SU831339A1 - Releasing coating for pattern equipment - Google Patents

Description

paraffin hlorparafin in the following ratio of ingredients, wt.%:

Kerosene 30-95

ChloroparaFin 5-70

ChloroparaFin (1U-6-01-568-76) is a low-viscosity liquid that mixes easily with kerosene at virtually any temperature and in any ratio without additional mixing.

Chloroparafin contains the following components, wt.%:

52-50

Paraffin Chlorine St. 46-48. Epoxidin

The rest is resin

The non-stick effect of chloroparaffin on steel casting is associated with the fact that the release coating that is applied to the model tooling during the manufacture of each half-form passes into the surface layer of the mold and, when metal is cast, it burns, forming an atmosphere saturated with chlorine and hydrogen, which protects metal from oxidizing it with air oxygen. When cast iron is produced, the antistick action is associated with the release of bright carbon from chloroparaffin of 20–25%.

The compositions and properties of the coating are given in table. 1 and 2.

Table 1

97 95 90 80 70 50 40 Kerosene Chlorpa5 10 20 30 50 60 Raffin Paraffin Viscosity, since 11 11 12 12 12 12 Friction coefficient 0.15 0.11 0.10 0.10 0.10 0.10

The coating is prepared by pouring kerosene and chlorine paraffin into one container in the required ratio. It is preferable to pour chloro-paraffin into kerosene. The preparation of the coating is greatly simplified by eliminating the melting and mixing of the components.

When working with chloroparaffin, no special precautions are required, as it is not a current | Sich, an explosive, volatile and spontaneous combustion product.

table 2

The optimum content of chloroparaffin in the release coating is 5-70% by weight.

The content of chlorine paraffin in the release coating is advisable to be set depending on the weight of the castings produced. For example, for castings weighing up to 20 kg, the release coating should contain 5-10 wt.% Chloroparafia, for castings weighing 200-300 kg - 60-70 wt.%.

When the content of chlorine paraffin in the release coating is less than 5%, the coefficient 30 20 85 85 80 70 80 10 15 20. 15.2 20.5 15 18 20.0 0.10 0.10 0.10 0.2 0.18 0.5

friction of the mixture according to the model equipment increases, which entails a deterioration in the quality of the surface of the forms.

An increase in the chloroparaffin content of more than 70 wt.% Is impractical, since no further improvement in the quality of the castings is observed, moreover, with a viscosity of more than 20 s, the coating hardly passes through the spraying device, which does not allow the coating to be applied to the equipment in a uniform layer the required amount during one cycle of the molding machine.

The proposed coating, by reducing the friction of the moldable mixture according to model equipment, makes it possible to increase the hardness of the packing in difficult-to-form places of the mold by 20 units. (hardness gauge), and in: an average of 10 units. This, in turn, makes it possible to increase the weight and dimensional accuracy of castings by an average of up to 3% by reducing the expansion of castings.

Due to the higher anti-burn properties of the proposed cast, compared to the known, the burner is reduced by 50%, thereby improving the quality of the surface of the castings.

The implementation of the invention allows to significantly reduce the friction of the molding mixture according to the model equipment, which

favorably affects the process of shaping, leads to an increase in hardness, and consequently, the density of the fork, the uniformity of its compaction, and all this leads to an increase in the geometric and weight accuracy of castings.

Claims (2)

1. USSR author's certificate No. 4X4039, cl. B 22 C 3/00, 1971. 2. Japanese patent 52-33827, cl. 11 A 213, 1977,