Sipxmach stamping service

10 common problems in progressive die stamping and solutions

10 common problems in progressive die stamping and solutions

Sipxmach stamping service
Sipxmach stamping service

In the stamping production of progressive stamping die, it is necessary to carry out specific analysis for the phenomenon of poor stamping, adopt effective treatment measures, and fundamentally solve the problems that occur, so as to reduce production costs and achieve smooth production. The following is the reason for the common bad stamping phenomenon in production and the treatment measures are as follows, for the mold maintenance personnel to refer to.

First, the progressive stamping punching edge

Cause:

  1. The knife edge wear,
  2. The gap is too large to repair the knife edge after the effect is not obvious,
  3. The knife edge collapse angle,
  4. The gap is unreasonable up and down offset or loose,
  5. Up and down dislocation.

Countermeasure:

  1. Grinding the knife edge,
  2. Control the precision of the convex and concave die machining or modify the design gap,
  3. Grind the cutting edge,
  4. Adjust the punching clearance to confirm the problem of the hole wear of the template hole or the processing precision of the molded part,
  5. Replace the guide or Remodeling.

Second,progressive stamping chipping crush

Cause:

  1. The gap is too large,
  2. Improper feeding,
  3. The stamping oil droplets are too fast, the oil is sticky,
  4. The mold is not demagnetized,
  5. The punch is worn, and the scrap is pressed onto the punch,
  6. The punch Too short, insufficient length of inserting die,
  7. Hard material, simple punching shape,
  8. Emergency measures.

Counter measures:

  1. Control the precision of the convex and concave die machining or modify the design clearance,
  2. Prun the strip when it is sent to the proper position and clean the mold in time,
  3. Control the amount of oil in the stamping oil, or change the oil to reduce the viscosity,
  4. Die, After the training, the magnet must be demagnetized (more attention should be paid to the iron,
  5. The punch is cut.
  6. Adjust the length of the punch into the die,
  7. Replace the material and modify the design. The punch is inserted into the end face or repaired. Bevel or arc (note the direction). Reduce the bonding area between the end face of the punch and the scrap,
  8. Reduce the sharpness of the edge of the die, reduce the grinding amount of the die edge, and increase the straight edge of the die. Roughness (covering) of the surface of the part, using a vacuum cleaner to absorb waste, reducing the speed of the collision and slowing the jumping.

Third, the blockage of the material for progressive die stamping

The reason:

  1. The leakage hole is small,
  2. The leakage hole is too large, and the material is rolled,
  3. The knife edge wears, the burrs are larger,
  4. The stamping oil drops are too fast and the oil is sticky,
  5. The surface of the straight edge of the concave die is rough, and the powder is sintered and adhered to the blade,
  6. The material is soft,
  7. Emergency measures.

Counter measure:

  1. Modify the leakage hole,
  2. Modify the leakage hole,
  3. The blade repair knife,
  4. Control the amount of oil dripping and replace the oil type,
  5. Surface treatment, polishing, pay attention to reduce surface roughness when processing, change materials,
  6. Modify the blanking clearance,
  7. The end face of the punching blade is trimmed with a slope or an arc (note the direction), and a vacuum cleaner is used to add air to the blanking hole of the pad.

Fourth, the material deviation size variation wit progressive die stamping

The reason:

  1. The convex and concave die edges are worn, and the burrs are generated (the shape is too large and the inner holes are small),
  2. The design size and gap are not appropriate, the processing accuracy is poor,
  3. The position of the lower punch and the die insert are uneven, and the gap is uneven,
  4. The leading pin is worn and the pin diameter is insufficient,
  5. The guide is worn,
  6. The feeder feed distance, pressure material, relaxation adjustment is improper,
  7. The mold closing height is improperly adjusted,
  8. The material of the stripping block is worn, and the material without pressure (strong pressure) is used (the material is pulled by the material to cause small punching),
  9. The unloading insert is too strong and the punching is too large,
  10. Variation of mechanical properties of stamping materials (intensity of elongation is unstable),
  11. When punching, the punching force pulls on the material, causing dimensional variation.

Countermeasure:

  1. Research the knife edge,
  2. Modify the design to control the machining accuracy,
  3. Adjust the position accuracy and punch the gap,
  4. Replace the guide pin,
  5. Replace the guide post and guide bush,
  6. Re-adjust the feeder,
  7. Re-adjust the closed mold height,
  8. Grinding or replacing the stripping insert, increasing the strong pressure function and adjusting the pressing material,
  9. Reduce the depth of strong pressure,
  10. Replace materials and control the quality of the feed,
  11. The end face of the punching blade is trimmed with a slope or an arc (note the direction) to improve the stress during the punching. When the license is issued, the loading part is placed on the unloading insert to provide a guiding function.

Five, material jammed for progressive high speed stamping

The reason:

  1. Feeder feed distance, pressing material, and loose adjustment are improper,
  2. Variation in the distance between production and delivery,
  3. The feeder is faulty,
  4. The material is curved, the width is super poor, and the raw edges are large,
  5. The mold is abnormally stamped, and the sickle bend is triggered,
  6. The guide material is insufficient in aperture, the upper mold pulls,
  7. The bending or tearing position is not smooth,
  8. The stripping function of the guide plate is improperly set, and the strip is on the strip,
  9. The material is thin, sent to the middle warp,
  10. The mold is not properly installed, and the deviation from the verticality of the feeder is large.

Counter measure:

  1. Re-adjustment,
  2. Re-adjustment,
  3. Adjustment and maintenance,
  4. Replace materials and control the quality of the feed,
  5. Eliminate the belt bending of the belt,
  6. Training and punching the positive hole convex, concave die,
  7. Adjust the strength of the stripping spring, etc.,
  8. Modify the guide material, anti-material belt,
  9. Add up and down pressing material between the feeder and the mold, and add a safety switch for the upper and lower extrusion,
  10. Rebuild the mold.

