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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.

Plastics Processing: How To Succeed In An Ever-Changing Industry, Part 1

In 1963, Bob Dylan famously sang, “The Times They Are a-Changin’.” While it is doubtful he had plastics processing in mind, the changes in our industry over the past 60 years have been staggering — and the pace of these changes is ever-increasing. How can today’s plastics processors keep up with technology and compete in the global marketplace? In this series, we will attempt to answer that question.

Learning to Embrace Change

Most plastics companies claim they are embracing change, yet the day-to-day actions of their technicians has barely changed in the past 5 or10 or even 20 years. Engineering and management may come up with innovative ideas. But for such ideas to work, your technicians need to be involved in implementing these changes on a day-to-day basis.

Scientific Processing

One of the most common changes taking place is the move from traditional processing to a scientific approach. ‘Scientific’ is not just a buzzword: There are systematic ways to approach the development of each process parameter, document each process, and troubleshoot any defect.

Contrary to what many company owners and managers believe, these advancements are not centered around purchasing a lot of shiny new equipment. The most important and meaningful changes are realized by improving the day-to-day practices of your technicians. Every manager should expect their technicians to process and troubleshoot your product the same way — each and every time the process runs. Following a scientific processing methodology ensures this consistency.

Less Talk, More Action

The most successful molders in the world are the ones who can implement change and are willing and able to take on new challenges. They not only have to talk about it, they must actually do it. Therefore, your company needs to put a system in place to help employees constantly improve and stay ahead of the competition. In our next post, we will examine some specific ways this can be accomplished.


What exactly is Scientific Molding? Click here to learn more. And feel free to contact us for more information about modernizing processing methodology in your facility.

Material Drying, Part 3: Common Dryer Types

Did you know there are 4 different types of material dryers commonly used in the plastics industry? In fact, many processing facilities are using the wrong type of dryer for their material drying application. In this post, we will discuss each type of dryer and its appropriate usage.

Hot Air Dryers

The most basic type of dryer is a hot air dryer.  These typically consist of a blower, filter, heater, and temperature controller. Such dryers are great with non-hygroscopic materials where removing surface moisture is needed or the material needs to be pre-heated for high-speed processing.

Desiccant Dryers

The most common dryer used in the industry is the desiccant dryer because they bring the dewpoint of the air down to -40°C (-40°F). These typically consist of an aftercooler, blower, desiccant bed, dewpoint sensor, heater, filter, temperature controller, and regeneration system. These are great at drying hygroscopic materials, but are very complex pieces of machinery which require a lot of maintenance to keep running.

Compressed Air Dryers

A simpler type of hygroscopic material dryer is the compressed air dryer. These are almost identical to a hot air dryer except they get their inlet air from your compressed air supply. If you air system is properly maintained, the compressed air dryer provides air as dry as negative 20 degrees Celsius. These systems are becoming very popular as hopper dryers for drying small amounts of materials as well as hygroscopic materials warm and dry in high-speed applications.

Vacuum Dryers

Vacuum dryers are the fastest, most efficient systems available for batch-drying hygroscopic materials. These systems heat the pellets in a canister and then draw a vacuum to quickly remove the moisture from the material. These systems are complex and expensive, but can dry a batch of material as quickly as 30 minutes! Desiccant dryers are the most commonly used systems in the plastics industry, but they are not always the best choice.


For more information about moisture measurement and material drying, be sure to check out Routsis Training’s Material Drying Technology. This online training programs give personnel a better understanding of how different polymers are best dried and prepared for reliable processing — and demonstrate how proper plastics material handling is critical to developing a consistent process and delivering quality products to your customers.

Material Drying, Part 2: Moisture Measurement

Just because the material has been dried at the specified temperature for the specified amount of time does not guarantee it is actually dried to the material supplier’s specifications. If you dry material in-house, you must have a method of measuring the actual moisture contained in the material.

In most hygroscopic materials, water attacks the polymer — resulting in shorter, weaker, and more brittle polymer chains. While a part molded from such material may look good, it can fail miserably in the field. If you grind up these weaker parts and then test the material shortly after processing, you will likely find the material has a moisture level much higher than the supplier’s recommendation.

Moisture Analyzers

The most common method of material moisture analysis is a Moisture Analyzer. In fact, many molders have one in the materials handling area and one in the quality department. These simply weigh a material sample, heat the sample, and measure the amount of moisture lost during heating.

For most materials, moisture analyzers are a great way to measure the moisture in your material. Unfortunately, for materials with lots of additives such as processing aides and flame retardants, it may falsely report these as moisture when they vaporize.

Relative Humidity Analyzers

Relative Humidity Analyzers use the weight of the sample combined with the relative humidity of the air around the sample after heating to determine the amount of moisture in the material. Since the relative humidity sensor only measures water, vaporized additives are not measured.

If you have unique materials which never seem to dry regardless of how long you dry them, you may want to consider investing in a relative humidity analyzer for your material.


