3D printing or additive manufacturing technology has been developing at a rapid pace. The 3D printing technology is at least three decades old; yet it was once looked at only as a novelty. It is only in the last decade that 3D printing had begun to show a great potential for future development. Indeed, 3D printing will propel the 4th industrial revolution forward, and bring in a new era for customized fabrication. There are many factors that have bought 3D printing into mainstay industrial progress; in this article we will concentrate on 3D printing material.
Till a few years back, 3D printing was primarily used in engineering to create only prototypes. However, recent advances in printing materials have now enabled 3D printers to make objects that are comparable with traditionally manufactured items. When they were first introduced, 3D printers mostly utilized plastic in one form or the other as the basic raw material. Moreover, plastic as a 3D printing material is available in all forms conceivable - powder, filaments, pellets, powder, filament, granules, resin, etc. The printing materials of today have come a long way since then - using everything from plastic to even concrete (yes, you heard that right!) as raw material. In addition, there are proprietary 3D printing materials introduced by companies like Stratasysand others, developed for specific applications.
Plastic 3D Printing Material
Plastics are still the most common 3D printing material. There are various forms of plastic; and different 3D printing technologies like FDM, SLA, SLS, etc use it in different forms. Nylon, or Polyamide, is commonly used in powder form with the sintering process or in filament form with the FDM process. Nylon is extremely strong, reliable and flexible material. It is available in different colours as well. One more advantage nylon has is that it can also be combined with other 3D printing material in a powder form.
ABS
ABS stands for Acrylonitrile Butadiene Styrene. It is an impact-resistant engineering thermoplastic & amorphous polymer that is made up of three monomers: acrylonitrile, butadiene and styrene. ABS is tough, has high impact strength and has good heat performance. Additionally, it is lighter than metals. For these reasons, it is very useful when it comes to automotive applications. ABS is one of the most versatile materials available for 3D printing today and is used in printers that use FDM (Fusion Deposition Modelling) technology. As a raw material, ABS comes in the form of a long filament wound around a spool. However, it is also available in liquid form and can be used in 3D printing processes that are based on Stereolithography and PolyJet processes.
PLA
Polylactic acid or Polylactide (PLA) is a biodegradable, aliphatic thermoplastic derived from renewable resources such as corn starch or sugarcane. It is used as a raw material for 3D printing that uses FDM technology and is routinely used to manufacture cups, plastic bags, cutlery and medical implants. PLA is available in a choice of colours, which is an added advantage.
PET
PET is the acronym for Polyethylene Terephthalate. PET is a versatile, safe, recyclable packaging material for food and non-food products. It is ubiquitous as plastic bottles and more specifically as packaged drinking water. PET is a popular 3D printing choice as it has the same strength as ABS, but is easier to use - like PLA. PET is water proof, food-safe and is available as a filament that can be extruded while 3D printing. When it cools down, PET will have a structure that is more crystalline. It is available in many variants as well, mostly blended with resins.
Polycarbonates
Polycarbonates are naturally transparent amorphous thermoplastics. They are extremely useful as they are able to transmit light almost as effectively as glass. They have high impact strength as well, making them a popular choice for roof tops, greenhouses, etc. In 3D printing, they are used where parts that need high resistance to heat are needed.
Apart from these popular materials, newer and innovative plastic is being used for 3D printing. Some of them are proprietary and emulate wooden finish, while some use recycled plastic (typically PET), flexible plastic filaments and carbon fibre filaments. Each of these plastics has its own advantages and disadvantages. While choosing plastic as a 3D printing material it is important to know which 3D printer supports what so that you make the correct choice, or partner with someone who can guide you. In India, DesignTech Systems is one such company that has expertise in 3D printing.
Metals in 3D Printing
When you think of metal, the first thing you think is 'strength'. When it comes to structural strength and durability, nothing quite beats components and objects made from metal and metal alloys. While the first 3D printing used plastic and its variants, printing technologies that used metal as a raw material have boosted the market for 3D printers. Today, metals are the fastest-growing segment of 3D printing. Metal additive processes such as metal powder bed fusion and directed energy deposition are potentially capable of producing high-quality, functional and load bearing parts from a variety of metallic powder materials.
Steel
Steel has been a popular choice for manufacturing components for ages. 3D printing of stainless steel involves binding the layers of stainless steel powder together with a bonding agent. This powder is sprayed with a binding agent which is then dried using some form of heat. Once it dries, the layering process is repeated till the object / component is completed. It is then dried in an oven. Stainless steel is one of the low cost and popular 3D printing materials.
Aluminium Alloys
Aluminium is a very popular choice for casting. 3D printing provides a viable alternative to casting in creating parts that have complex geometry and fine finish. It combines good thermal properties coupled with low component weight. Aluminium alloys that include silica and magnesium offer good strength as well as hardness.
Titanium
Among all metals, Titanium has the highest strength-to-weight ratio. Alloyed with aluminium or vanadium, it beats low to medium grade stainless steels as far as sheer strength is concerned. 3D printing takes advantage of the properties of this metal in printing components where light weight is essential viz. aeronautic and health care sectors. Titanium 3D printing is especially gaining traction in the medical field because of its biocompatibility. It is supplied in powder form.
Precious Metals
Gold and silver are the most popular 3D printing materials within the precious metals category. Both are usually used for making ornaments. In fact, Stratasys and other 3D printing manufacturers have come with exclusive printers that can print gold ornaments. Apart from these two metals, palladium and platinum can also be used as 3D printing material. For printing purposes, all the precious metals are supplied in powdered form.
In addition to the above materials, other metals and alloys like copper, chrome, cobalt and bronze can also be used for 3D printing. You can consult experts like DesignTech Systems (India) for more information.
Miscellaneous 3D Printing Material
One of the most important advantage 3D printing has over traditional printing is indeed the ever expanding availability of raw material. A few of the popular 3D printing material also includes ceramics, bio materials and even food. As 3D printing technology improves, the choice is only going to grow.