Mechanical Characterization of Spray-Dried Granules by Compression Stress-Relaxation Technique. Analysis of Compression Behavior.

Tsubaki, JunIchiro; Mori, Takamasa; Konishi, Toshiyuki; Tsuruta, Akihisa; Mori, Hideki; Yokoyama, Toyokazu; Matsubara, Sadanobu

doi:10.2109/jcersj.107.1093

Cited by 4 publications

(1 citation statement)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In previous papers6), 7) a new evaluation technique has been developed for characterizing compressive behavior of spray-dried granules, using the conventional compression and stress-relaxation test. Experiments with spray-dried alumina granules prepared under the various conditions demonstrated that the visco-elastic deformation should characterize the compressive behavior of granules.…”

Section: Introductionmentioning

confidence: 99%

Optimization of Granules and Slurries for Press Forming.

Tsubaki

Yamakawa

Mori

et al. 2002

J. Ceram. Soc. Japan

Self Cite

View full text Add to dashboard Cite

The present paper deals with the determination of optimal conditions for preparing spray-dried granules and slurries, based on the characteristics of granules and supplied slurries. These characteristics were evaluated by the compression and stress-relaxation method, and by the centrifugal consolidation method, respectively. Spray drying of the flocculated slurry resulted in low-density granules with a spherical and solid morpholo gy, which ensures a high compressibility. Another important factor governing the press forming is to adjust the amount of binder so as to improve the visco-elastic deformation of granules; this leads to a better homogeneity of the resulting compacts.

show abstract

Section: Introductionmentioning

confidence: 99%

Optimization of Granules and Slurries for Press Forming.

Tsubaki

Yamakawa

Mori

et al. 2002

J. Ceram. Soc. Japan

Self Cite

View full text Add to dashboard Cite

show abstract

均質な圧縮成形体へのか粒設計

Shimosaka

Suzukawa

Shirakawa

et al. 2003

KAGAKU KOGAKU RONBUNSHU

View full text Add to dashboard Cite

Optimization of Experimental Conditions for the Compression and Stress Relaxation Test of Spray-Dried Granules.

Mori

Tsubaki

2002

J. Ceram. Soc. Japan

Self Cite

View full text Add to dashboard Cite

Mechanical propertiesof spray-dried granules have been characterized in compression by repeatedly ap plying and stopping stress. In order to shorten the experimental time and obtain optimal conditions for relia bly evaluating the relaxation behavior, we discussed the influence of compression rate, compression number, relaxation time and initial height of the granule bed, respectively. It was found that the stress relaxation of granules increased with increasing compression rate. It was also demonstrated that the stress relaxation was almost independent of the initial height of the granule bed. Furthermore on the one time compression and stress relaxation test, the results were found to be in good agreement with those obtained from the mul tiple compression and stress relaxation test. These results show that the experimental time can be shortened from a few hours to about ten minutes.[ 1. Introduction In the press forming process of ceramics, it is important to accurately characterize the mechanical properties of spray-dried granules. In many researches on the characteri zation of granules, the mechanical properties were often evaluated by applying the conventional compression test,1)-3) in which the packing density of granule bed was measured as a function of applied pressure, or the single granule compression test,4),5) in which the strength of a granule was measured. These methods give us information only on the density of green body, but not on the homogenei ty of green body.In pharmaceutical science, the static compression behav iors and the tablettabilities of the agglomerated crystals and the original crystals were investigated and compared by measuring the stress relaxation.6) In this report it was found that the relaxation pressure of the agglomerated crystals was higher than that of the original crystals. It was also shown that the tensile strength of the tablet of agglomerated crystals was greater than that of the original crystals. However several kinds of agglomerated powders were not compared, therefor it is not clear the difference of the break ing and/or deforming behavior of agglomerated powders and how to prepare the optimum agglomerated powders for the press forming. Furthermore the effect of the experimen tal conditions on the stress relaxation behavior has not been discussed sufficiently. In food science, compression and stress relaxation tests have been used for the textual evalua tion of various fruits and other food commodities.7) However there is no report to adapt a compression and stress relaxation test for characterization of ceramics gram ules.In our previous works8)-10) a new evaluation technique has been developed for characterizing compaction behavior of spray-dried granules, using the compression and stress relaxation test. In previous reports we discussed the differ ence of the breaking and/or deforming behavior between binder contained granules and binder less granules. It was shown that the relaxation ratio (the ratio of the relaxation pressure to the applied pressure) of binde...

show abstract

Mechanical Characterization of Spray-Dried Granules by Compression Stress-Relaxation Technique. Analysis of Compression Behavior.

Cited by 4 publications

References 0 publications

Optimization of Granules and Slurries for Press Forming.

Optimization of Granules and Slurries for Press Forming.

均質な圧縮成形体へのか粒設計

Optimization of Experimental Conditions for the Compression and Stress Relaxation Test of Spray-Dried Granules.

Contact Info

Product

Resources

About