17 Injection Molding Problems And Solutions

After reading, you will know 17 injection molding problems and solutions.

Injection molding problems and Solutions 1. Scrap jumping hole

1. The punch length is not enough to replace the punch according to the punch edge cutting into the concave die a material thickness plus 1mm
2. The clearance of the concave die is too large, cut into the sub to reduce the clearance or reduce the clearance with the phi machine
3. The punch or template is not demagnetized. Use a demagnetizer to demagnetize the punch or template.

Injection molding problems and Solutions 2. Scrap blocking hole

1. Small drop hole or drop hole offset to increase the drop hole so that the drop material smoothly
2. The drop hole has chamfering increase the drop hole to remove the chamfer
3. The knife mouth is not put a taper line cutting taper or reverse the expansion of the hole to reduce the length of the straight wall position
4. The straight wall of the cutter is too long to drill holes on the opposite side, so the straight wall of the cutter is shortened
5. Edge collapse, resulting in a large phi, blocking material to re-grind the edge

Injection molding problems and Solutions 3. Burr

1. Edge collapse, resulting in too large a burr to regrind the edge
2. Punch and concave die clearance is a too-large line cut into the block. Re-match the clearance
3. Poor finish of concave die cutter polishing cutter straight wall position
4. The clearance between the punch and concave die is too small, save the die again and match the clearance.
5. If the maximum material force is too large, reverse pull out the phi front to change the spring and reduce the maximum material force.

Injection molding problems and Solutions 4. The cutting edge is not flush

1. Positioning offset to adjust the positioning
2. There is single-sided molding. Pull the material to increase the pressure force, and adjust the positioning.
3. Design errors, resulting in uneven joint knife re-line cutting edge knife edge inlay block
4. Feeding is not allowed to adjust the feeder.
5. The calculation of the feeding step is wrong. To recalculate the step, re-determine the position of the connecting knife.

Injection molding problems and Solutions 5. Punch easy to break

1. The closing height is too low, and the punch cut into the knife mouth part is too long to adjust the closing height
2. Improper positioning of material, causing the punch to cut a single side, adjust the positioning or feeding device due to uneven force fracture
3. The lower die waste blocks the cutter opening, causing the punch to break and re-drill the big drop hole to make the drop material smoothly.
4. The fixed part of the punch (clamping plate) and the guiding part are repaired or re-cut into the block to make the punch go up and down smoothly (hitting plate) offset.
5. Poor guidance of the punching plate, resulting in unilateral stress on the punching head and re-matching the gap of the punching plate.
6. The punch cutter is too short, interfering with the beating board, changing the punch, and increasing the length of the cutter part.
7. The punch is not fixed well and moves up and down. Re-fix the punch so that it cannot move up and down.
8. The punched edge is not sharp. Regrind the edge.
9. The punch surface is strained, and the force is uneven when taking off the material. Change the punch again.
10. The punch is too thin, too long, or not strong enough. Change the punch type.
11. The punch hardness is too high. If the punch material is not correct, change the punch material, and adjust the heat treatment hardness.

Injection molding problems and Solutions 6. Iron chips

1. Crimping bar misalignment recalculates the position of the crimping bar or bending position
2. The bending gap is too small, extrusion of iron chips to readjust the gap, or grinding forming block, or grinding forming punch
3. The bending convex die is too sharp to repair the R angle
4. The jointing knife mouth material is too little to re-join the knife mouth
5. The pressure bar is too narrow to regrind the pressure bar

Injection molding problems and Solutions 7. Poor budding

1. The center of the bottom hole of the sprouting and the center of the sprouting punch do not overlap to determine the correct center position, move the position of the sprouting punch, or move into sprouting – side high – side low, or even rupture the position of the pre-punching hole, or adjust the positioning
2. An uneven gap of concave die, resulting in low budging-side-high-side repair with a budging gap or even rupture
3. The bottom hole of the pumping bud does not meet the requirements, resulting in the height of the pumping bud and recalculation of the bottom hole aperture, pre-punching hole increase or decrease the diameter deviation, or even rupture

Injection molding problems and Solutions 8. Poor injection molding

1. Forming die convex die is too sharp, resulting in material pulling and cracking forming convex die repair R angle, knife mouth at the appropriate repair R angle
2. Insufficient forming punch length, failing to form the correct length of the calculated punch to adjust the actual length of the punch to achieve the requirements of the shape
3. If the forming punch is too long and the material at the forming area is deformed, determine the punch’s correct length and adjust the punch’s length to meet the requirements until the punch is broken.
4. Defective material at the forming area causes pulling and cracking of the material, repairing the R angle, or reducing the forming height.
5. Poor positioning, resulting in poor forming adjust positioning or feeding device
6. Forming gap is too small to cause a pulling or deformation deployment gap

