Powder Injection Molding of Mullite: The Study of Binder Dissolution Behavior during Debinding Step Using Statistical Methods

The purpose of this work is to use the statistical methods including linear regression and statistical hypothesis test to study the dissolution behavior of polyethylene glycol (PEG), a water-soluble binder, during debinding step of the green specimens of mullite formed by powder injection molding (PIM). Two systems of composite binders were investigated including (A) 80 wt% polyethylene glycol (PEG) and 20 wt% polyvinyl butyral (PVB) and (B) 78 wt% PEG, 20 wt% PVB, and 2 wt% steric acid (SA)The lab-scale plunger type PIM machine was used to prepare the green specimens consisting of mullite powder and the composite binder. The possible solid loadings of the green specimens that could be prepared by this machine were 50, 52, and 54 vol% mullite (50, 48, and 46 vol% binder). The debinding was done by soaking the green specimens in the warm water at 40 or 60 oC to remove PEG. At level of significance 0.05 for statistical analysis, the dissolution behavior of PEG can be fitted with Avarami equation. In addition, from the Avarami equation obtained from each experimental condition, the dissolution rate of PEG was independent of the parameters used in this study including solid loading in the green specimens, water temperatures for debinding, and composite binder systems.

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Statistical Analysis of Binder Behavior during Debinding Step in Powder Injection Molding (PIM)

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.970.172 ◽

2014 ◽

Vol 970 ◽

pp. 172-176 ◽

Cited By ~ 3

Author(s):

Parinya Chakartnarodom ◽

Nutthita Chuankrerkkul

Keyword(s):

Linear Regression ◽

Injection Molding ◽

Hypothesis Test ◽

Powder Injection Molding ◽

Statistical Hypothesis ◽

Powder Injection ◽

Dissolution Behavior ◽

Linear Regression Method ◽

Statistical Hypothesis Testing ◽

Statistical Hypothesis Test

The aim of this paper is to propose the approach for applying statistical methods (linear regression and statistical hypothesis testing) to study the behavior of binder during binder removing (debinding) step in powder injection molding (PIM) and also the parameters that affect the binder removing rate. In this work, the binder system under the investigation is the composite binder of 85wt% polyethylene glycol (PEG) and 15 wt% poly (methyl methacrylate) (PMMA) where PEG can be removed from the green product by using warm water while PMMA is removed later during sintering. At 0.05 level of significance, the linear regression method and the statistical hypothesis test prove that the dissolution behavior of PEG can be described using Avarami equation. Furthermore, the dissolution rates of PEG were independent of all parameters used in this study including binder contents in the green products, temperatures, and powder sizes.

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Powder Injection Molding of Mullite: The Study of Mechanical and Physical Properties of the Sintered Products Using Statistical Methods

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.690.92 ◽

2016 ◽

Vol 690 ◽

pp. 92-96

Author(s):

Parinya Chakartnarodom ◽

Nuntaporn Kongkajun ◽

Nutthita Chuankrerkkul

Keyword(s):

Flexural Strength ◽

Injection Molding ◽

Statistical Methods ◽

Sintering Temperature ◽

Hypothesis Test ◽

Polyvinyl Butyral ◽

Powder Injection Molding ◽

Statistical Hypothesis ◽

Powder Injection ◽

Statistical Hypothesis Test

The aim of this work is to propose the application of statistical methods (linear regression and statistical hypothesis test) to analyze the effect of parameters used in powder injection molding including sintering temperature and the feedstock composition on the flexural strength, the porosity and the density of the sintered specimens of mullite prepared by powder injection molding (PIM) and using the composite binder consisting of 80 wt% polyethylene glycol (PEG) and 20 wt% polyvinyl butyral (PVB) for molding. The lab-scale plunger type PIM machine was used to prepare the specimens. The feedstock compositions were 50 to 54 vol% mullite, and the sintering temperatures were 1300 and 1400 °C. At level of significance 0.05 for statistical analysis, feedstock composition did not affect flexural strength, porosity, and density of the sintered specimens. For sintering temperature, the specimens sintered at 1400 °C have the greater density and the lower porosity. However, the flexural strength of the specimens sintered at 1300 °C and 1400 °C are statistically similar.

