Numerical and experimental investigations of a conformally cooled maraging steel injection molding tool fabricated by direct metal printing

Abstract In order to meet increasing performance demand from high-performance computing (HPC) and edge computing, thermal design power (TDP) of CPU and GPU needs to increase. This creates thermal challenge to corresponding electronic packages with respect to heat dissipation. In order to address this challenge, two-phase immersion cooling is gaining attention as its primary mode of heat of removal is via liquid-to-vapor phase change, which can occur at relatively low and constant temperatures. In this paper, integrated heat spreader (IHS) with boiling enhancement features is proposed. 3D metal printing and metal injection molding (MIM) are the two approaches used to manufacture the new IHS. The resultant IHS with enhancement features are used to build test vehicles (TV) by following standard electronic package assembly process. Experimental results demonstrated that boiling enhanced TVs improved two-phase immersion cooling capability by over 50% as compared to baseline TV without boiling enhanced features.

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Three-dimensional numerical and experimental investigations on polymer rheology in meso-scale injection molding

International Communications in Heat and Mass Transfer ◽

10.1016/j.icheatmasstransfer.2009.08.011 ◽

2010 ◽

Vol 37 (2) ◽

pp. 131-139 ◽

Cited By ~ 32

Author(s):

C.Y. Khor ◽

Z.M. Ariff ◽

F. Che Ani ◽

M. Abdul Mujeebu ◽

M.K. Abdullah ◽

...

Keyword(s):

Injection Molding ◽

Three Dimensional ◽

Experimental Investigations ◽

Polymer Rheology ◽

Meso Scale

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Development of Advanced Hybrid Polymer Melt Delivery Systems for Efficient High Precision Injection Molding

Journal of Manufacturing Science and Engineering ◽

10.1115/1.4046833 ◽

2020 ◽

Vol 142 (7) ◽

Author(s):

Chandresh Thakur ◽

Khalid Alqosaibi ◽

Animesh Kundu ◽

John P. Coulter

Keyword(s):

Injection Molding ◽

Polymer Melt ◽

Acrylonitrile Butadiene Styrene ◽

Experimental Investigations ◽

Liquid Crystal Polymers ◽

Ansys Fluent ◽

Engineering Plastics ◽

Software Modules ◽

Melt Manipulation ◽

Butadiene Styrene

Abstract A novel melt manipulation “RheoDrop” concept for hot runner injection molding is presented. In this concept, a controlled rotational shear is applied to a polymer melt in the hot drop to reduce its viscosity without raising the temperature. This is achieved by providing a transient rotational motion to the valve pin in the hot drop. This strategy is developed to mitigate issues associated with cold slug formation during injection molding in hot runner systems. The cold slug formation is particularly relevant for injection molding of engineering plastics such as liquid crystal polymers (LCPs) for medical and electronic applications. Analytical and experimental investigations were performed to validate the concept. The efficacy of the concept is assessed analytically utilizing a combination of two software modules, autodesk, moldflow and ansys fluent. The results confirmed that the concept was able to produce enough shear to reduce the dynamic viscosity between injection molding cycles. A prototype RheoDrop system was designed and developed and retrofitted in a four drop hot runner system mold to experimentally validate the concept. Preliminary experiments were performed utilizing acrylonitrile butadiene styrene, and parts were successfully fabricated at temperatures that are too low for traditional molding in a hot runner system.

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