Injection molding problems and Solutions 9. Bending size

1. The mold is not adjusted in place to cause angular error resulting in size bias adjustment of the closing height is poor or poor angle difference
2. Elasticity is not enough to cause a bad angle resulting in size deviation for spring
3. The material does not meet the requirements of the angle caused by bad size for the material or readjusting the gap deviation
4. Material thickness deviation caused by bad angle leads to size deviation to determine the material thickness, change the material, or re-adjust the gap difference
5. Improper positioning leads to size deviation. Adjust the positioning to make the size OK
6. Design or processing errors caused by the bending male block between the interpolation welding grinding, eliminating the gap between the block, resulting in a small bending size
7. Forming male no R angle, in the angle and other normal conditions forming male repair R angle under the bending height is small
8. Both sides of the bending size are large, plus the pressure bar
9. Single-sided bending pull material caused by size instability increases spring force, adjusting the positioning
10. Gap unreasonable, causing bad angle and size deviation repair gap
11. The folding knife height is not enough. Bending the punch into the folding knife is too short of increasing the height of the folding knife, so the bending punch as far as possible into the folding knife force bit caused by bad angles morel. The bending speed is too fast, resulting in bending root deformation adjustment speed ratio control. Choose a reasonable speed.
12. Unreasonable structure, bending knife is not set into the fixed template, re-milling groove, the bending knife set into the template stamping, resulting in large gaps.
13. Forming male heat treatment hardness is insufficient, resulting in pressure line collapse or reshaping the male pressure line flattening.

Injection molding problems and Solutions 10. Not unloading material

1. Improper positioning or improper feeding to adjust the positioning or feeding device
2. Not enough position avoidance to repair the position avoidance
3. The inner guide column is strained, causing poor activity of the playing board to replace the inner guide column
4. Punch strains or the surface is not smooth, replace the punch
5. Unreasonable placement of the top material pin. Reposition the top material pin
6. The top material force is not enough, or the stripping force is not enough to replace the top material spring or stripping spring
7. The punch and the plywood plate do not fit smoothly.
8. Forming slider does not fit smoothly. Repair the slider and guide slot to make it fit smoothly.
9. The heat treatment of the punching plate is not suitable, and the deformation of the punching plate after a while is reground to correct the deformation.
10. The punch is too long, or the length of the top material pin is not enough to increase the length of the top material pin or replace it with a punch of a suitable length.
11. If the punch is broken, replace the punch.
12. The template is not magnetic. The workpiece is brought up to the template to demagnetize.

Injection molding problems and Solutions 11. Feeding is not smooth

1. The die is not set up correctly, resulting in the material belt and feeder and die re-set the die or adjusting the feeder is not in the same straight line.
2. The material belt is not flat. Adjust the leveling machine or replace the material.
3. Not unloading the material caused by the feeding is not a smooth reference to not unloading the material to solve the countermeasures.
4. The positioning is too tight. Adjust the positioning
5. If the guide pin is too tight, or the straight wall is too long, adjust the guide pin
6. If the punch is not fixed well or is too long to interfere with the material belt, change the length of the punch and fix it again.
7. The top material pin is too short. The material belt interferes with the forming block. Adjust the top material pin length to avoid interference.
8. Improperly arranged floating block position adjust the floating block position.

Injection molding problems and Solutions 12. Bad riveting

1. Mold closure height improper riveting is not in place to adjust the closure height
2. The workpiece is not put into position. Positioning deviation adjust positioning
3. The workpiece before riveting is not good for confirming the bud hole. Refer to the bud hole bad solutions to deal with confirming whether the riveting hole is chamfering, such as no chamfering to increase the chamfer
4. The riveting punch is not long enough. Replace it with a suitable length punch.
5. The riveting punch does not meet the requirements. Confirm and use the riveting punch that meets the requirements.

Injection molding problems and Solutions 13. Missing or installed

1. Carelessly set up the wrong punch
2. Punch without a directional mark.

Injection molding problems and Solutions 14. Install the wrong screw

1. Do not know the thickness of the template to understand the thickness of the template is too long or too short
2. Not careful enough, not enough experience to choose the appropriate screws

Injection molding problems and Solutions 15. Disassemble the mold

1. pinhole is not clean pinhole pin wipe it clean. When dismantling the mold should first remove the positioning pin is easy to damage when installing the mold, should first use the screw guide. After playing the positioning pinhole
2. The assembly and disassembly of the mold program are not correct. When playing down the pin, do not touch the pinhole

Injection molding problems and Solutions 16. Positioning pin

1. hole wall stretched hair, scratched resulting in too tight group mold, carefully check whether the pinhole stretched hair, otherwise, should not hit the pinhole reamed
2. Pinhole deviation or no escape hole below the additional positioning pin escape hole

Injection molding problems and Solutions 17. The spring is too long

1. Do not pay attention to the depth of the spring hole to measure the depth of the spring hole, calculate the amount of compression of the spring, reselect the spring cannot be pressed down to
2. Not careful enough, not enough experience to the appropriate spring under the dead point