The Effect Of Feed Ingredients On The Effect Of Granulation Process
May 17, 2021
Generally speaking, the factors that affect granulation are the source of raw materials, the moisture in the raw materials, the content of starch, protein, fat, crude fiber, the bulk density, the structure and particle size of the materials, and so on.
1. Particle size: The powder is pulverized to a fine size, which is beneficial to the progress of hydrothermal treatment. On the contrary, coarse-grained powder has low water absorption capacity and poor quenching and tempering effect.
2. Bulk density: The bulk density of the material has a direct impact on the output. When making the same granules and granulating materials with large capacity, the output is high and the power consumption is small. On the contrary, the output is low and the power consumption is high.
3. The influence of material chemical composition
1) Starch: Different forms of starch have different effects on granulation. The surface of the raw starch particles is rough, and the resistance to granulation is large. When the content of raw starch is high, the granulation yield is low and the compression mold is severely worn. The raw starch particles have poor binding ability with other components, and the final product is loose. The cooked starch, that is, gelatinized starch, exists as a gel after conditioning and absorbing water. The gel facilitates the passage of the material through the die holes and increases the granulation yield. At the same time, the gel can bond other components around after drying and cooling, so that the granular product has better quality. In the quality process, the starch granules are partially damaged and gelatinized in the process of being steamed and squeezed by the pressure mold and the pressure roller, and the viscosity will be produced, so that the prepared granule structure is precise and the quality is improved. In addition to the structure and properties of various starches, it is also related to the fineness of the powder. Therefore, when using corn and sorghum as the main raw materials, the crushing particle size should be paid attention to before pelleting.
2) Protein: The protein is heated and deformed to enhance the bonding force.
3) Grease: The oil inherent in the raw material does not cause the oil to be squeezed out due to the temperature and pressure during the granulation process, so it does not have a great impact on the granulation, and the addition of oil has obvious effects on the output and quality of the granulation. influences. Adding 1% grease to the material will make the particles softer, and will significantly increase the pelleting output, and will reduce the effect of the abrasion of the pressure die and the pressure roller. However, the raw material contains high oil content before granulation, and the obtained granules are loose. The amount of fat added before granulation should be limited to less than 3%.
4) Molasses: usually added in an amount less than 10%, it can be used as a binder, which is good for enhancing the hardness of the particles, and its effect depends on the material's ability to absorb molasses.
5) Fiber: There is no cohesive force by itself, but if there is too much fiber and the resistance is too large, the output will be reduced and the die will wear quickly. Materials with high crude fiber content are loose and porous inside, so the moisture content of the mold should be controlled. If the moisture is too high and the temperature is also high, the particles will expand rapidly after being ejected from the mold and are easy to crack.
6) Heat-sensitive raw materials: When adding certain vitamins, seasonings and other materials that are easily damaged by heat, the granulation temperature should be appropriately lowered and excessive addition is required to ensure the effective content of these ingredients in the finished product.
4. Binders Some feeds contain not many starches, proteins or other components that have a binding effect, making it difficult to make pellets. Therefore, it is necessary to add a binder to make the particles reach the desired degree of firmness.
