SU442002A1 - Coating for metal molds - Google Patents

Description

one

1 The invention relates to the field of foundry, in particular to coating compositions of metal forms.

A coating of known casting molds is known, consisting of thermal insulating filler, silver graphite, bentonite, water, and sulfite-alcohol stillage.

However, the use of such a coating does not ensure the production of high-quality castings.

The purpose of improving the physical properties of the coating and eliminating the chill casting of castings is polyvinyl acetate glue (PVA) introduced into the composition of the proposed coating, and expanded perlite was used as a thermal insulating filler (in weight I:

Expanded pert20-23

Bentonite 10-12, Silver Gras- J

fit3-4

Polyvinyl acetate adhesive 0.1-0.2 Water Else.

The polyvinyl acetate adhesive is a latex plasticized dibutyl phthalate, which is taken up to 5.

Expanded perlite is used with a grain size of 0.05-0.3 mm. shesfo

/ expanded perlite as a heat insulating material can be used substances that impose a small volumetric (200 kg / mkg), low thermal conductivity (O, 06-0.10 kcal / m. hour and softening temperature 950-cp. C.

11р, the folded painting can be used, for example, in the casting of water and sewer pipes by the centrifugal method.

Prosher of the most optimal coating composition for metal (by weight): Expanded perlite 22 Bentonite II Silver Grain 3.8 PolyBINYLA acetate adhesive 0.2 Water 63 The specified composition is applied to a rotating preheated mold, creating a coating layer after evaporation of water O, 2 -0, 4 mm. : Bentone ging, included in the composition of the coating, improves the suspension's ability to spray when applied to a mixture and partially fulfills the role of a binding material. Silvery graphite increases the compliance of the coating and facilitates removal of the casting from the mold. Polyvinyl acetate adhesive helps to achieve a uniform coating layer. The decomposition products of the adhesive TWO., Formed under the action of the heat of the molten metal in the process of casting the pipe, contribute to the peeling of the coating from the brick and removing it from the latter together with the pipe. The low thermal conductivity of the coating makes it possible to obtain cast-iron pipes without bleaching throughout the entire wall thickness. The composition of the proposed coating. It can be shchmenny for the production of chipped off castings WATER WATER Sewer chimney of OTHERCong-iron castings produced in metallic forms,; . IZOBRKGSHIN The coating for metal forms, which includes thermal insulating filler, silver graphite, bentonite and VO.TSU, which is designed to improve the thermophysical properties of the coating and eliminate the chill casting of castings polyvinyl acetate adhesive, and expanded perlite was used as a thermal insulating filler with the following ratio of components (in weight): expanded perlite 20-23 Bentonite 10-12 Graphite silver 3-4 Polyvinyl acetate adhesive 0.1-0.2 Water Remaining.