Plastic manufacturing and injection molding is a large industry. Nearly 900,000 Americans work in this industry. It is an important part of the United States job force and every state has at least one facility that handles plastic manufacturing and injection molding. There are approximately 16,000 such facilities nationwide. In 2012, $373 billion in products was shipped by this industry. The plastic injection molding process is a complicated one and in between projects the equipment needs to be purged.

Tips for improving the plastic injection molding process through better purging.

The purging process can be expensive, time consuming and be very detrimental to the bottom line for the plastic injection molding company.

1. How to handle light to dark color transitions. To get rid of the dark color effectively and efficiently, it is good to melt it. This is done by heating up the hot runners and the nozzle. The purging compound representative can offer guidance as to hot much the temperature needs to be increased to achieve the desired results. By melting the color, it becomes much easier to remove from the equipment.
2. More short shot bursts remove more color than longer ones. If you use a smaller shot when changing the color in a large ton press, meaning a press that is larger than 200 tons, it will be more effective at cleaning out the equipment. The best thing to do is shrink the shots so they are at about 10% of their absolute maximum.
3. Be diligent with your maintenance. Prevent carbon build up by cleaning it off of the equipment often. It has a tendency to be deposited during the plastic injection molding process. Any build up will make the clean up take longer. You want to get the carbon off before it has built up too many layers. This is especially important for the screw. If it gets too much build up, you will have to remove it and manually clean it. By properly maintaining it, you will save yourself that hassle.
4. Make sure you turn the plastic injection molding process off correctly. If you purge your equipment before you turn it off, it will be much easier to clean it and remove the color. Purging it at this point prevents carbon from accumulating on key areas like the screw. The purging process is a lot easier when done at this point as well.
5. Develop a policy for how the entire machine is cleaned. The hopper and conveying system need to be cleaned to get rid of the old color and ready everything for the new one. Sometimes, a color will get stuck in one of these parts and then contaminate the next color you add.
6. Check the resin. The last thing to check is the resin. Make sure it is free of the old color.

The plastic injection molding process is used to make a wide variety of products from drinkware products and food packaging containers to pharmaceutical bottles. It is a key part of the plastics industry and these are ways in which it can run smoother.