3D printing Different
3D printing Different Bioplastics for 3D printing Besides ABS as a fossil-based plastic, when talking about 3D printing, often only PLA is mentioned. But there are quite a few more bioplastics already being used as environmentally friendly materials for 3D printing. In this article, the authors give a brief introduction to the application of some typical bioplastics in the current 3D printing field. PLA In Fused Deposition Modelling (FDM), a PLA filament allows the production of high quality prints. 3D printed parts from PLA filaments show much less warping and curling. Thus PLA can be successfully printed without the need for a heated bed. Other details such as sharp corners and edges print well and PLA printed objects will generally have a rather glossy look and feel. Kids can easily make their fantastic ideas come true without any worry about toxic evaporates as PLA is FDA (US Food and Drug Administration) certified. Scientists are researching the use of PLA in Selective Laser Sintering (SLS), too. The authors believe that the potential of PLA to be used for SLS in the future is as huge as it is for FDM. For the future, one target of modifying PLA is to make it stronger and maybe even allow transparent 3D prints. PVA PVA or polyvinyl alcohol is a biodegradable and watersoluble polymer product made from fossil resources. As a new material for making FDM filaments PVA can be used as temporary supporting material for overhangs in the 3D-printing process. After printing it can easily dissolve in water with no odour and no toxic residues, which mean that it is very convenient to clear up. Esun has produced such support material and it enjoys considerable popularity. In addition, PVA performs very well in combination with PLA. PHA PHA (polyhydroxyalkanoates) are a family of 100 % biobased and biodegradable polyesters. On the aspect of 3D printing, PHA is comparable to PLA. It can be applied in the form of filaments in FDM and first attempts are proceeding to research usability for SLS. However the price of this kind of filament is somewhat higher than PLA, and its processing window is narrow. PHA creates a slight odour during 3D printing. Nevertheless blends of PLA and PHA are also already available. PBAT PBAT (poly (butylene adipate-co-terephthalate) is a biodegradable aliphatic aromatic copolyester, today mainly produced from fossil resources (with first attempts to make it at least partly biobased). One of the unique features is its enhanced ductility compared with that of other 3D printable bioplastics. In 3D printing it can be used to make FDM filament. PBAT has already gained much popularity due to its biodegradability and its ductility. Esun’s new flexible PBAT product can replace conventional TPU and TPE for more environmentally friendly products. PETG Partly biobased PETG (polyethylene terephthalate co- 1,4-cylclohexylenedimethylene terephthalate) is a clear, transparent, amorphous thermoplastic that can be injection moulded or extruded. PETG can be semi-rigid to rigid and it is fully recyclable. PETG gives a good gas barrier and a fair moisture barrier, as well as presenting a good barrier to alcohol and other solvents. At the same time, it is strong and impact-resistant. Although already some companies have By: Yihu (Kevin) Yang, CEO, Yu Wang, Xianglian Xiao, Daimei Chen and Jun Qiu Shenzhen Esun Industrial Co., Ltd. Shenzhen, Guangdong, China 28 bioplastics MAGAZINE [06/14] Vol. 9
3D printing By: Yihu (Kevin) Yang, CEO, Yu Wang, Xianglian Xiao, Daimei Chen and Jun Qiu Shenzhen Esun Industrial Co., Ltd. Shenzhen, Guangdong, China produced FDM filament from PETG, it is a still a new and unique filament that has some very interesting characteristics with regards to transparency and strength. PCL Polycaprolactone (PCL) is a biodegradable polyester with a low melting point of around 60 °C and a glass transition temperature of about −60 °C. PCL has been approved by FDA in specific applications in the human body, such as a drug delivery device, a suture or adhesion barrier. Esun’s PCL FDM filament is an ecofriendly and non-toxic product, thus it is safe for printing food contact and skin contact products. Due to its low melting point the 3D printing nozzle doesn’t need to be too hot, so injuries can possibly be prevented. An important feature are PCL’s shape memory properties. This means the printed object has kind of a memory and under the stimulus of certain conditions it can be automatically assembled into a preset shape. In the field of medicine, this application has more practical value. It can for example, be used to make biological heart stents. Polyamide 11 Polyamide (PA) 11 is known as a long carbon chain nylon made from castor oil. Although it may seem strange, 3D printing with polyamide 11, due to its flexibility, was recently applied to print a unique bathing suit. The material is strong and elastic, so it would not break during printing. Biobased TPU Biobased TPU is a new generation of thermoplastic polyurethanes that it can be synthesized from PLA polyols and PCL polyols, and is, for instance, produced by Esun. Its renewable resource content is as high as 60 % and it can be recycled after use. The mechanical properties are excellent: it exhibits a good hydrolysis resistance and good adhesion, and it can withstand high pressures. In addition its density is lower than that of fossil based TPU. In 3D printing, it was shown to be a kind of elastic line material for a wide range of applications, such as 3D printed shoes, bracelets, etc. Outlook The development of 3D printing for personalized use still requires further development. Customers want accurate printing with fast printing speed. In some fields of application multi-coloured printing is very much in demand. More important, customers may require the use of more and more environmentally-friendly and healthy consumable materials. In many respects certain bioplastics can meet these requirements, so Esun is looking to perfect the balance between the two factors. Eventually the ability to print objects at home may change how we think of manufacturing for small businesses. Reference [1] Fleming, M.: What is 3D Printing? An Overview http://www.3dprinter.net/reference/what-is-3d-printing www.brightcn.net bioplastics MAGAZINE [06/14] Vol. 9 29
