Colorant Mixing Issues

In a recent processing forum there was a common question regarding color swirls and colorant mixing. There were many common responses such as adding back pressure, speeding up screw speed, slowing down screw speed, changing screws, adding mixing elements, etc. Let’s get back to basics for a moment… RE Colorants: The aspect particular to colorants […]

NEW! Free Purging Cost Analysis App

Routsis Training has developed a new Purging Cost Analyzer app to help scientific injection molders compare the cost of different purging methods. This free tool serves as a companion to the purging strategies discussed in our Purging for Scientific Molders online training series. Automatically calculate costs associated with purging compound, machine downtime, labor, production resin, scrap & […]

Never Empty the Barrel

The only time you should empty the barrel of your machine is when you are preparing to remove the screw. Concern: When discussing purging with most injection molders, the first step they follow is to empty the barrel of material. This practice is much less common in both extrusion and blow molding, but for some reason […]

Excessive Injection with Multi-Cavity Molds

You should always transfer from injection to packing with all cavities short-shot. Question: Let’s say a mold is imbalanced, the injection speed is 4 IPS and the mold is filled to 95% full. The first cavities finish filling at one speed and the last cavity to fill would fill faster than the first cavities. Why […]

Improving the Strength of Ribbon

Increasing the rate of production is an easy way to increase the linear strength of an extrudate. Question: We are blending 3 different types of PE as well as adding rubber to produce a decorative ribbon. Should we also add a grade of PP to increase the product strength? My Response: Blending more materials would […]