Improvement in the Permeability Characteristics of Injection Mold Fabricated by Additive Manufacturing and Irradiated by Electron Beams

2017 ◽  
Vol 11 (1) ◽  
pp. 97-103 ◽  
Author(s):  
Hiroshi Koresawa ◽  
◽  
Hironobu Fujimaru ◽  
Hiroyuki Narahara
Keyword(s):  
Electron Beam ◽  
Additive Manufacturing ◽  
Injection Molding ◽  
High Speed ◽  
Water Repellency ◽  
Milling Process ◽  
Sintered Body ◽  
Permeability Characteristics ◽  
Manufacturing Method ◽  
Fundamental Experiment

This paper describes a metal mold with permeability fabricated by metal laser sintering with high-speed milling, which is an additive manufacturing method, and discusses the improvement in permeability. In this method, the sintered body is produced with gas exhaust tubes based on the porous structure. To maintain permeability, ensuring that the gas exhaust tube is not blocked is essential. Blockages may occur because of reasons such as the deformation of the gas exhaust tube due to the milling process during fabrication and generation of mold deposits within the gas exhaust tube during injection molding. In this research, by irradiating the surface of a sintered body, with a gas exhaust tube, by an electron beam, water repellency attributed to the reduction in surface free energy and recovery of permeability are confirmed. Further, in a fundamental experiment with an injection molding machine, the permeability of a permeable sintered body irradiated an electron beam increased by approximately 2.8 times as compared to the permeability of a sintered body that was not irradiated.

scholarly journals Increasing the Sustainability of the Hybrid Mold Technique through Combined Insert Polymeric Material and Additive Manufacturing Method Design

2022 ◽  
Vol 14 (2) ◽  
pp. 877
Author(s):  
Ellen Fernandez ◽  
Mariya Edeleva ◽  
Rudinei Fiorio ◽  
Ludwig Cardon ◽  
Dagmar R. D’hooge
Keyword(s):  
Additive Manufacturing ◽  
Injection Molding ◽  
Acrylonitrile Butadiene Styrene ◽  
Measured Temperature ◽  
Steel Mold ◽  
Cooling Cycle ◽  
Polyamide 11 ◽  
Manufacturing Method ◽  
Cycle Times ◽  
Molded Parts

To reduce plastic waste generation from failed product batches during industrial injection molding, the sustainable production of representative prototypes is essential. Interesting is the more recent hybrid injection molding (HM) technique, in which a polymeric mold core and cavity are produced via additive manufacturing (AM) and are both placed in an overall metal housing for the final polymeric part production. HM requires less material waste and energy compared to conventional subtractive injection molding, at least if its process parameters are properly tuned. In the present work, several options of AM insert production are compared with full metal/steel mold inserts, selecting isotactic polypropylene as the injected polymer. These options are defined by both the AM method and the material considered and are evaluated with respect to the insert mechanical and conductive properties, also considering Moldex3D simulations. These simulations are conducted with inputted measured temperature-dependent AM material properties to identify in silico indicators for wear and to perform cooling cycle time minimization. It is shown that PolyJetted Digital acrylonitrile-butadiene-styrene (ABS) polymer and Multi jet fusioned (MJF) polyamide 11 (PA11) are the most promising. The former option has the best durability for thinner injection molded parts, and the latter option the best cooling cycle times at any thickness, highlighting the need to further develop AM options.

Design and Manufacture of Injection Mold Inserts Using Electron Beam Melting

2014 ◽  
Vol 136 (6) ◽  
Author(s):  
Arif Rochman ◽  
Althea Kate Borg
Keyword(s):  
Electron Beam ◽  
Additive Manufacturing ◽  
Injection Molding ◽  
Heat Conductivity ◽  
Electron Beam Melting ◽  
Injection Mold ◽  
Cooling Performance ◽  
Cooling Channels ◽  
Design And Manufacture

The capability of producing injection tool inserts using an additive manufacturing (AM) technology was investigated. Using electron beam melting (EBM), the restriction of drilling straight cooling channels could be eliminated and freeform channels with sufficient powder removal were achieved. EBM parameters and the design of the cooling channels strongly influence the sintering degree of the powder trapped in the channels and thus the ease of the powder removal. Despite the low heat conductivity of the new inserts made from Ti6Al4V, the cooling performance was the same as for the conventional inserts. However, the use of Ti6Al4V is advantageous, since the expanding agent used in injection molding is very corrosive.

Image quality vs data obtainment in biological electron microscopy

1986 ◽  
Vol 44 ◽  
pp. 42-43
Author(s):  
J. E. Johnson
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Electron Beam ◽  
Image Quality ◽  
High Speed ◽  
Early Period ◽  
Early Years ◽  
Fluorescent Screen ◽  
Embedding Medium

In the early years of biological electron microscopy, scientists had their hands full attempting to describe the cellular microcosm that was suddenly before them on the fluorescent screen. Mitochondria, Golgi, endoplasmic reticulum, and other myriad organelles were being examined, micrographed, and documented in the literature. A major problem of that early period was the development of methods to cut sections thin enough to study under the electron beam. A microtome designed in 1943 moved the specimen toward a rotary “Cyclone” knife revolving at 12,500 RPM, or 1000 times as fast as an ordinary microtome. It was claimed that no embedding medium was necessary or that soft embedding media could be used. Collecting the sections thus cut sounded a little precarious: “The 0.1 micron sections cut with the high speed knife fly out at a tangent and are dispersed in the air. They may be collected... on... screens held near the knife“.

A Procedure for Determining the Operating Modes of Electron Beam Wire Feed Layer-Wise Deposition for Additive Manufacturing

Vestnik MEI ◽  
2017 ◽  
pp. 8-14 ◽  
Author(s):  
Aleksandr V. Gudenko ◽  
◽  
Viktor К. Dragunov ◽  
Andrey Р. Sliva ◽  
◽  
...  
Keyword(s):  
Electron Beam ◽  
Additive Manufacturing ◽  
Operating Modes ◽  
Wire Feed

HIGH SPEED ELECTRON BEAM THERAPY

1967 ◽  
Vol 99 (4) ◽  
pp. 932-938 ◽  
Author(s):  
A. ZUPPINGER
Keyword(s):  
Electron Beam ◽  
High Speed ◽  
Electron Beam Therapy
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