Molding grinders

Prepared feeds are marketed in various forms from very fine particles through cmmbles, flakes, and pellets. Pelleted rations may be hard, semimoist, or moist. Hard pellets typically contain less than 10% water and can be stored under cool, dry conditions for at least 90 days without deterioration of quahty. Semimoist pellets are chemically stabilized to protect them from degradation and mold if they are properly stored, while moist pellets must be frozen if they are not used immediately after manufacture. Moist feeds are produced in machines similar to sausage grinders. 

The epoxy and silicone-epoxy resins were molded into 37-mm diameter by A-mm thick discs. These were ground in a SPEX model 800A carbide lined two-ball grinder, and the resulting powder sieved to provide controlled sample configurations for laboratory analyses. 

The effect of product form was examined by taking the pellet samples used in Section 2 and making plaques and powder. The powder samples were fabricated in a cryogenic grinder, and the plaques were compression molded. 

For a plastic to be suitable for RM, it must flow well enough to cover the mold surface evenly. As a powder, it must have a small-enough particle size and a low-enough melt viscosity to flow without bubbles or voids. Because it will be in contact with air on the inside, it must have good thermal stability. PE usually has a melt index of at least 2 to 3, in order to flow adequately. Solid plastics generally must be reduced to a uniform powder (via grinders, etc.) that will go through a 35 mesh screen, which is about 0.020 in. (500 /im) in diameter. 

Combination of press side for mold room or blow molding trim combined with central grinder for reject parts ... 

Anderson and Walker used on-line visible/NIR spectroscopy to measure fat content of ground beef streams. Thirty blocks of frozen beef from three truckloads each of nominally 50% and 15% fat were studied. The 27-kg blocks were ground and formed into a continuous stream on a conveyor with a custom molding head attached to the grinder. A diode-array type spectrometer was used to take reflectance measurements from the stream, which moved at 1.0 m/min. Measurements were made each 3.3 cm, and samples were collected from the stream such that each sample was represented by two successive measurements. The fat content of each sample was determined by ether extraction. SEP values for the calibration and validation data sets were 1.00% to 1.68% and 2.15% to 2.28% fat, respectively. Predictions for the fat content of an entire block gave SEPs of 0.70% to 1.05% fat. The results showed that the molding head was effective and that the NIR was suitable for accurate on-line measurements (19). 

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