How to make the shape in the graphite production process of graphite products?

By:Yvonne Aug 26, 2020

There are various shapes of graphite products, and there are four main methods: molding, extrusion, extrusion, and isostatic pressing.
How to make the shape in the production process of graphite products
There are various shapes of graphite products, and there are four main methods: molding, extrusion, extrusion, and isostatic pressing.
1) Molding method
Using a vertical press, first make a mold according to the shape and size of the product, and then put a certain amount of kneaded paste or powder into the mold on the worktable of the press, and start the press to treat the paste or powder Apply pressure and maintain it for a certain period of time to make it shape, and then eject the pressed embryo from the mold. The molding method can be divided into one-way pressing and two-way pressing, hot pressing and cold pressing according to different processes and equipment. The molding method is suitable for pressing products with small dimensions in the three directions and the same three-dimensional dimensions, uniform density, and high-strength structure, but the products are anisotropic and are mainly used to produce electrode paste, anode paste and various specialties Graphite products.
2) Extrusion method
The extrusion method uses a horizontal extruder. The paste is first loaded into the press chamber, and the main plunger of the press is used to apply pressure to the paste. The nozzle in front of the material chamber that is consistent with the cross-sectional shape and size of the product is extruded, and then cut with a cutter according to the required length, which is the extruded green embryo. The extrusion method is suitable for rods, pipes or other special-shaped products with relatively large L/D. The extrusion method can be produced continuously, with high production efficiency, simple operation and high degree of mechanization, but the product has low volume density and mechanical strength, and has anisotropy. It is mainly used to produce graphitized electrodes, carbon electrodes and carbon blocks.
3) Vibration method
Vibration is to put the paste into the mold placed on the vibrating table of the vibration forming machine, and then place a heavy hammer on it, and use the high-speed vibration of the vibrating table to make the paste compact and form. The vibrating molding machine has a simple structure. As long as a small molding pressure is applied to the paste, a larger size product can be produced. It is especially suitable for the production of thick and short products and some special-shaped products with the same dimensions in the three directions of length, width and thickness, such as Pre-baked anodes, cathodes, carbon blocks and large or extra large carbon electrodes and cockles.
4) Isostatic pressure method
Isostatic pressure is completed in an isostatic pressure vessel. It fills the compressed powder into an elastic mold made of rubber or plastic, seals it and puts it in a high-pressure vessel, and uses an ultra-high pressure pump to drive high-pressure liquid medium (oil or Water), the pressed powder is pressed and formed. Isostatic pressing includes cold isostatic pressing and hot isostatic pressing. Isostatic pressing can produce isotropic products and special-shaped products with uniform structure, high density and strength. It is generally used to produce special graphite and large-size special graphite products.