Разработка ионно-плазменной технологической установки для нанесения функционального покрытия на крышки масляных фильтров, страница 7

Flushing the cleared details is not less important operation, than clearing as on surfaces of details after cleaning operation always there are washing-up liquids  which should be removed in dry or liquid kind. After degreasing in solvents the cleared details rinse in baths with pure solvent rests of which evaporate.

Thus, processing of products by trichloroethylene is spent consistently in two baths with solvent, warmed up to 60оС. Duration of processing in each of baths makes 5 minutes.

The second stage of clearing is chemical degreasing. Water solutions for chemical degreasing contain the components forming soluble connections with saponifiable fats, couplings of a fatty film reducing force and mechanical pollution with the metal surface, facilitating solutions washing off and preventing corrosion of metal during degreasing. Such components are alkalis, phosphates, silicates and surface-active substance (SAS).

On the alkalinity degree degreasing solutions can be divided into three groups: heavy-alkaline for rough clearing of steel details (pH=12 … 14), middle-alkaline for clearing details before drawing of coverings (pH=10 … 12) and alkalescent for degreasing nonferrous and light metals (pH=8 … 10).

Phosphates improve washing ability of solutions, reduce rigidity of water, and promote dispersion of formed calcium and magnesium salts.

To improvement of details surface clearing quality from various pollution, reduction of process duration, alkalinity decrease of water degreasing solutions apply additives in a bath of SAS. Now use anionic SAS alkylsulfonate, sulfonal НП-3, sulfonal НП-1, ДС-РАС, nonionic SAS syntanol ДС-10, syntamid-5 and a number of others.

Including in degreasing solution of SAS in some times reduces duration of process. Activity of the additive increases, if alkaline salts are simultaneously entered into a solution. The some SAS, for example, syntanol, can be applied both in alkaline, and in sour solutions that is especially important at simultaneous degreasing and etching of metals.

To degreasing steel details apply solution into which structure enter 10 g/l trinatriumphosphate technical, 5 g/l sodium tripolyphosphate, 8 g/l syntanol ДС-10. Degreasing in the solutions containing syntanol, conduct at 65^оС, duration of processing in all cases makes 1-2 minutes.

The Bath for degreasing should have a drain pocket for regular removal of the pollution  layer collecting on a solution surface. The best result in this relation is given with the bath equipped by the pump which, taking away a pure solution from its bottom part, submits it again to the bath from above that promotes continuous updating of the electrolit superficial layer and removal of pollution in a drain pocket. Except for stationary baths, for degreasing use special washing installations which allow automating and accelerating process of clearing to a certain extent. In this case it is used a bath which contains one lot of products. Products place on the pallet and place in the bath. After processing the pallet with products take from the bath and send on following operation. Time of processing t_шт=2 minutes.

The third stage is washing in warm water at temperature 40ºС. Products place on the pallet and place in the bath. After processing the pallet with products take from the bath and send on following operation. Time spent for operation - t_шт=10 minutes.

The fourth stage of surface preparation is drying. Drying spend in oven, a steam cleaner or in the pure furnace by the hot filtered air. In developed technological process drying is made in oven. Products are located in oven in quantity of 15 items, after drying are taken, cooled and act on a following stage of processing. Time of drying t_шт=20 minutes, temperature of drying 80^оС.

After extraction of products from oven, they are subjected to the visual inspection over absence on them of smudges of water, fatty stains. In case of unsatisfactory surface condition the detail comes back to repeated clearing.