Did you know that additively manufactured parts require several treatments after being printed? The required post-processing depends on the requirements and printing method of the manufactured part. The processes most commonly used after printing are depowdering, removal of support structures, surface treatment and hardening. In this respect, ADDIBLAST post-processing solutions bring together three key post-processing solutions within the same product line: depowdering, powder recovery and surface treatment of 3D-printed parts, whether made from plastic or metal.  

The extraordinary growth of the additive manufacturing industry has spurred the creation of new guidelines and requirements for the surface treatment of unconventional structures and materials. The ADDIBLAST smart solution series is the latest user-friendly line of machines from FerroČrtalič, a company boasting over 55 years of tradition, continuous development and a drive for excellence, which is an indispensable surface treatment partner to various industries such as aeronautical, medical, automotive, foundry, and more. The new machines are specifically designed for additional processing (also referred to as post-processing) in additive manufacturing (AM), better known as 3D printing. The family of new machines follows Industry 4.0 guidelines and includes state-of-the-art automated solutions of key processes for more efficient depowdering of parts, recycling of excess powder and surface treatment of 3D-printed products, regardless of the material used. The goal is to achieve the immediate usefulness of 3D-printed parts in practice and to reduce costs.

BAM is an ergonomic and user-friendly solution for the surface treatment of 3D parts. It is suitable for various processes such as smoothing, roughing, unifying and polishing surfaces, for removing support structures, and precisely removing powder from extremely complex structures. It is made of stainless steel and is suitable for all types of shot-blasting media. 

As a market first, it comes with a built-in automatic filling system for the pressure micro-blasting system called AddiMiniBlast, which was developed specifically for the ADDIBLAST line. The BAM line comprises both injector-suction and pressure-blasting systems, allowing users to adapt extremely quickly to the required treatment process itself. 

The BAM working cabinet is electronically height-adjustable and allows ergonomic adjustments for different users. It is suitable for standing or seated operation. Its large window and thoughtfully designed interior lighting provide optimal view and visual control of the process. It is designed for a wide range of additive manufacturing technology users, from enthusiastic individuals, small laboratories, development hubs, prototype centers to 3D parts serial production plants.

 

The additive industry's technology is still faced with challenges in terms of optimizing costs in the production of 3D parts compared to standard manufacturing processes. Efficient depowdering and recycling of excess powder enable the return of unused material back to the printing process, playing a key role in reducing costs and raising the usability of 3D printing technology.

MARS03 

MARS03 offers compact, user-friendly manual and automated solutions that support various depowdering applications at the same time from extremely complex, unique structures to massive 3D structures. The whole system allows components to communicate and exchange data amongst each other. For safe loading of heavier parts, the cabinet can be equipped with a uniquely executed automatic top-lifting door, which allows easy and safe handling of printed parts.

The system is compliant with the ATEX Directive, so the treatment of titanium and aluminium powder is not a problem since the system is designed to create and maintain a controlled inert atmosphere by keeping oxygen levels in the range of of 2 to 4 percent. 

The machine takes advantage of manipulating friction forces through vibration. Depending on the direction of the vibration, different mechanisms lead to an observable reduction in friction. When the surface below the mass vibrates in a sliding movement, the friction force has an accelerating effect for a short period of time rather than a breaking effect. As shown in the article titled "Vibration-Assisted Handling of Dry Fine Powders", the use of vibration enhances the handling of dry fine powders. Vibrations can be used to fluidize powders, prevent deposit build-ups, reduce effective friction, and deagglomerate, disperse and mix powders. Depending on the application, low-frequency or high-frequency vibrations are required to achieve optimum results in increasing flowability, reducing friction forces and separating agglomerates. The application of vibration is therefore a powerful technique for improving the dosing, transport, deagglomeration, dispersion and mixing of fine powders [1].

The machine uses a pneumatic turbine vibrator to vibrate parts that are fixed to the turntable. The part vibration frequency can be set by adjusting the air pressure connected to the turbine actuator and will be different for every part because it is closely linked to part weight. A part can be rotated on two axes, which can also be used for adjusting the incline of the surface where powder is trapped. With the combination of rotation and vibration, the machine is able to remove loose powder in tough-to-reach places. This way, depowdering can be automated in a closed environment. 

There are many articles on powder reuse in metal AM and understanding its impact on the final product; for example "The observations from this study suggest that there is no requirement to dispose of unmelted Ti6Al4V after it has been cycled around the AM250 system a limited number of times. This does, however, depend on the specific requirements of the component material properties, in which case a stringent blending regime may be required for traceability. The effects of powder reuse may potentially be different for other materials, in terms of physical property effects. However, because titanium has a high propensity to pick up interstitial impurities, the pick-up rates observed can be thought of as a 'worst case' for commonly used metal AM powders." [2]

Let's take, for instance, printing with a 40% efficiency rate, meaning that 40% of the total build volume represents actual parts. This means that 60% of the powder would be wasted if disposed of. But this proportion of the powder can be reused, directly cutting the cost per part. 

The STAR solution is designed as a central station that allows continuous and automatic process of pneumatic transfer, recycling and conditioning of powder from various sources. It provides direct connections to a 3D printer and a powder removal system (MARS 03), and it can also be used for purifying virgin powder before being used in a 3D printer. Powder recovery and conditioning bring significant improvements to the additive manufacturing serial production. 

All functions of the machines are controlled by a user-friendly PLC unit, which enables control over all parameters and provides visual information on the machine's condition and the amount of powder collected via a built-in weight measurement system in each collector. The described system has great advantages in terms of connectivity and communication with other equipment, as the STAR solution shares its operating status and parameters with MARS units.

The combination of MARS 03 depowdering station and STAR 02 powder recovery and conditioning unit presents a world-class novelty. The system runs in a closed-loop inert atmosphere with oxygen levels maintained in the range of 2% to 4%. This feature prevents contaminant and oxidation layers from forming on powder during depowdering and conditioning, taking powder reusability to a new level. Solutions like this help bring additive manufacturing technology a step closer to mass production while reducing the cost per part and creating outstanding added value for the most demanding industries such as aviation and medicine.

To explore the complete ADDIBLAST solution series, visit www.addiblast.com.

1. Paul D.; Peter B.; Tobies H. and Walter S. Vibration-Assisted Handling of Dry Fine Powders (2018)

2. Whittaker D. Understanding the impact of powder reuse in metal Additive Manufacturing (2017)

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SI-8350 Dolenjske Toplice, Slovenia 

Tel. +386.7.38 45 100

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