A Study of Polyvinyl Butyryl Based Binder System in Titanium Based Metal Injection Moulding

2012 ◽  
Vol 520 ◽  
pp. 167-173 ◽  
Author(s):  
G. Thavanayagam ◽  
De Liang Zhang ◽  
K.L. Pickering ◽  
Stella Raynova
Keyword(s):  
Thermal Analysis ◽  
Injection Moulding ◽  
Twin Screw Extruder ◽  
Metal Powders ◽  
Binder System ◽  
Mixing Conditions ◽  
Screw Extruder ◽  
Metal Injection Moulding ◽  
Twin Screw ◽  
Mechanical Mixer

Metal injection moulding (MIM) is an innovative injection moulding technique widely used to produce complex shaped components from feedstock composed of metal powders and thermosetting or thermoplastic binders. In MIM, binder selection and formulation are considered as critical processes since binder characteristics dictate the success of MIM. The purpose of this study is to determine the feasibility of polyvinyl butyryl (PVB) based binder system in Ti-6Al-4V(wt.%)/binder feedstock, as well as to understand the effects of key parameters, such as powder loading and mixing conditions on the rheological properties of a feedstock. In this study, PVB, polyethylene glycol (PEG), and stearic acid (SA) were chosen to formulate a multi-component binder system to prepare Ti-6Al-4V based feedstock with the aid of three types of mixers: a compounder, a modified mechanical mixer and a twin screw extruder. Further, morphological analysis was performed using optical microscopy and scanning electron microscopy. Thermal analysis was performed using simultaneous differential thermal analysis and thermogravimetric analysis. Results showed that binder formulation was reasonably successful with the aid of both mechanical mixer and a twin screw extruder under certain mixing conditions, and the critical powder loading was 68 vol.%, resulting in an optimum powder loading of 63 vol.% .

Kinetics of Titanium Metal Injection Moulding Feedstock Thermal Debinding

2015 ◽  
Vol 828-829 ◽  
pp. 158-164 ◽  
Author(s):  
Ronald Machaka ◽  
Hilda Kundai Chikwanda
Keyword(s):  
Injection Moulding ◽  
Catalytic Effect ◽  
Inert Atmosphere ◽  
Metal Powders ◽  
Binder System ◽  
Degradation Behaviour ◽  
Metal Injection Moulding ◽  
Thermal Debinding ◽  
Degradation Step ◽  
Kinetics Of

Controlled thermogravimetric pyrolysis of a metal injection moulding (MIM) feedstock was performed in order to characterize the associated thermal debinding processing in an inert atmosphere. The feedstock was formulated using Ti-6Al-4V metal powders and a newly developed MIM binder system. The catalytic effect of the metal powder on the decomposition of the binder components in the MIM feedstock is observed. The thermogravimetric analysis also reveals that thermal debinding is characterized by a multistage degradation behaviour of the binder system. In order to determine the kinetic parameters of the degradation step Ozawa and Ozawa-Flynn-Wall methods were applied. Activation energies with the degree of thermal debinding are deduced and discussed in terms of the decomposition of the binder components in the MIM feedstock.

Development of PEG/PMMA Based Binders for Ti-Metal Injection Moulding

2016 ◽  
Vol 704 ◽  
pp. 130-138 ◽  
Author(s):  
Muhammad Dilawer Hayat ◽  
Peng Cao
Keyword(s):  
Injection Moulding ◽  
Void Formation ◽  
Green Manufacturing ◽  
Interesting Problem ◽  
Metal Powders ◽  
Binder System ◽  
Metal Injection Moulding ◽  
The World ◽  
Crystallization Inhibitor ◽  
Increasing Demand

As the world is moving towards green manufacturing, there is an increasing demand for the use of clean and environmentally friendly binder systems in metal injection moulding (MIM) industry. One example of these developed binders is polyethylene glycol (PEG) - polymethyl methacrylate (PMMA) based system. We have systematically evaluated and optimized this binder system, and reported some interesting new results. In this article, we reported the effect of PEG molecular weight on rheological properties of the feedstock and its water debinding behaviour. We also investigated the effects of different surfactants on MIM feedstock rheological and mechanical properties, and identified a potential surfactant that enhances compatibility between the binder components and metal powders. Furthermore, we reported an interesting problem – ‘voids formation’, which is associated with PEG crystallization. To minimize this void formation a crystallization inhibitor is incorporated in the PEG/PMMA system, thereby eliminating the void formation while maintaining the clean nature of this system. This paper is concluded with some new thoughts with regard to binder design.

Reactive Blending in a Twin Screw Extruder

1996 ◽  
Vol 11 (2) ◽  
pp. 139-146 ◽  
Author(s):  
A. De Loor ◽  
P. Cassagnau ◽  
A. Michel ◽  
L. Delamare ◽  
B. Vergnes
Keyword(s):  
Twin Screw Extruder ◽  
Reactive Blending ◽  
Screw Extruder ◽  
Twin Screw

SME-Arrhenius Model for WSI of Rice Flour in a Twin-Screw Extruder

2005 ◽  
Vol 82 (5) ◽  
pp. 574-581 ◽  
Author(s):  
Hanwu Lei ◽  
R. Gary Fulcher ◽  
Roger Ruan ◽  
Bernhard van Lengerich
Keyword(s):  
Rice Flour ◽  
Twin Screw Extruder ◽  
Screw Extruder ◽  
Arrhenius Model ◽  
Twin Screw

scholarly journals Effects of a Twin-Screw Extruder Equipped with a Molten Resin Reservoir on the Mechanical Properties and Microstructure of Recycled Waste Plastic Polyethylene Pellet Moldings

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1058
Author(s):  
Hikaru Okubo ◽  
Haruka Kaneyasu ◽  
Tetsuya Kimura ◽  
Patchiya Phanthong ◽  
Shigeru Yao
Keyword(s):  
Mechanical Properties ◽  
Mechanical Performance ◽  
Value Added ◽  
Industrial Applications ◽  
Twin Screw Extruder ◽  
Screw Extruder ◽  
Polymer Properties ◽  
Wide Range ◽  
Twin Screw ◽  
Recycled Plastics

Each year, increasing amounts of plastic waste are generated, causing environmental pollution and resource loss. Recycling is a solution, but recycled plastics often have inferior mechanical properties to virgin plastics. However, studies have shown that holding polymers in the melt state before extrusion can restore the mechanical properties; thus, we propose a twin-screw extruder with a molten resin reservoir (MSR), a cavity between the screw zone and twin-screw extruder discharge, which retains molten polymer after mixing in the twin-screw zone, thus influencing the polymer properties. Re-extruded recycled polyethylene (RPE) pellets were produced, and the tensile properties and microstructure of virgin polyethylene (PE), unextruded RPE, and re-extruded RPE moldings prepared with and without the MSR were evaluated. Crucially, the elongation at break of the MSR-extruded RPE molding was seven times higher than that of the original RPE molding, and the Young’s modulus of the MSR-extruded RPE molding was comparable to that of the virgin PE molding. Both the MSR-extruded RPE and virgin PE moldings contained similar striped lamellae. Thus, MSR re-extrusion improved the mechanical performance of recycled polymers by optimizing the microstructure. The use of MSRs will facilitate the reuse of waste plastics as value-added materials having a wide range of industrial applications.

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