Quick link of the Troubleshooting Guide:
Dark brown spots
Spots and stripes still visible even the molding parts have the correct color.
| Troubleshooting | Solution Guide | |
| Injection molding machine |
1. The last production of degradable plastics materials in the cylinder, screw, valve adapter maybe curing inside the aggregate hot runner pipe. |
Use cleaning compounds or high molecular weight PMMA material to clean the injection cylinder unit. |
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2. Plastic material traps in the cylinder device’s dead area or stagnant area, causing it to stay too long in the high temperature. |
1. cylinder and screw should be removed and thoroughly clean the surfaces in contact with the polymer melt. | |
| 2. Check whether the nozzle is located correctly in injection cylinder. | ||
| 3. Use open or direct type nozzle to replace opening and closing nozzle. | ||
| 4. Check the stop valve for cracks, etc. Change a new device if necessary. | ||
| 3. Plastic enters the mold cavity too fast causing excessive shear polymer. | Reduce the injection speed. | |
| 4. Melt temperature is too high. | 1. Reduce fire zone melt temperature in a feed tank. Check the flow rate if its sufficient for cooling the hopper locking device, adjust the flow rate if necessary. | |
| 2. Reduce the cycle time to increase plastic that is passed by the cylinder device. | ||
| 5. Using the incorrect screw surface speed and back pressure, causing the molten plastic over cut. | Use minimum back pressure and the correct use of the screw surface speed | |
| 6. Use a correct type of screw design in the process of plastic. | Use a lower rate of a extrusion screw. | |
| Mold | 1. Grease or oil occur within the mold. | Mold and nozzle should be removed and thoroughly cleaned. |
| 2. Gate is too small. | Increase the gate size. | |
| 3. Wall injection molded too thin, so that plastic flow is not sufficient to pass through, so it causes no degradation. | Check the correctness and consistency of wall thickness, if necessary, will be modified. | |
| 4. Hot runner mold produces impurities. | The hot runner mold aggregates tube completely remove and clean. | |
| Plastic | 1. PVC or other heat-sensitive plastic appear impurities. | Check the source of impurities, especially with PVC manufacturing and conveying plastic pipe part. |
| 2. Excessive heating of the back using the previous materials. | Strict inspection after the separation of impurities in materials. | |
| 3. Due to the lack of room cleaning or plastic dry cause plastic blended with burnt particles. | Dry cleaning and reuse of some materials. | |
| 4. Poor plastic flow characteristics caused by Insufficient lubrication of plastic. | Adda certain amount of external lubricant (such asZeng0. 05%to0. 1% zinc stearate). |
