In the manufacturing and debugging deep drawing stamping, or stamping parts, some bad phenomena often occur: the stamping process of die has been verified by CAE software simulation, but the mass production is completed after the mold is finished. There are problems in the process, such as cracking or wrinkling; even some molds are very good in debugging on the test, but after lifting to the production line, the stamp products are not qualified and cannot meet the technical requirements; there are also some systems. In the mass production process, most of the product quality is no problem, but there will always be several pieces NG.

Through last week Fujipunch ship mold to Vietnam, we concluded that stability issues can be divided into process stability issues and production stability issues.

1. Process stability refers to a qualified and stable process plan, the process plan must be able to meet a certain range of process conditions (such as the amount of blank holder force) within a certain range, can also get a qualified product . In actual production, there are often some process plan is no problem by design. Also no problems are found through CAE simulation software analysis, but it is found to be extremely sensitive to changes in process conditions during production. Small changes in process conditions often lead to large changes in product quality. This problem can be classified as a process stability problem.

2. The problem of production stability refers to the change of conditions such as the background of the noise generated in the production process, such as the change of the thickness of the sheet material, the instability of the material properties, the change of the lubrication conditions and the offset of the pressure center of the machine tool. So that stamping parts is unqualified or the scrap rate is too high.

In the field of deep drawing stamping manufacturing or the stamp parts, the engineer has the suitable solution in the technical design stage and in the production stage. But reality often has a certain gap with the expectations of technicians. Many times, based on existing experience or current traditional CAE analysis methods, the stability problems in the process design scheme cannot be found. This is to be checked by the cooperation of the mold designer and the mold adjustment master.