Common mold stability problems and solutions

Update:25-08-2020
Summary:

During the use of the Plastic Injection Molds, it is ne […]

During the use of the Plastic Injection Molds, it is necessary to adopt a certain production line according to the production requirements or technical requirements. Sometimes when some details are not paid attention to, many factors will cause the instability of the mold, which will seriously affect the use of the mold manufacturing workpiece. Therefore, we must pay attention to related stability issues when manufacturing.

 

Stability of die and stamping and its influencing factors

 

What is stability? Stability is divided into process stability and production stability. Process stability refers to a stable process plan for producing qualified products; production stability refers to a stable production capacity during the production process.

 

Let us first take a look at the main factors that affect the stability of mold and stamping forming. They are: the use of mold materials; the strength requirements of mold structural parts; the stability of stamping material performance; the fluctuation characteristics of material thickness; the range of material change The resistance of the tensile ribs; the range of the blank holder force; the choice of lubricant.

 

Comprehensively weigh various factors affecting stability

 

It is worth noting that in the stamping process, since each stamping sheet has its own chemical composition, mechanical properties and characteristic values ​​closely related to stamping performance, the performance of stamping materials is unstable, the thickness of stamping materials fluctuates, and The change of stamping material not only directly affects the accuracy and quality of stamping forming, but also may cause damage to the mold.

 

 

Take stretch ribs as an example, it occupies a very important position in stamping forming. In the stretch forming process, the forming of the product requires a certain amount of tension that is appropriately distributed along the fixed periphery. This tension comes from the force of the stamping equipment, the deformation resistance of the material at the edge, and the flow resistance on the blank holder surface. . If the flow resistance only depends on the blank holder force, the friction between the mold and the material is not enough.

 

For this reason, it is necessary to set up a tensile rib that can produce greater resistance on the blank holder to increase the resistance of the feed, so that the material produces greater plastic deformation to meet the requirements of plastic deformation and plastic flow of the material. At the same time, by changing the size and distribution of the resistance of the stretched ribs, and controlling the speed of the material flowing into the mold and the amount of feed, the effective adjustment of the tensile force and its distribution in each deformation zone of the stretched part is realized, thereby preventing stretching Product quality problems such as cracks, wrinkles, and deformation during forming.

 

It can be seen from the above that in the process of formulating the stamping process and mold design, the size of the tensile resistance must be considered, and the tensile ribs are arranged according to the change range of the blank holder force and the form of the tensile ribs are determined, so that each deformation area is deformed as required The way and the degree of deformation are completed.

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