Powder Processing Inc.
306 Winding Brook Lane, Unit # 101
Bradenton, FL 34212
Phone: (631) 868-0102 - Fax: 941-567-5695
Cell: 516-637-2116 -
Email: rkkloss@aol.com

Consulting Services: We can help solve your most difficult powder processing problems!



Pharmaceutical Company Specializing in Eye CareProducts

Problem: The Company could not manufacture an active pharmaceutical product that met their specification using the active raw material being produced in its European plant.

Analysis: In reviewing the analytical test data for the raw material, I observed that the raw material producing out of specification finished product had a high level of very small particles that were interfering with the manufacturing process of the finished product.

Background: The manufacturing process for the raw material started with a reaction with the active material precipitating out of solution and then being filtered and vacuum dried. The dried active was milled in a hammer mill, mixed to obtain uniformity and then jet milled in two steps.

Solution: I found that the reaction/ precipitation process was out of control. The Company impemented my recommended changes to this part of their process. I found no problems with the hammer milling and blending steps but the jet milling was not in control. I changed the jet milling conditions for both steps in the procedure so that fewer fines were produced during the jet milling process.

Conclusion: The precipitation procedure was making particles that had a low density so they broke up too easily in the jet milling steps. By implementing my recommendations the dried particle was much more dense. The feeding rate of the volumetric feeder in the jet milling process varied from fast to slow depending on the amount of material in the hopper. I had them maintain a constant level in the hopper and I adjusted the feed rate for both jet milling steps in order to produce a raw material with a constant acceptable particle size distribution. With these changes, the Company was able to resume manufacturing acceptable finished product.

Nutraceutical Raw Material Company Supplying an Ingredient for Nutraceutical Tablets

Problem: The raw material is a natural ingredient made from berries grown in the rain forest. The final product was spray dried but the resultant material did not meet specifications with respect to bulk density. This resulted in problems manufacturing the tablet on high speed tablet presses.

Analysis: Spray drying a natural berry product with a high glucose content is a problem due to the dried product becoming sticky. I observed that the raw material company was only measuring bulk density. When I additionally measured the raw material's particle size distribution, I found that the raw material contained too many small particles.

Background: The berries are picked in the Brazil rain forest and processed in Peru. The berries are homogenized with water to form a solution that is high in Vitamin C with a high glucose content. To spray dry this material it is necessary to add maltodextrins to the solution as a carrier in the spray drier. The company doing the spray drying had large spray driers but did not have a strong technical staff.

Solution: I observed that the spray drying company was using substantially less maltodextrins than normally used and recommended for this type of product so I increased the amount of maltodextrins in the formula slightly. This change gave the plant more flexibility with respect operating conditions. The company is using a disc spray nozzle to atomize the liquid. I had the company slow down the disk speed (rpm) but due to mechanical limits with their speed control this was not sufficient so I also had the company slow down the liquid feed rate. These changes increased the products particle size and brought the bulk density into specification. Since Vitamin C decomposes with heating, I had to lower the inlet air temperature because the particles now spent more time in the drier.

Conclusion: The changes that I implemented resulted in a product with a bulk density and particle size distribution that could be manufactured in high speed tablet presses. While the Peruvian spray drying company has good equipment and follows good manufacturing procedures they did not have the knowledge that allowed them to change manufacturing conditions.

Post Script: While I was in Peru, I gave a one day seminar on particle size analysis, powder processing, grinding technology and spray drying equipment / processing. This was attended by individuals from companies throughout Peru.

Chocolate Manufacturing Company Supplying Agglomerated Hot Cocoa Products

Problem: The Company is agglomerating a hot cocoa product containing cocoa powder, sugar, non dairy creamer and proprietary flavors. They were not able to manufacture an agglomerated product that met their customer's requirements for bulk density and rapid dissolution rate.

Analysis and Background: The Company is using steam to agglomerate the product but the product that they were making was too dense and took too long dissolve. All the ingredients are blended in a double ribbon blender, milled in a hammer mill and steam agglomerated. The company is using commercial grades of granulated sugar and commercial grades of cocoa. The cocoa has a very fine particle size distribution and the granulated sugar is relatively coarse. The steam agglomerating process works by wetting the powder causing the individual particles to stick together. The hammer mill was a single speed mill with a fairly open screen size.

Solution: I did not observe any problems with the mixing process as the material leaving the mixer was fairly uniform. I observed that the hammer mill was not contributing anything to reducing the particle size of the powder blend feeding the agglomerator. I had the company install a variable high speed motor with a higher hp on to the hammer mill in order to grind the blend into a smaller uniform particle size. This allowed all the particles and especially the sugar to be uniformly wetted by the steam. This generated an agglomerate that was less dense with an open particle lattice. Initially we made an agglomerated product that dissolved very fast but the density was too low so I had to adjust the operating parameters to meet the customer's specifications.

Conclusion: The Company now has the equipment and knowledge to make a number agglomerated hot cocoa products that meet different specifications.

Company Needing to Make a Liquid Addition to a Fine Powder

Problem: The Company was adding a strong mineral acid to a fine powder in a double ribbon blender. The resultant product was very lumpy and the acid was not well distributed.

Analysis: The liquid was not being evenly distributed in the powder because of the small particle size distribution of the powder. A double ribbon blender works best when the powder is free flowing. The fine powder was not free flowing.

Solution: This was an easy problem to solve. It was necessary to utilize a high shear mixer such as a plow/chopper mixer in order to distribute the liquid into the powder evenly throughout the blender. These are normally batch mixers because the mixing is so efficient that good mixes are obtained very fast. In this case the large production volume meant that a continuous mixer was required. It was necessary to design a continuous mixer with minimal back mixing in order to obtain a uniform product.

Conclusion: The Company can now make an acceptable product.

Chemical Company Processing Uranium Powder for Nuclear Reactors

Problem: The Company wished to automate their manufacturing process and needed help with handling the very fine raw material.

Analysis: The Raw material was mostly minus 325 mesh and did not flow easily. It was being granulated in a roller compactor with milling system but the resultant granulation was not consistent.

Solution: The addition of automatic vibration with a high amplitude and low frequency helped to solve the flow problems. The hopper feeding the roller compactor varied in level and this caused the feed screw to feed the rolls inconsistently. By controlling the level of powder in the hopper, the granulated product became more consistent.

Conclusion: A more consistent granulation resulted in better downstream processing.


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