This edition highlights our latest projects focused on powder processing innovations. At Delft Solids Solutions, we don’t just provide laboratory services; we also offer lab-scale industrial process setups. These setups enable us to simulate real industrial conditions and include a range of powder processes, such as cryogenic milling, mixing, granulation, coating, and pneumatic conveying.
Each process plays a vital role in powder technology. For instance, cryogenic milling stabilizes powders by cooling them, making it possible to achieve fine particle sizes without heat-related degradation. Mixing ensures a uniform distribution of particles, which is essential for product consistency. Granulation enhances flowability and handling, while coating modifies particle surfaces to meet specific requirements. Pneumatic conveying, meanwhile, provides an efficient, safe means to transport powders throughout processing systems.
Dutch Processing of Cocoa Nibs: Enhancing Taste and Preserving Health Benefits
Cocoa nibs typically undergo a process called the Dutch process, where they are alkalized to create a milder-tasting final product. These nibs contain beneficial flavonoids, compounds known for their antioxidant properties. Cocoa Powder Processing focuses on two key aims: (1) transforming cocoa nibs into granules with a milder taste, and (2) applying a protective coating on these granules to prevent the flavonoids from oxidizing when exposed to air.
Delft Solids Solutions’ Powder Processing Steps for Cocoa Nibs
Delft Solids Solutions has successfully achieved the dual aims of producing milder-tasting cocoa granules and protecting flavonoids from oxidation through an advanced combination of powder processing steps:
Cryogenic Milling: Micronizing Cocoa Nibs
Cryogenic milling is ideal for micronizing heat-sensitive materials, making it highly effective in the food industry. At Delft Solids Solutions, we’ve optimized the cryogenic milling process by using liquid nitrogen alongside a carefully selected sieving fraction for cocoa nibs. This approach achieves the perfect balance between grinding yield and particle size while maintaining the quality of the powder. Powder Processing through Cryogenic milling has proven to be a reliable process, delivering a narrow particle size distribution essential for high-quality cocoa powder.
Granulation for Cocoa-Based Mixture Agglomeration
In cocoa-based powder mixtures—composed of cocoa powder, sugar, and an alkalizing agent—sugar plays a dual role as a sweetness enhancer and a binder. The granulation process, conducted in a high-shear granulator, agglomerates these ingredients into uniform granules. This specialized granulator includes a chopper, impeller, and a precise water-dosing system. The flexible mixing chamber doubles as a mixing environment, reducing attrition and preventing powder segregation during charge and discharge actions.
Optimizing granulation involves adjusting process parameters like impeller speed, chopper speed, binder percentage, and processing time. These adjustments allow us to customize the granules in terms of size and density, meeting the quality requirements for various applications. Granulation offers advantages beyond easy handling, including reduced dustiness, which lowers explosion risk, and minimized segregation, ensuring product uniformity throughout.
Mixing for Alkalizing and Homogenizing Cocoa Powder
To achieve optimal alkalization and homogenization, we have refined the mixing process for cocoa powder. Using a small bench-top high-shear mixer, we’ve obtained highly homogeneous mixtures with perfectly alkalized cocoa powder. This process produces a high-quality blend with a narrow particle size distribution, essential for ideal binder dispersion in further processing.
The homogeneity achieved extends uniformly from top to bottom in each batch. High-shear mixing offers additional benefits by breaking down any unwanted agglomerates under the controlled moist and alkalized environment. This method also requires less time than traditional mixing, reducing the risk of flavonoid oxidation and preserving antioxidant quality.
Coating to Protect Flavonoids from Oxidation
To shield the flavonoids in cocoa granules from oxidation, we apply a shear-thinning syrup coating. This process takes place in a coating pan equipped with a precise drying and dosing system, ideal for heat-sensitive products like cocoa.
We optimized the coating by adjusting parameters such as coating concentration, dosing rate, pan rotation speed, and process time. This versatile coating process can accommodate various materials, ensuring an effective protective layer for different applications. The result is a stable, high-quality coating that preserves the integrity of cocoa’s beneficial flavonoids.
Understanding Particle Wear in Pneumatic Conveying of Infant Formula
In manufacturing infant formula, powder products often travel between units via pneumatic conveying. However, particle wear is a major challenge in these systems. This wear can significantly alter product quality by affecting solubility, bulk density, particle size, and shape—and it can easily generate fines.
Delft Solids Solutions offers lab-scale Powder Processing testing that replicates industrial conveying, allowing us to quantitatively predict powder and granule wear. Key factors in particle wear include the design and operating conditions of the pneumatic conveying system.
Specifically, bend types, air velocity, and the number of bends are critical parameters that impact particle integrity during transport. By adjusting these conditions, we help optimize the conveying process to maintain infant formula quality and consistency.
Mimicking Industrial Conveying on a Lab Scale
To accurately quantify particle wear in pneumatic conveying, we conduct lab-scale experiments that replicate industrial conditions. These experiments allow for precise control over three critical parameters: air velocity, bend shapes, and the number of bends.
Air Velocity: We use a diluted-phase flow, with adjustable air speeds of 3 m/s, 5 m/s, and 7 m/s. These speeds represent typical velocities used in conveying processes, ensuring realistic results.
Bend Shapes: Our setup includes three widely-used industrial bend shapes—radius, mitred, and T-shape bends. Each shape provides different impacts on particle wear, allowing us to assess their effects comprehensively.
Number of Bends: Our system can accommodate up to nine bends, covering conditions seen in most industrial plants. This flexibility enables us to mimic a broad range of real-world conveying setups, accurately predicting wear behavior under varying configurations.
These lab-scale experiments provide valuable insights, helping optimize conveying parameters to minimize particle wear and maintain product quality.
