CS270991B1 - Wax modelling material - Google Patents

Abstract

The solution concerns a wax modelling paste used for creation of wax models with inserted ceramic cores of a very thin cross section. This wax paste contains paraffin as a carrying component in which micro-wax, ceresine, natural resin and stearic acid are dissolved. The liquidity and running property of the wax modelling paste into very fine cavities of metallic mould is achieved by adding vaseline oil.

Description

(57) The _{present invention} relates to a wax modeling mass which is used for making wax models from embedded ceramic cores of very thin cross-section. This wax pattern mass contains paraffin as the carrier component in which microwax, ceresin, vegetable resin and stearic acid are dissolved.

CS 270 991 B1

CS 270 991 Bl

The invention relates to a wax pattern mass, in particular for making wax patterns with an inserted ceramic core of thin cross section.

In the casting of various components by the melt process model, wax model compositions of compositions such as montan wax, paraffin, ceresin and stearin are used to make wax models. These wax patterns show considerable water affinity, high brittleness, and poor runability into metal molds.

Other wax patterns contain only montan wax and microcrystalline wax, which no longer have an undesirable affinity for water.

However, there are a number of difficulties in making wax patterns with a thin ceramic core inserted, such as casting different nozzles, since these wax patterns require high pressure for the perfect injection of the ceramic core. This results in breakage or complete destruction of the ceramic core of thin section.

It is therefore an object of the invention to overcome this drawback of wax modeling materials. to provide such a model wax mass that would require low pressure when spraying ceramic cores and that would exhibit high fluidity and run-in to very small cavities of metal molds while maintaining all other necessary properties of the wax model masses.

The objective is achieved by a wax model mass comprising 40 to 10 wt. 52 to 54 ° C, 40 to 20 wt. % microwax having a drop temperature of 85-95 ° C; 15-40 wt. m.p. 45-55 ° C; 3-10 wt. % vegetable resin, 1 to 10 wt. % of stearin according to the invention, further comprising 1 to 10 wt. % vaseline oil.

The wax pattern of the present invention exhibits high fluidity and flushability in very fine metal mold cavities using minimal injection pressure, while retaining all the required properties of the wax pattern materials, such as low adhesion to the metal mold walls, easy and ashless removability from the mold shell cavities, low thermal expansion.

The invention is illustrated in more detail by the examples of the composition of the wax pattern mass and its components.

Example 1 wt. % paraffin w / w; % microwax w. % ceresin wt. % resin of plant mass. % stearin wt. % vaseline oil

Example 2 wt. % paraffin w / w; % microwax w. % ceresin

CS 270 991 B1 wt. % vegetable resin

7.5 wt. % stearin

7.5 wt. % vaseline oil

Example 3 ¹ wt. % paraffin w / w; % microvolume wt. % ceresin wt. % resin of plant mass. % stearin wt. % of vaeeline oil

Paraffin with a melting point of 52-54 ° C is a white solid with a coarse crystalline structure, ensuring perfect homogeneity and mixing of all the components that dissolve in it in any ratio and give the finished models a smooth and glossy surface. Chemically, paraffin is a mixture of saturated paraffinic hydrocarbons of a saturated series obtained by dewaxing mineral oils.

Ceresin with a melting point of 45-55 ° C is a white to slightly yellow substance containing predominantly a mixture of isoparaffinic hydrocarbons, which significantly affects the mechanical properties of the wax model mass, in particular its elasticity and ductility.

Microcrystalline wax having a drop temperature of 85 to 95 ° C, a dynamic viscosity at 100 ° C of 80 to 110 cP, a penetration at 25 ° C in the range of 5 to 15 is a petroleum petrolatum composed of a mixture of hydrocarbons of alkanes and alkenes with a very fine microcrystalline structure. content of bound oils.

Stearin is a mixture of solid fatty acids, especially stearic, palnitic and oleic. It is obtained by the cleavage and distillation of solid fats such as bone fat, tallow or palm fat. With the other components of the wax model mass improves their flowability.

Vegetable resin is part of a plant secretion that flows spontaneously from some tree plants. It is a nitrogen-free substance, constituting the last stage of spontaneous or forced oxidation of essential oils. It is light yellow, shapeless, fragile and shiny. It gives the wax model mass higher strength and hardness in solid state.

Vaseline oil is a mixture of lower, liquid, paraffinic saturated hydrocarbon series hydrocarbons obtained by dewaxing mineral oils and refining paraffin. Its addition to the wax pattern mass significantly improves the flowability and hence the agglomeration into the fine cavities of the metal molds, further reducing adhesion to the metal mold walls.

The production of the wax pattern mass from the above-described components is conveniently accomplished by melting, first melting the paraffin, then ceresin, microwax, stearin, resin, and finally mixing the vaseline oil in the perfectly melted mixture.

Claims (1)

CS 270 991 B1 SUBJECT TO THE INVENTION A wax modeling mass, in particular for making wax models having an inserted ceramic core of a thin cross-section, comprising 40 to 10 wt. 52 to 54 ° C, 40 to 20 wt. % microwax having a drop temperature of 85-95 ° C; 15-40 wt. m.p. 45-55 ° C; 3-10 wt. % vegetable resin, 1 to 10 wt. % vegetable resin and 1 to 10 wt. % stearin, further comprising 1 to 10 wt. % vaseline oil.