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Fortify Expands Composites 3D Printing with Continuous Kinetic Mixing System

Fortify is one of a number of startups that are developing unique technologies for 3D printing composites. While we await the commercial release of the company’s digital light processing (DLP) system for 3D printing composite materials, Fortify has released more information about when that release is to come, along with news of a new product, its Continuous Kinetic Mixing (CKM) system.

Fortify’s Fluxprint method upgrades traditional DLP technology through the use of a proprietary magnetic system. As illustrated in the video below, Fluxprint relies on printing with resins loaded with reinforcement material (e.g., fibers, ceramics, metals) that have been coated in a magnetic material. During the printing process, a magnet within Fortify’s printer orients these materials in an optimized manner depending on the application. By combining the embedded additives with the proper orientation, the technology can improve strength, stiffness, toughness, wear, and heat deflection temperature, and electrical properties

The CKM system is a material mixing module that ensures that the additives within loaded photopolymers are uniformly distributed while preventing sedimentation and aggregation. While this module will be unique to Fortify’s 3D printers, this sort of technology may be crucial to any sort of vat photopolymerization 3D printer that uses loaded resins. We’ve covered stories about a variety of photopolymers with specialty additives. Perhaps a similar mixing process could facilitate their printing and increase the adoption of such materials.

With the CKM announcement, Fortify has also stated that it is expanding its printing and manufacturing capacity with the goal of shipping its first printers to select customers this summer. Up until now, the company has been printing parts for customers, specifically for the production of tooling for injection molding applications.

A part printed by Fortify used for injection molding.

Through the use of proprietary ceramic reinforcement materials, Fortify has been able to print molds with complex geometries and enhanced physical properties for plastic injection molding. The company has since expanded this capability to metal injection molding (MIM), blending ceramic fibers with resin to create parts that can weather the extreme heat and pressure of MIM.

Chris Aiello, Technical Sales Manager at Alpha Precision Group, said of this new capability, “For years our customers have been asking us for a better way to prototype parts with our production metal injection molding process. Speed, dimensional accuracy, and production intent processes are critical for our customer’s development efforts. Fortify finally showed us a tooling solution that holds up to our MIM process, and checks all the boxes for our customers requirements.”

It’s interesting to note that Fortify is framing the CKM system as a module, as is the case for its Flexprint “fiber alignment module”. We’ll have to see how the modularity of Fortif’s products affects the company’s business and technological strategy. This could mean the need to purchase or lease specific modules separately from the printer itself. Or it could mean that Foritfy plans to release a number of interesting modules over time that may be swapped or included into a broad portfolio of printing systems intended by the startup.

The concept of modularity for tech products is a potentially exciting one, as it makes it possible to upgrade hardware more easily, without completely replacing or overhauling the entire machine. When it comes to consumer goods, modularity has been struggling. Google shelved its modular smartphone and Nascent Objects was acquired by Facebook before we could see if its modular electronics would get off the ground.

For industrial products and individual subcomponents, hardware modules may be easier to pull-off. Swappable printheads, for instance, are common. We’re still awaiting some of the hardware modules related to quality assurance and automation alluded to by Origin when it first unveiled its programmable photopolymerization process. Carbon also said that it would be developing modular hardware to interface with Carbon Connectors built into its equipment. When and if modular hardware becomes a thing has yet to be seen, but if it does, it could have an important impact on the disposability/obsolescence mindset currently exhibited by tech companies.

The post Fortify Expands Composites 3D Printing with Continuous Kinetic Mixing System appeared first on 3DPrint.com | The Voice of 3D Printing / Additive Manufacturing.

Recycling in Additive Manufacturing: Coming Full Circle with End-of-Life Glass Fiber Reinforced Composites

In the recently published ‘Remanufacturing of end-of-life glass-fiber reinforced composites via UV-assisted 3D printing,’ authors Andrea Mantelli, Marinella Levi, Stefano Turri, and Raffaella Suriano, from Politecnico di Milano, opened a study to investigate the potential of 3D printing for end-of-life (EoL) composites.

