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Sipxmach shares: A simple method to solve the problem of jumping waste (scrap jumping out of high speed stamping die), make your progressive stamping more efficient

Whether there is any problem with the mold requires actual inspection. Usually, the number of new mold will have problems, which requires the fitter master according to the actual adjustment.

However, some problems are entirely avoidable or predictable. For example, in the high-speed mold, the common problem of mold test is “jumping waste” (jumping waste, refers to the mold operation, the waste should fall through the mold hole, but was pushed to the die surface, and affecting production)

When this problem occurs, the waste products brought to the mold surface can easily damage the plate, punch or cutting edge; affecting the quality of stamping parts; reducing the service life of the mold and reducing the production efficiency.

This is the most common and worrying “big problem” with high-speed models.

The cause of jumping waste

1. Causes

2. bring the waste up

In the process of high-speed stamping, the movement speed of the punch is more than 800m/s, and the stamping oil is generally used, resulting in local vacuum between the punch and waste materials.

In particular, when the stamping material is thin, the scrap weight will be light, and the friction with the blade will be very small.

In the upward process of the punch, the scrap is carried out the die surface by the punch, and jumping waste occurs.

2. Main factors

There are many factors that affect waste jumping, such as:

  • Punch avalanche Angle
  • Punch passivated
  • Excessive stamping oil
  • Thin material
  • Punch effective blanking too short, etc

3. prevention methods

1. Reduce the contact area between the punch and the product

  • A.Groove on the punch contact surface.
  • 3. dig a slot in the middle of the punch
  • B.For large and irregular punches, dig a pit in the middle of the punches’ contact surface to reduce the contact area.
  • 4. reduce the contact area
  • C. Grind the punch into abnormal shape.
  • 5. abnormal shape punch
  • D. Design mold with blow hole to prevent the punch from driving waste by blowing air in the middle of the punch.
  • E. For SKD11 punch, spring pin can be added in the design to prevent jumping waste.


2. increase the friction of knife edge to scrap

  1. For insert or combination cutting edge, “cover” around 1mm below the cutting edge to increase the friction of scrap in the cutting edge.
  2. For the auxiliary process steps, such as side edges and cutting edges of material distributing stations, the scarp shape can be appropriately complicated to increase the clamping force of scarp in the die and prevent scarp jumping.

6. designed mold

3. Other methods

  • A. use a vacuum cleaner to remove waste products to prevent jumpers.
  • B. Keep the punch and knife edge sharp and add stamping oil appropriately.

Anyway, there are many reasons that affect waste jumping, and many ways to prevent it. This is just a summary of little effective methods Sipxmach has used in this stamping process.

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