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Application of Statistical Analysis in the Powder Injection Molding (PIM) of Mullite

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.659.53 ◽

2015 ◽

Vol 659 ◽

pp. 53-57

Author(s):

Parinya Chakartnarodom ◽

Nuntaporn Kongkajun ◽

Nutthita Chuankrerkkul

Keyword(s):

Statistical Analysis ◽

Flexural Strength ◽

Injection Molding ◽

Hypothesis Test ◽

Least Square Method ◽

Powder Injection Molding ◽

Least Square ◽

Statistical Hypothesis ◽

Powder Injection ◽

Mullite Powder

In this work, the statistical analysis methods, including least square method and statistical hypothesis testing, were used to study the flexural strength and density of the specimens formed from mullite powder by powder injection molding (PIM). The feedstock for PIM consist of mullite powder and the composite binder consisting of 78 wt% polyethylene glycol (PEG), 20 wt% polyvinyl butyral (PVB), and 2 wt% stearic acid (SA). The PIM machine used in this work was the lab-scale plunger type. The compositions of the feedstock that could be injection molded by this machine were 50, 52, and 54vol% mullite. After molding, PEG in the green specimens was removed prior to sintering by soaking the specimens in the water at 60 °C for 24 hours while PVB and SA were removed during sintering. The sintering temperatures were 1300 to 1450°C. At significance level of 0.05, the least square method and the statistical hypothesis test showed that both feedstock compositions and sintering temperatures used in this work affected the densities of sintered specimens. However, the increasing of the flexural strength of sintered specimens was mainly by the increasing of the sintering temperature.

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Optimization of powder injection molding of feedstock based on aluminum oxide and multicomponent water-soluble polymer binder

Polymer Engineering & Science ◽

10.1002/pen.21928 ◽

2011 ◽

Vol 51 (7) ◽

pp. 1376-1382 ◽

Cited By ~ 16

Author(s):

Berenika Hausnerova ◽

Lucie Marcanikova ◽

Petr Filip ◽

Petr Saha

Keyword(s):

Injection Molding ◽

Aluminum Oxide ◽

Powder Injection Molding ◽

Polymer Binder ◽

Water Soluble ◽

Powder Injection ◽

Soluble Polymer ◽

Water Soluble Polymer

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Online Rheometry Investigation of Flow/Slip Behavior of Powder Injection Molding Feedstocks

Polymers ◽

10.3390/polym11030432 ◽

2019 ◽

Vol 11 (3) ◽

pp. 432 ◽

Cited By ~ 1

Author(s):

Daniel Sanetrnik ◽

Berenika Hausnerova ◽

Vladimir Pata

Keyword(s):

Surface Roughness ◽

Injection Molding ◽

Slip Velocity ◽

Wall Slip ◽

Powder Injection Molding ◽

Water Soluble ◽

Powder Injection ◽

Powder Particle Size ◽

Slip Effect ◽

Rectangular Slit

Wall slip in the flow of powder injection molding (PIM) compounds can be the cause of unrealistically low viscosity values, and can lead to a failure of flow simulation approaches. Regardless of its importance, it has been considered only scarcely in the rheological models applied to PIM materials. In this paper, an online extrusion rheometer equipped with rectangular slit dies was used to evaluate the slip velocity of commercial as well as in-house-prepared PIM feedstocks based on metallic and ceramic powders at close-to-processing conditions. The tested slit dies varied in their dimensions and surface roughness. The wall-slip effect was quantified using the Mooney analysis of slip velocities. The smaller gap height (1 mm) supported the wall-slip effect. It was shown that both the binder composition and the powder characteristic affect slip velocity. Slip velocity can be reduced by tailoring a powder particle size distribution towards smaller particle fractions. The thickness of the polymer layer formed at the channel wall is higher for water-soluble feedstocks, while in the case of the catalytic polyacetal feedstocks the effect of surface roughness was manifested through lower viscosity at smooth surfaces.

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