Their expectations of this work are environmentally sustainable structures that can be created affordably and fast, with complex geometries and suitable mechanical properties. Suggested applications are street furniture and urban renewal—all for a ‘circular economy model.’ The researchers delve deeper into the topic of recycling in 3D printing; and while it may sometimes be a complex procedure, it is critical due to the large amounts of materials being discarded whether at the end of their usefulness or considered waste after a failed print.

Pointing out that fiber-reinforced polymers are a ‘peculiar class of engineering materials,’ the researchers are aware of the challenges in recycling—in comparison to thermoplastics, richer in nature due to multiple materials. Because ever-increasing amounts of this composite waste are reaching the end-of-life (EoL), it is critical now to find better ways to recycle, rather than dumping these parts into landfills. Ultimately, what the researchers would like to see is a movement away from ‘take, make, and dispose,’ and one toward ‘reusing, recycling, repairing, and remanufacturing.’

In most programs today, the costs of recycling outweigh the advantages—and especially with glass fiber reinforced composites (GFRCs). These materials can in some cases be recycled via grinding, splitting, or hot and/or cold crushing and forming. Recycled glass fibers can also be used as fillers. The researchers also state the potential for using waste polymers to make filament.

“Very recently, continuous carbon fiber reinforced thermoplastic composites have been recycled and remanufactured by means of fused deposition modeling (FDM) technology,” state the researchers.

Here, they experimented with the 3D printing of GFRCs to explore the efficacy in reusing shredded solid recyclates.

Compositions of the recycled GFRCs

The research team noted the best success in printing with the composition 20D45R as the object produced was ‘flawless.’ They were able to modify their 3D printer, adding a third UV-LED and specific support for these features.

“In an LDM-based printing process, the study of the rheological behavior of printable inks is crucial because ink viscosity influences its flow through the extrusion nozzle, hence, affecting the printability of extruded inks and the possibility to obtain three-dimensional objects,” stated the researchers. “To analyze the rheological behavior of different printable inks, several compositions were investigated at varying the percentage of the reactive diluent and recycled GFRCs.”

Stress ramp test results for three-dimensional printable inks

The 3D printed composites exhibited good surface quality, although samples did show elongation at break which was ‘slightly higher’ than the printed composites. It was suspected this may be due to defects in the composite samples themselves.

Compositions, three-dimensional printed objects and their corresponding process parameters for three three-dimensional printable inks

3D printed structures were polished and then treated with a gel coat application, smoothing out the texture as well as offering a better aesthetic appearance.

Infill patterns were fabricated with success, and overhangs with a tilt angle of 30° were printed without any need for supports.

“The results of this work show for the first time that a low-cost UV-assisted three-dimensional printing technology can be used for the remanufacturing of GFRCs and some complex structures were printed as a proof-of-concept,” concluded the researchers. “This study opens the way towards the re-introduction of GFRC waste from diverse application fields (e.g. wind turbines blade and construction components) to the production cycle of high-performance composites.”

Recycling in 3D printing is an expansive topic today, from comparing materials to bringing thermoplastics full circle, and even recycling nuclear materials.

What do you think of this news? Let us know your thoughts; join the discussion of this and other 3D printing topics at 3DPrintBoard.com.

[Source / Images: ‘Remanufacturing of end-of-life glass-fiber reinforced composites via UV-assisted 3D printing’]

The post Recycling in Additive Manufacturing: Coming Full Circle with End-of-Life Glass Fiber Reinforced Composites appeared first on 3DPrint.com | The Voice of 3D Printing / Additive Manufacturing.

Portugal: Cork 3D Printing Composite Shows Promise for Enhancing Polyurethane Foams

In the paper “3D printed cork / polyurethane composite foams,” authors N. Gama, A. Ferreira, and A. Barros-Timmons delve further into the world of enhanced materials for better performance in thermal applications. Here, they explore the use of cork in creating a 3D printing composite for PU foams—often used in insulation, including the ‘sprayed in place’ foam, popular due to:

Low conductivity
High mechanical stability
Good chemical stability

Because of the low thermal conductivity, the authors state that PU foams are more likely to offer strength in required applications and can be controlled for specific functionality by adjusting how pores are filled via reactants—making such products useful in the aerospace and automotive industries for both sound and impact absorption.

