The issues you mentioned regarding the die punch breaking easily, iron filings, poor sprouting, and molding problems are indicative of several possible problems in the injection molding process. Let’s address each of these issues separately:
- Die Punch Breaking Easily: This could be due to excessive stress on the die punch, caused by factors like improper design, high injection pressure, excessive mold temperature, or poor material selection. It’s essential to ensure the die punch material is strong enough to withstand the molding forces and to verify that the design and manufacturing process of the punch are appropriate for the specific application.
- Iron Filings: The presence of iron filings in the molded parts indicates possible contamination of the plastic material or mold. These filings may come from the mold itself or other components used during the molding process. It’s crucial to inspect and clean the mold regularly to prevent any contamination from affecting the quality of the molded parts.
- Poor Sprouting: Poor sprouting, or improper gate design, can lead to defects like insufficient filling, flow marks, or even incomplete mold cavity packing. It’s essential to ensure proper gate design and positioning to achieve consistent and uniform flow of the plastic material during injection.
- Molding Problems: Molding problems could encompass a wide range of issues such as warping, sink marks, voids, or surface defects. These problems may arise from factors like inconsistent cooling, improper mold venting, incorrect molding parameters, or poor part design. Conducting a thorough analysis of the molding process and addressing each specific issue is crucial for resolving molding problems.
To address these issues effectively, it is recommended to involve experienced mold engineers and process technicians. They can conduct a comprehensive analysis of the injection molding process, mold design, material selection, and processing parameters to identify the root causes of the problems. Regular mold maintenance, proper mold design, material selection, and optimization of processing parameters are key to preventing these issues and achieving high-quality molded parts.
Die punch is easy to break, iron filings, poor sprouting and molding
- The punch is easy to break
a. The closing height is too low, and the cutting edge of the punch is too long. Adjust the closing height
b. Improper material positioning causes the punching punch to cut one side, and the positioning adjustment or feeding device is broken due to uneven stress
c. The cutting edge is blocked by the waste of the lower die, causing the punch to break, and the blanking hole is drilled again to make the blanking smooth
d. Fix the fixed part (clamp plate) and the guide part of the punch or re thread the cutting block to make the punch move smoothly up and down (punching plate)
e. The punching plate is poorly guided, which causes the punch to be forced on one side and the punching plate clearance is repaired
f. The punch knife edge is too short, which interferes with the punching plate. Replace the punch, and increase the length of the knife edge
g. The punch is not fixed well, and it moves up and down. Fix the punch again to prevent it from moving up and down
h. The punch edge is not sharp, regrind the edge- The punch surface is strained, and the punch is replaced when the force is uneven during stripping
j. Punch is too thin, too long, and the strength is not enough. Change the punch type again
k. The hardness of the punch is too high. The punch material is not correct. Replace the punch material and adjust the heat treatment hardness- Iron filings
a. Rebar dislocation Recalculate the rebar position or bending position
b. If the bending clearance is too small, extrude iron filings to readjust the clearance, or grind the molding block, or grind the molding punch
c. The bending punch is too sharp to trim the R angle
d. There is too little material to connect the knife edge
e. The pressing rib is too narrow, regrind the pressing rib- Poor sprouting
a. The center of the bud bottom hole does not coincide with the center of the bud punch to determine the correct center position, or move the position of the bud punch, or move it to the position of the bud – high side – low side, or even break the dynamic pre punching hole, or adjust the positioning
b. Uneven clearance of concave die, resulting in low or even broken budding edge high edge repair budding clearance
c. The sprouting bottom hole does not meet the requirements, resulting in sprouting height and recalculation of the bottom hole diameter, increase or decrease the diameter deviation of the pre punched hole, or even crack- Poor molding
a. The punch of the forming die is too sharp, which causes the material to crack. The forming punch shall be trimmed with an R angle, and the knife edge shall be properly trimmed with an R angle
b. The length of the forming punch is not enough, resulting in the failure to calculate the correct length of the punch. Adjust the actual length of the punch to meet the forming requirements
c. The forming punch is too long, and the material at the forming part is deformed. The correct length of the punch is determined. Adjust the actual length of the punch to meet the requirements until the punch breaks
d. The material at the forming part is not enough to cause tension crack. Calculate the material to expand, or trim the R angle, or reduce the forming height
e. Poor positioning, resulting in poor molding Adjust the positioning or feeding device
f. The forming gap is too small, causing tension crack or deformation, and the gap is adjusted
