scholarly journals Taguchi Optimization of Roundness and Concentricity of a Plastic Injection Molded Barrel of a Telecentric Lens

Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3419
Author(s):  
Chao-Ming Lin ◽  
Yun-Ju Chen

Plastic is an attractive material for the fabrication of tubular optical instruments due to its light weight, high strength, and ease of processing. However, for plastic components fabricated using the injection molding technique, roundness and concentricity remain an important concern. For example, in the case of a telecentric lens, concentricity errors of the lens barrel result in optical aberrations due to the deviation of the light path, while roundness errors cause radial stress due to the mismatch of the lens geometry during assembly. Accordingly, the present study applies the Taguchi design methodology to determine the optimal injection molding parameters which simultaneously minimize both the overall roundness and the overall concentricity of the optical barrel. The results show that the geometrical errors of the optical barrel are determined mainly by the melt temperature, the packing pressure, and the cooling time. The results also show that the optimal processing parameters reduce the average volume shrinkage rate (from 4.409% to 3.465%) and the average deformations from (0.592 mm to 0.469 mm) of the optical barrel, and the corresponding standard deviation values are reduced from 1.528% to 1.297% and from 0.263 mm to 0.211 mm, respectively. In addition, the overall roundness and overall concentricity of the barrel in the four planes are positively correlated.

2012 ◽  
Vol 488-489 ◽  
pp. 269-273 ◽  
Author(s):  
G.S. Dangayach ◽  
Deepak Kumar

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%.


2018 ◽  
Vol 62 (3) ◽  
pp. 241-246 ◽  
Author(s):  
Dániel Török ◽  
József Gábor Kovács

In all fields of industry it is important to produce parts with good quality. Injection molded parts usually have to meet strict requirements technically and aesthetically. The aim of the measurements presented in our paper is to investigate the aesthetic appearance, such as surface color homogeneity, of injection molded parts. It depends on several factors, the raw material, the colorants, the injection molding machine and the processing parameters. In this project we investigated the effects of the injection molding machine on surface color homogeneity. We focused on injection molding screw tips and investigated five screw tips with different geometries. We produced flat specimens colored with a masterbatch and investigated color homogeneity. To evaluate the color homogeneity of the specimens, we used digital image analysis software developed by us. After that we measured the plastication rate and the melt temperature of the polymer melt because mixing depends on these factors. Our results showed that the screw tips (dynamic mixers) can improve surface color homogeneity but they cause an increase in melt temperature and a decrease in the plastication rate.


2019 ◽  
Vol 18 (01) ◽  
pp. 85-102 ◽  
Author(s):  
Sagar Kumar ◽  
Amit Kumar Singh

This paper presents a systematic methodology to determine optimal injection molding conditions for minimum warpage and shrinkage in a thin wall relay part using modified particle swarm optimization algorithm (MPSO). Polybutylene terephthalate (PBT) and polyethylene terephthalate (PET) were injected in a thin wall relay component for different processing parameters: melt temperature, packing pressure and packing time. Further, Taguchi’s L9 (3[Formula: see text] orthogonal array is used for conducting simulation analysis to consider the interaction effects of the above parameters. A predictive mathematical model for shrinkage and warpage is developed in terms of the above process parameters using regression analysis. ANOVA analysis is performed to establish statistical significance within the injection molding parameters. The analytical model is further optimized using a newly developed MPSO algorithm and the process parameters values are predicted for minimizing shrinkage and warpage. The predicted values of shrinkage and warpage using MPSO algorithm are improved by approximately 30% as compared to the initial simulation values and comparable to previous literature results.


2013 ◽  
Vol 561 ◽  
pp. 239-243 ◽  
Author(s):  
Yong Nie ◽  
Hui Min Zhang ◽  
Jia Teng Niu

This article is using Moldflow analysis and orthogonal experimental method during the whole experiment. The injection molding process of motor cover is simulated under various technological conditions.After forming the maximum amount of warpage of plastic parts for evaluation.According to the range analysis of the comprehensive goal, the extent of the overall influence to the processing parameters, such as gate location, melt temperature, mold temperature and holding pressure is clarified.Through analyzing the diagrams of influential factors resulted from the simulation result,the optimized process parameter scheme is obtained and further verified by simulation.


