Custom Processing Services Blog

Trust Your Toll Processor on Target Specifications and Quality

Chris Lenosky, Dec 3, 2020 6:45:00 AM


If you’re working with a toll processor to dry, mill, or blend materials, and you need to achieve specific particle sizes and/or distributions, then it’s important to get a sense of their ability to analyze and verify quality outcomes, both during and after processing.

Particle size measurements — maximums, minimums, and averages; distributions; and percentiles within a sample — all can have an impact on your product’s in-use performance. Other measures and tests can also play an important part in quality assurance, and can be required in certain industries.

And even as your toll processor may be responsible for just one ingredient of a more complex product, the material characteristics of every single ingredient contribute to the overall quality of that final product. For example, in paints and coatings, particle size can affect the final product’s matte, gloss, or texture in a finish. 

It’s important to know that you can trust your toll processor to deliver on their quality promise, so that in turn, you can deliver on yours with confidence.

Let’s take a look at some of the most important particle and material specifications your toll processor should be able to test for, and how those analyses can help you achieve your product and quality goals.

Particle Size Analysis

Laser diffraction particle size analysis is a robust and versatile method for measuring particle size in a material. Your toll processor should have an extensive range of equipment types to help ensure that they can analyze many different material types. Particles measured by laser diffraction can range from the 100s of nanometers to millimeters (or 1000s of microns).

All laser diffraction equipment operates on the same principle — that is, it measures the interaction of light with particle surfaces. Laser diffraction analysis is quick to complete and can deliver several important values, including:

  • Minimum and maximum particle size,
  • Average size within the distribution range, and
  • Particle size percentiles within the sample

Before applying the laser to measure for this type of analysis, dry, milled products must be dispersed, either in a fluid or in a stream of air. This makes laser diffraction ideally suited for testing a very broad range of products resulting from jet milling, mechanical milling, and wet-milling processes. The very broad size range it can measure also makes it a versatile option.

Sieve testing is one of the oldest — yet still very valuable — technologies for sorting and evaluating particle size. Milled material is placed on a sieve, which is then agitated or shaken, allowing particles to pass through the sieve openings, which are certified for accuracy in sizing.

Larger particles remain in the sieve, and they can be further evaluated for a clearer understanding of the characteristics and particle sizes in the whole sample.

Because these two types of tests work very differently to achieve similar measurements, they can be used in tandem as a check on one another, providing even greater certainty for the values.

Often, customers know exactly what their target particle size ranges are — but if you don’t, that’s okay. An experienced toll processor’s quality experts and process engineers can work closely with you to correlate particle size values with your desired product characteristics.

A dedicated technical team can run pilot trials and deliver smaller batches in varying particle size ranges to help you determine the optimal specifications for your desired end product — and then, in turn, optimize for efficiency and cost when scaling up to production-level equipment.

Other Tests & Analyses

Most projects in technical grade drying, milling, and blending can be tested for physical properties beyond particle size such as bulk density, and moisture content. Wet-milled products sometimes require pH testing.

Customers can require specific tests depending on a product’s end use, or products in certain markets can call for specific tests, including FDA-required analyses. Food or pharma grade materials may require microbiological testing and other chemical tests, such as nitrogen measurement (for calculating protein content) and carbon measurement. 

A toll processor can often perform at least some of these tests in-house. Often, they can coordinate with a trusted third-party analytical service to perform advanced chemical analysis as needed.

Calibration & Standards

Standards and qualification of testing and analytical laboratory equipment fall under quality management standards and are outlined in certification standards. Some types of equipment, once out of calibration, are replaced rather than recalibrated. Calibration, whether performed in-house or through qualified, approved suppliers, is meticulously documented and follows a regimented schedule.

Due to the nature of scientific measurement and differences of equipment and other variables, your toll processor will work closely with your own quality teams to reconcile perceived differences in measured values. Expert quality leads are familiar and comfortable with this process, and you should also expect to feel comfortable with the process and results. 

Expect your toll processor’s quality team to work hand-in-hand with production and provide a constant, accessible presence on site during all processing shifts. In addition, expect production leaders and operators to provide the equipment know-how to make adjustments based on test results to optimize production quality and achieve your desired end goal.

Integrity & Accountability

Quality testing is integral to establish trust in your toll processor. While no one wants to be the one to interrupt production, quality testing is critical to ensuring that the materials processed meet your quality standards. A vigilant toll processor is always monitoring raw materials as they come in, scrutinizing for off-spec characteristics in feedstock, as well as testing to verify quality and validate their processes.

You should be able to trust that your toll processor will alert you to any raw material concern and will quarantine the material in question while awaiting your feedback on further testing and handling. Expect open communication and transparency about any material question or quality concern, as your toll processor works with you to maximize outcomes without sacrificing quality standards.

Processes work best when transparency goes both ways. This includes both process and material knowledge, and more is always better. A safety data sheet (SDS) is required, but that’s the minimum, and often it is just the beginning. While inert ingredients may not be listed in the SDS, they are there nonetheless, and your toll processor still interacts with them. 

The more data you can provide, the better equipped your toll manufacturer is from the start and the faster and more accurately they can help you achieve your desired end result.

You can get a better understanding of the many terms surrounding toll processing and material characteristics when you download our Particle Technology Glossary. Get started by clicking the link below, and if questions persist after you’ve read it, contact us here.New call-to-action

Posted in:Toll Processing