Sequential injection molding of thermoplastic polymers. Analysis of processing parameters for optimal bonding conditions

2002 ◽  
Vol 42 (11) ◽  
pp. 2172-2181 ◽  
Author(s):  
A. R. Carella ◽  
C. Alonso ◽  
J. C. Merino ◽  
J. M. Pastor
Keyword(s):  
Injection Molding ◽  
Processing Parameters ◽  
Sequential Injection ◽  
Thermoplastic Polymers

Diamond Machinable Sol-Gel Silica Based Hybrid Coatings for High Precision Optical Molds

2010 ◽  
Vol 438 ◽  
pp. 65-72 ◽  
Author(s):  
Andreas Mehner ◽  
Ju An Dong ◽  
Timo Hoja ◽  
Torsten Prenzel ◽  
Yildirim Mutlugünes ◽  
...  
Keyword(s):  
Injection Molding ◽  
High Precision ◽  
Sol Gel ◽  
Processing Parameters ◽  
Hybrid Coatings ◽  
Optical Elements ◽  
Optical Components ◽  
New Approach ◽  
Free Silica ◽  
Gel Processing

The demand for high precision optical elements as micro lens arrays for displays increases continually. Economic mass production of such optical elements is done by replication with high precision optical molds. A new approach for manufacturing such molds was realized by diamond machinable and wear resistant sol-gel coatings. Crack free silica based hybrid coatings from base catalyzed sols from tetraethylorthosilicate (TEOS: Si(OC2H5)4) and methyltriethoxysilane (MTES: Si(CH3)(OC2H5)3) precursors were deposited onto pre-machined steel molds by spin coating process followed by a heat treatment at temperatures up to 800°C. Crack-free multilayer coatings with a total thickness of up to 18 µm were achieved. Micro-machining of these coatings was accomplished by high precision fly cutting with diamond tools. Molds with micro-structured coatings were successfully tested for injection molding of PMMA optical components. The wear resistance of the coatings was successfully tested by injection molding of 1000 PMMA lenses. Hardness and elastic modulus of the coatings were measured by nano indentation. The chemical composition was measured by X-ray photo electron spectroscopy (XPS) as a function of the sol-gel processing parameters.

Analysis on vibration characteristics of screw in filling process of dynamic injection molding machine

2016 ◽  
Vol 36 (8) ◽  
pp. 861-866 ◽  
Author(s):  
Quan Wang ◽  
Zhenghuan Wu
Keyword(s):  
Injection Molding ◽  
Processing Parameters ◽  
Axial Vibration ◽  
Filling Process ◽  
Molding Machine ◽  
Lumped Mass ◽  
Injection Molding Machine ◽  
Injection Speed ◽  
And Performance ◽  
Injection Screw

Abstract This paper presents a study of the characteristics of axial vibration of a screw in the filling process for a novel dynamic injection molding machine. By simplifying a generalized model of the injection screw, physical and mathematic models are established to describe the dynamic response of the axial vibration of a screw using the method of lumped-mass. The damping coefficient of the screw is calculated in the dynamic filling process. The amplitude-frequency characteristics are analyzed by the simulation and experimental test of polypropylene. The results show that the amplitude of a dynamic injection molding machine is not only is related to structure parameters of the screw and performance of the material, such as non-Newtonian index, but also depends on the processing parameters, such as vibration intensity and injection speed.

scholarly journals Effects of Injection Molding Screw Tips on Polymer Mixing

2018 ◽  
Vol 62 (3) ◽  
pp. 241-246 ◽  
Author(s):  
Dániel Török ◽  
József Gábor Kovács
Keyword(s):  
Injection Molding ◽  
Processing Parameters ◽  
Raw Material ◽  
Molding Machine ◽  
Surface Color ◽  
Melt Temperature ◽  
Injection Molding Machine ◽  
Aesthetic Appearance ◽  
Molded Parts ◽  
Injection Molded

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.

Warpage and Shrinkage Analysis and Optimization of Rapid Tooling Molded thin Wall Component Using Modified Particle Swarm Algorithm

2019 ◽  
Vol 18 (01) ◽  
pp. 85-102 ◽  
Author(s):  
Sagar Kumar ◽  
Amit Kumar Singh
Keyword(s):  
Injection Molding ◽  
Process Parameters ◽  
Simulation Analysis ◽  
Statistical Significance ◽  
Particle Swarm ◽  
Processing Parameters ◽  
Particle Swarm Algorithm ◽  
Thin Wall ◽  
Polybutylene Terephthalate ◽  
Melt Temperature

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.

scholarly journals Optimization of processing parameters for minimizing warpage of large thin-walled parts in whole stages of injection molding

2014 ◽  
Vol 32 (11) ◽  
pp. 1535-1543 ◽  
Author(s):  
Tong Wen ◽  
Xia Chen ◽  
Chen Yang ◽  
Lan-tao Liu ◽  
Liang Hao
Keyword(s):  
Injection Molding ◽  
Processing Parameters ◽  
Thin Walled

scholarly journals On the Injection Molding Processing Parameters of HDPE-TiO2 Nanocomposites

Materials ◽  
2017 ◽  
Vol 10 (1) ◽  
pp. 85 ◽  
Author(s):  
Abdel-Hamid Mourad ◽  
Mohammad Mozumder ◽  
Anusha Mairpady ◽  
Hifsa Pervez ◽  
Uma Kannuri
Keyword(s):  
Injection Molding ◽  
Processing Parameters
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