Influence of process parameters and post-molding condition on shrinkage and warpage of injection-molded plastic parts with complex geometry

Guerra, Nayrim Brizuela; Reis, Tiago Marcelo; Scopel, Tiago Fernando; Lima, M. V. D. de O.; Figueroa, Carlos A.; Michels, Alexandre F.

doi:10.1007/s00170-023-11782-7

Cited by 6 publications

(3 citation statements)

References 40 publications

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“…Generally, the production costs associated with utilizing the WCC or CCC in molds or dies, employing techniques such as direct metal laser sintering, atom diffusion additive manufacturing, selective laser sintering, diffusion bonding, direct metal deposition, or electron beam melting, can be prohibitively high. It is worth noting that WCC-equipped molds or dies find applications in rotational molding [ 32 ], centrifugal molding [ 33 ], powder injection molding [ 34 ], plastic injection molding [ 35 ], and blow molding [ 36 ]. A specific observation is that molds or dies with the WCC, produced through selective laser melting [ 37 ], may encounter issues such as cooling water leakage at connection points.…”

Section: Resultsmentioning

confidence: 99%

Development of a Silicone Rubber Mold with an Innovative Waterfall Cooling Channel

Kuo,

Lin,

et al. 2024

Polymers

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A conformal cooling channel (CCC) follows the mold core or cavity profile to carry out uniform cooling in the cooling stage. However, the significant pressure drop along the cooling channels is a distinct disadvantage of the CCC. In this study, an innovative waterfall cooling channel (WCC) was proposed and implemented. The WCC cools the injected products via surface contact, replacing the conventional line contact to cool the injected products. The WCC was optimized using numerical simulation software. Silicone rubber molds with two kinds of cooling channels were designed and implemented. The cooling time of the molded part was evaluated using a low-pressure wax injection molding machine. The experimental results of the cooling time of the molded part were compared with the simulation results from numerical simulation software. The results showed that the optimal mesh element count was about 1,550,000 with a mesh size of 1 mm. The simulation software predicted the filling time of the water cup injection-molded product to be approximately 2.008 s. The cooling efficiency for a silicone rubber mold with a WCC is better than that of the silicone rubber mold with a CCC since the core and cavity cooling efficiency is close to 50%. The pressure drop of the WCC is smaller than that of the CCC, which reduces the pressure drop by about 56%. Taking a water cup with a mouth diameter of 70 mm, a height of 60 mm, and a thickness of 2 mm as an example, the experimental results confirmed that the use of the WCC can save the cooling time of the product by about 265 s compared with the CCC. This shows how a WCC can increase cooling efficiency by approximately 17.47%.

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Section: Resultsmentioning

confidence: 99%

Development of a Silicone Rubber Mold with an Innovative Waterfall Cooling Channel

Kuo,

Lin,

et al. 2024

Polymers

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“…These six process variables are widely recognized as representative factors in injection-molding processes. They are commonly applied as process conditions in actual injection-molding analyses or experiments and are considered key process variables in various studies for optimizing injection-molding processes [3,4,6,8,9,[11][12][13][15][16][17][18]. The melt temperature and mold temperature ranges for the injection-molding experiments were set from 200 • C to 240 • C at three levels, as shown in Table 4, based on the recommended conditions provided by the resin manufacturer (LG Chem, Seoul, Republic of Korea) and using material data from Autodesk Moldflow Insight 2023 (45.1.117), an injection-molding analysis software.…”

Section: Experimental Conditionsmentioning

confidence: 99%

“…Given the characteristics of this process, variables such as melt temperature, mold temperature, and injection speed are critical factors in determining the quality of molded products. Therefore, optimizing these factors is a critical process for improving product quality and productivity in the injection-molding process [3][4][5][6].…”

Section: Introductionmentioning

confidence: 99%

A Study on the Architecture of Artificial Neural Network Considering Injection-Molding Process Steps

Lee,

Kim,

Kim

2023

Polymers

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In this study, an artificial neural network (ANN) was established to predict product properties (mass, diameter, height) using six process conditions of the injection-molding process (melt temperature, mold temperature, injection speed, packing pressure, packing time, and cooling time) as input parameters. The injection-molding process consists of continuous sequential stages, including the injection stage, packing stage, and cooling stage. However, the related research tends to have an insufficient incorporation of structural characteristics based on these basic process stages. Therefore, in order to incorporate these process stages and characteristics into the ANN, a process-based multi-task learning technique was applied to the connection between the input parameters and the front-end of the hidden layer. This resulted in the construction of two network structures, and their performance was evaluated by comparing them with the typical network structure. The results showed that a multi-task learning architecture that incorporated process-level specific structures in the connections between the input parameters and the front end of the hidden layer yielded relatively better root mean square errors (RMSEs) values than a conventional neural network architecture, by as much as two orders of magnitude. Based on these results, this study has provided guidance for the construction of artificial neural networks for injection-molding processes that incorporates process-stage specific features and structures in the architecture.

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Cooling efficiency enhancement using a rapid tool with a surface-cooled waterfall cooling channel

Kuo,

Lin,

et al. 2024

Int J Adv Manuf Technol

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Influence of process parameters and post-molding condition on shrinkage and warpage of injection-molded plastic parts with complex geometry

Cited by 6 publications

References 40 publications

Development of a Silicone Rubber Mold with an Innovative Waterfall Cooling Channel

Development of a Silicone Rubber Mold with an Innovative Waterfall Cooling Channel

A Study on the Architecture of Artificial Neural Network Considering Injection-Molding Process Steps

Cooling efficiency enhancement using a rapid tool with a surface-cooled waterfall cooling channel

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