SU1342883A1 - Method of heating cold press mould for moulding glassware - Google Patents

Abstract

The invention relates to the technology of pressing glassware such as hubcaps or bowls. The purpose of the invention is to increase the durability of the mold. After installation of the mold, the rejected glassware is inserted into it. The glass mass is then manually loaded into the cavity of the glassware located in the mold. After warming up the mold, the mold is removed from which the solidified casting is removed. With this, the temperature drop is reduced, and consequently, the magnitude of the thermal shock is doubled. 1 ill., 1 tab.

Description

The invention relates to methods for preheating dies for pressing glass products such as caps or bowls.

The purpose of the invention is to increase the stability of the mold.

It is known that the intensity of the thermal interaction between the metal mold and the melt can be controlled by creating a certain thermal resistance at the interface of the melt and the working surface of the mold. Due to lower thermal conductivity compared to metal

and chill occurs thermal resistance to heat transfer

the cladding between the casting 15 at this temperature, the mold is opened and the partially complete molding is removed from the molten glass.

The table shows the temperature of the working surface of the mold without installing the 20th glass cap and installing it into the mold.

From the table it can be seen that during the first 3 s from the moment of contact of the drop of molten glass with the mold

one

T

E

.

R

E cr

where ft is the thermal conductivity coefficient of the refractory coating;

the thickness of the refractory coating layer;

thermal conductivity of refractory coating. Thus, the use of an insert with a low thermal conductivity allows one to reduce a sharp drop in temperature in the first seconds of heating.

The drawing shows the scheme of heating the cold glass form.

In the mold 1, a glass article 2 and molten glass 3 are placed. The method of heating a cold mold is carried out as follows.

After installing a new mold, the rejected glassware is inserted into it. Then the molten glass mass is manually or automatically loaded into the cavity of the glassware 2, which is in the mold. After warming up the mold, a mold is made from the mold, from which the solidified casting, baked from glass unit 2 and glass mass, is removed.

For example, a 130 kg mold is heated to make

25 (time during which a small temperature difference occurs), the working surface of the mold without the inserted cap warms up to I4l c and the temperature difference is 116 C. The working wall of the mold with the insert30

35

40

The heated cap warms only to 76 ° C, and the temperature difference is 51 ° C.

Thus, the installation of a glass cap before heating a cold mold reduces the temperature drop, and hence the magnitude of the thermal shock twice.

Claims (1)

Invention Formula 45 The method of heating a cold mold for pressing glass products such as caps by feeding molten glass into its cavity, characterized in that, in order to increase the durability of the mold, a defective product is installed in the cavity 50 i ° P b before feeding the glass mass. glass caps with a wall thickness of 12-15 mm and a weight of 1.5 kg. At the beginning of the shift, after the mold is installed on the table, under a pressing mechanism, a glass bell is inserted into it, which has previously been pressed, annealed and rejected on the chip. After 1 minute, melted glass mass is poured in with a spoon from the furnace and at 1300 ° C the glass bell is loaded until it is completely filled. The glass melt is in the mold 424 until the mold surface reaches a temperature of 260 ° C. With (time during which a small temperature difference occurs), the working surface of the mold without the inserted cap warms up to I4l c and the temperature difference is 116 C. The working wall of the mold with the insert The heated cap warms only to 76 ° C, and the temperature difference is 51 ° C. 35 40 Thus, the installation of a glass cap before heating a cold mold reduces the temperature drop, and hence the magnitude of the thermal shock twice. Invention Formula The method of heating a cold press-FORM for pressing glassware of the type of caps by feeding molten glass into its cavity, characterized in that, in order to increase the durability of the mold, a defective product is installed in the cavity i ° P b before feeding the glass mass. 25 101 25 47 141,152 178 260 47 76 94 260