Papers by Keyword: Latex Binder

Abstract: In the processing of semiconducting electro ceramic materials the use of appropriate binder can lead to improve characteristics of powder which will reduce density gradient in the green body during compaction. The binder system is anticipated to have an influence on the grain growth and microstructure which in turn affect the electrical performance. To investigate this phenomenon, TiO₂ powder doped with tungsten oxide (WO₃), silicon oxide (SiO₂) and bismuth oxide (Bi₂O₃) was processed with and without various percent of latex binder. The prepared samples were characterized by evaluating the physical properties like green density, fired density, axial and radial shrinkage, micro hardness and compressive strength. It was observed that TiO₂ processed with latex binder exhibited higher green density and less axial and radial shrinkage compared to powder processed without binder. However, the binder level did not have any significant influence on the other characteristics of varistor discs. SEM analysis indicated that the average grain size was also influenced by the percent of binder used and but the higher average grain size was obtained for discs without any binder.

Abstract: Ceramic membrane has been extensively studied for a half of century. The research of alumina membranes was improved a great deal, however, they have always been considered as an opportunity in commercial product. In this research, submicron alumina powders, AKP-30 were deposited on the porous alumina tube support containing approximately 40% porosity by dip coating. The effects of solid loading, dispersant, and binder system on colloidal process were evaluated. It was found that the thickness of membrane layer depend on the type of binders (latex binder, polyvinyl alcohol binder, and poly (ethylene oxide) polymer binder) and dipping time when the withdrawal speed was constant. The proper suspension of 30 wt.% AKP-30 alumina powder with 18.8 wt.% latex binder provided proper sintered membrane without cracking or delaminating. The porosity and average pore size of coating layer was about 29% and 0.06 μm, respectively at a sintering temperature of 1400°C for 2 hr. The membrane layer was likely to thicken with increasing dipping time. The thickness of membrane after sintering was about 30-40 μm at a few second of dipping time.

Abstract: A new method, which allowed lamination at room temperature without any additional adhesive, was described in this paper. A low Tg styrene-acrylic latex binder was used to forming the green tape via a water-based slurry. The green tapes could adhere to each other at room temperature under low or slight pressure. The density and deformation of laminated green parts depended significantly on lamination pressure, but the density of green parts did not increase after the lamination pressure exceeded a specific value of 4MPa. The interface between the tapes had been investigated in the green and sintered state by SEM. The experimental results showed that the microstructure of interface and density of lamination ceramics was a function of fraction of binder, plasticizer, and laminated pressure.