scholarly journals Assessing the Suitability of Freeform Injection Molding for Low Volume Injection Molded Parts: A Design Science Approach

2021 ◽  
Vol 13 (3) ◽  
pp. 1313
Author(s):  
Elham Sharifi ◽  
Atanu Chaudhuri ◽  
Brian Vejrum Waehrens ◽  
Lasse Guldborg Staal ◽  
Saeed Davoudabadi Farahani
Keyword(s):  
Additive Manufacturing ◽  
Injection Molding ◽  
Design Science ◽  
Series Production ◽  
Short Series ◽  
Science Approach ◽  
Molded Parts ◽  
Injection Molded ◽  
Low Volume ◽  
Cross Case Analysis

Low-volume manufacturing remains a challenge, especially for parts that need to be injection-molded. Freeform injection molding (FIM) is a novel method that combines elements from direct additive manufacturing (DAM) and injection molding (IM) to resolve some of the challenges seen in low-volume injection molding. In this study, we use a design science approach to explore the suitability of FIM for the manufacturing of low volume injection-molded parts. We provide an overview of the benefits and limitations of traditional IM and discuss how DAM and indirect additive manufacturing (IAM) methods, such as soft tooling and FIM, can address some of the existing drawbacks of IM for short series production. A set of different parts was identified and assessed using a design science-based approach to demonstrate how to incubate FIM as a solution to address the challenges faced in short series production with IM. This initial process innovation was followed by solution refinement, involving the optimization of the FIM processes. Finally, a “cross-case” analysis was conducted using the framework of context, intervention, mechanism and outcomes to generate insights about the generalizability of the results. It is concluded that FIM combines the short lead-times, low start-up costs and design freedom of DAM with the versatility and scalability of IM to allow manufacturers to bring low volume products to the market faster, more cheaply and with lower risk, and to maintain the relevance of these products through easy customization and adaptations once they have been launched.

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.

Direct Sinter Bonding of Metal Injection-Molded Parts to Solid Substrate Through Use of Deformable Surface Microfeatures

2013 ◽  
Vol 1 (1) ◽  
Author(s):  
Thomas Martens ◽  
M. Laine Mears
Keyword(s):  
Injection Molding ◽  
Solid Substrate ◽  
Metal Injection Molding ◽  
Full Density ◽  
Metal Powders ◽  
Molded Parts ◽  
Primary Obstacle ◽  
Injection Molded ◽  
Sinter Bonding ◽  
Micro Features

In the metal injection molding (MIM) process, fine metal powders are mixed with a binder and injected into molds, similar to plastic injection molding. After molding, the binder is removed from the part, and the compact is sintered to almost full density. Though able to create high-density parts of excellent dimensional control and surface finish, the MIM process is restricted in the size of part that can be produced, due to gravitational deformation during high-temperature sintering and maximum thickness requirements to remove the binding agents in the green state. Larger parts could be made by bonding the green parts to a substrate during sintering; however, a primary obstacle to this approach lies in the sinter shrinkage of the MIM part, which can be up to 20%, meaning that the MIM part shrinks during sintering, while the conventional substrate maintains its dimensions. This behavior would typically inhibit bonding and/or cause cracking and deformation of the MIM part. In this work, we present a structure of micro features molded onto the surface of the MIM part, which bonds, deforms, and allows for shrinkage while bonding to the substrate. The micro features tolerate plastic deformation to permit the shrinkage without causing cracks after the initial bonds are established. In a first series of tests, bond strengths of up to 80% of that of resistance welds have been achieved. This paper describes how the authors developed their proposed method of sinter bonding and how they accomplished effective sinter bonds between MIM parts and solid substrates.