2014 ◽  
Vol 1052 ◽  
pp. 495-502
Author(s):  
Fung Huei Yeh ◽  
Ching Lun Li ◽  
Bing Ming Chen

The paper studies the optimal parameters of injection molding to avoid the deformation, warping, short shot, and surface defects for the plastic components of Braille display cell. At first the Pro/Engineer parametric software is applied for the entity design and rendering. Then the Mold-Flow software is used for mold flow analysis on the influence of each injection parameters. The results show mold temperature, melt temperature, injection pressure, and filling time are the most influential factors on reducing component deformation. Besides, the L9 orthogonal array of Taguchi method is applied to find out the optimal parameters of injection molding. The deformation, short shot and surface defects of the plastic components in Braille display cell are reduced.


2013 ◽  
Vol 347-350 ◽  
pp. 1163-1167
Author(s):  
Ling Bai ◽  
Hai Ying Zhang ◽  
Wen Liu

Moldflow software was used to obtain the best gate location and count. Influence of injection molding processing parameters on sink marks of injection-piece was studied based on orthogonal test. The effects of different process parameters were analyzed and better process parameters were obtained. Results of research show that decreasing melt temperature, mold temperature, the increasing injection time and packing pressure can effectively reduce the sink marks index.


2011 ◽  
Vol 179-180 ◽  
pp. 1193-1198 ◽  
Author(s):  
Tang Qing Kuang

Water assisted injection molding is a pretty novel way to fabricate hollow or more complicated parts. Its molding window and process control are more critical and difficult since additional processing parameters are involved. A simulation model for the filling stage of a pipe cavity during short-shot water assisted injection molding was proposed. The finite element/finite difference/control volume methods were adopted for the numerical simulation. A numerical study, based on the single factor method, was conducted to characterize the effect of different processing parameters on the short shot water-assisted injection-molding of thermoplastic composites, including short-shot size, melt temperature, mold temperature, water temperature and water pressure. For the factors selected in the simulations, short-shot size was found to be the principal parameters affecting the water penetration length while melt temperature, mold temperature, water temperature, water pressure were found to have little effect on the penetration of water.


2010 ◽  
Vol 37-38 ◽  
pp. 570-575 ◽  
Author(s):  
Bao Shou Sun ◽  
Zhe Chen ◽  
Bo Qin Gu ◽  
Xiao Diao Huang

To optimize injection molding warpage, this paper applies the uniform design of experiment method to search for the optimal injection molding processing parameters. The warpage. simulation analysis is accomplished by emplying Moldflow software. The melt temperature, mold temperature, injection time and packing pressure are regarded as processing parameters, and processing parameters are optimized through establishing a regression equation, and the optimization result and influence factors are analyzed. The results show that uniform design of experiment can reduce number of experiments used effectively and the quality of the product is greatly improved by the optimization method.


2014 ◽  
Vol 541-542 ◽  
pp. 359-362 ◽  
Author(s):  
Gyung Ju Kang

This Paper Presents the Optimization of Injection Molding Conditions to Minimize the Warpage and Volumetric Shrinkage Using Design of Experiments and Taguchi Optimization Method. Considering the Process Parameters such as Injection Time, Packing Pressure, Packing Pressure Time, and Cooling Time, a Series of Mold Analysis are Performed. Orthogonal Arrays of Taguchi, the Signal-to-Noise(S/N) and Analysis of Variance (ANOVA) are Utilized to Determine the Optimization Parameter Levels and to Find out Principal Processing Parameters on Warpage and Volumetric Shrinkage. from the Results it is Clear that Warpage and Volumetric Shrinkage are Reduced. also, the Dominant Parameters were Cooling Time and Packing Time for Warpage, on the other Hand, the most Important Factor for Shrinkage was Injection Time. from this, it can be Concluded that Taguchi Method is very Suitable to Solve the Warpage and Volumetric Shrinkage Problems in Injection Molding Parts.


2012 ◽  
Vol 217-219 ◽  
pp. 2065-2069 ◽  
Author(s):  
Ji Ping Chen ◽  
Zhi Ping Ding

Based on experimental method of factorial design, numerical simulation of injection molding using Moldflow software has been done. The effects of the gate number-distribution, melt temperature, packing pressure, packing time, injection time, etc. on volumetric shrinkage and the two-way interactions among factors in injection molding of plastic part have been researched. The regression model for volumetric shrinkage of plastic part has been obtained through multiple linear regression analysis of the experimental data. The optimization model has been established to optimize processing parameters setting leading factors which effect volumetric shrinkage as design variables and regression model of volumetric shrinkage as objective function. The volumetric shrinkage value of plastic part is less than the minimum volumetric shrinkage value of the main experiment, which indicates that the method has a good practical value in engineering.


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