Technodigm Innovation Technodigm Innovation
Technodigm Innovation
November 08, 2023

Case Study: Additive Manufacturing – Liquid 3D-Printing

Dispensing of Silicones, Polyurethanes, Ceramic Pastes, etc. in 3D-Printers

Requirement & Task:

3D-printing technologies and processes are replacing many conventional methods of manufacturing nowadays. Especially the speed and flexibility of getting parts is unbeatable by using 3D-printers. Compared to traditional technologies, like mechanical processing, additive manufacturing allows to get e.g., prototypes or time-critical parts within hours or even minutes. In general, there are many different methods of additive manufacturing (3D-printing): metal forming or casting processes, filament printing process (FLM), or milling methods (e.g., plastics or metal parts), as well as Fused Deposition Modelling (FDM) or Stereo Lithography (SLA), When it comes to liquid 3D-printing technology, different types of fluids or pastes are applied by a dosing head layer by layer to form the requested part. At this application 1- or 2-component adhesives or pastes are very often used, such as silicones, polyurethanes, epoxies or ceramic pastes or even food and materials, like chocolate or bio printing materials. The main challenges for liquid 3D-printing are fast, precise and accurate dispensing processes, without any contamination and deformation. Of course, a reasonable cost and pricing structure is also required, in order to be competitive in this cost sensitive market.

Solution:

The PCP-technology is offering the best solution to fulfil these specific requirements. The technology of progressive cavity pumps (eccentric screw pumps) allows dispensing of different dosing volumes in a very precise way (deviation of repeatability or accuracy only +/-1%). This precision ensures a perfect manufacturing quality of the printed parts without any deviations. The combination of rotor and stator within the PCP-dispenser as core parts guarantees this accuracy. As there is always a fixed volumetric output of the pump by one turn, this dosing head could be easily integrated into automated and existing 3D-printing systems and software. As weight, space and cost is always very important for 3D-printer-manufacturers, VISEC provides the manufacturers only the core part of PCP-pumps (rotor, stator and seals). These parts could then be integrated into the dosing heads, developed by the 3D-printer manufacturer. VISEC is offering different stators (depending on the used liquids) with specific rubber mixtures. Also, different rotors could be supplied, depending for example on the content of abrasive particles (e.g., at ceramic pastes). Here, VISEC has developed a special coating mixture and method to offer a very resistant and hard surface to withstand even extreme influences by very abrasive pastes and liquids.

Advantages & Benefits:

As the manufacturers could only use the core components of PCP-dispensers (supplied by VISEC), this offers the highest grade of flexibility and freedom. The printer companies are totally free to consider their own specific requirements regarding design, use of existing components (e.g., motors and software) and also cost considerations. This flexibility is a big advantage and the manufacturers could use their own self-designed pump housing (e.g., with less weight or space requirements) or other parts.

The PCP-technology itself offers tremendous advantages and benefits when these 3D-printing materials should be dispensed.

By using the PCP-technology an accuracy and repeatability of +/- 99% could be guaranteed. A clean and safe process will be ensured by the adjustable suck-back of the dispenser. This helps to avoid any type of dripping or tailing, where the printed parts could be damaged or affected by wrong dosing results.

For abrasive ceramic pastes, special developed rubber material for the stators and coating of rotors extends the life time of the rotor to 4-5 times in comparison to a standard hard-chrome plated rotor assembly and even the life-time of the stator could be extended to 2-3 times compared to a stator with standard rubber. Compared to competitor’s products, the life-time of these parts is much higher. This means less production interruptions, more process reliability and safety, higher quality standard and of course, less costs.

For applications in the Food & Pharma sector (e.g., Bio-Printing), the VISEC components could be also used in a perfect way: due to FDA compliance and clean manufacturing methods, rotors, stators and sealing rings fits perfectly for these applications. 

visec systems

For more information on Technodigm™ solutions, check out our fluid dispensing systems and UV intensity measurement systems.