ViscoTec Introduces Two-Component Print Head for 3D Printing Viscous Materials

3D printing capabilities have come a long way quite quickly, but there’s still a long road ahead as materials development races to keep up with the demands of possibility. There’s been a major call, particularly in the medical industry, for 3D printed silicone, as its use would make way for major advances. Work has been ongoing in the development of reliable, repeatable technology for 3D printing silicone, with several new methods arising over recent months. This week in Germany, ViscoTec has introduced a new print head set for use in 3D printing two-component viscous materials such as silicone.

ViscoTec has its roots in producing pump technology and notes that it “primarily deals with systems required for conveying, dosing, applying, filling and emptying medium to high-viscosity fluids.” The German company, which began developments in 1980 as a department of Resch Maschinenbau and was officially founded in 1997, began working with 3D printing technologies in 2014 with the introduction of a paste extruder, leveraging its dosing technology to enter the market. The following year, ViscoTec introduced its FDD (Fluid Dosing and Deposition) Starter Kit to incorporate 3D printing of viscous materials into existing equipment. As 3D printing has continued to develop and look to multi-material capabilities, ViscoTec has likewise continued to evolve — the new ViscoDUO-FDD 4/4 print head is designed for use with viscous materials in a simple-sounding setup adaptable to a variety of customer hardware options.

Liquids and pastes aren’t the most common materials for extrusion-based 3D printing, though their use — and demand — has been on the rise. And ViscoTec, with its legacy work in dosing technology to back it up, has been taking heed.

“…[I]n addition to the classical materials in 3D printing, viscous fluids and pastes based on a two-component polymer are increasingly used. These include, for example, silicones, epoxy resins, polyurethanes, acrylates and polyester resins,” ViscoTec says in announcing the new print head.

“Instead of an FDM extruder, the print head is implemented in the 3D printer and controlled with existing software solutions. This makes the purchase of other software unnecessary – and therefore, no extra cost for the customer! In addition, this control ensures exact adherence to the mixing ratio of the two materials over the entire printing process.”

Endless piston principle

ViscoTec looks back to its endless piston principle, which drives the technology it uses in 3D printing, focusing on process-safe processing of viscous and pasty materials. The company notes that its product design is supplemented by generative production, as precise repeatability is critical in every industry where its dosing technology is used.

The ViscoDUO-FDD 4/4 print head employs a “special geometry” with the rotating displacement principle at its core. Key to its operation is assurance of clean material handling and precise mixing. Material is continuously axially transported, ViscoTec explains, in a precisely defined chamber:

“By reversing the direction of rotation a breakage of the thread is generated – to ensure absolutely clean printing results. A purely volumetric technology that makes high-precision 3D printing possible.”

The print head features programmable retraction, designed to prevent material drippage and ensure precision in material deposition. It was designed for use in industrial and professional applications.

“The 2-component print head is connected to the mixing head via two separate flow-optimized channels,” ViscoTec explains. “Mixing of the two materials first takes place in the mixing tube. After completing the printing operation, the mixing tube can be easily removed and disposed of. The print head can also be filled over a longer period, since the separate extruder units prevent the materials from curing.”

ViscoTec lists as the advantages of the ViscoDuo-FDD 4/4:

• Adjustable and correct mixing ratio
• Use of application-specific materials
• No curing in the print head thanks to a static mixing tube
• Process safety through pressure monitoring
• Various curing methods – e.g. UV, heat or humidity

As 3D printing developments continue to focus on materials such as silicone, applications surrounding them will benefit from enhanced precision and capabilities for complex geometries and precisely designed creations. Discuss in the ViscoTec forum at 3DPB.com.