Lignin Archives - Perfect 3D Printing Filament

Belfast: 3D Printing with Antioxidant PLA Composites Shows Potential in Medical Applications

In the recently published ‘Antioxidant PLA Composites Containing Lignin for 3D Printing Applications: A Potential Material for Healthcare Applications,’ Belfast researchers experiment with new 3D printing materials. Due to its strength as a biopolymer and an antioxidant, the research team combined lignin with poly(lactic acid) in FDM 3D printing.

Scheme of the different meshes produced using FFF.

Coating PLA pellets with LIG powder and castor oil, which is biocompatible, they extruded the material at 200 °C. The researchers reported LIG loadings that ranged from 0% to 3% (w/w). With the goal of providing additional, beneficial features to PLA, the research team tried varied strategies, to include incorporating molecules with antioxidant properties to PLA.

“The unrestrained production of free radicals and reactive oxygen species is linked with the onset of diseases such as rheumatoid arthritis, atherosclerosis or cancer,” stated the researchers. “Accordingly, the development of antioxidant compounds/materials can contribute to reduce the concentration of these compounds. Moreover, it has been shown that the excess of reactive oxygen species prevents wound healing. Accordingly, antioxidants have been proposed to control oxidative stress in wounds to accelerate their healing.

Photographs of: PLA and PLA coated pellets (A); LIG and TC containing PLA filaments (B); LIG and TC containing 1 cm × 1 cm squares prepared using 3D printing (C); and different shapes printed using the filament containing 2% (w/w) LIG (D).

Previously, SLA 3D printing was used to fabricate antioxidant vascular stents with bioresorbable abilities, while SLS 3D printing was used to create materials with antioxidants to promote cell growth. While the actual compound was not disclosed, the researchers reported that they used UV-stable polyamide 12 material with antioxidant properties. LIG is known to possess both antioxidants and antimicrobes and incidentally, is also the second most abundant polymer on our planet—with researchers still having plenty of studying to do—especially for biomedical applications.

As the researchers combined LIG with PLA here, the intent was to develop a composite for healthcare as the materials were combined through extrusion, characterized, and then actually used in FDM 3D printing. It is expected that these composites can be used for wound dressings due to the potential for localized antibacterial qualities. Here, the researchers used tetracycline (TC) as the antibacterial agent.

Used in wound dressings, the composite made up of LIG and PLA would allow for customization of size and shape—and not only that, PLA offers a biodegradable form.

“The present work showed that PLA and LIG can be combined easily by coating PLA pellets with LIG. Other alternatives to prepare PLA/LIG composites have been explored but they require organic solvents or more complex equipment such as twin screws extruders,” concluded the researchers.

“Antioxidant packaging can be used to improve the condition and increase the shelf-life of packaged food. Due to the enhanced cell proliferation on antioxidant materials, these materials can be used for tissue culture applications or even for regenerative medicine. Due to the versatility of FFF, complex geometries can be prepared such as scaffolds. However, before this type of material can be implanted into humans, the safety of lignin-based materials should be evaluated. It has been reported before that LIG-based materials are biocompatible, but more studies should be performed.”

Experimental setup used to measure drug diffusion trough the 3D printed meshes (A); photographs of the 3D printed meshes made of PLA and 2% (w/w) LIG (B); and CUR release through 1.5 mm (C) and 1 mm (D) 3D printed meshes (n = 3).

As the range of 3D printing materials continues to expand, so does research and development of composites, from thermoset composites for aerospace to glass composites, nanocomposites, and more.

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: ‘Antioxidant PLA Composites Containing Lignin for 3D Printing Applications: A Potential Material for Healthcare Applications’]

The post Belfast: 3D Printing with Antioxidant PLA Composites Shows Potential in Medical Applications appeared first on 3DPrint.com | The Voice of 3D Printing / Additive Manufacturing.

Improved FDM 3D Printing with Lignin Biocomposites

In the recently published ‘Lignin: A Biopolymer from Forestry Biomass for Biocomposites and 3D Printing,’ international researchers Mihaela Tanase-Opedal, Eduardo Espinosa, Alejandro Rodríguez, and Gary Chinga-Carrasco explore a very specific area of materials related to biopolymers.

As composites are used more often these days to improve existing materials—especially in 3D printing—alternative materials like wood are being experimented with also. Fiber-based biocomposites and lignin can be better options than petrochemical-based products. For this study, the authors gleaned lignin from spruce trees being reduced to pulp. They used the material to create composite filaments, printing sample dogbones to test mechanical properties.