For more information about moisture measurement and material drying, be sure to check out Routsis Training’s Material Drying Technology. This online training programs give personnel a better understanding of how different polymers are best dried and prepared for reliable processing — and demonstrate how proper plastics material handling is critical to developing a consistent process and delivering quality products to your customers.

Material Drying, Part 1: Dewpoint Meters

Materials that need to be dried require a reliable supply of heated and dried air. The dryness of the air is measured using a dewpoint meter. In practice, there are several ways this can be accomplished. What is the best method? Which type of sensor is most accurate? In this post, we will answer some common questions about dewpoint measurement.

Onboard Dewpoint Sensors

Many desiccant dryers have the option of being purchased with an on-board dewpoint meter. We strongly recommend this option. Even though these onboard sensors are typically oxide-based — which means they can drift ±5° or even ±10° dewpoint. While not extremely accurate, an onboard dewpoint meter provides a quick and convenient indication of the relative dryness of the air.

One of the best uses for such onboard sensors to alert you to potential issues with the dryer. To accomplish this, set an alarm on the dryer to notify you when the desiccant or regeneration cycle is failing to keep the air dry. This works well as a real-time indicator of the dryer’s effectiveness, or lack thereof.

Dryers equipped with dewpoint meters are typically capable of being set to regenerate when the desiccant bed reaches a pre-determined setpoint. This allows much more accurate control over the dryness of the air — as well as ensuring the bed regenerates only when necessary, in order to maximize its longevity.

Without an onboard dewpoint meter, there is no fast method to check the performance of the dryer and desiccant beds. Keep in mind these onboard meters will still need to be verified 2 or 3 times a year to ensure they are functioning properly. This is accomplished with a portable dewpoint meter.

Portable Dewpoint Meters

Every processing facility that uses material dryers should have several portable dewpoint meters available for maintenance and materials handling personnel to use. Meters with polymer-based sensors are preferable, as these are much more accurate than oxide-based sensors. These units are typically suitcase-sized with on-board batteries so they can easily be used out on the floor.

By installing test ports in your dryers and hoppers, you can use portable meters to draw air samples and test the air being provided to the hopper, within the hopper, returning from the hopper, and at the feedthroat. These measurements can quickly tell you how well the dryer is performing.

Feedthroat dewpoint measurement can also ensure the material entering the barrel is fully dried and there are no leaks causing the material to pick up moisture. Portable dewpoint meters are a great way to field-check the dryer’s onboard dewpoint meter whenever its accuracy is in question.

Without dewpoint measurement methods, there is no way to ensure your equipment is functioning and drying the material properly.


For more information about moisture measurement and material drying, be sure to check out Routsis Training’s Material Drying Technology. This online training programs give personnel a better understanding of how different polymers are best dried and prepared for reliable processing — and demonstrate how proper plastics material handling is critical to developing a consistent process and delivering quality products to your customers.

Quality Control? Quality Assurance? Learn the difference between QA and QC

The terms “QA” and “QC” are used frequently (and often interchangeably) in the plastics industry. But what do these terms actually mean? What is the role of each in delivering quality parts to your customers? In this post, we’ll demystify Quality Assurance and Control and explain how each plays an integral in your business.

Having visited thousands of processing facilities around the world, Routsis Training has found this is more than mere confusion over the terminology. In fact, it’s quite common to see so-called ‘Quality Assurance’ departments that are actually just performing ‘Quality Control’ duties.

Quality Control

ISO 9000 defines Quality Control as, ‘A part of quality management focused on fulfilling quality requirements.’ In practice, this process involves visually inspecting, measuring, and/or testing parts to ensure they meet the customer’s requirements.

Since inspecting every single part is time consuming, most Quality Control departments institute specific procedures designed to detect and isolate bad product, such as first piece approval and routine inspections. During this process, a sample of product is retained and then put through a pre-approved series of visual, dimensional, and/or physical tests.

The theory behind quality control is that if a routine sampling of product is good, the products manufactured between the samplings should also be good. Most manufacturers use these quality control measures to help ensure customer satisfaction.

Quality Assurance

According to ISO 9000, Quality Assurance is ‘A part of quality management focused on providing confidence that quality requirements will be fulfilled.’ This may sound the same at first. But here is the key difference: while QC focuses on verifying that acceptable product is being, QA focuses on verifying that a good process is being used to make acceptable product.

In plastics processing, there are many ways to make an acceptable product that will pass initial inspection using completely different processes. The long-term ramifications of product manufactured using a different process can be anything from basic part discoloration to catastrophic part failure.

Summary

Here is the best way to differentiate the roles of QA and QC: Quality Control focuses on part monitoring while Quality Assurance focuses on process monitoring. Remember: Your customer is expecting you to produce the same product with the same process each and every time. To accomplish this, you need to be using both QC and QA measures.


In practice. delivering consistent quality to your customers is a plant-wide initiate and not solely the purview of the QA and QC departments. Routsis Training offers extremely cost-effective in-house training for all production personnel.

Our Professional Certification Portals are an excellent tool for training and benchmarking your entire workforce. We offer Quality Certification tracks for Injection Molders, Blow Molders, as well as Single Screw and Twin Screw Extrusion.