This informative blog allows plastics professionals to discuss plastics training and technology. Brought to you by Routsis Training: the plastic industry's premiere training provider.

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 is that they have a low molecular weight carrier to allow it to melt and disperse the colorant early in the screw. If the carrier is compatible with PP, the suggestions below should help you.

RE Melt Temp: If the melt temperature is too low, the carrier will melt too late in the barrel and will not have time to melt, especially in a GP screw. This is why it is critical to know what resultant melt temperature provides the correct color with you colorant and base resin. Too low a temp will provide poor mixing, too high a temp will degrade the colorant resulting in off color or off gloss. If you need more heat, add heat through barrel temperature. If you need more mixing, then you add back pressure, but only after you have verified the melt temperature is correct. Screw RPM can either add heat by breaking chains or lower temp by pumping un-melted pellets to the front of the screw… neither is good.

Re Documentation: The above is why to have good process documentation so you know what specific process parameters give you good parts including melt temp (measured using a thin k-type probe), recovery time, & back pressure (converted to/from plastic pressure if you are going from machine to machine).

UPM Invests in Training From Routsis

Routsis Training has been cited once again in a Plastics News article. The article outlines a new strategy by Universal Plastic Mold, Inc. — who are investing in new energy-saving systems, more automation, and training from Routsis.

UPM uses Routsis’s RightStart™ system to ensure their employees get the most out of their training.

Click here to read the complete article on Plastics News’s website.

Trademark Plastics Says Routsis Training’s an Intergral Part of Their New Business Model

In a recent article in Plastics News, Trademark Plastics Inc. of Riverside, CA mentioned Routsis Training as an important aspect of their changing business model. They’ve downsized their workforce and now they’re relying on a smaller number of highly-skilled employees, which requires more advanced training.

Trademark Plastics uses Routsis’s RightStart™ ongoing training system to increase their productivity and profits as they migrate away from manual labor and toward an engineering-based approach to providing custom injection molding services.

Click here to read the complete article on Plastics News’s website.

Decatur Plastic Products Expanding With Routsis Training

Decatur Plastic Products, Inc. — a custom injection molding company based in Indiana — is investing heavily in training as part of a $3,000,000 expansion of their facilities.

A recent article in Plastic News details Decatur’s use of Routsis’s online training courses to allow employees to improve their skills. Decatur is also increasing employees’ pay as they progress through the training.

Click here to read the complete article on Plastics News’s website.

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 & rework
  • Compare as many different purging compounds and/or methods as you like
  • Print a detailed cost analysis of your chosen purging compounds and methods
  • Export your cost analysis data to a spreadsheet (CSV format)
  • Use your smartphone machine-side to conveniently record purging data

This app runs on any modern computer or handheld device with an internet connection.

Click here to access the software.