EA009228B1 - Release coating for pattern fitting - Google Patents

Abstract

Release coating for pattern fitting relates to foundry, namely, to release coating compositions having antiburning properties stipulated by ability of coatings to separating “bright carbon”, since the release coating comprising petroleum base and still bottoms after processing synthetic fatty acids KO or USK-1, further contains flototar, and refiltered industrial oil as the petroleum base with the following component ratio, (wt %): refiltered industrial oil 60-70; still bottoms after processing synthetic fatty acids KO or USK-1 25-30; flototar 5-10. The release coating provides obtaining sharp “bright” pattern image without sloughing and edges jerking, burnt-on elimination in the bottom half-mold when moulding castings from 40 to 104 kg, improving surface quality and castings appearance.

Description

The invention relates to the field of foundry production, in particular to the compositions of the separation coatings for model equipment, namely, to the compositions of the separation coatings with non-stick properties, due to the ability of the coatings to release "shiny carbon" when casting molds with cast iron.

There are many technical solutions relating to the composition of the release coatings, using the effect of the release of "shiny carbon" (England, patent number 1034219, NC V3E, publication 1966; magazine "Foundry production" No. 11, 1964, p.39; USSR , A.S. № 827241, MPK V22S 3/00, BI No. 17, 1981).

In the compositions of the release coatings cited in these sources, substances having a certain ability to release "shiny carbon" were used: lamp soot, bakelite varnish, chloroparaffin, polystyrene, vat residues from the production of synthetic fatty acids (KO, USK-1).

For example, it is known separation coating for model equipment of the following composition, wt.%:

Kerosene (oil base) 30-95

Chloroparaffin 5-70 (USSR, AS, No. 831339, IPC V22C 3/00, BI No. 19, 1981).

Chloroparaffin - a substance capable of releasing "brilliant carbon" in the amount of 20-25%. However, this coating did not find application, since the required surface quality of the castings was not ensured.

The closest solution to the technical essence is a release coating for model equipment of the following composition, wt.%:

Graphite silver 20-30

White spirit35-40

Distillation residues from the processing of synthetic fatty acids35-30 (USSR, AS No. 827341, IPC V22S 3/00, BI No. 17.1981,).

The separation coating, which is applied to the model tooling, passes into the surface layer of the mold in the process of compaction and, when the mold is cast with metal, it burns out with release of “shiny carbon”.

This release coating has not found application in the foundry industry for the following reasons:

1. Existing separation coating devices in foundry shops do not ensure uniform distribution of the coating with a conditional viscosity of 30 s or more over the surface of the model equipment.

2. The presence of a solid fraction of the coating - silver graphite leads to delamination of the coating and clogging of the nozzles.

3. In the process of forming silver graphite accumulates in the corners of the models, as a result of casting they have burrs along the plane of the connector, which increases the complexity of cleaning operations.

4. The flash point in an open crucible KO and USK-1 is about 80 ° C, therefore this separation coating belongs to the class of dangerous liquids according to GOST 12.1. 044-89.

An object of the invention is to eliminate these disadvantages, namely:

1. Creating a separating coating composition capable of forming a uniform layer (film) on the surface of the model equipment of such thickness that would ensure a high-quality imprint of models and the presence in the surface layer of a form of “shiny carbon” in an amount sufficient to obtain high quality surface castings.

2. Development of a release coating, with conditional viscosity according to VZ-4, which allows the coating to be carried out using any existing devices in foundry shops, or manually (quat, brush).

3. Elimination of separation of the release coating and ensuring stable operation of the spray devices.

4. Improving fire safety in foundries by increasing the flash point in an open crucible to values that allow the separation coating to be classified as low-hazard liquids according to GOST 12.1.044-89.

The technical result from the use of the claimed invention is the provision of the coefficient of external friction of the pair “molding mixture-model” not more than 0.11; the release of "shiny carbon" release coating is not less than 20%, viscosity B 3-4 is not less than 20 s and not more than 25 s, the flash point in an open crucible is not less than 100 ° C.

