Custom Processing Services Blog

How to Choose Materials & Toll Processors for Jet Milling Success

KT Brickman, Feb 24, 2023 1:10:00 PM

Jet Milling Particles

Jet milling is a versatile particle size reduction process. Ingredients in pharmaceuticals, cosmetics, paints and pigments, industrial chemicals, and other applications are typically jet milled to achieve exceptionally small, uniform particles with large, performance-enhancing surface areas.

Since jet milling methods don’t generate heat and present a low contamination risk, there’s a widely held belief that any material is suitable for the process. A variety of materials can be jet milled, but not all — and that’s where the expertise and guidance of your toll processing partner proves even more valuable.

The Impact of Moisture on Jet Milling

Successful jet milling depends upon particles of raw material colliding with each other in a stream of high-pressure, compressed gas to the point of fracturing. The smaller, fractured pieces are then collected and classified for use within an application.

Since particle collisions and fracture are central to the jet milling method, materials must have characteristics that are conducive to breakage or crumbling. There is a definite division in what constitutes “good” and “bad” jet milling materials, but moisture is universally the top characteristic to be avoided in feed materials.

Why? Moisture can cause feed materials to flow slowly, greatly decreasing the throughput. It can also cause material to cling to jet mill grinding chamber walls and classifier components, which could result in costly production line downtime, defective milling, and excessive waste.

An experienced toll processor takes a two-pronged approach to managing moisture. The first and most obvious is thoroughly drying feed materials prior to jet milling. The second is paying close attention to ambient conditions that could impact moisture content — such as the heat and humidity of a summer day.

Toll processors attuned to potentially moisture-rich processing environments will proactively schedule jet milling to avoid adverse circumstances and ensure quality outcomes without disrupting production timelines.

Moisture content is an important focus area for optimal jet milling, but there are other considerations that help determine which materials are better — or worse — for this specific milling method.

Characteristics Quick LIst: Best Jet Milling Materials

  • Abrasive
  • Brittle
  • Dense
  • Hard
  • Friable (easy to crumble)
  • Temperature-sensitive*

Characteristics Quick List: Less Successful Jet Milling Materials

  • Elastic
  • Wet
  • Sticky
  • Light and fluffy
  • High molecular weight
  • Structurally complex
  • Easily deformed
  • Shock absorbent
  • Difficult to accelerate

Putting Materials to the Test

Working with an expert toll processing partner is the surest way to ensure materials behave as anticipated on the jet mill.  

The breadth of experience CPS has with materials and industries often helps streamline jet milling preparation, as the history informs expectations around how a particular material will mill.

In the event an unfamiliar material is presented for potential jet milling, CPS conducts pre-production testing to eliminate guesswork. Feasibility studies and pilot test runs on smaller batches of material are cost-effective ways to understand material responsiveness to jet milling and how it will help:

  • Assure reliable quality
  • Meet regulatory requirements
  • Ensure predictable, repeatable, and consistent production

*Requires expert toll processor guidance and specific raw feeds

Jet milling is a practical solution for many industries and applications, provided the right materials and toll processing partner are used.

Learn more about the basic principles and benefits of this in-demand particle size reduction milling method in Jet Milling Services Fundamentals: A Manufacturer’s Guide. Click the button below to download your copy of this valuable resource now.

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Posted in:Toll Processing