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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.

Using Process Monitoring Systems

Process monitoring systems are a great resource for the Scientific Molder.

Question:

We already have a {brand-name} production monitoring system and are now considering using it to also monitor the process.

My Response:

In practice most companies use such systems helpful to look for individual short shots or analysis of past problems. This is essentially quality control and is an important use for the system, but not its highest potential.

The important factor is to have a good basic scientific molding process than compensates for normal variation. With this in place, you can then use your process monitoring to identify a process shift. This allows your technician to then go to the machine and determine what changed and its effect on the quality of the process and parts. If used in conjunction with a good process, monitoring can be effectively used to provide quality assurance as well as quality control.

For example, you would rather your system to indicate a change such as a shift in transfer pressure and have your process tech head to the machine to determine the cause. It could be problem such as a blocked cavity, dying nozzle heater band, or it could also be something simple like a material lot change with a lower melt flow. You want your tech to understand what a high transfer pressure could signify, locate the cause, and then determine its significance.

If the change above was due to an equipment problem, the tech would then go about either fixing it or having it fixed.

If the change was due to a lot change in our example above, the tech might need to adjust the transfer to make the short shot the same weight as the standard, verify the quality of the part, and then adjust the process limits (such as +/-5%) to accommodate the new lot of material. The key in Scientific Troubleshooting is the change has been identified and a knowledge-based action was made using actual data with the intent of maintaining a good process known to make good parts for your customer.

Additional Thoughts:

The key to the above situation is to first ensure the tech has a good understanding of Good Scientific Documentation, Basic Scientific Processing, and Scientific Troubleshooting. Without this, the tech tends to just turn off or change the alarm because the parts look good, though the process may be different and thus producing suspect parts.

Injection Molding Training Now Available in French

Routsis Training announces the release of thirty-two online courses in French. Six of the courses comprise Routsis’s Scientific Molding 101 grouping, which lays the foundational knowledge base necessary for the success of any injection molding employee and provides them with in-depth processing information to better prepare them for making appropriate and cost-effective decisions when establishing or improving a scientific molding process.

Twenty-six Scientific SkillSet™ courses provide a unique learning experience that combines detailed, step-by-step online instruction with practical hands-on labs and worksheets. Each course/worksheet combinations focuses on developing important processing-related skills that translate directly to troubleshooting, optimizing and documenting any injection molding process.

“These French courses were produced to meet the training demands from multinational companies that have injection molding facilities in France, Canada and Belgium,” says Andy Routsis, President of Routsis Training.

These French language injection molding training programs are an expansion of Routsis Training’s catalog of multi-language courses, which already features training in English, Spanish, Portuguese, Mandarin, and Bahasa Malaysia.

The new online courses — and all existing Routsis Training courses — are cross-platform and can be played using any web browser and on any tablet or smartphone.

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.