Six, the material with a sickle bend

The reason:

  1. Stamping burrs (especially on the carrier),
  2. The material is burr, the mold has no trimming,
  3. The punching depth is not too deep (too deep or too shallow),
  4. Stamping damage, there are debris in the mold,
  5. The local pressure material is too deep or partially damaged to the part,
  6. Mold design.

Counter measure:

  1. Training the cutting edge,
  2. Replace the material and add a trimming device to the mold,
  3. Re-adjust the depth of the punch,
  4. Clean the mold to solve the problem of chipping and crushing,
  5. Check and adjust the height and size of the stripping and die inserts, and repair the damage,
  6. Using the bending mechanism to adjust.

Seven, the punching and blanking head is broken or fractured

The reason:

  1. caused by chipping, chip blocking, material jammed etc.,
  2. Improper feeding, cut half of the material,
  3. Insufficient punch strength,
  4. The size of the punches is too close, the material is pulled during the punching, and the small punch is broken,
  5. The punch and the die are too sharp,
  6. The blanking clearance is small,
  7. No stamping oil or stamping oil used is highly volatile,
  8. The gap between the punching gap is uneven, offset, and the convex and concave molds interfere,
  9. The precision of the stripping insert is poor or worn, and the precision guiding function is lost,
  10. Mold orientation is not allowed, wear,
  11. The materials of convex and concave molds are improperly selected and the hardness is improper,
  12. The guide member (pin) is worn,
  13. The gasket is not properly installed.

Countermeasure:

  1. Solve problems such as chipping, chip blocking, and material jam,
  2. Pay attention to feeding, timely trimming the tape, timely cleaning the mold,
  3. Modify the design, increase the overall strength of the punch, reduce the size of the straight edge of the die, pay attention to the slope of the edge of the punch and the curved shape, and cut the small part,
  4. The length of the small punch is shorter than that of the large punch,
  5. Modify the design,
  6. Control the processing precision of the convex and concave die or modify the design gap, and the punching gap of the small part is appropriately increased,
  7. Adjust the amount of oil in the stamping oil or change the oil type,
  8. Check the accuracy of each forming part and apply adjustment or replacement to control the machining accuracy,
  9. Training or replacement,
  10. Replace the guide post and guide sleeve, pay attention to daily maintenance,
  11. replace the use of materials, use the appropriate hardness,
  12. Replace the guide member,
  13. Correction, the number of gaskets should be as small as possible, and the steel pad should be used. The gasket under the die should be placed under the gasket.

Eight, bending deformation size variation

The reason:

  1. The guide pin is worn and the pin diameter is insufficient,
  2. The bending guide position is poor in precision and wear,
  3. Bending convex and concave die wear (pressure loss),
  4. the mold is not enough,
  5. material slip, bending convex, concave mold without guiding function, no preloading when bending,
  6. The mold structure and design dimensions are poor,
  7. the punching edge, causing poor bending,
  8. There are more shims in the convex and concave molds at the bending parts, resulting in unstable dimensions,
  9. Material thickness size variation,
  10. Material mechanical energy variation.

Countermeasure:

  1. Replace the guide pin,
  2. Re-grind or replace,
  3. Re-grind or replace,
  4. Check and correct,
  5. Modify the design, add lead and preload function,
  6. Modify the design size, break the bend, increase the bending and shaping,
  7. Research the cutting edge of the material level,
  8. Adjustment, using the overall steel pad,
  9. Replace materials and control the quality of the feed,
  10. Replace materials and control feed quality.

Nine, the height of the stamping parts (when more than one module)

The reason:

  1. The punching edge,
  2. The punching piece is crushed and there is debris in the mold,
  3. Convex, concave mold (bending position) pressure loss or damage,
  4. Turn over the material when punching and shearing,
  5. Wear and pressure loss of relevant pressing parts,
  6. The relevant tearing position tearing size is inconsistent, the knife edge wear,
  7. The pre-cut depth of the relevant breakable bits is inconsistent, and the convex and concave molds are worn or chipped,
  8. The convex and concave molds of the relevant convex parts have chipping or wear and tear,
  9. Mold design defects.

Countermeasure:

  1. Research the cutting edge of the material level,
  2. clean the mold, solve the problem of floating materials,
  3. Re-train or replace new parts,
  4. Study and cut the cutting edge, adjust or add strong pressure function,
  5. Check and implement maintenance or replacement,
  6. Repair or replacement, to ensure that the tearing condition is consistent,
  7. Check the condition of pre-cut convex and concave molds, and carry out maintenance or replacement,
  8. Check the condition of the convex and concave molds and carry out maintenance or replacement,
  9. Modify the design, add high and low adjustments or add plastic working stations.

Ten. Improper maintenance

The reason:

  1. The mold has no foolproof function, and negligence in the group mode leads to the reverse direction and misalignment (referring to different stations),
  2. The insert that has been offset by the gap is not restored as it is.

Countermeasure:

  1. Modify the mold to increase the anti-stay function,
  2. Make a mark on the mold, and make necessary inspections and confirmations after the mold is set, and make a written record for inquiries.

This is 10 common problems in progressive die stamping and solutions, welcome stamping or machinery engineers to correct it, thank very much in advance

For more sourcing about progressive die stamping please check wiki: https://en.wikipedia.org/wiki/Progressive_stamping,  or Video: https://www.youtube.com/watch?v=6Xtrbkx5QJw&t=35s

Source from https://sipxmach.com/10-common-problems-in-progressive-die-stamping-and-its-solutions/