Materials like cork can also be used to further reduce thermal conductivity and act as a damping agent, and have been found effective in previous studies in liquified form too. With the advent of 3D printing and additive manufacturing, a variety of new geometries can be produced, and in many new materials—including a wide range of composites today. TPU (Pearlthane 11H94) was used in this study, with cork powder residue. The composite material was mixed to create a filament then used to fabricate the PU forms with an Anycubic Chiron 3D printer.

3D sketch of the PU foam.

The researchers found the cork to have a ‘pronounced effect’ on the filament; however, while increasing the amount of cork residue, they noticed it caused the filament to become ‘rougher,’ suggesting ‘insufficient impregnation’ of the cork.

“Nonetheless, voids were not observed, which are known to be starting points of material failure under stress, indicating good wettability of the cork by the TPU,” stated the researchers.

The cork also decreases the strength of tensile properties in the 3D printed foam samples, with the authors reporting a reduction of up to 15 percent. While they point out that this does ‘suggest lower bond performance,’ interlayer bonding may not be compromised as the foams are more vulnerable to compression stress. Because of that, the team does not expect maximum tension and elongation at break to cause any defect in the performance of the 3D printed foam samples.

“From the results obtained, it was observed that the presence of cork affects the morphology of the ensuing foams, leading to rougher skeletons as well as to the presence of voids in the struts of the resulting PU foams. Due to the presence of cork as well as to the presence of voids, the resulting foams presented lower density, lower thermal conductivity and proved to be more flexible. Moreover, the addition of cork did not affect the thermal stability of the composites and despite of affecting the layer-to-layer bonding performance may not compromise its application,” concluded the researchers.

“Besides their thermal insulation properties, their elastomeric behavior suggests that the 3D printed foams produced may be used as thermal insulation, sound absorption or as damping materials. Moreover, progresses in the 3D printing technology, may increase the added value of the 3D printed foams for example in medical applications such as wound care or surgical aids. Yet, thorough compatibility tests would be required.”

SEM images of PU foam-0cork (a); PU foam-1cork (b), PU foam-3cork (c) and PU foam-5cork (d).

You might be surprised to find out how often foam is the center of 3D printing research and innovation, from ink to aerospace applications for NASA, and even syntactic filaments designed to create foam for marine use. Find out more about composites in foam fabrication here. Discuss this article and other 3D printing topics at 3DPrintBoard.com.

Images of PU foam-0cork (a); PU foam-1cork (b), PU foam-3cork (c) and PU foam-5cork (d).

[Source / Images: 3D printed cork / polyurethane composite foams]

3D Printed Flax Fiber Biocomposites Show Potential in Structural Applications

In ‘3D printing of continuous flax fiber reinforced biocomposites for structural applications,’ authors A Le Duigou, A. Barbé, E. Guillou, and M. Castro examine recent, increased interest in using natural materials like flax in 3D printing with filaments like PLA.

Focusing on FDM 3D printing, the researchers experimented with creating biocomposites with optimized mechanical properties through the inclusion of continuous flax fiber/PLA (cFF/PLA) composite filaments. They created a customized extrusion technique for use with the composite, which the authors state ‘evidenced a homogeneous distribution of yarn within the cross-section, while the twisted flax yarn led to fiber-rich areas at mesoscale.’

The research team was interested in creating a new composite with flax due to a ‘promising range’ of mechanical properties—often challenging to find with all the suitable qualities required. They explain that many biocomposites are popular today, but still possess less-than-suitable mechanical properties when using many different natural fibers.

“The cFF/PLA showed tensile modulus and strength values that exceeded the only available published result on continuous natural fiber printed composites by >4.5 times,” stated the researchers. “Tensile properties were in the same range as those for continuous glass fiber/PolyAmide (PA) printed composites, paving the way for the use of biocomposites in structural applications. Their weakest point was their transverse properties that remained poorer than similar flax/PLA thermocompressed composites.”