This technical result is achieved due to the fact that the release coating for model tooling, including the oil base and bottoms from the processing of synthetic fatty acids KO or USK-1, additionally contains flotohmudron, and as the oil base - rega

- 1 009228 non-irradiated industrial oil, in the following ratio of components (parts by weight):

Regenerated Industrial Oil 60-70

Distillation residues from the processing of synthetic fatty acids TO or USK-125-30

Flotohudrone5-10

The inventive composition provides anti-friction and anti-burn properties of the release coating. As an antifriction additive used flotohud oil, which is a mixture of secondary tar, obtained from the distillation of fatty acids, isolated from the tar of various primary vegetable oils. Being an active surface-active substance (surfactant), flotohud oil helps reduce the coefficient of external friction of the pair “model-molding mixture” to 0.10 and reduce adhesion to 0.03 kg / cm ² , which contributes to obtaining a high-quality imprint of the model. Increasing the flotohudron content above 10% helps to reduce the yield of “shiny carbon”, while its content of less than 5% contributes to an increase in the friction coefficient, deterioration of compaction and cleanliness of the surface of castings.

KO or UKS-1, produced according to TU 38107123-89, is used as an anti-stitch additive, representing vat residues obtained as a result of processing (rectification or distillation by distillation) of crude fatty acids, C21 fraction and above, mainly saturated monocarboxylic, non-saponified substances and resinous condensation and polymerization products dissolved in a mixture of paraffin hydrocarbons. The content of the specified nonstick additive in an amount of more than 30% will help to reduce the flash point in an open crucible to a temperature of less than 90 ° C, which will impair the fire safety in the workshops; the content of bottom residues of less than 25% will lead to a decrease in the yield of "shiny carbon" and the deterioration of the cleanliness of the surface of castings.

Industrial regenerated oils are used as a solvent. These are oils of the I-20AR and I-30AR brands, manufactured according to TU 112-003-84. Regenerated industrial oils are preferable to fresh industrial oils, as they contain asphalt-resinous substances, providing an output of "brilliant carbon" of regenerated oils up to 18%. A content of more than 70% in the separation coating of the regenerated industrial oil will lead to a decrease in the yield of “shiny carbon”, and when its content is less than 60%, a decrease in viscosity and flash point in an open crucible is observed.

Separating coating is prepared by mixing all the ingredients at a temperature of 30-40 ° C for 3-5 minutes. The coating is applied to the model tooling using any of the known methods, for example, using a brush, a cloth or a spraying device until a uniform layer forms on the surface of the tooling. Separating coating suitable for application on models of plastic, steel, cast iron, aluminum, bronze and wood. Then the raw mold is applied to the model tooling and compacted with one of the known methods to form a mold. In the process of its manufacture, the separation coating applied to the model passes to the working surface of the form and remains on it in the form of a racing uniform layer, while ensuring a high-quality imprint of the models.

In tab. 1 shows examples of specific performance of the compositions of the proposed release coating and the properties of its constituent materials. In tab. 2 presents the properties of the composition of the separation of the coatings are given in table. one.

Compositions No. 1, 2, 3, called “Litaparm-P”, were industrially tested in foundry shops No. 1 and No. 2 of the Electromachine-Building Plant of OAO Eldin (Yaroslavl).

The results of industrial tests are as follows:

1. Obtained a clear “shiny” imprint of the form without flaking and undermining the edges.

2. Eliminated burner in the lower half-form in the manufacture of castings "bed" weighing from 40 to 104 kg.

3. Improved surface quality and appearance of castings "bed" and "shield".

The composition of the separation coating is designed for individual, flow-mechanized, and for the automated production of raw forms.

Examples of specific performance

Table 1

Material The compositions of the separation coatings, the masses. h Material properties one 2 3 The output of the "shiny carbon",% Flash point in open crucible, ° С Conditional viscosity according to VZ-4 at 20 ° С, s Regenerated oil 60 65 70 17.3 160 24 KO thirty - - 28.5 60 sixteen USK-1 - 27 25 28.5 60 sixteen Flotohudron ten eight five 13.6 230 23

- 2 009228

Separation Coating Properties

table 2

Properties The compositions of the separation coatings one 2 3 The output of the "shiny carbon",% 20.29 20.44 20.29 Conditional viscosity according to VZ-4 at 20 ° С, s 21.5 21.76 22.0 Coefficient of external friction at a pressure of 1 MPa 0.10 0.10 0.10 Flash point in open crucible, ° С 112 115 121 Adhesion value, kgf / cm ² 0.03 0.03 0.03

Claims (1)

Separation coating for model equipment, including oil base and bottoms from the processing of synthetic fatty acids KO or USK-1, characterized in that it additionally contains flotogudron, and as an oil base - regenerated industrial oil in the following ratio, wt.h. : Regenerated industrial oil Vat residues from the processing of synthetic fatty acids KO or USK-1 Flotogudron 60-70 25-30 5-10