Natural-fiber biocomposites offer the following:

Affordability
Good mechanical properties
No emission of toxins
Light weight

PLA is a popular polymer used in 3D printing, and as the authors remind us, it is actually a biopolymer—featuring good mechanical properties, biodegradability, easy melt-processability, and much more; however, it is also not always cost-effective or suitable for every project. As a composite, however, PLA becomes more versatile.

“Each year, over 50 million tons of lignin are produced worldwide as a side product from biorefineries, of which 98% are burned to generate energy. Only 2% of the lignin has been used for other purposes, mainly in applications such as dispersants, adhesives, and fillers,” state the researchers.

“Without modification, lignin can be directly incorporated into a polymeric matrix, such as UV-light stabilizer, antioxidant, flame retardant, plasticizer, and flow enhancer to reduce production cost, reduce plastic, and potentially improve material properties.”

As 3D printing brings so many advantages forth to industrial users, with the ability to create affordable and complex structures, as well as leaving behind less waste and energy usage, materials like lignin are attractive for use when mixed with other polymers. For this study, the researchers focused on PLA/soda lignin biocomposite filament for 3D printing.

“A motivation for selecting soda lignin is that it is sulphur-free. Soda lignin was thus expected to reduce the typical smell that is experienced when melt-processing biocompounds containing kraft lignin or lignosulfonates,” stated the researchers.

Samples were assessed for:

Mechanical (tensile testing)
Thermal (TGA, DSC analysis)
Morphological (SEM)
X-ray diffraction
Antioxidant properties

An original Prusa i3 MK3S was used in FDM 3D printing of the dogbone samples, with a length of 63mm and width of 3mm. Three sets were printed, as well as a phone case. The biocomposite demonstrated an increase in mechanical properties when temperatures were increased, with elastic modulus decreasing by 25% to 32%. Lignin offered an improvement in ductility, but a decrease in plasticity.

Mechanical properties of PLA and PLA/Lignin biocomposites.

Stress−strain curves for the different biocomposites

Antioxidant properties were also confirmed, showing that 3D printed samples with lignin had even more antioxidant capability than PLA, meaning there is the potential for use for other applications such as food packaging.

“The suitability of the PLA/lignin biocomposite filament for 3D printing was also tested, by printing a smartphone protective case,” stated the researchers. “The printing process revealed a good performance of the lignin-containing filament, and a functional protective case was effectively 3D printed. PLA/Lignin filaments are a plausible option for lignin utilization with potential in, e.g., rapid prototyping and consumer products. It is worth to mention that the typical smell from some lignins was not detected during the extrusion of the filaments or during the printing process, which is an additional advantage of using soda lignin in PLA biomaterials.

“Biocomposites exhibited good extrudability and flowability with no observable agglomeration of the lignin. This suggests that lignin-containing biocomposites are plausible alternatives for 3D printing applications.”

3D printing of a smartphone protective case with PLA/lignin biocomposite filament

The use of composites today is a growing trend due to the ability to improve prototypes and parts, from glass composites to copper metal to particle reinforced nanocomposites. 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 – ‘Lignin: A Biopolymer from Forestry Biomass for Biocomposites and 3D Printing’]

The post Improved FDM 3D Printing with Lignin Biocomposites appeared first on 3DPrint.com | The Voice of 3D Printing / Additive Manufacturing.

Adding Lignin & Curcumin to PLA for 3D Printed Wound Healing Meshes

As innovation in materials grows into a vast science—especially within the 3D and 4D printing realms, medical patients of today and the future can look forward to improved, patient-specific care. Researchers from Queen’s University Belfast study the implications and potential with enhanced PLA in ‘Antioxidant PLA Composites Containing Lignin for 3D Printing Applications: A Potential Material for Healthcare Applications.’

Lignin (LIG) is a natural biopolymer containing antioxidants. To see if these properties would carry through after serving as a coating for PLA pellets and then being 3D printed, the researchers placed the material into an extruder at 200 ◦C. Their suppositions proved correct as not only did the filament work successfully, but it passed on antioxidants.

“A wound healing model compound, curcumin (CUR), was applied in the surface of the mesh and its diffusion was studied,” stated the researchers. “It was observed that the dimensions of the meshes affected the permeation rate of CUR. Accordingly, the design of the mesh could be modified according to the patient’s needs.”

