scholarly journals Integrated Optimum Layout of Conformal Cooling Channels and Optimal Injection Molding Process Parameters for Optical Lenses

2019 ◽  
Vol 9 (20) ◽  
pp. 4341 ◽  
Author(s):  
Chen-Yuan Chung
Keyword(s):  
Additive Manufacturing ◽  
Injection Molding ◽  
Process Parameters ◽  
Large Diameter ◽  
Melt Temperature ◽  
Conformal Cooling ◽  
Cooling Channels ◽  
Highly Efficient ◽  
Conformal Cooling Channels ◽  
Filling Time

Plastic lenses are light and can be mass-produced. Large-diameter aspheric plastic lenses play a substantial role in the optical industry. Injection molding is a popular technology for plastic optical manufacturing because it can achieve a high production rate. Highly efficient cooling channels are required for obtaining a uniform temperature distribution in mold cavities. With the recent advent of laser additive manufacturing, highly efficient three-dimensional spiral channels can be realized for conformal cooling technique. However, the design of conformal cooling channels is very complex and requires optimization analyses. In this study, finite element analysis is combined with a gradient-based algorithm and robust genetic algorithm to determine the optimum layout of cooling channels. According to the simulation results, the use of conformal cooling channels can reduce the surface temperature difference of the melt, ejection time, and warpage. Moreover, the optimal process parameters (such as melt temperature, mold temperature, filling time, and packing time) obtained from the design of experiments improved the fringe pattern and eliminated the local variation of birefringence. Thus, this study indicates how the optical properties of plastic lenses can be improved. The major contribution of present proposed methods can be applied to a mold core containing the conformal cooling channels by metal additive manufacturing.

scholarly journals Dynamic conformal cooling improves injection molding

2021 ◽  
Vol 114 (1-2) ◽  
pp. 107-116
Author(s):  
Andreas Kirchheim ◽  
Yogeshkumar Katrodiya ◽  
Livia Zumofen ◽  
Frank Ehrig ◽  
Curdin Wick
Keyword(s):  
Additive Manufacturing ◽  
Injection Molding ◽  
Injection Molding Process ◽  
Layer By Layer ◽  
Mold Surface ◽  
Molding Process ◽  
Conformal Cooling ◽  
Cooling Channels ◽  
Heating And Cooling ◽  
Conformal Cooling Channels

AbstractTo achieve a certain visual quality or acceptable surface appearance in injection-molded components, a higher mold surface temperature is needed. In order to achieve this, injection molds can be dynamically tempered by integrating an active heating and cooling process inside the mold halves. This heating and cooling of the mold halves becomes more efficient when the temperature change occurs closer to the mold surface. Complex channels that carry cold or hot liquids can be manufactured close to the mold surface by using the layer by layer principle of additive manufacturing. Laser powder bed fusion (L-PBF), as an additive manufacturing process, has special advantages; in particular, so-called hybrid tools can be manufactured. For example, complex tool inserts with conformal cooling channels can be additively built on simple, machined baseplates. This paper outlines the thermal simulation carried out to optimize the injection molding process by use of dynamic conformal cooling. Based on the results of this simulation, a mold with conformal cooling channels was designed and additively manufactured in maraging steel (1.2709) and then experimentally tested.

The Effect of Injection Molding Process Parameters on the Buckling Properties of PBT/Short Glass Fiber Composites

2011 ◽  
Vol 284-286 ◽  
pp. 550-556 ◽  
Author(s):  
Ming Hsiung Ho ◽  
Pin Ning Wang ◽  
Chin Ping Fung
Keyword(s):  
Injection Molding ◽  
Glass Fiber ◽  
Process Parameters ◽  
Injection Molding Process ◽  
Skin Area ◽  
Molding Process ◽  
Melt Temperature ◽  
Short Glass Fiber ◽  
Filling Time ◽  
Short Glass

This study investigates the effect of various injection molding process parameters and fiber amount on buckling properties of Polybutylene Terephthalate (PBT)/short glass fiber composite. The buckling specimens were prepared under injection molding process. These forming parameters about filling time, melt temperature and mold temperature that govern injection molding process are discussed. The buckling properties of neat PBT, 15 wt%, and 30 wt% are obtained using two ends fixed fixture and computerized closed-loop server-hydraulic material testing system. The fracture surfaces are observed by scanning electron microscopy (SEM). The global buckling forces are raised when increased the fiber weight percentage of PBT. Also, the fracture mechanisms in PBT and short glass fiber matrix are fiber pullout in skin area and fiber broken at core area. It is found that the addition of short glass fiber can significantly strengthen neat PBT.

scholarly journals Optimization for Reducing Warpage in Injection Moulding

2018 ◽  
Vol 2 (5) ◽  
pp. 25-31
Author(s):  
Keyword(s):  
Injection Molding ◽  
Process Parameters ◽  
Large Scale ◽  
Simulation Software ◽  
Optimum Process ◽  
Injection Molding Process ◽  
Molding Process ◽  
Melt Temperature ◽  
Product Cycles ◽  
Filling Time

Injection molding is a standout technique utilized for the fabrication of thermoplastic parts in industry due to short product cycles, high part quality, good mechanical properties and low cost for large scale manufacturing. In molded case circuit breaker (MCCB), Trip-bar is one of the most critical components as safety is concerned which is manufactured by injection molding process. To get it manufactured within the specified warpage and deformities free, number of mold flow simulations is carried out using Creo-MoldFlow. The outcomes of the simulation are used to design the mold tool and the process parameters for injection molding are optimized. For process parameter optimization Taguchi based experimental design and ANOVA analysis is done. The objective of this work is to optimize the injection molding process parameters such as filling time, melt temperature and mold temperature to minimize the warpage. CAE flow simulation software is used to simulate the process and Grey Relational Analysis (GRA) is used to find out optimum process parameters.

scholarly journals Enhancing the Structural Strength for Injection Molding Tooling With Conformal Cooling Channels Using ANSYS Software

2021 ◽  
Author(s):  
Chil-Chyuan Kuo ◽  
Zheng-Yan You
Keyword(s):  
Injection Molding ◽  
Production Rate ◽  
Thermal Management ◽  
Structural Strength ◽  
Conformal Cooling Channel ◽  
Conformal Cooling ◽  
Cooling Channels ◽  
Conformal Cooling Channels ◽  
Average Variation ◽  
Different Diameters

Abstract Injection molding of wax patterns faces increasing demands for production rate. Proper thermal management of the injection molding tooling is capable of improving the production rate. Precise temperature control is a key to shorten the cooling time using the conformal cooling channels which are conformal to the molding cavity. However, the service life of the injection molding tooling with cooling channels will reduce significantly because the structural strength will reduce obviously. In this study, the feasibility of applying the increase in the mold thickness to maintain the structural strength of the injection molding tooling with cooling channels was verified through simulation and experiments conducted. It was found that the average variation between the results of simulation and the experiment is about 24.9%. The approximately amount of the increase in the thickness required for different diameters of cooling channels can be determined according to the trend equation of y=1.3429x-2.3429. The results can provide a reference for the conformal cooling channel design.

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