Do you want to optimize your purging program by using the right amount of purging compound for your machine? Do you know how to perform an initial test and measure the purging compound accurately? You must read this blog if you answered yes to any of these questions. I will show you how to define the amount of purging compound you need for each case and machine and how to avoid common mistakes affecting your results.
Let’s get started. Here are some steps to follow to calculate the right amount of purging compound for your machine:
Step 1: Consult with the manufacturer of the purging compound and follow their recommended purging procedure. This is crucial to ensure you use the purging compound correctly and effectively. Different purging compounds may have other procedures, such as temperature settings, injection speed, back pressure, etc. You need to follow the procedure that matches your purging compound.
Step 2: Perform an initial test on your machine using the recommended purging procedure. This is where you check the cleaning performance of the purging compound and how much material comes out of the machine. You need to monitor the test carefully and observe when the material changes from the resin to the purging compound. You can assign someone else to watch for this while you control the machine.
Step 3: Separate the resin pile from the purging compound pile and weigh only the purging compound from the machine. This is the amount of purging compound you need to use for your machine the next time you purge. Do not include the amount of resin or purging compound in the machine. You can also record the purging time and the scrap percentage for future reference.
Step 4: Repeat the test if necessary to confirm the results. You can also compare the results with other methods or purging compounds to see which gives you the lowest Cost Per Purge. The Cost Per Purge is calculated by adding the cost of the purging compound, the resin cost, and the downtime cost. You want to choose the method or purging compound that gives you the best cleaning performance with the least amount of material, time, and scrap.
The procedure and ways of measuring and weighing the materials are critical in optimizing the consumption of purging compounds after the initial test. The initial test should define the performance of the purging process and its cost-benefit compared to another method. So, in comparing methods, you need to consider the percentage of scrap, the purging time, and the amount of purging compound to be fed to the machine the next time.
For more information on purging processes or how you can benefit from using purging compounds to improve the efficiency of your thermoplastic process, contact us. We would like to know about your operation and be able to give you a customized proposal.
Lenny Gutierrez is a Purging Expert & Technical Sales Representative with over 20 years of experience in the plastics industry. He was responsible for the growth of the Mexican & South American Asaclean markets before sharing his expertise and friendly disposition with molders, extruders, and blow molders in the midwest.