The Differences between Cold Press and Hot Press in the Manufacture of Diamond Tools

In the production of diamond segments, diamond grinding blocks, small diamond blades and diamond grinding wheels, one method is to first cold press them into their required profiles and then put them into a kiln for sintering. Another method is to directly sinter them under a certain pressure.

The first method is usually called cold press. It first uses a press machine to cold press the mixture of diamonds and bond powder to their profiles, and then put them in a kiln with reduction atmosphere to sinter them. Though its yield is big, its production procedure and equipment are complex; the blanks after the cold pressing are subject to damage in movements; and the sintering period can be several hours. Also, as the blanks are not pressed during the sintering, the end products’ density is low, so they are subject to deformation, and their quality can not be guaranteed.

The second method is usually called hot press. It puts the diamond mixture into a mold, and then uses a dedicated sintering press machine to press it to its profile and sinter it to an end product at one time. Its production procedure is simple; its sintering density is high; and the end products’ quality is good. Its production period is normally within 15 minutes. This method is widely used by the industry.