Study of the Structural Characteristics of Mold for Precise Injection Molding

2011 ◽  
Vol 291-294 ◽  
pp. 610-613
Author(s):  
Hong Lin Li ◽  
Zhi Xin Jia
Keyword(s):  
Injection Molding ◽  
Process Parameters ◽  
Structural Characteristics ◽  
Injection Mold ◽  
Industrial Products ◽  
Balance System ◽  
Molded Parts ◽  
Manufacturing Accuracy ◽  
Injection Molded

With the improvement of accuracy requirements for industrial products, the precise injection molding is replacing the traditional injection molding quickly and widely. Many factors influence the quality of injection-molded parts greatly, such as the property of the plastics, mold structure and the manufacturing accuracy, injecting machine and the injecting process parameters. In this paper, the work is emphasized for the influence of mold structure on the quality of injection-molded parts. Eight portions of injection mold are analyzed, including the cavities and cores, the guide components, the runner system, the ejection system, the side-core pulling mechanism, the temperature balance system, the venting system and the supporting parts. The structural characteristics of the above eight portions are presented.

Study on Improving the Life of Stereolithography Injection Mold

2012 ◽  
Vol 468-471 ◽  
pp. 1013-1016 ◽  
Author(s):  
Hua Qing Lai
Keyword(s):  
Injection Molding ◽  
Injection Molding Process ◽  
Injection Mold ◽  
Molding Process ◽  
Molded Parts ◽  
Injection Molded ◽  
Plastic Parts ◽  
Assembly Operations ◽  
Conventional Injection Molding ◽  
Shape And Size

Molding is one of the most versatile and important processes for manufacturing complex plastic parts. It is a method of fabricating plastic parts by utilizing a mold or cavity that has a shape and size similar to the part being produced. Molten polymer is injected into the cavity, resulting in the desired part upon solidification. The injection-molded parts typically have excellent dimensional tolerance and require almost no finishing and assembly operations. But new variations and emerging innovations of conventional injection molding have been continuously developed to offer special features and benefits that cannot be accomplished by the conventional injection molding process. This study aims to improving the life of stereolithography injection mold.

scholarly journals Reducing the Burn Marks on Injection-Molded Parts by External Gas-Assisted Injection Molding

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4087
Author(s):  
Jiquan Li ◽  
Wenyong Liu ◽  
Xinxin Xia ◽  
Hangchao Zhou ◽  
Liting Jing ◽  
...  
Keyword(s):  
Image Processing ◽  
Injection Molding ◽  
Delay Time ◽  
Quantitative Method ◽  
Surface Defect ◽  
Processing Method ◽  
Traditional Methods ◽  
Molded Parts ◽  
Injection Molded ◽  
Conventional Injection Molding

A burn mark is a sort of serious surface defect on injection-molded parts. In some cases, it can be difficult to reduce the burn marks by traditional methods. In this study, external gas-assisted injection molding (EGAIM) was introduced to reduce the burn marks, as EGAIM has been reported to reduce the holding pressure. The parts with different severities of burn marks were produced by EGAIM and conventional injection molding (CIM) with the same molding parameters but different gas parameters. The burn marks were quantified by an image processing method and the quantitative method was introduced to discuss the influence of the gas parameters on burn marks. The results show that the burn marks can be eliminated by EGAIM without changing the structure of the part or the mold, and the severity of the burn marks changed from 4.98% with CIM to 0% with EGAIM. Additionally, the gas delay time is the most important gas parameter affecting the burn marks.

scholarly journals Selecting spare parts suitable for additive manufacturing: a design science approach

2020 ◽  
pp. 1-18
Author(s):  
Atanu Chaudhuri ◽  
Hasse Andreas Gerlich ◽  
Jayanth Jayaram ◽  
Abhijeet Ghadge ◽  
Johan Shack ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Design Science ◽  
Spare Parts ◽  
Science Approach

scholarly journals Peculiarities of Injection Molding Conducting Composites

2018 ◽  
Vol 248 ◽  
pp. 01006
Author(s):  
Yovial Mahyoedin ◽  
Jaafar Sahari ◽  
Andanastuti Mukhtar ◽  
Norhamidi Mohammad ◽  
Iqbal
Keyword(s):  
Composite Material ◽  
Carbon Black ◽  
Injection Molding ◽  
Test Procedure ◽  
Molded Parts ◽  
Twin Screw ◽  
Probe Test ◽  
Injection Molded ◽  
Conducting Composites

