This MOM glossary covers the key technical terms used in industrial powder dosing and powder filling projects. It is designed to provide clear, neutral, and practical definitions, while explaining why each concept matters when choosing the right filling technology, machine configuration, tooling, and line organization.
How to use this industrial powder filling glossary: if a term appears in a technical specification, production line audit, or engineering discussion, you will find a concise definition, its impact on industrial filling performance, and links to related MOM resources for deeper technical guidance.
Table of Contents
- Abrasive
- Cohesive powder
- Sticky powder
- Corrosive powder
- Free-flowing powder
- Heterogeneous powder
- Homogeneous powder
- Hygroscopic powder
- Automatic weighing instrument (AWI)
- Legal metrology
- Gravimetric filling
- Dusty powder
- Volumetric filling
Abrasive powder
An abrasive powder is composed of hard particles capable of causing wear on mechanical components during handling and dosing operations.
Impact on powder filling
Abrasive powders progressively wear dosing tools, especially auger screws and contact parts. As wear increases (sharp edges, inconsistent screw pitch), dosing accuracy decreases due to variations in the delivered volume. This directly impacts filling precision, repeatability, and overall machine performance.
Recommended solution
Applying surface treatments (such as coatings or hardening processes) significantly improves wear resistance and extends tool lifespan. Another approach is to use harder materials for critical components, particularly dosing screws used in auger filling machines.
Cohesive (agglomerating) powder
A cohesive powder is a powder that naturally tends to form lumps or agglomerates due to inter-particle forces.
Impact on powder filling
A free-flowing (non-cohesive) powder flows continuously and evenly. In contrast, a cohesive powder flows in irregular lumps with variable mass. This variability creates inconsistent flow, leads to pulsation effects during dosing, and reduces filling accuracy and repeatability.
Recommended solution
Using agitators or stirring devices inside the hopper helps break agglomerates without damaging the product. This improves powder flowability, ensures a more consistent mass flow, and increases dosing accuracy in powder filling machines.
Typical industrial applications
Some dietary supplements, such as protein powders, are typically cohesive and prone to agglomeration.
Sticky powder
A sticky powder is a powder whose composition promotes adhesion to metal or polymer surfaces in processing and filling equipment.
Impact on powder filling
Sticky powders tend to adhere to dosing tools during operation. Over time, material builds up on the auger screw and contact surfaces. This gradual buildup reduces the effective volume of the screw, leading to dosing drift and reduced filling accuracy.
Recommended solution
Optimizing screw geometry (for example, flight angle and design) can reduce sensitivity to buildup. Another effective approach is applying surface treatments or coatings to limit adhesion and improve cleanability.
Typical industrial applications
Certain peptides are particularly sticky and prone to adhesion during powder filling operations.
Corrosive powder
A corrosive powder is a powder whose chemical composition can attack or degrade materials such as metals, seals, and polymers in contact with the product.
Impact on powder filling
Corrosive powders can damage dosing tools, hoppers, and machine frames, especially when fine particles spread onto surrounding structures. Corrosion gradually alters mechanical tolerances, may lead to dosing drift, and significantly reduces equipment lifespan.
Recommended solution
For product-contact parts, select chemically compatible materials such as technical polymers or specific coatings. It is also essential to minimize product retention zones and implement regular cleaning procedures to limit corrosion effects.
Typical industrial applications
Caustic soda and chlorine-based pool treatment products are highly corrosive powders.
Free-flowing powder
A free-flowing powder is a highly fluid powder that flows easily under the effect of gravity.
Impact on powder filling
At the end of the dosing cycle, flow inertia inside the auger combined with gravity can cause residual flow. This leads to powder dribbling, which may contaminate the filling area, dirty containers, and reduce dosing consistency.
Recommended solution
Optimizing the screw geometry (for example, flight angle) can significantly reduce residual flow. Another approach is to adjust the screw deceleration profile to limit product inertia at the end of the filling cycle.
Typical industrial applications
Printer toner is a highly free-flowing powder.
Heterogeneous powder
A heterogeneous powder is a blend in which components have different properties (density, particle size, particle shape, etc.) and may separate under the effect of vibrations or handling (segregation or de-mixing).
Impact on powder filling
De-mixing compromises the uniformity of the final product and may lead to regulatory non-compliance, particularly in pharmaceutical applications where content uniformity is critical.
Recommended solution
Avoid conveying systems that promote vibrations (such as certain vibratory feeders), as they accelerate segregation. Prefer vertical auger dosing combined with gravity feeding. Limiting drop heights during product transfer also helps reduce the risk of de-mixing.
