It is critical that your perform a rear zone temperature study on each of your molding machines. Just because two machines have the same brand and are running the same material, the optimal rear zone temperature is most often different.
Question: We run the same grade of PP on all our jobs and all the machines are the same brand. Do I really need to perform this test on each machine?
My Response: Yes, each machine may or may not be the same optimal rear zone temperature. I have seen a difference of 50°F using two similar machines with the same grade of material. Keep in mind, you also need to check the melt temperature since the temperatures are likely to be different.