![]() The CASMIZER P4 can evaluate up to 60 images per second and the total analysis time is usually less than three minutes. The huge advantage of this arrangement is the vast amount of sample that can be processed in a very short analysis time of only a few minutes. This allows the simultaneous measurement of several size and shape parameters like width, length, equal area diameter, aspect ratio, roundness, compactness and many more. The resulting shadow projections are captured by a camera system and evaluated in real time. The particles under investigation are conveyed by a vibratory chute into the measurement zone where they are passing a planar light source in free fall. The CAMSIZER P4 dynamic digital image analyzer determines particle size and shape in a range from 20 μm to 30 mm and is therefore ideally suited for the routine analysis of foundry sand. The AFS number is considered proportional to the number of grains per unit weight. Note that the resulting AFS number gets bigger as the average size decreases. Each fraction is multiplied with a weighting factor, the results are added together and divided by 100. This number is calculated from the size distribution, which is determined by standard ASTM sieves. A standard parameter to express the size of molding sands is the AFS fineness number (AFS = American Foundry Society). Foundry sands usually have a size distribution from 0,1 mm – 0,8 mm with a mean size between 0,2 mm and 0,45 mm. The grain size is carefully monitored since it has an impact on the surface structure of the cast piece, which will be too rough if the particle size is too large. For this application, it is necessary to use a high-quality sand, which is almost pure quartz (SiO2) to prevent reactions between the mold and the liquid metal.įurthermore, the sand must have a good gas permeability and low compressibility. The sand can be recycled and used for new molds by removing the remainders of the binder. The liquid metal is cast into the mold and after the after the workpiece is completely hardened, it is released from the sand. This sand core defines the structure of the future workpiece (Fig. ![]() ![]() resins) and pressed into the desired shape by a machine. First, a suitable sand is mixed with a binder (e. Sand is the ideal medium to cast liquid metal into a desired form.
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