SU801960A1 - Releasing coating for pattern equipment - Google Patents

Description

one

The invention relates to a foundry, in particular, to compositions of release coatings for model tooling used mainly in the manufacture of raw sand-clay forms of machine molding.

Known separation coating containing kerosene and mineral oil I.

However, such a coating has a high viscosity and can be applied with a relatively thick layer, which does not provide the required accuracy of the molds or cores.

Closest to the invention to the technical essence and the achieved result is a coating containing kerosene and fatty oleic acid 2.

However, this release coating contains a significant amount of expensive oleic acids. In addition, oleic acid has a specific odor. OntiiT applications of such

Coatings showed that vapors of sprayed acid, released into the atmosphere of the workshop, irritate respiratory organs of workers.

The aim of the invention is the reduction of the cost of the starch: hygienic conditions and a reduction in the cost of the coating.

The goal is achieved by the fact that the coating additionally contains mineral oil in the following ratio of ingredients, wt.%: Mineral oil 4, O-6, O Oleic acid 1, O-4, O Kerosene Else

The preparation of the separation coating should be followed. The mineral oil and oleic acid, which is a fatty acid, is added to kerosene and mixed until a homogeneous solution is obtained. The resulting liquid is applied to the model line by spraying, for example, PU} GE, and other known methods.

The introduction of a separating coating of mineral oil in combination with a reduced content of fatty acid does not increase the adhesion of the mixture to the model.

Examples of release coating compositions and their adherence values are given in Tables I and 2 below.

The compositions of the individual coatings according to the invention were tested under production conditions, composition No. 3, and coatings without oleic acid MI and without mineral oil, No. 2.

These coatings were applied to model tooling in the manufacture of sandy-clay forms on the automatic molding line of the Kupnoye foundry, which has the following physical and mechanical properties;

ffr.

hedgehog, kgf / cm

kgf / cm

Humidity,%

Gas permeability, units Forms compacted at too kgf / cm.

The quality of the form was evaluated by the hardness of the end surface of the lower middle dummy, measured by a hardness meter, mod. 071. 310.

The minimum hardness value is observed when using composition No. I When using composition No. 3, a narrower range of hardness distribution is provided, and in the interval 56-7O 84% of all measurements for composition No. 2 are 50.4%. for the composition number 1 - 49,19). The average hardness values are respectively 63.7; 36.44; 53.8.

Thus, the composition number 3 provides higher stability of the quality of forms.

The implementation of the invention makes it possible to completely eliminate the adhesion of the mixture to the model equipment and to improve the sanitary and hygienic working conditions, since there is practically no specific smell and irritation of the respiratory tract due to the low content of oleic acid. Table 1

Kerosene 94.5 93.5 92.5 91.5 91.5 Specific shear force (stickiness), kgf / cm 0.19 0.182 0.157

Kerosene

Industrial oil

Oleic acid

Table 2

100

92.5

2.1 0.141 0.138 0.19 0.186 0.157 0.137 0.134 94.5 9492.5 91 9O Table 3

Hardness of forms, units, with a frequency of observations of this value of hardness,%:

when making raw sandy clay forms, including kerosene and oleic acid, it is different from the fact that, in order to improve the soil safety and cost reduction, the coating additionally contains mineral oil in the following ratio of ingredients (in weight,%):

Sources of information taken into account in the examination of t. Krivishshy M. Ya. And others. Cellular concretes. M., Stroyededat, 1972, p. 31.

2. USSR author's certificate No. 4OO4O2, cl. In 22 SZ / OO, 1972.

Claims (1)

SUMMARY OF THE INVENTION Separation coating for model equipment used primarily in the manufacture of raw sandy clay forms, including kerosene and oleic acid, which are distinguished by the fact that, in order to improve sanitary conditions and reduce production costs, the coating additionally contains mineral oil in the following ratio of ingredients (in weight.%) : Oleic acid 1.0-4.0 Mineral oil 4 _ъ 0-6,0 Kerosene Else