Powder sampling and particle size determination pdf
Powder Sampling and Particle Size Determination - PDF Free DownloadThe purpose of this paper is to describe the use of LGC Promochem AEA to AEA monosized fiberanalog shape standards in the study of the effect of particle shape on laser diffraction LD particle size analysis psa. Flow speed settings, sample refractive index values, and sample cell types were varied to examine the extent to which the shape effect on LD psa results is modified by these variables. The volume and number probability plots resulting from these measurements were each characterized by a spread in the particle size distribution that roughly extended from the breadth to the longest dimension of the particles. For most of the selected sample refractive index values, the volume probability plots were characterized by apparent bimodal distributions. The results, therefore, provide experimental verification of the conclusions from theoretical studies of LD psa system response to monosized elliptical particles in which this apparent bimodality was the predicted result in the case of flow-oriented particles. The data support the findings from previous studies conducted over the past 10 years that have called into question the verity of the tenets of, and therefore the value of the application of, the equivalent spherical volume diameter theory and the random particle orientation model to the interpretation of LD psa results from measurements made on nonspherical particles. National Center for Biotechnology Information , U.
Micromeritics: distribution curves and particle size determination methods
Particle size analysis
Particle size analysis is part of particle science , and its determination is carried out generally in particle technology laboratories. The particle size measurement is typically achieved by means of devices called Particle Size Analyzers PSA which are based on different technologies, such as high definition image processing , analysis of Brownian motion , gravitational settling of the particle and light scattering Rayleigh and Mie scattering of the particles. The particle size can have considerable importance in a number of industries including the chemical,food, mining, forestry, agriculture, nutrition, pharmaceutical, energy, and aggregate industries. There are a large number of methods for the determination of particle size, and it is important to state at the outset, that these different methods are not expected to give identical results: the size of a particle depends on the method used for its measurement, and it is important to choose that method for its determination which is relevant to its use. The size of materials being processed in an operation is very important. Having oversize material being conveyed will cause damage to equipment and slow down production.
Dexamethasone-Loaded Silicone for Implantable Systems. Nanomilling Feasibility Program. Knowledge of the particle size distribution PSD of powder systems is a prerequisite for most manufacturing operations, including those associated with the production of pharmaceutical and biopharmaceutical products. If the PSD is not controlled in a process, high rejection rates can result and significant production losses can be incurred. Particle size analytical results are most applicable when samples drawn are representative and the appropriate dispersion techniques are used. The majority of variation in particle sizing measurements is traceable to either incorrect sampling or sample preparation.
T. Allen, Particle Size Measurement, Volume 1, Powder sampling and Particle Size Analysis, Classification and Sedimentation methods.
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Table of contents
Part 6: Micromeritics - Particle size determination (Optical Microscopy)
Dexamethasone-Loaded Silicone for Implantable Systems. Nanomilling Feasibility Program. The population of particles in a powder, as described by its particle size distribution PSD , affects the properties of a powder and dispersions in many important ways. For example, in industrial applications, it determines the setting time of cement, the hiding power of pigments, the activity of catalysts, the taste of food, and the sintering shrinkage of metallurgical compositions. The relevance to the Pharmaceutical industry is that the stability, aesthetics, rate of absorption and total bioavailability, to name a few properties, are all strongly affected by the size of the particles that comprise the powder or dispersion.
Skip to main content Skip to table of contents. Advertisement Hide. Particle Size Measurement. Front Matter Pages i-xxii. Sampling of powders. Pages