What to pay attention to when using a sanding machine
To achieve the ideal grinding effect, not only to have efficient equipment, but also to have a certain amount of technology. In grinding, you should generally pay attention to the following aspects of the problem.
1. Pre-dispersion. Pre-dispersion is an essential process for grinding using a sanding machine. EnterSand GrinderThe material is necessary even, such as uneven feed, not only easy to form pipe obstruction, and the formation of grinding start stage of the grinding effect decline, so it is necessary to pre-dispersion.
2. Grinding media. Grinding medium is with the sanding machine supporting the grinding data, the material crushing depends on it to achieve, so its physical and chemical indicators and application methods have a direct impact on the use of sanding machine, can be said to determine whether the grinding process is the key to success. The general selection of grinding medium should be spherical, good chemical stability, neutral, wear-resistant, impact resistance, no adverse effects on fluorescent brightener. Can be used steel beads, glass beads, ceramic granules, zirconia and so on, but the use of more is zirconia. The relative density of the grinding medium varies greatly depending on the data, in general, the relative density of the medium is related to the viscosity of the slurry, and the viscosity of the slurry suspension is generally ideal for the medium around the 0.04-0.08PA.S. Commonly used, the use of relative density of 2-3 grinding media conditions are shown in table 1-4-5
The efficiency of spherical grinding medium is higher, the more uniform the particle size distribution of the medium, the more uniform the particle size of the product, the higher the grinding power and product quality, and the grinding medium is not easy to break. In general, the size of the medium used to guess the size of solid particles and the size of the product particle size requirements to determine. The medium particle size used for the grinding of fluorescent brightener is generally the filling rate of 0.6-1.5mm grinding medium has a direct effect on the grinding power and the consumption of the medium. The filling rate of the general grinding medium, about 50%-60% of the useful volume of the open vertical sanding machine for the grinding container, and the useful capacity of the closed vertical or horizontal sanding machine (including double cooling, biaxial type) for the grinding container (70%-80% of the constant accumulation).
3. Conditioning viscosity. The size of the material viscosity in the sanding machine affects the grinding efficiency, the viscosity control is necessary with the size of the grinding medium and changes, the particle size of the grinding medium can be larger, the particle viscosity is smaller, the general solid rate control in the 20%-30% to adhere to the viscosity in a certain range.
4. Temperature control. Because of the conflict of the media in the grinding process to produce heat, so that the temperature rise, will form a decrease in viscosity, but also may cause crystal changes, become the desired crystal type, and then affect the performance of the product, so most of the selection of lower grinding temperature.
5. Organization of the process. Because fluorescent brighteners often have to be grinded several times to meet the requirements of use, the organization of the process should be carefully studied in order to obtain a narrower distribution of material particles and higher grinding power.
Control of 6.PH values. In order to insist on the stability of the material in the grinding process and the colloidal dispersion of the particles in a good state, it is generally necessary to use acid or alkali (such as phosphoric acid or sodium hydroxide, etc.) to be mixed in crystallization or set in the particles of alkali or acid (these alkali or acid will be released in the grinding), the general control of ph=8-8.5
7. Get together. Dispersed fluorescent brightener in the grinding or its slurry before the spray drying a part of the seizure agglutination, in order to make the spray after the product can be better dispersed, fluorescent brightener before drying, the homogenization can be used to solve the polymerization.
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