Other fiber composites such as glass, carbon, and aramid are also being studied to improve 3D printing performance, as materials are ‘impregnated to create improved structures. Using their on-site customized Prusa i3 3D printer, an Arduino card to control fan rotation, and Simplify3D software, the researchers created samples that could then be evaluated and compared with results of previous studies.

Extrusion parameters to produce continuous flax/PLA filaments.

As a yarn, flax is an obvious choice for a composite to be featured in textile applications—allowing for better strength in weaving; however, the authors point out that fiber bundles were observed in ‘twisted architectures,’ affecting both the porosity content and overall microstructure.

“In addition, the flax yarn exhibited a deviation from the center of the filament that appears to be due to the co-extrusion die. Indeed, during the co-extrusion process, the polymer flows perpendicular to the flax yarn, which results in its positioning at the edge of the filament,” stated the authors.

“Trial tests have shown that a fiber volume content above 35% within filaments led to difficulties in obtaining high-quality printed samples. Thus, in the present work the developed cFF/PLA filaments contained a lower volume fraction of 30.4 ± 0.8% (w_f ≈ 34.5%), which was close to commercial high-performance carbon/polyamide filaments [15,16]. Printing filaments did not affect fiber content and therefore cFF/PLA biocomposites had a similar fiber fraction than those of filaments.”

Longitudinal properties were improved in comparison to:

Pure PLA (×7 for stiffness and ×4.5 for strength)
Discontinuous natural fiber reinforced 3D printed biocomposites (×11 for stiffness and ×10 for strength)
Available data on continuous jute/PLA printed biocomposites (×4.5 for stiffness and ×4.5 for strength)

The researchers think these properties could be explained by intrinsic, higher mechanical properties of flax, the higher aspect ratio of the fiber yarns, and better fiber content and homogeneity overall.

“The non-linear tensile behavior was found to be typical of natural fiber unidirectional composites with properties that were comparable to those of long flax fiber composites manufactured by thermocompression, VARTM, and AFP, as well as continuous glass/PA composites produced by a commercial 3D printer. Such high measured performance opens up 3D printed biocomposites to structural applications,” concluded the researchers.

“The weakest point of cFF/PLA printed composites was their transverse properties that remained lower than similar flax/PLA thermocompressed composites. The damage mechanism observed during tensile tests was similar to that observed in continuous synthetic fiber/polymer printed composites with filaments unwinding.”

(a) Microstructure of a continuous flax fibre/PLA (cFF/PLA) filaments, (b) SEM microphotograph of cross section of untested cFF/PLA samples, (c) cFF/PLA transversally printed (90°) and (d) cFF/PLA longitudinally printed (0°). Details of panel d showing (e) loops overlap and (f) regular loops.

Materials science in relation to 3D printing has come a long way just in the past few years. Although popularity is ever-increasing with desktop users, researchers and industrial manufacturers continue to use filaments like PLA, but are now accentuating them with a variety of other materials to create composites with graphene, continuous fibers, and even wood.

Find out more about the use of natural fibers like flax here. What do you think of this news? Let us know your thoughts! Join the discussion of this and other 3D printing topics at 3DPrintBoard.com.

Macroscopic image of (a) longitudinal, (b) transverse fracture of cFF/PLA printed parts. SEM microphotograph of (c) longitudinal transverse fracture of cFF/PLA printed parts and (d) transverse fracture of cFF/PLA printed parts. White arrows evidence fibre bundle debonding and matrix failure.

[Source / Images: 3D printing of continuous flax fiber reinforced biocomposites for structural applications]

Penn State: 4D Printing with Wood Composites for Architectural Applications

In ‘Designing for Shape Change: A Case study on 3D Printing Composite Materials for Responsive Architectures,’ Elena Vazquez, Benay Gursoy, and Jose Duarte present details on customizing parts to optimize shape changing behavior. Forging straight ahead into the 4D, the Pennsylvania State University researchers delve more comprehensively into smart materials and how they are able to morph depending on user requirements and changes in the environment—whether due to temperature, moisture, or other elements.

