity before the injection of the feedstock; and in the second one, the pin cores were positioned in the cavity, just after the feeding phase of the injection mold. An experimental injection mold designed and manufactured to test both processes was developed to produce ceramic disk with Ø 50 x 2 mm with four holes of Ø 5 mm, equally and radially distributed through the disk. The feedstock was composed of 86 wt% alumina (Al2O3) and 14 wt% organic vehicle based on paraffin wax. Heating and cooling systems controlled by a data acquisition system were included in the mold. The results showed that there were no welding lines with the post-injection process, proving to be an option for creating holes in the ceramic parts produced by LPIM. It was observed that best results were obtained at 58 °C mold temperature. The pins extraction temperature was about 45 °C, and the injection pressure was 170 kPa.

Effect of Process Parameters on Warpage of Printer Board with Metal-Insert

2014 ◽  
Vol 1004-1005 ◽  
pp. 1141-1146
Author(s):  
Cheng Juan Liu ◽  
Xian Kun Huang ◽  
Qiu Ping Wu ◽  
Hai Qin He ◽  
Yan Ping Li
Keyword(s):  
Process Parameters ◽  
Mold Temperature ◽  
Melt Temperature ◽  
Influence Of Process Parameters ◽  
Forming Quality ◽  
Metal Insert ◽  
Injection Process ◽  
Development Cycle ◽  
Packing Time

In order to study the influence of process parameters on forming quality of printer board with metal-insert,shorten the development cycle,reduce the enterprise cost,the warp trend and reasons of injection process parameters,including packing time,hold pressure,mold temperature,melt temperature,on the warpage of the part were analyzed by means of software moldflow. The results show that warpage amounts decreases with packing time and hold pressure increasing,larger packing time and longer hold pressure is advantageous to the injection parts molding;And warpage amounts increases with mold temperature and melt temperature increasing,the lower mold temperature and melt temperature is advantageous to the injection parts molding;Among the four parameters,the melt temperature had the greatest influence,followed by the mold temperature and the hold pressure,packing time had the minimal influence on the warpage.

Coupled Simulation of Plastic Part and Mold Temperatures in the Filling Process of Rapid Heat Cycle Injection Molding

2010 ◽  
Vol 97-101 ◽  
pp. 3179-3182 ◽  
Author(s):  
Ji Tao Liu ◽  
Guo Qun Zhao ◽  
Yan Jin Guan ◽  
Gui Long Wang
Keyword(s):  
Injection Molding ◽  
Simulation Method ◽  
Mold Temperature ◽  
Heating Process ◽  
Filling Process ◽  
Coupled Simulation ◽  
Plastic Part ◽  
Molding Process ◽  
Heat Cycle ◽  
Flow Equations

A fully transient method for the simulation of the coupled plastic part and mold temperature in the filling stage of Rapid Heat Cycle Molding process was presented. Unlike the constant temperature boundary conditions in conventional injection molding simulation methods, the mold temperature was assumed to be variable in the filling process. The mold temperature in the heating process was first simulated. In the filling process, the flow equations were solved only on the cavity domain, while the energy equations were solved in a coupled manner for the cavity and mold domain at the matrix level. The temperature evolution in a two-dimensional filling process with heated mold was simulated. Numerical results showed that the proposed coupled simulation method provides reliable temperature estimations in mold filling process.

Molding Analysis of Multi-Cavity Aspheric Lens and Mold Designing

2009 ◽  
Vol 83-86 ◽  
pp. 77-87
Author(s):  
Jui Cheng Lin ◽  
King Sun Lee
Keyword(s):  
Residual Stress ◽  
Flow Analysis ◽  
Mold Temperature ◽  
Mold Design ◽  
Geometric Errors ◽  
Cooling Systems ◽  
Optical Lens ◽  
Injection Process ◽  
Mold Flow ◽  
Mobile Phone Camera

The key of qualities of optical lens created by injection molding are geometric errors and distribution of residual stress. This study analyses a mobile phone camera lens with aspheric optical lens created by one mold and 16 cavities. Mold flow analysis was used to simulate geometric shapes of different gates and design cooling systems to control mold temperatures. Mold temperature was controlled during the actual injection process and simulation results were used as the basis for mold design. The effects of cold-wall-mold on lens residual stress are discussed. The experiment result showed that higher mold temperatures are helpful to reduce residual stress. An aspheric mould measurement system was used to measure both the mold and the product. The results showed that the replicating capacity is satisfactory with a molding error of 3.604μm.

Optimization of Process Parameters for Injection Molding Based on Taguchi Technique

2012 ◽  
Vol 538-541 ◽  
pp. 1170-1174
Author(s):  
Shi Jun Fu
Keyword(s):  
Injection Molding ◽  
Process Parameters ◽  
Orthogonal Design ◽  
Mold Temperature ◽  
Optimum Process ◽  
Process Conditions ◽  
Injection Time ◽  
Melt Temperature ◽  
Injection Process ◽  
Packing Pressure

In this paper, Taguchi and CAE technique are combined to study the influence of process conditions on the warpage of injection molding parts through twice orthogonal design experiments, and the injection process parameters are optimized according to the warpage. For the parameters selected, melt temperature and packing pressure have effects on the warpage of injection molding parts are highly significant, injection time is significant, other parameters have little effects. Within the range of experiments, the warpage decreased with the rise of the melt temperature and packing pressure. At last, the optimum process parameters of injection are that the mold temperature is 60°C, packing time is 10s, melt temperature is240°C, packing pressure is 115MPa and injection time is 0.4s.

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