Common Defects and Measures for Stamping Components

The waste, foreign body pressure marks of stamping components

• Causes: Foreign object pressure marks are caused by foreign objects or dust falling into the upper and lower molds, creating uneven surfaces. Waste material is caused by the failure to timely clean up the waste generated during the production process, carrying punching waste into the work area. The punching process has the highest probability of waste material.

• Cause factors: Raw material dirt, burrs, slag generation during stretching, equipment dirt, stamping mold dirt, board debris.

• Inspection methods: Mainly through visual observation, oilstone testing, and tactile inspection.

• Preventive measures: Timely clean up waste material.

The wrinkling of stamping components

• Causes: Insufficient stretching of the sheet during forming results in localized wrinkles. This is mainly caused by excessive edge pressure on the flanges or tangential deformation caused by too large a resistance, resulting in instability and wrinkle formation.

• Cause factors: Low cushion pressure, low mold balance block pressure, excessive oil application, cracks resulting in flow, weak pressure due to foreign matter contamination.

• Inspection methods: Mainly through measurement, visual observation, and tactile inspection.

• Preventive measures: The main method is to increase the edge pressure of the edge ring and appropriately enlarge the material size, such that it remains in a stable state during stretching, which can reduce wrinkle formation.

The scratching of stamping components (elongation marks)

• Causes: The mold surface is not smooth, resulting in line scratches on the board.

• Cause factors: Sharp pressure damage on the concave-convex mold surface, too small or uneven gaps between the concave-convex molds, rough surface of concave mold fillet, foreign matter pressing the surface due to dirty working surface or material during punching, low concave-convex mold hardness, and metal debris attached to the surface after punching can cause elongation marks on the working surface after stretching.

• Inspection methods: Mainly through visual observation and tactile inspection.

• Preventive measures: Grind or polish the scratched surface of the mold, adjust and widen the gap between the concave-convex molds, grind and polish the radius of the fillet on the concave mold, keep the mold surface clean, and increase the hardness of the mold surface.

Scratching of stamping components

• Causes: Surface scratches caused by human or foreign object contact.

• Inspection methods: Mainly through visual observation and tactile inspection.

• Preventive measures: Pay attention to this issue during production and use to prevent and solve it.

The presence of multiple holes, few holes, changes in hole shape, and incomplete hole punching of stamping components

• Causes of hole shape change: Large gaps between concave-convex molds, non-uniform gaps between concave-convex molds.

• Causes of incomplete hole punching: Insufficient mold travel, improper positioning.

• Cause factors: Too many or too few punching heads, broken punching heads, poor gap between punching materials and punching heads, or material carryover.

• Inspection methods: Mainly through hole counting, measurement, visual observation, and tactile inspection.

• Preventive measures: Adjust the gap between concave-convex molds, brush oil frequently, adjust the slide to the appropriate height during commissioning, and strictly follow the operating procedures during production.