For a wide variety of products, including powders, granules, active ingredients, and heat-sensitive materials, maintaining particle integrity can mean the difference between a product that functions as intended and one that doesn’t meet quality standards.
Readco Kurimoto’s continuous mixing technology was developed to provide efficient and consistent mixing while protecting the structure of each particle that passes through the machine.
Reasons Particles Degrade During Mixing
There are predictable reasons why particles degrade during mixing.
1. Uncontrolled Shear
Batch mixers typically use high-speed blades or paddles that generate significant shear forces to break particles before the blending is complete.
2. Excessive Exposure Time
Batch processes are limited only by the time required to achieve a uniform blend. Ingredients remain in a vessel under constant motion until the desired blending is achieved. The longer ingredients remain in the vessel, the greater the amount of heat, friction, and mechanical stress that develops.
3. Nonuniform Motion
Inside a large batch tank, ingredients do not always move uniformly. Some areas experience intense mixing forces while others may be subject to very little. Inconsistent motion is common and can lead to the fracturing of delicate particles and nonuniform results throughout multiple batches.
Each of the above limitations is due to the fact that very few aspects of batch mixing are controllable. Since quality depends on particle integrity, “uncontrollable” becomes a significant limitation.
Why It Is Important to Preserve Particles and Ways to Save Them
When particles break down, the final product may show different characteristics. For example, pharmaceutical dosage accuracy can be affected by broken particles, food texture can change, inclusions can break apart due to physical forces and chemical reactions, and flow can be impacted by broken particles in specialty chemical products. Even a minimal amount of particle breakdown will contribute to poor product quality.
Therefore, the equipment used to process the materials must also preserve the materials’ integrity. Readco processors meet and exceed both ASME and ASTM standards and are available in various alloys, including 316 stainless steel, Hastelloy, and Alloy 20 for difficult applications. Close manufacturing tolerances ensure that no additional variability is created by the processor, and little to no downtime occurs.
If you want to prevent damage and maintain particle integrity when mixing, the core principles are straightforward:
- Apply only the shear required by the application. Gentle mixing prevents unnecessary breakage.
- Keep mixing time as short as possible. The longer the material is stressed, the more likely it is to be damaged. Continuous mixing naturally limits exposure.
- Choose a screw design that suits the material. Engineers can select elements that move and mix particles in a controlled way without crushing them.
- Use the right metallurgy. The correct alloy reduces friction, supports cleanability, and helps protect particle structure.
These steps make it easier to maintain product quality and reduce the risk of particle-related failures.
Continuous Mixing Eliminates the Most Common Sources of Particle Damage
Continuous mixing eliminates the uncertainty of a batch tank by creating a controlled and engineered environment for mixing. Unlike traditional batch mixing, where a full vessel of product is agitated for a relatively long time, the Readco Kurimoto Continuous Processor continuously moves material through a predetermined path at a steady pace. Because the movement of the material is predictable, the shear forces applied during mixing can be adjusted to match the properties of the material being mixed, rather than exceeding them. Working with smaller amounts of material in a continuous flow allows the mixing process to occur quickly and efficiently.
Below are some examples of how this translates into actual applications.
Shear forces are purposefully generated, not by accident
Using a twin-shaft screw design, engineers can specify the exact mixing action that is necessary for the particular formulation being processed. Elements of the screws can be positioned to provide folding, conveying, dispersion, low-shear action, or high shear if necessary.
Material spends less time under mechanical stress
One of the greatest benefits of continuous processing is the short residence time of the material in the mixing chamber. Material is subjected to the minimum amount of time required to perform the mixing function. In contrast, in batch processing, ingredients are subjected to potentially hours of mechanical stress in the form of mixing action, abrasion against the vessel walls, and contact with other ingredients to ensure that the entire batch of material is mixed.
All particles are treated equally
Continuous mixing eliminates the randomness associated with batch processing. Each ingredient passes through the mixing chamber in a predetermined manner, eliminating all potential for dead zones, stagnation, and impact-induced damage.
Explore a Mixing Solution Built for Your Material
If maintaining particle integrity is important for your process, choose Readco Kurimoto. Our engineers will analyze your formula to develop a customized system that produces consistent results with minimal disruption to your particles.
Contact us today, and we can work together to develop the best possible solution for you.