The use of PLA is popular for many reasons, beginning with its percieved biodegradability factor, and lack of toxicity. Suitable for FFF 3D printing, the vegetable-based filament can be combined with other molecules and has shown increasing merit for medical applications, especially in accelerating healing of wounds. This type of study has not been expansive previously, however, harnessing the power of lignin’s antioxidant and antimicrobial properties. Lignin is of interest as an extremely abundant polymer that the researchers contend is highly unexploited. It is an affordable material to acquire and use, and useful in a variety of other applications currently.

Scheme of the different meshes produced using FFF.

The researchers used different types of mesh with a 2 percent combination of LIG in the PLA, along with curcumin (CUR) applied in the material and diffused. They discovered better effectiveness with the meshes when using a size of 1mm. The research team also found that the release rate was delayed if they used both the mesh and a soluble PVA film, printed with the mesh on an FDM 3D printer with a dual extruder. The PVA film may also function in dual capacity as it not only delays the release of CUR, but also keeps the wound moist.

“A potential scenario for this material is as a wound dressing material due to the antioxidant activity of the composite material that can contribute to wound closure. Due to the low price of 3D printing equipment and its versatility, these materials can be used in hospitals to print wound dressings for patients on demand,” concluded the researchers.

“Due to the enhanced cell proliferation on antioxidant materials [16], these materials can be used for tissue culture applications or even for regenerative medicine. Due to the versatility of FFF, complex geometries can be prepared such as scaffolds. However, before this type of materials can be implanted into humans, the safety of lignin-based materials should be evaluated. It has been reported before that LIG-based materials are biocompatible [45] but more studies should be performed.”

3D printing continues to make substantial impacts in the medical arena, innovating for better ways to heal wounds, along with improving drug-delivery systems, and assisting in tissue regeneration. 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.

Experimental setup used to measure drug diffusion trough the 3D printed meshes (A);
photographs of the 3D printed meshes made of PLA and 2% (w/w) LIG (B); and CUR release through
1.5 mm (C) and 1 mm (D) 3D printed meshes (n = 3).

[Source / Images: Antioxidant PLA Composites Containing Lignin for 3D Printing Applications: A Potential Material for Healthcare Applications]

Cooking with soy: Lithuanian team proves vegetable oil can be used for 3D printing

A team of researchers from Kaunas University of Technology (KTU) and Vilnius University, Lithuania, have proved that a material based on cooking oil can be used for 3D printing. Known as AESO (acrylated epoxidized soybean oil) the material is undergoing testing for its potential to replace petroleum-derived resins, and has been shown to work without the use of […]

Oak Ridge National Laboratory Investigates New Lignin-Nylon Composite 3D Printing Material

Lignin is an organic polymer that is present in the cell walls of many plants, giving them rigidity such as in wood and bark. It’s also a byproduct of biorefinery processes, and, thanks to work by researchers at Oak Ridge National Laboratory (ORNL), it could make up a new kind of 3D printing material. The research is documented in a paper entitled “A path for lignin valorization via additive manufacturing of high-performance sustainable composites with enhanced 3D printability.“

“Finding new uses for lignin can improve the economics of the entire biorefining process,” said ORNL project lead Amit Naskar.

The researchers combined a melt-stable hardwood lignin with conventional plastic – a low-melting nylon – and carbon fiber to create a composite with excellent mechanical properties and strength between layers, as well as extrudability. One of the issues of lignin is that it chars easily and can only be heated to a certain temperature before it becomes too viscous to be extruded. When the researchers combined it with nylon, however, they found that its room temperature stiffness increased while its melt viscosity decreased. The composite had tensile strength similar to nylon alone and lower viscosity than ABS or polystyrene.

The researchers conducted neutron scattering at the High Flux Isotope Reactor and used advanced microscopy at the Center for Nanophase Materials Science to investigate the composite’s nuclear structure. They discovered that the combination of lignin and nylon “appeared to have almost a lubrication or plasticizing effect on the composite,” according to Naskar.

“Structural characteristics of lignin are critical to enhance 3D printability of the materials,” said ORNL’s Ngoc Nguyen.

The researchers were also able to mix a higher percentage of lignin – 40 to 50 percent by weight – and then add 4 to 16 percent carbon fiber. The result was a new composite that heats up more easily, flows faster, and results in a stronger 3D printed product.

“ORNL’s world-class capabilities in materials characterization and synthesis are essential to the challenge of transforming byproducts like lignin into coproducts, generating potential new revenue streams for industry and creating novel renewable composites for advanced manufacturing,” said Moe Khaleel, Associate Laboratory Director for Energy and Environmental Sciences.