Typical industrial applications
Pharmaceutical products are often composed of a bulk excipient and an active ingredient, making them sensitive to segregation.
Homogeneous powder
A homogeneous powder is a blend with a uniform composition throughout the entire batch.
Impact on powder filling
A homogeneous powder ensures consistent composition from one batch to another and facilitates high dosing repeatability and process control.
Hygroscopic powder
A hygroscopic powder is a powder that absorbs or retains moisture from the surrounding air.
Impact on powder filling
Depending on environmental conditions (temperature and humidity), the physical properties of the powder change. Moisture absorption alters bulk density and cohesion, which affects powder flow and reduces dosing repeatability.
Recommended solution
Operate in a humidity-controlled environment whenever possible. When humidity control is not feasible, prefer gravimetric dosing or volumetric systems with trend correction to compensate for variations in powder behavior.
Typical industrial applications
Many pharmaceutical products, as well as food powders such as chicory and various spices, are hygroscopic.
Automatic weighing instrument (AWI)
An IPFA is an automatic weighing instrument as defined by European regulations. It may take the form of a gravimetric filling machine (dosing unit) or a checkweigher.
Impact on powder filling
A gravimetric filling machine subject to legal metrology must undergo initial verification (for example, conformity assessment under Module D). This verification certifies that the equipment complies with regulatory requirements over a defined weighing range, including maximum permissible errors, accuracy, and dosing repeatability.
Limitations
The design and placing on the market of an IPFA require the manufacturer to obtain a EU type-examination certificate issued by a notified body (such as LNE in France). Equipment used under legal metrology must also undergo periodic inspections to ensure continued compliance.
Typical industrial applications
Prepackaged products intended for consumer sale and applications subject to legal metrology requirements.
Legal metrology
Legal metrology refers to the regulatory framework and procedures designed to ensure consumer protection and the accuracy of measurements used in commercial transactions.
Impact on powder filling
Operators involved in packaging must implement procedures and controls to ensure that the declared net weight on the packaging corresponds to the actual content of the prepackaged product.
Recommended solution
Manufacturers and packers can:
– Implement statistical net weight control using a non-automatic weighing instrument.
– Use a gravimetric filling machine compliant with legal metrology requirements (automatic weighing instrument).
– Integrate a checkweigher (automatic weighing instrument) for systematic in-line inspection.
Typical industrial applications
Prepackaged products intended for consumer sale.
Gravimetric filling
A gravimetric filling system uses a weighing device (load cell) to continuously measure the product weight and stops dosing once the target weight is reached.
Impact on powder filling
Gravimetric dosing provides high accuracy and compensates for variations in bulk density and powder flow behavior.
Limitations
Micro-dosing applications require load cells with very high resolution (for example 0.01 g). In such cases, environmental factors such as air movements or mechanical vibrations can affect weighing accuracy. A volumetric dosing system may therefore offer better stability.
Gravimetric dosing typically operates in two phases: a fast bulk filling phase followed by a slower fine dosing phase to reach the target weight with precision. As a result, it is generally slower than volumetric filling.
Typical industrial applications
Filling of dietary supplements, large-volume packaging, or applications subject to legal metrology requirements.
Dusty powder
A dusty powder is a powder that easily generates fine particles during handling or flow, which can become airborne.
Impact on powder filling
Fine particles can contaminate the packaging area, reduce packaging cleanliness, and create safety risks such as dust explosion hazards (ATEX), inhalation exposure, or cross-contamination. This may also lead to compliance issues in regulated industries.
Recommended solution
Avoid dosing systems that generate vibrations (such as vibratory feeders). Implement dust extraction or vacuum systems in the filling area. Reduce drop heights during product transfer and dosing. Limit agitator speed in the hopper, as excessive rotation can generate additional fines.
Typical industrial applications
Certain spices, such as cinnamon, as well as some dietary supplements like collagen, are particularly dusty.
Volumetric filling
A machine performs volumetric dosing when the target setpoint corresponds to a defined volume of product to be delivered.
Impact on powder filling
Volumetric dosing typically operates at a constant speed, allowing high throughput and high filling rates. It is particularly suitable for micro-dosing applications when the powder behavior remains stable.
Limitations
Dosing repeatability strongly depends on the stability of bulk density and powder flow. Variations in these properties can lead to dosing drift.
Using a post-dosing weighing system with trend correction helps compensate for these variations and improves overall accuracy.
Typical industrial applications
High-speed filling lines and micro-dosing applications in pharmaceutical or cosmetic industries.
To learn more about industrial powder filling, explore our complete guide to industrial powder filling, covering technologies, powder behavior, and key parameters for accurate and efficient dosing.