How to Handle with the Ten Common Malfunctions for Stamping Die?(1)

During stamping production, we must to do concrete analysis for defective stamping situation, adopt effective countermeasures, sovle the problem redically. Only in this way, we can cost down the production cost, and do smooth production. Now i will show you how we handle with the ten common malfunctions during our stamping production:

Stamping Burr
The reason why burrs came out as blow:

1. Die insert abrasion;
2. The gap is too big, there is no evident effect by grinding and repair the die;
3. Die insert corner-chipping;
4. The gap between punch and die unreasonable, it can be shift up and down or losening;
5. Tooling dislocated

The relative countermeasures as blow:

1. Grinding and repair the die.
2. Control the fabrication precision or change the designing gap.
3. Grinding and repair the die.
4. Adjust stamping gap,confirm the die plate’s cavity hole wearing situation or check on the forming insert’s fabrication precision.
5. Change guiding elements or re-assemble the die.

Jumping Scrap Crushing
The reason why crushing came out as blow:

1. Gap is too big;
2. Unsuitable feeding;
3. Too much stamping oil,scraps pasted on the part;
4. Tooling without demagnetization;
5. Punch weared, scraps pressed on the punch;
6. Punch is too short, length isn’t enough when inserted to the die;
7. Raw material is too hard, part with easy sharp;
8. Emergency measurement;

The relative countermeasures as blow:

1. Control the fabrication precision or change the designing gap.
2. Cut the material strip when feeding to the right position, and clean the tooling meanwhile.
3. Control the stamping oil adding speed, or change oil to reduce it’s voscosity.
4. After grinding, part must do demagnetization process. (especially for stamping steel material)
5. Grinding core plate die.
6. Adjust the length when punch blade into the die.
7. Change raw material,revise the design, punch blade side pack out or sharped with a slope or arc (pay attention to the direction), reduce the joint area between punch blade area and the scraps.
8. Reduce die blade’s sharpness and grinding size, add surface roughness of the punch blade. use cleaner to collect the waste material, bring down the stamping speed,in order to avoide jumping scraps.

Scrap Jam
The reason why scrap Jam came out as blow:

1. Drain hole is small;
2. Drain hole is a little big,scraps turning over;
3. Die weared, burr is too big;
4. Stamping oil added speeding, got problem for oil-sticking;
5. Die blading surface is too rough, power scraps sintering attached to the blade;
6. Raw material is too soft;
7. Emergency measurement;

The relative countermeasures as blow:

1. Change the drain hole.
2. Change the drain hole.
3. Repairing the die.
4. Control oil quantity or change oil.
5. Surface treatment, poishing,during fabrication reduce surefece roughness; Change material.
6. Modify blanking clearance.
7. Punch blade side modified with slope or arc (pay attention to the direction), use cleaning, blowing at the blanking hole on base plate.

Blanking Offset, Dimension Out Of Range
Reasons show as blow:

1. Die weared, come into being burrs (sharp is big,inner hole is a little small);
2. Unsuitable designing size and clearance, bad fabrication precision;
3. Punch and die insert offset at blanking area, clearance unevenness;
4. Pilot pin weared, pin diameter isn’t enough;
5. Guiding element weared;
6. Unsuitable max feed, swage setting,relaxation for the feeder;
7. Improper die height;
8. Unload insert’s pressure level weared, no swage setting function (small punch hole caused by traction over material);
9. Unload insert crush too deep,piloting hole out of range;
10. Stamping material machinical performance variation (The intensity of elongation isn’t stable);
11. Dimension out of range since raw material tract by blanking strength during blanking stage;

The relative countermeasures as blow:

1. Grinding the die.
2. Modify the design, control fabrication precision.
3. Adjust the position precision and blanking clearance.
4. Change piloting pin.
5. Change guide pillar and guide sloove.
6. Re-adjust the feeder.
7. Re-adjust the die height.
8. Grinding or change the unload insert, add its forcing function, adjust swage setting.
9. Reduce forcing deepth.
10. Change material, control feedstock quality.
11. Punch blade modified with slope or arc(check the direction), in order to improve force situation during blanking stage. If possible can add guiding function on the unload insert at blanking area.

Material Stucking
Reasons summarized as blow:

1. Unsuitable max feed, swage setting, relaxation for the feeder;
2. Max feed changed during production;
3. Feeder breakdown;
4. Material arc-sharped, width out of tolerence, big burr;
5. Camber caused by unnormal tooling stamping;
6. Guiding hole is small, punch set pull material;
7. Bending or tearing stage upper and lower stripping unsmoothly;
8. Guide plate equipped with improper stripping function, stripper on belt;
9. Raw material is too thick to warping during feeding stage;
10. Improper tooling setup, wrong vaticality when matched with feeder;

The relative countermeasures as blow:
1&2. Re-adjustment.

1. Adjust and maintainence.
2. Change material,control feedstock quality.
3. Remove stripper camber.
4. Gringing punch and die for piloting hole.
5. Adjust stripping spring force.
6. Modify guide plate, avode stripper on belt.
7. Add upper material between feeder and tooling, also add up and down material safety switch.
8. Re-setup the die.