The potential of 3D printing should not be new news to anyone. It seems that there are countless stories found in scientific journals, websites, and other publications that delve into the seemingly endless possibilities that we are only now starting to fully explore. However, for all its potential, 3D printing is still plagued by several limitations. Not the least of these limitations is the lack of printing materials available. This post will introduce the most commonly used 3D printing materials, the downsides of these materials, and progress into developing new 3D printing materials.
Currently, nearly all 3D printing is performed by using thermoplastics. Thermoplastics are characterized by their ability to be molded or formed when the material is within an appropriate temperature gradient. There is a wide range of thermoplastics used, including VPAs, Nylons, Ethylenes, and Polycarbonates. However, the vast majority of 3D printing is done with two main types of thermoplastics, PLA and ABS. PLA, or Polylactic acid, is perhaps the most popular material source for 3D printing hobbyists. The material is primarily composed of corn starch and sugar cane and is known for its environmentally friendly impact. ABS, or Acrylonitrile Butadiene Styrene, is the most common type of thermoplastic for 3D printing beyond the hobbyist level. In fact, for professional 3D printing, ABS all but completely dominates the field of thermoplastics. The benefits of ABS are many and diverse. According to 3D Printing Industry.com, ABS is inexpensive and includes more post process options than PLA. Furthermore, since ABS can be both molded and extruded, it can be implemented in a very versatile range of designs (3D Printing Industry).
One advantage of thermoplastics is that they can come in wide variety of colors (Source: 3Ders.org)
Unfortunately, there are several problems associated with ABS thermoplastics. First, ABS riddles when exposed to UV radiation, causing ABS models to quickly drop in quality when exposed to sunlight for long periods of time. Although the final product is not overly expensive, ABS is oil-based and production comes at a high energy cost. 3D Printing Industry.com reports that 2 kg of oil are necessary to produce 1 kg of ABS plastic. Given that this plastic makes up nearly all professional 3D models, one can quickly imagine how much oil consumption ABS production requires. Also, ABS releases toxic fumes when it is heated to the necessary levels for the phase change to occur. These toxic fumes are not particularly environmentally friendly and prove to be a safety hazard without proper ventilation. Finally, ABS suffers from many of the downfalls that all thermoplastics suffer from. In general, thermoplastics are inaccurate, lack material strength, are temperature sensitive, unreliable, and are overall unfit for many roles beyond prototyping.
Researchers are continuing to develop new 3D printable materials – including metals! (Source: 3DPrint.com)
New materials continued to be developed for 3D printing, and these new materials expand far beyond the scope of just thermoplastics. In particular, significant advancement has been done regarding metal-based printing materials. In fact, many 3D printing dealers already sell metal-based inks, called direct metal laser sintering (DMLS) (GPI). However, DMLS is still relatively new and the scope is largely limited by large costs and incapability with the vast majority of 3D printing systems. Research is also being conducted to develop “4D Printing.” 4D printing utilizes thermomechanical properties of materials such that the 3D printed parts “transform” under varying temperature conditions. The name is derived from the time and temperature based dependency of the material. Although this and other experimental materials continue to open new possibilities for 3D printing, they are far into the future.
Clearly, 3D printing is here to stay. The impact it has already made is undeniable. Even so, limitations to 3D printing materials continue to hold back the technology from fulfilling its true potential.
Alison Jaenicke says
Metal 3D printing sounds fascinating!
Lots of good information here, Michael. I would have liked to hear a little more about the practical applications of 3D plastics printing…what are some of the things people are using it for?
zak5068 says
The idea of 4D printing seems very interesting and could use some additional elaboration. What makes it 4 dimensional and what are the advantages?
I like that you talk about the advantages, disadvantages, new developments. Is this how you will be organizing your lit review? Try to address a specific question regarding 3D printing and organize your info to best answer that question.