Looking into past studies regarding the ability for building systems to become enhanced due to ‘shifting environmental conditions,’ the authors became inspired, envisioning new concepts for architectural 4D frameworks—along with embracing the concept of unpredictability within these frameworks that can be viewed as opportunities to learn. Their question, and mission, became not only how to harness such capabilities, but also how to control them as they formed a unique ‘hydroactive architectural skin system’ that would morph in reaction to moisture in the air. The materials are a 3D printed, wood-based, bio-composite. With customized settings, the team was able to study the behavior of the material, along with comparing notes to previous 4D experiments using wood.

The framework for systematic explorations in 3D printing bilayer composite materials.

“In the case of wood-based composites, 3D printing enables the design of specific patterns for layers that lead to differential swelling and then to shape-change,” state the researchers.

Six 3D printed bilayer composite samples of PLA with varying tool path geometry and their response to being immersed in hot water.

In setting parameters for 3D printing, the team used the Silkworm plug-in for Grasshopper to customize the G Code—thus establishing control not only over the nozzle, but also the printing pattern. This means being able to manipulate the fiber orientation and shape-changing dynamics. Additional identified parameters are as follows:

Number of print layers
Layer height
Order for active and constraint layers in the bilayer configuration
Road distance controlling porosity

“The 3D printing settings that we control also through custom G Code include bed and nozzle temperatures and the 3D printing speeds,” state the researchers. “Another parameter that is in play while 3D printing is the filaments used, and whether the objects are printed using a single material or with multiple materials.”

In beginning the case study, the team 3D printed some samples with PLA to have a baseline for comparing. The next set of ‘explorations’ included the use of Laywood, a wooden material made up of 40wt% wood fiber. The authors state that samples printed with Laywood offer an elongation rate of 106% if substantial amounts of humidity are present. Activators are both temperature and humidity, with the amount of time samples were exposed directly corresponding to the level of effect.

The shape changes of the six bilayer wood-based bio composite samples with 10 minute intervals for a total duration of 40 minutes.

Aware of the effect that both porosity and print angles had on activated shapes, the researchers created 175 x 75mm prototypes in the form of combined triangles. They discovered that samples subjected to humidity deformed from 70 minutes onward.

Prototype design for a hydroactive architectural skin

“To assess how the samples keep changing shape over hours instead of minutes, we recorded shape-change of prototype B over a period of 7 hours,” said the researchers.

The shape-changes of the Prototype A with 10 minute intervals, B) The
shape-changes of Prototype B with 2 hours intervals.

During their experimenting, the researchers discovered that they could change porosity levels—which allowed them to control the 4D models. They were also able to use the study parameters to control the level of transparency in the ‘architectural skins’ they created. As many other research studies before this have made note of, 3D printing will allow for the fabrication of complex geometries. In relation to this project, the authors note that many other types of material could be used in creating the architectural skin system. In noting also that single-material prototypes deformed completely when subjected to humidity, the authors suggest that in the future a multi-material approach could be more successful

“In the explorations conducted, design decisions orchestrate the interdependence between geometry -from tool path to overall form, 3D printing settings, and time, as the added dimension in the design process. Time, in this study represents shape transformation, and we argue that a systematic material exploration and computation brings us one step closer to controlling this dynamic behavior in designing for shape-change,” concluded the researchers.

“We postulate that once the shape-changing behavior is formalized through systematic material explorations, material intelligence can be embedded in parametric computer models. This constitutes a next stage in this research and can enable us to explore design variations in the computer prior to materialization. It will also allow us to create computer simulations to assess the performance of the architectural skin designs in controlling air flow, daylight and interior temperature.”

Scientists involved in 3D printing research are hard at work around the world improving and perfecting different ways to use the technology. Along with making continually new strides in software and hardware for 3D printing, the study of materials is a strong center of focus—and composites have become very popular with strengthening metals used in the process, from carbon nanotube composites to PEEK composites or trials with continuous fiber.

[Source / Images: ‘Designing for Shape Change: A Case study on 3D Printing Composite Materials for Responsive Architectures’]