The investigations in this study focused on the characteristic of feedstock in an effort to understand the mechanism of injection molded in composite material. A composite, which has 75% wt. filler, consist of graphite (G), carbon black (CB) and polypropylene copolymer (PP). Twin-screw co-rotating extruder used for mixing materials. The conductivity of the molded parts measured using a four-point probe test procedure. The results showed that the injection molding conducting composites, which aggregated into larger clusters, tended to disperse unevenly into the PP, resulting in fewer particle-particle contacts and, consequently, a lower-conductivity composite in some part of the molded.

scholarly journals Surface Homogeneity of Injection Molded Parts

2018 ◽  
Vol 62 (4) ◽  
pp. 284-291 ◽  
Author(s):  
László Zsíros ◽  
József Gábor Kovács
Keyword(s):  
Injection Molding ◽  
Evaluation Method ◽  
Solid Phase ◽  
Color Space ◽  
Processing Parameters ◽  
Injection Molding Process ◽  
Mold Surface ◽  
Molding Process ◽  
Molded Parts ◽  
Injection Molded

In this paper we are presenting a novel method for color inhomogeneity evaluation. We proved that this method has a higher than 95 % linear correlation coefficient if results are correlated with human visual evaluations.We applied this evaluation method to analyze the homogenization in the injection molding process, therefore we measured the homogenization properties of various solid phase masterbatches on injection molded parts. We tested the effects of the processing parameters of injection molding and analyzed various dynamic and static mixers as well. We have also measured the influence of the mold surface texture on the sensation of inhomogeneities on the part surface.We have carried out our tests on an injection grade ABS material using various masterbatches. The method was based on the digitization of the molded flat specimens. The images of these specimens were evaluated with an own developed formula using the CIELAB color space resulting high correlation with human visual inspections.

The Deformation Analysis and Optimization of the Injection Molded Parts Based on the Moldflow and Minitab Software

2013 ◽  
Vol 753-755 ◽  
pp. 1180-1183 ◽  
Author(s):  
Na Li ◽  
Hong Bin Liu ◽  
Hai Tao Wu
Keyword(s):  
Injection Molding ◽  
Process Parameters ◽  
Optimization Design ◽  
Deformation Analysis ◽  
Molded Parts ◽  
Injection Molded ◽  
The Common ◽  
Plastic Parts ◽  
Cae Technology

The deformation seriously affects the quality of the products, which is one of the common defects of plastic parts in the injection molding. Factorial design and CAE technology was used to study the product's warping rate influence in this paper. The minimum warping rate was obtained through the Minitab software and the optimized process parameters are verified with the Moldflow software. Experimental results show that the optimization design is effective and the warpage of the product is reduced.

Scaling Issues in Miniaturization of Injection Molded Parts

2004 ◽  
Vol 126 (4) ◽  
pp. 733-739 ◽  
Author(s):  
Donggang Yao ◽  
Byung Kim
Keyword(s):  
Injection Molding ◽  
Size Effects ◽  
Second Order ◽  
Viscous Heating ◽  
Scaling Analysis ◽  
Flow Process ◽  
First Order ◽  
Relative Contribution ◽  
Molded Parts ◽  
Injection Molded

Miniaturization of injection molded parts causes changes in the relative contribution of relevant design and process parameters. As a result, scaling-related size effects occur. Size effects can be either of the first order or of the second order. First-order size effects can be predicted using standard modeling, while second order ones cannot. This paper deals with first-order size effects encountered in injection molding miniaturized parts. Through the scaling analysis of the heat transfer and flow process in injection molding, the size effects on the change of molding characteristics including viscous heating, freezing time, capillary force effect, and moldability were identified. Strategies were consequently proposed to alleviate or eliminate the scaling-related molding difficulties in molding ultrathin-wall parts and microparts. Particularly, a scalable filling process was presented, with experimental verification.

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