Technology of alkyd enamel production (technical diagram)

This work describes a step-by-step technology for the production of alkyd enamel, attached is a production flow chart Description of the production technology for alkyd enamel 1) Loading of raw materials into a dysolver and production of pigment suspension. The pigment suspension is manufactured in a dysolver (pos. 2.1) equipped with a toothed disk stirrer. Before loading the raw material, the disolver is checked for cleanliness and serviceability. If necessary, the dysolver is closed with a solvent. Components are loaded according to loading recipes (Table 2.4). The fan is turned on. Varnish through the weight gauge (pos. 2.7) installed on the scales (pos. 2.8), by pump (pos. 2.11) is supplied to the dysolver (pos. 2.1). When the stirrer is in operation, pre-weighted weights are loaded in small portions (pos. 2.6) pigments. After loading, the contents are mixed for 30 minutes until a uniform mass is obtained. Homogeneity of the pigment suspension is checked by pouring the sample onto the glass. At the same time, a sample is taken to check the viscosity of the suspension. If the viscosity of the suspension is greater than the required one, additional lacquer may be added and the lacquer content of the finished enamel shall be in accordance with the standard prescribed by the recipe. The finished pigment slurry is pumped to a bead mill for dispersion. 2) Dispersing the pigment slurry on a bead mill. Pigments are dispersed on a beaded mill (pos. 2.3). As grinding bodies, glass balls (beads) with a diameter of 2‒4 mm are used. The mass of the beads in the cup of the mill ‒ 50 kg. The bead mill is equipped with water cooling to prevent overheating of the pigment suspension, since the dispersion process is accompanied by significant heat generation. The temperature of the slurry at the outlet of the bead mill shall be within (45 ± 5) ° C. The temperature of the slurry during dispersion is controlled by supplying water to the cooling jacket of the bead mill. The amount of pigment slurry entering the mill is controlled by the feed pump variator so that the degree of slurry rubbing is not higher than 30 μm. 3) Manufacture of enamel and stop it "on the type." Enamel manufacture and its setting "to the type" by color, viscosity and content of non-volatile substances is performed in the mixer (pos. 2.12). To mixer (pos. 2.12) varnish is supplied through weight gauge (pos. 2.7) installed on the scales (pos. 2.8) by pump (pos. 2.11). The pigment slurry is pumped to the mixer (pos. 2.5) from intermediate container (pos. 2.4). When feeding the slurry, it is necessary that the mixer mixer is operated to prevent the paste from settling. The mixer is supplied by counter (pos. 2.9), siccative. After loading, the contents are mixed for 1 hour, then the viscosity is checked (to be in accordance with Table 2.1), kept for 4 hours with the agitator off to stabilize the viscosity, and then mixed for 30 minutes. Viscosity is checked. If the viscosity has increased, the solvent is added, stirred for 30 minutes, held for 1 hour with the stirrer turned off, stirred for 15 minutes, the viscosity is determined. This process is repeated until the viscosity of the two samples taken sequentially for a period of at least 1 hour, being within the normal range, differs from each other by no more than 5 s. The amount of solvent used in this process should not exceed 10% of the weight of enamel. Finished enamel is checked for compliance with all requirements of GOST 926-82. 4) Filtration, drain to container. Finished enamel from mixer by pump (pos. 2.13) is supplied through the filter (pos. 2.14) for packing in a barrel and drums (pos. 2.15) installed on the scales (pos. 2.2), and packing in small containers is performed through the collector (pos. 2.16), also using a filter.