摘要 |
The invention relates to a method for the manufacture of an annular article, which substantially consists of metal, ceramic material, and/or polymer. A cavity in a die is filled with a formable working material, which shall form said article. A tubular, upper punch (17) is introduced into the upper mouth of a hole in a die (34), so that a closed mould cavity is formed. The upper punch and a lower punch (27) are simultaneously struck towards one another at such a high velocity that the working material is plasticized and flows out and fills the mould cavity, and thereafter the upper punch is removed. Then, a mandrel (35) in the lower punch is driven out of the annular body by means of a mandrel expulsor (170), which is pressed against the mandrel from above, and thereafter the annular body is from below pushed out of the die by mean of the lower punch. The invention also relates to an equipment for the carrying out of the method.
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