If your plastic injection molding machine isn’t working properly, there are a few things you can do to troubleshoot the issue. First, check to make sure that all of the machine’s parts are properly lubricated. If they aren’t, then you’ll need to lubricate them yourself. Next, check to see if there is anything blocking the machine’s moving parts. If there is, then you’ll need to remove the obstruction. Finally, if the machine is still having problems, then you may need to call a technician to come and take a look at it.
What are the most common problems with plastic injection molding machines, and how can you troubleshoot them yourself?
If you’re running a plastic injection molding operation, there are a few common problems that you might encounter. In this article, we’ll take a look at some of the most common issues and offer some tips on how to troubleshoot them yourself.
Flash
Problem:
One of the most common problems is flash. This occurs when molten plastic leaks out of the mold cavity and onto the machine. Flash can be caused by a number of factors, including improper mold design, incorrect injection pressure, or worn out mold components.
Troubleshooting:
If you notice flash on your machines, the first thing you should do is check the mold design. Make sure that the mold is properly vented and that there are no areas where plastic can leak out. Next, check the injection pressure and make sure it’s set correctly. Finally, inspect the mold components for wear and tear and replace them if necessary.
Sink Marks
Problem:
Another common problem is sink marks. This occurs when the molten plastic doesn’t fill the entire mold cavity evenly. Sink marks can be caused by a number of factors, including improper injection pressure, incorrect gate size, or inadequate venting.
Troubleshooting:
If you notice sink marks on your parts, the first thing you should do is check the injection pressure and make sure it’s set correctly. Next, check the gate size and make sure it’s large enough to allow the molten plastic to flow evenly into the mold cavity. Finally, check the venting and make sure that there are no obstructions preventing the molten plastic from flowing evenly.
If you’re still having problems with your parts, it’s a good idea to contact a professional plastic injection molding company. They can help you troubleshoot your machines and find the root cause of the problem. Once they’ve identified the problem, they can help you find a solution that will keep your parts looking great.
Short shot
Problem:
The volume of melted plastic injected is less than the theoretical value, and the product is incomplete. Possible causes include insufficient melting and plasticizing of the resin, poor flow of the melt, or incorrect molding conditions.
Solutions:
Include adjusting the injection pressure, screw speed, or temperature; modifying the mold design; or using a different resin.
Shrinkage
Problem:
The contraction of a plastic product during cooling, which can cause warping or deformation. Possible causes include incorrect molding conditions, such as too high of a mold temperature or too fast of an injection speed.
Solutions:
Include modifying the mold design or changing the molding conditions.
Warpage
Problem:
The deformation of a plastic product during cooling, caused by differential contraction between the outer and inner surfaces. Possible causes include incorrect molding conditions, such as too high of a mold temperature or too fast of an injection speed.
Solutions:
Include modifying the mold design or changing the molding conditions.
Burning
Problem:
The degradation of the plastic resin due to too high of a molding temperature. Burning can cause black specks or discoloration in the finished product.
Solutions:
include reducing the molding temperature or using a different resin.
Poor appearance
Problem:
Aesthetically displeasing appearance of the plastic product, due to imperfections in the surface finish. Possible causes include incorrect molding conditions, such as too high of a mold temperature or too fast of an injection speed.
Solutions:
Include modifying the mold design or changing the molding conditions.
Voids
Problem:
Empty spaces within the finished plastic product, caused by gas bubbles that were not properly vented from the melt during injection. Possible causes include incorrect molding conditions, such as too low of a mold temperature or too slow of an injection speed.
Solutions:
Include modifying the mold design, adjusting the injection pressure, or increasing the mold temperature.
Poor weld line strength
Problem:
The joint between two pieces of plastic that has been joined together by welding is weak. Possible causes include incorrect weld line design, incorrect welding conditions, or incompatible materials.
Solutions:
Include redesigning the weld line, changing the welding conditions, or using different materials.
Brittleness
Problem:
The plastic product is fragile and breaks easily. Possible causes include incorrect molding conditions, such as too high of a mold temperature or too fast of an injection speed.
Solutions:
Include modifying the mold design or changing the molding conditions.
Nozzle drool
Problem: Plastic resin dripping from the nozzle of the injection molding machine. Possible causes include incorrect nozzle design or faulty seals.
Solutions:
Include redesigning the nozzle or replacing the seals.
Final Words
When it comes to plastic injection molding, there are a few common problems that you might encounter. But with a little troubleshooting, you can usually find the root cause of the problem and fix it yourself. If you have any questions, be sure to contact a professional plastic injection molding company. They’ll be able to help you troubleshoot your machines and find a solution that will keep your parts looking great.
