Compaction behavior of cellulose polymers

A Comparison of the Direct Compression Characteristics of Andrographis paniculata, Eurycoma longifolia Jack, and Orthosiphon stamineus Extracts for Tablet Development

“…Following this equation, the particles which are subjected to a compressive force in a confined space are viewed as a system in equilibrium at all stages of compression, so that the products of the pressure term and the volume term are constants. Figures 4 (a-b) shows that the linear trends of the Kawakita and Lüdde plots for 0.5 g and 1.0 g of herbal extract feed powders were similar to the compression characteristics of cellulose polymers (Shivanand and Sprockel, 1992), and the trends reported by Ahmad (2007) for Eurycoma longifolia Jack and Andrographis paniculata ground powders at similar pressures and feed quantities. Based on the constant a, the Eurycoma longifolia Jack extract powder exhibited the highest volume reduction of the powder bed followed by Andrographis paniculata and Orthosiphon stamineus extract powders for 0.5 g of feed powders (Table 3).…”

Biomass Feedstock Pre-Processing – Part 2: Densification

“…Occasionally, the sum of coefficients (a 1 + a 2 ) for agricultural biomass was observed to be above unity. The phenomenon of having sum of coefficient more than unity was also observed by Adapa et al (2002 and2009a), and Shivanand and Sprockel (1992), which implies that the densification could not be fully attributed to the two mechanisms of compression as assumed by the Cooper and Eaton (1962) model (Adapa et al, 2010a). In the Kawakita and Ludde (1971) model, constant a represents the initial porosity of the sample.…”

Influence of pregelatinization on the physicochemical and compressional characteristics of starches obtained from two local varieties of Dioscorea rotundata

“…a and b are constants which are obtained from the slope and intercept of kawakita plots respectively. The reciprocal of b is related to the pressure term, P k , which is the pressure required to reduce the powder bed by 50% [16]. The precompression density (Do) was calculated as a ratio of the loose bulk density to the particle density.…”