Molding Parameters Design for Meso and Micro Components Using Polylactic Acid (PLA)

Author(s):  
Rossella Surace ◽  
Vincenzo Bellantone ◽  
Irene Fassi

Abstract Currently, the increasing interest in the study of Polylactic acid (PLA) polymer has been motivated by the potential of such material for consumer and biomedical applications. PLA is a thermoplastic polymer, biodegradable, compostable and deriving from renewable natural sources as starch and sugar. Injection molding is the most widely used process for thermoplastic micro-featured parts for to its capacity to manufacture low-cost and high repeatable micro-parts. The use of PLA for injection molded micro components is still not well stabilized due to the slow crystallization kinetics, not suitable for high performance applications. In this work, preliminary experimental studies have been performed to analyze the filling ability of PLA in a meso and a micro parts using different molding conditions to evaluate process parameters influence. The experiments results are discussed in the paper and show that injection molding proved to be suitable for meso-micro PLA product manufacturing.

Processes ◽  
2018 ◽  
Vol 6 (8) ◽  
pp. 124 ◽  
Author(s):  
Kevin Hinkle ◽  
Xiaoyu Wang ◽  
Xuehong Gu ◽  
Cynthia Jameson ◽  
Sohail Murad

In this report we have discussed the important role of molecular modeling, especially the use of the molecular dynamics method, in investigating transport processes in nanoporous materials such as membranes. With the availability of high performance computers, molecular modeling can now be used to study rather complex systems at a fraction of the cost or time requirements of experimental studies. Molecular modeling techniques have the advantage of being able to access spatial and temporal resolution which are difficult to reach in experimental studies. For example, sub-Angstrom level spatial resolution is very accessible as is sub-femtosecond temporal resolution. Due to these advantages, simulation can play two important roles: Firstly because of the increased spatial and temporal resolution, it can help understand phenomena not well understood. As an example, we discuss the study of reverse osmosis processes. Before simulations were used it was thought the separation of water from salt was purely a coulombic phenomenon. However, by applying molecular simulation techniques, it was clearly demonstrated that the solvation of ions made the separation in effect a steric separation and it was the flux which was strongly affected by the coulombic interactions between water and the membrane surface. Additionally, because of their relatively low cost and quick turnaround (by using multiple processor systems now increasingly available) simulations can be a useful screening tool to identify membranes for a potential application. To this end, we have described our studies in determining the most suitable zeolite membrane for redox flow battery applications. As computing facilities become more widely available and new computational methods are developed, we believe molecular modeling will become a key tool in the study of transport processes in nanoporous materials.


Nanomaterials ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1435 ◽  
Author(s):  
Gang Wei ◽  
Coucong Gong ◽  
Keke Hu ◽  
Yabin Wang ◽  
Yantu Zhang

Hydroxyapatite (HA) has been widely used in fields of materials science, tissue engineering, biomedicine, energy and environmental science, and analytical science due to its simple preparation, low-cost, and high biocompatibility. To overcome the weak mechanical properties of pure HA, various reinforcing materials were incorporated with HA to form high-performance composite materials. Due to the unique structural, biological, electrical, mechanical, thermal, and optical properties, graphene has exhibited great potentials for supporting the biomimetic synthesis of HA. In this review, we present recent advance in the biomimetic synthesis of HA on graphene supports for biomedical applications. More focuses on the biomimetic synthesis methods of HA and HA on graphene supports, as well as the biomedical applications of biomimetic graphene-HA nanohybrids in drug delivery, cell growth, bone regeneration, biosensors, and antibacterial test are performed. We believe that this review is state-of-the-art, and it will be valuable for readers to understand the biomimetic synthesis mechanisms of HA and other bioactive minerals, at the same time it can inspire the design and synthesis of graphene-based novel nanomaterials for advanced applications.


2013 ◽  
Vol 747 ◽  
pp. 583-586 ◽  
Author(s):  
H. Özkan Gülsoy

This study focuses on the injection molding of Ti-Fe alloys. Low cost Ti alloy (Ti-Fe) was manufactured following a powder injection molding route. The Ti and Fe powders were dry mixed and molded with wax based binder. Binder debinding was performed by solvent and thermal method. After dedinding, the samples were sintered at 1100 oC and 1300 oC for 1 h in vacuum. Metallographic studies were conducted to extend densification and the corresponding microstructural changes. The sintered samples were characterized by measuring tensile strength, elongation and hardness. All powder, fracture surfaces of molded and sintered samples were examined using scanning electron microscope. The sintered density, tensile strength and hardness of injection molded Ti-Fe samples increases with increasing sintering temperature.


