The Flow Behavior of Core Material and Breakthrough Phenomenon in Sandwich Injection Molding

2003 ◽  
Vol 18 (4) ◽  
pp. 405-411 ◽  
Author(s):  
D. Watanabe ◽  
U. S. Ishiaku ◽  
T. Nagaoka ◽  
K. Tomari ◽  
H. Hamada
Keyword(s):  
Injection Molding ◽  
Flow Behavior ◽  
Core Material

The Flow Behavior of Core Material and Breakthrough Phenomenon in Sandwich Injection Molding

2003 ◽  
Vol 18 (4) ◽  
pp. 398-404 ◽  
Author(s):  
D. Watanabe ◽  
U. S. Ishiaku ◽  
T. Nagaoka ◽  
K. Tomari ◽  
H. Hamada
Keyword(s):  
Injection Molding ◽  
Flow Behavior ◽  
Core Material

The Characterization and Flow Behavior of 316L Stainless Steel Feedstock for Micro Metal Injection Molding (μMIM)

2010 ◽  
Vol 44-47 ◽  
pp. 2872-2876
Author(s):  
Pei Li Haw ◽  
Norhamidi Muhamad ◽  
Hadi Murthadha
Keyword(s):  
Stainless Steel ◽  
Injection Molding ◽  
316L Stainless Steel ◽  
Flow Behavior ◽  
Palm Stearin ◽  
Metal Injection Molding ◽  
Injection Molding Process ◽  
Binder System ◽  
Molding Process ◽  
Rheological Characterization

The rheological behaviors of the Micro Metal Injection Molding feedstock are important for the stability of the feedstock during micro injection molding process and quality of the final micro-components. Homogeneous feedstocks are preferable for MIM process to ensure the dimensional consistency of molded components and prevent the defects of powder-binder separation or particle segregation. In this work, feedstocks with various formulations of 316L stainless steel and binder system were prepared by using Brabender Plastograph EC Plus mixer. The binder system comprises of palm stearin, polyethelene (PE) and stearic acid. In order to obtain the viscosity, activation energy, flow behavior and mold ability index, the rheological characterization of the feedstocks were investigated in numerous conditions by using Shimadzu 500-D capillary rheometer The study showed that all of the 316L stainless steel feedstocks are homogenous with pseudo-plastic behaviors.

scholarly journals New Feedstock System for Fused Filament Fabrication of Sintered Alumina Parts

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4461 ◽  
Author(s):  
Dorit Nötzel ◽  
Thomas Hanemann
Keyword(s):  
Injection Molding ◽  
Material Selection ◽  
Flow Behavior ◽  
Ceramic Materials ◽  
Maximum Temperature ◽  
Powder Injection ◽  
Fused Filament Fabrication ◽  
Sintered Ceramic ◽  
Whole Process ◽  
Dependent Flow

Only a few 3D-printing techniques are able to process ceramic materials and exploit successfully the capabilities of additive manufacturing of sintered ceramic parts. In this work, a new two component binder system, consisting of polyethyleneglycol and polyvinylbutyral, as well stearic acid as surfactant, was filled with submicron sized alumina up to 55 vol.% and used in fused filament fabrication (FFF) for the first time. The whole process chain, as established in powder injection molding of ceramic parts, starting with material selection, compounding, measurement of shear rate and temperature dependent flow behavior, filament fabrication, as well as FFF printing. A combination of solvent pre-debinding with thermal debinding and sintering at a reduced maximum temperature due to the submicron sized alumina and the related enhanced sinter activity, enabled the realization of alumina parts with complex shape and sinter densities around 98 % Th. Finally the overall shrinkage of the printed parts were compared with similar ones obtained by micro ceramic injection molding.

Study on the Flow Behavior in Thin Cavity during Water-Assisted Injection Molding

2011 ◽  
Vol 467-469 ◽  
pp. 80-83
Author(s):  
Tang Qing Kuang ◽  
Kun Han
Keyword(s):  
Injection Molding ◽  
Control Volume ◽  
Fluid Model ◽  
Flow Behavior ◽  
Experimental Result ◽  
Bulk Temperature ◽  
Injection Molding Process ◽  
Molding Process ◽  
Injection Location ◽  
Good Agreement

A numerical simulation model for the flow behavior of fluids in thin cavity during water assisted injection molding process is built up by adopting general Newtonian fluid model for the filling stage and non-Newtonian and compressible fluid model for the packing stage separately. Finite element/finite difference/control volume methods are adopted for the simulation of melt front, pressure variation at injection location, water thickness fraction and bulk temperature about a plate with trapezoidal cross-section. The simulated melt front location and shape have good agreement with experimental result. In comparison with the simulation results of conventional injection molding, it turns out that water assisted injection molding can obtain parts with low pressure requirement, perfect surface quality and rapid cooling.

Process Development for the Ceramic Injection Molding of Oxide Chopped Fiber Reinforced Aluminum Oxide

2017 ◽  
Vol 742 ◽  
pp. 231-237 ◽  
Author(s):  
Metin Tülümen ◽  
Thomas Hanemann ◽  
Michael J. Hoffmann ◽  
Rainer Oberacker ◽  
Volker Piotter
Keyword(s):  
Injection Molding ◽  
Fiber Orientation ◽  
Average Length ◽  
Flow Behavior ◽  
Fiber Content ◽  
Oxide Ceramic ◽  
Fiber Reinforced ◽  
Mechanical Reinforcement ◽  
Ceramic Injection Molding ◽  
Fiber Orientation Distribution

In this study, it was tried to develop a process chain for ceramic injection molding of Al2O3-chopped-fiber reinforced oxide-ceramic-matrix-composite. The feedstocks are compounded at 50 Vol. % filling degree of solid (Al2O3 μ-powder (Taimei Chemicals Co. Ltd.) and 3,2 mm chopped fibers (3M)), in which fiber content varies from 0 Vol. % to 100 Vol. %. As binder system, PE + Paraffin Wax + Stearic Acid are used. The ingredients are compounded in a kneader (Brabender) at 125°C and after the viscosity measurement in the high pressure capillary rheometer at 160°C and certain shear rates, the feedstock is injection molded (Battenfeld) at 160°C, which is followed by debinding process, including chemical (in n-Hexane) and thermal steps, and 2h sintering at different temperatures. Flow paths in the machinery parts, rheological properties of binding system, fiber content and the fiber orientation have significant effect on the flow behavior of the feedstock, fiber -orientation, -distribution & -length, which are crucial to understand the properties of end-parts like mechanical reinforcement of the fibers. The fibers in the sintered parts are ca. 200 μm in average length. The fibers in the feedstock show different orientations depending on the part-geometry and the green bodies have different densities depending on sintering temperature, amount of dispersant and fiber orientation.

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