how to make a graphite mold?
High-purity graphite is chemically treated, washed with water and expanded at high temperature to obtain a flexible and fluffy graphite material. This is not the ultimate goal. The ultimate goal is to make graphite products for various purposes. If it is made of graphite paper foil, it must be processed by forming and processing graphite products of various specifications, shapes and sizes by mechanical methods. There are currently several forming methods: (1) Rolling method; graphite tube, graphite tube, graphite groove, graphite rod, etc. (2) Molding method; (3) Extrusion method.
1. Rolling forming method
Mainly for pressing graphite paper foil or sheet. There are two types: single-layer flat continuous rolling and multi-layer flat continuous rolling.
1. Single-layer flat continuous grinding and pressing method
This grinding pressing method can press flexible graphite into a plate without any binder. The whole process is carried out on the special equipment inserted into the roller compactor.
The structure of the roller compactor: hopper 1, vibrating feeding device, 2, conveyor belt 3, four pressure rollers 4, a pair of heaters 5, a roller that controls the thickness of the sheet, an embossing or pattern roller 8 and Roll 9 cutting knife 10 finished roll
Working process: High purity graphite enters the feeding device from the hopper and falls on the conveyor belt. Through the crushing pressure of the pressure roller, a material layer of a certain thickness is formed. The heating device generates high-temperature heating to remove the residual gas in the material layer, replace the unexpanded graphite and expand once. Then the preliminarily formed reverse material is sent to a roller with a controlled thickness and size, and pressed again according to the specified size, and braked to obtain a flat plate with uniform thickness and a certain density. After being cut by a cutter, the finished tube is rolled.
2. Single-layer flat plate grinding and pressing method
Single-layer flat plate grinding and pressing, although the pressing plate is flat and smooth, it should not be too thick. When the one-time molding is too thick, its uniformity and density are difficult to guarantee. In order to make a thick board, multi-layer single boards are overlapped and pressed into a multilayer composite board. Filling should be added between every two layers and then rolled into shape. After molding, heat treatment is required to make tungsten carbide and harden. The multi-layer flat plate rolling method is carried out on a multi-layer continuous rolling machine.
The working process of the multi-layer continuous rolling machine: the veneer is led out from the veneer by winding the roller, and after the two sides of the soil are connected by the segmented coating roller, it is combined with the winding roller and the veneer to become a Sanhe thick plate, which enters the gap of the roller for grinding Into a certain thickness. Then send it into the heater to heat and dry. Through the thickness control roller, the thickness is adjusted to the specified size, and then sent to the roasting device for roasting. After carbonization and carbonization, it is press-formed after using a compression roller.
The continuous rolling grade used can compress flexible graphite plates with a thickness of 0.6~2mm. This is a laminated single-layer rolling machine, but due to the thickness of the plate, it will also bring about the disadvantages of plate segmentation, which brings trouble to use. The reason is that the gas overflows and stays in the middle of the interlayer during pressing, which interferes with the tight bonding between the layers. The way to improve is to solve the exhaust problem during the pressing process.