Author(s):  
Kevin R. Hinkle ◽  
Xiaoyu Wang ◽  
Xuehong Gu ◽  
Cynthia J. Jameson ◽  
Sohail Murad

In this report we have discussed the important role of molecular modeling, especially the use of the molecular dynamics method, in investigating transport processes in nanoporous materials such as membranes. With the availability of high performance computers, molecular modeling can now be used to study rather complex systems at a fraction of the cost or time requirements of experimental studies. Molecular modeling techniques have the advantage of being able to access spatial and temporal resolution which are difficult to reach in experimental studies. For example, sub-Angstrom level spatial resolution is very accessible as is sub-femtosecond temporal resolution. Due to these advantages, simulation can play two important roles: Firstly because of the increased spatial and temporal resolution, it can help understand phenomena not well understood. As an example, we discuss the study of reverse osmosis processes. Before simulations were used it was thought the separation of water from salt was purely a coulombic phenomenon. However, by applying molecular simulation techniques, it was clearly demonstrated that the solvation of ions made the separation in effect a steric separation and it was the flux which was strongly affected by the coulombic interactions between water and the membrane surface. Additionally, because of their relatively low cost and quick turnaround (by using multiple processor systems now increasingly available) simulations can be a useful screening tool to identify membranes for a potential application. To this end, we have described our studies in determining the most suitable zeolite membrane for redox flow battery applications. As computing facilities become more widely available and new computational methods are developed, we believe molecular modeling will become a key tool in the study of transport processes in nanoporous materials.


Author(s):  
Jang Min Park ◽  
Seok Jae Jeong ◽  
Seong Jin Park

In the present work, experimental studies are carried out to understand orientation kinematics of pigment flakes during the injection molding process. The injection molding experiments are carried out using ABS resin compounded with aluminum flakes. Thin specimens are sliced off from the injection molded sample, and then the orientation distribution is observed using transmitted microscopy. Generally, the microscopic result shows a sandwich structure where the orientation state near the mid-plane differs significantly from that around the surface. Particularly at the weldline region, locally different orientation is observed near the part surface, which is the result of fountain flow at the melt front. Also the effect of mold temperature on the flake orientation is presented.


Author(s):  
M. S. Rabbi ◽  
Tansirul Islam ◽  
G. M. Sadiqul Islam

AbstractFor the last couple of decades, researchers have been trying to explore eco-friendly materials which would significantly reduce the dependency on synthetic fibers and their composites. Natural fiber-based composites possess several excellent properties. They are biodegradable, non-abrasive, low cost, and lower density, which led to the growing interest in using these materials in industrial applications. However, the properties of composite materials depend on the chemical treatment of the fiber, matrix combination, and fabrication process. This study gives a bibliographic review on bio-composites specially fabricated by the injection-molding method. Technical information of injection-molded natural fiber reinforcement-based composites, especially their type and compounding process prior to molding, are discussed. A wide variety of injection-molding machines was used by the researchers for the composite manufacturing. Injection-molded composites contain natural fiber, including hemp, jute, sisal, flax, abaca, rice husk, kenaf, bamboo, and some miscellaneous kinds of fibers, are considered in this study.


2020 ◽  
Vol 841 ◽  
pp. 300-305
Author(s):  
Masahiro Kimura ◽  
Toru Shimizu ◽  
Hisaki Watari

In recent years, metal injection molding (MIM) has been adopted as a process of manufacturing a solenoid valve which is a component of an electronic fuel injector, and PB permalloy component has been commercialized. However, Ni that is an element of PB permalloy is expensive material, and it makes difficult to produce the injector component in low cost. To reduce the production cost, we can use Fe-Cr alloys, although there are few studies on Fe-Cr alloys by MIM process. In this study, Fe-Cr-Si alloy specimens were manufactured by MIM process and the magnetic and mechanical properties were investigated. From these results, we found that high performance Fe-Cr-Si alloy can be obtained by setting Si content to 3% and reducing Cr content.


2013 ◽  
Vol 699 ◽  
pp. 875-882 ◽  
Author(s):  
Muhammad Rafi Raza ◽  
Faiz Ahmad ◽  
M.A. Omar ◽  
R.M. German ◽  
Ali S. Muhsan

316L stainless steel is widely used in various industries due to low cost, ease of availability and exceptional combination of mechanical properties along with corrosion resistance as compared to the other available metal alloys. In powder injection molding, debinding is very critical step and improper debinding can change the final properties dramatically. In the present study, affects of debinding on mechanical properties of powder injection molded 316L stainless steel were studied. The prepared feedstocks were molded according to MPIF 50 standard using vertical injection molding machine (KSA100). The plastic binder was removed at 450°C from the molded test samples using two different furnaces i.e. commercial and laboratory furnace followed by the sintering in vacuum, hydrogen, mixture of H2 and N2 (9:1) and nitrogen at 1325°C for 2hr with post sintering cooling rate 3°C/min . Test samples debound in commercially available furnace showed 97% densification and higher mechanical properties. The corrosion resistance was reduced due to presence of residual carbon during thermal debinding. The presence of carbon and formation of carbides and nitrides were confirmed by XRD and microstructural analysis. The results showed that the test samples debound in commercial furnace showed brittle behavior due to the presence of carbides and nitrides. Test samples sintered in N2 showed 96.3% density and tensile strength 751MPa. This value of strength is twice as compared to the sample debound in laboratory furnace followed by the sintering in vacuum. The achieved mechanical properties in vacuum sintered samples were comparable to the wrought 316L stainless steel (according to ASTM standard).


Alloy Digest ◽  
2005 ◽  
Vol 54 (3) ◽  

Abstract MoldStar 90 is a high-performance beryllium-free copper alloy for the blow-molding and injection-molding industries. This datasheet provides information on composition, physical properties, hardness, tensile properties, and compressive strength. It also includes information on machining, joining, and surface treatment. Filing Code: CU-732. Producer or source: Performance Alloys.


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