3D printing with cellulose
Enabling a more sustainable on-demand economy with cellulose-based 3D printing
The on-demand economy, where goods are produced only when and where needed, is booming with the help of 3D printing. But there’s a problem: the plastics commonly used as printing materials are made using non-renewable, non bio-compatible materials that are challenging to recycle using existing processes. Cellulose-based 3D printing materials offer a renewable bio-based alternative that greatly reduces the environmental burden of the technology – enabling the creation of new products and markets that can contribute to a sustainable on-demand society.
By Travis Larson
3D printing is an additive manufacturing process where objects are created by depositing a material such as plastic, metal, ceramics, or even food proteins one layer at a time based on digital models created using computer-aided design (CAD). Local production with 3D printers replaces logistics chains and factory production, reducing waste and pollution while increasing customer satisfaction. Not only can consumers get their hands on the product immediately, but there is also greater flexibility to customize items according to their individual preferences.
However, there is a downside to the current model of 3D printing – much of it relies on plastics created from fossil fuels. As well as using up a non-renewable resource, plastic can be difficult to recycle and ultimately creates a significant volume of waste at the end of the product lifecycle. Another issue is that some plastics need to be processed to make them suitable for 3D printing. The plasticizers and other chemicals used in this process can contain allergenic compounds or generate harmful emissions during use, which means 3D printers need to be placed in well-ventilated areas to ensure safety.
Giving the environment a break – and creating new business – with native cellulose
Wood-based cellulosic 3D-printing materials offer a sustainable bio-based alternative to plastics. Although native cellulose is not a thermoplastic material, it can be chemically modified so that it can be processed in the same way as regular oil-based plastics. Cellulose is not only non-allergenic, but it also tolerates high temperatures and is an excellent electrical insulator. Cellulosic material is lightweight and can be processed into multiple forms – filament, powder, or paste – increasing the types, flexibility, and complexity of end products that can be printed.
Cellulose-based pastes and cellulose derivatives can be fine-tuned to suit a wide range of different applications, including textiles, spare parts, decorative items, and low-volume consumer goods. “Cellulose-based materials are easy to chemically modify – we can make them hard or soft, transparent or elastic as needed. This is a unique property compared to plastics, metals, or polylactic acid, and allows the creation of entirely new types of products,” says Panu Lahtinen, Senior Scientist, VTT.
Another advantage of native cellulose is its biocompatibility, which makes it suitable for medical applications – for example, slow-release therapeutic drugs can be incorporated into a 3D-printed cellulose-based implant. Its high water content and unique absorption properties also make it suitable for applications such as creating a scaffold for printing tissue. Orthopedics and prosthetics can also be customized to fit each individual patient perfectly. “This is where 3D printing really makes sense,” says Hannes Orelma, Senior Scientist, VTT. “We’ve already created an artificial bone paste that can be used to print prosthetics unique to each patient based on a 3D scan of their body. Cellulose-based materials are not only cell-friendly, they can open up a whole new range of products for tissue-engineering or bio-based sensors.”
Cellulose materials in action
Given the benefits, it is not surprising that cellulose-based printing materials are already being used to replace plastics and other materials in 3D printing.
For example, engineering giant ABB partnered with VTT to create cellulose-based electrical insulation components for power transformers. “The current process for manufacturing state-of-the-art transformer insulation components is labor-intensive, as well as energy- and time-consuming, because it involves a lot of manual operations and tooling for molding components, “ explains Lukasz Matysiak, Principal Scientist, ABB Corporate Research. “Working with VTT, we discovered that it is possible to produce the components we need without molds. With 3D cellulose printing we can have a single production platform for multiple components that is not only more flexible and productive, but also better for the environment.”
3DTech, a Finnish company specializing in cellulose-based 3D printing solutions and associated technology development, worked with VTT and ABB on the this project. Tomi Kalpio, co-founder of the company, sees the application as just one of many potential areas where the technology could prove a big advantage. “Any industrial application that uses tooled or molded plastic components that need to be modified or tailored could achieve big savings in production, transport, and warehousing costs. With 3D printing you can make 100 tailored components for the same price as 100 identical components. Using cellulose-based printing material also means you can recycle everything at the end of the product lifecycle too.”
Printing the future with VTT
One potential bottleneck for implementing bio-based 3D printing is a lack of in-house expertise when it comes to choosing or developing a bio-based printing material. That’s where VTT can help. “We have world-class competence in the development of bio-based printing materials,” says Panu Lahtinen. “We’ve been working with biomaterials for over 20 years and with 3D biomaterials for more than five years.”
VTT can offer support at each step of the project, including material selection and development, planning and developing production, and product roadmapping. “Basically, if someone wants to print something using a cellulose-based material, we can help them, whether it’s choosing the right material or developing an existing one to make it stronger, lighter, or more flexible,” says Panu Lahtinen. “And even if the material is already exactly right, we can help our customers develop new applications they may never even have considered.”
The ultimate aim is to help turn environmentally friendly 3D printing from a niche process into a mainstream success. Lukasz Matysiak thinks that this is inevitable, “This is just the beginning of the journey. 3D printing with cellulose material will follow the same development path as 3D printing with plastics and metals, and in a few years it will be much more common, with many new applications.”
“Bio-based 3D printing will not only help reduce waste, particularly harmful plastic waste, but it will lead to entirely new products and applications in everything from wearable tech to medicine to housing,” says Hannes Orelma. Tomi Kalpio agrees, “3D printing is already used in almost every industry, so why not make the switch to cellulose material? For example, car manufacturers are already developing bio-based 3D printed components, while in the medical field human organs have been created for testing medicines on. The possibilities are endless.”
Tiia-Maria Tenhunen, Research Scientis, Tiia-Maria.Tenhunen@vtt.fi, +358 40 744 7846
Hannes Orelma, Senior Scientist, Hannes.Orelma@vtt.fi, +358403543143
Panu Lahtinen, Senior Scientist, Panu.Lahtinen@vtt.fi, +358405349794