Injection Molding is a very intense process. It involves moving hundreds to thousands of pounds of steel in a few seconds, holding this steel under large tonnages of force from multiple sides and injecting plastic into them not only high pressures but also very hot conditions. All of this just to make what could be a simple plastic part. Once the plastic piece has been made the whole process is repeated, and repeated, and repeated. With such high demand to keep these injection molding machines running it is very important to give the mold the attention it needs to hold up to all of the pressure put on it.
An injection mold can be made up of hundred of pieces each with a specific function. When all of these pieces are functioning under the conditions described above it only makes sense that the pieces should be examined for wear and have any maintenance required performed in a timely manner. Maintenance is often overlooked due to production demands but many times this it is worse to put it off then inspect for problems now. Once a problem has occurred it may already be to late.
mSetting a scheduled maintenance plan can help prevent catastrophic failure of equipment. When equipment is inspected on a regular basis, the wear of different parts can be seen as it is happening. As parts get worn new parts can be ordered and installed before part failure is reached. Noticing wear on a part can also help diagnose possible design problems with the tool.
There are signs to look for when taking apart an injection mold. This can range from score marks on the side of a block to wear lines in a hole. Small metal shavings can build up and cause even worse grinding or parts. Lack of lubrication can lead to the early wear of parts. When possible, moving surfaces should be greased.
When a mold is out for inspection, it is also a good time to look at shutoffs that are created by core pins, slides, and ejector pins. Moving pieces have the tendency to wear which means these shut offs have the potential to fail. This type of failure is usually gradual and seen in the form of flash. Flash may be acceptable on a final molded part but can be a sign of wear happening to the mold. Once flash is there, it will not go away until replacement parts are installed in the mold to fix the problem.
Creating a maintenance schedule is an important step to meeting the demands of Injection Molding behind buying a machine and building a mold.