Molding tool for molten metal or glass
A molding tool made of carbon or graphite, namely a casting mold or a casting core for the processing of molten metal or to a molding tool for the processing of molten glass, such as for example a blow mold and a method for producing the molding tool.
1. A method for producing a moulding die for molten metal or glass, comprising the following steps:
a) providing a powdered composition, which consists of carbon particles in a proportion of at least 50 wt. %,
b) providing a liquid binder,
c) planarly depositing a layer of the powdered composition provided in a), and locally depositing droplets of the liquid binder provided in b) to said layer, and repeating step c) a discretionary number of times, wherein the step of locally depositing the droplets in subsequent repetitions of said step c) is adjusted according to a desired shape of the moulding die to be produced,
d) curing or drying the binder and obtaining the moulding die;
wherein the carbon particles consist of acetylene coke.
2. The method according to claim 1 , wherein the moulding die is heat-treated at least 500° C.
3. The method according to claim 1 , wherein the moulding die is heat-treated at least 2,000° C.
4. The method according to claim 1 , wherein the moulding die is subject to supplementary densification one or more times, this process comprising the following steps:
impregnating with a carbon-delivering medium, and
carbonising at a temperature of between 500° C. and 1,300° C.
5. The method according to claim 1 , wherein the particles of the powdered composition in the grain size range of d50 have a shape factor (width/length) of at least 0.5 on average.