The lignin-nylon composite is patent-pending, and the researchers will continue to work with it to refine it and find other ways to process it. ORNL has been working with lignin for several years, and has done a lot of work with other novel 3D printing materials as well. As the researchers point out, petroleum-based thermoplastics still dominate the 3D printing materials market; the market for wood- and plant-based 3D printing materials is still limited because of their inherent difficulties in melt processing.

“Our study opens a new avenue of using isolated lignin as a feedstock for formulating 3D-printing materials having superior mechanical and printing characteristics,” they conclude. “Our findings have the potential to create additional revenue streams for biomass processing industries via the added value of lignin. In addition, it may accelerate installation of pilot biomass fractionation units in rural areas before feeding the whole biomass to a biorefinery and boost local polymer compounding industries that manufacture or compound materials for 3D printing and injection molding.”

Authors of the paper include Ngoc A. Nguyen, Sietske H. Barnes, Christopher C. Bowland, Kelly M. Meek, Kenneth C. Littrell, Jong K. Keum and Amit K. Naskar.

Discuss this and other 3D printing topics at 3DPrintBoard.com or share your thoughts below.

[Source/Images: ORNL]

ORNL Develops a New 3D Printing Material and Showcases Several Others

Lignin is a complex organic polymer that is an important part of the cell walls of many plants, making them woody and rigid. It’s also a 3D printable material, much like cellulose, another building block in plant cells. Oak Ridge National Laboratory (ORNL), a research organization that has done a great deal of important work with 3D printing, has developed a new 3D printing material using lignin.

[Image: Ngoc Nguyen/Oak Ridge National Laboratory, U.S. Dept. of Energy]

The plant-based material, according to ORNL, has excellent printability and performance. Lignin also happens to be a byproduct of the biofuels process, and could become a valuable coproduct with its use as a 3D printing material.

The material is made by combining lignin, rubber, carbon fiber and ABS. Components 3D printed with the material have 100 percent improved weld strength between layers compared to ABS alone.

“To achieve this, we are building on our experience with lignin during the last five years,” said ORNL’s Amit Naskar. “We will continue fine tuning the material’s composition to make it even stronger.”

The details of the patent-pending process have been published in a paper entitled “A general method to improve 3D-printability and inter-layer adhesion in lignin-based composites,” which you can access here. Authors of the paper include Ngoc A. Nguyen, Christopher C. Boland, and Amit K. Naskar.

More of ORNL’s 3D printing expertise was in the spotlight recently as Secretary of Energy Rick Perry traveled to the facility to dedicate Summit, the world’s fastest and smartest scientific supercomputer. Perry didn’t stand at any ordinary wooden podium – he stood behind a futuristic 3D printed podium, courtesy of ORNL. With the exception of the microphone and the wiring, every part of the podium was 3D printed, using different technologies and materials.

The top of the podium was 3D printed with 20% carbon fiber ABS, using a Blue Gantry large-scale polymer deposition system. The printing took six hours, and then the piece was coated with a Tru-Design sand coat with clear paint and a flattening agent. The pedestal was 3D printed with 30% bamboo reinforced with 70% PLA, also using a Blue Gantry System and Tru-Design clear paint and a flattening agent. The component took three hours to 3D print. The Department of Energy seal on the podium was 3D printed from a titanium alloy using an Arcam electron beam melting system. It took nine hours and 44 minutes to print.

The podium is a showcase of the speed and effectiveness of 3D printing, no matter what the technology used. The complex DOE seal traditionally would have to be cast, but 3D printing it was much faster and did not require the use of a die. Attendees at the presentation were able to see how ORNL’s Manufacturing Demonstration Facility saved money, time and reduced waste through its use of technology. The final product is attractive, with a twisting, multi-sided brown pedestal and a silvery top with the DOE seal prominently displayed. It’s also a highly functional podium, sturdy and durable, with the advanced coatings applied to it making it resistant to rain, sun, or other outdoor elements.

Discuss this and other 3D printing topics at 3DPrintBoard.com or share your thoughts below.

[Sources/Images: ORNL, Department of Energy]

Oak Ridge scientists develop plant based renewable 3D printing material, 100% improvement on ABS

A team from the Materials Science and Technology Division at Oak Ridge National Laboratory (ORNL) has published a study describing a significantly improved 3D printing material. Writing in the scientific journal Applied Materials Today, the patent-pending process is described as giving “100% improved inter-layer adhesion strength” when 3D printed. Sustainable 3D printing composites To produce […]