Additive manufacturing has been on the rise for its quick cycle time and ability to manufacture complex parts easily.

3D Printing is a versatile additive manufacturing technique that can be used to print complex structures of various materials.

With the rise in popularity of 3D Printing and its availability in small desktop models, manufacturers have been developing innovative 3D printing materials to stand out from the competition.

In this article, I have discussed the various basic and innovative 3D printing materials and their applications.

Materials Walkthrough

3D printing is gaining popularity due to its wide variety of materials that can be used for printing complex and intricate objects.

With the constant addition of new members to the list of 3D printing materials, there are various materials that can be used for printing almost anything.

Rubber

Natural rubber cannot be used for 3D printing because the vulcanization prevents the rubber from melting.

When subjected to heat, rubber tends to burn without melting.

Although it is impossible to 3D print natural rubber, some rubber-like thermoplastic materials can be used for 3D printing.

Thermoplastic Polyurethane (TPU)

TPU is a flexible linear elastomeric polymer that offers high abrasion and chemical resistance and can withstand low-temperature conditions.

This makes TPU ideal for industrial applications like gaskets, soft phone cases, vibration dampening, etc.

Furthermore, the ability to withstand low temperatures and resistance to harmful UV rays enables TPU to be used for making items required for outdoor applications.

Thermoplastic Elastomer (TPE)

TPE is a flexible thermoplastic material, also known as thermoplastic rubber.

It is a mixture of plastic as the base material and rubber as the alloying material, which enables it to have properties of thermoplastics with the flexibility of elastomers.

TPE posseses excellent thermoforming characteristics, which makes it easy to be used for 3D printing applications.

It is used in various industrial applications like dust covers, window insulations, vibration-damping, etc.

Silicone

Silicone is a relatively new material in 3D printing.

It has excellent mechanical properties that makes it ideal for applications involving high resistance to heat and UV radiations.

3D printing silicone has low resistance to tearing and is generally used for making molds for various casting applications.

Plastic Resins

Plastic resins are used to produce high-precision parts with quick cycle time.

These are generally liquid photopolymers used with SLA 3D printers.

The two most commonly used plastic resins are Rigid polyurethane and Flexible polyurethane.

Rigid Polyurethane

Rigid polyurethane is a casting resin that cures quickly to transform into a rigid plastic compound that offers high impact strength and resistance to heat.

It also offers good resistance to abrasion and is used for applications prone to wear and tear due to abrasive conditions.

Rigid polyurethane is a quick-setting polymer free from harmful components like mercury, TDI, or MOCA.

These resins are generally used for making prototypes, composite wood for flooring, automobile components, and applications requiring heat insulation.

Flexible Polyurethane

Flexible polyurethane is a lightweight casting resin generally used in furniture, mattresses, vehicles, etc.

It is a quick-setting polymer than can be used for making different shapes with the desired level of firmness.

Flexible polyurethane is widely used in applications where sturdiness and comfort are of priority.

Metals

3D printing metals has revolutionized the manufacturing industry.

The high precision and repeatability of 3D printers enables to manufacture metal objects with intricate and complex geometries that were almost impossible by traditional manufacturing techniques.

3D printing of metals is generally performed by SLS, SLM, or DMLS 3D printing technique.

Stainless Steel 

Stainless steel is one the most popularly used metal in 3D printing.

It provides a sturdy build and high corrosion resistance at an affordable price.

The high strength and ability to provide good structural integrity even to the most intricate elements make stainless steel an excellent choice for printing large-sized objects with intricate patterns.

It is a lightweight metal with high heat resistance used in various military, automobile, manufacturing, medical, and decorative applications.

One of the most common 3D printing techniques used for stainless steel is “Binder jetting”.

In this technique, stainless steel is used in powdered form, and a binding agent is used to bind the powdered steel in the desired shape.

The nozzle moves around the powdered stainless steel and sprays the binding agent to create layers of steel, while a heating lamp is used to dry the layers.

Copper

Copper is one of the newly introduced metals to 3D metal printing.

Its high reflectivity and heat conductivity made it a challenge to 3D print copper.

However, recent developments have successfully overcome these challenges, and 3D printing copper is now used in various applications like rocket propulsion engines, heat sinks, etc.

3D printing copper reduces the cost of manufacturing and improves efficiency by printing complex parts with high precision.

Apart from stainless steel and copper, there are various other 3D printing metals, like aluminum, titanium, etc.

Plastic Filaments

Plastics, especially thermoplastics, are the most commonly used materials in 3D printing.

These materials are relatively easier to print and are generally used for printing objects such as toys, phone cases, hand tools, etc.

Depending upon their physical and mechanical properties, there are three main types of thermoplastic that are commonly used in FDM printers.

Polylactic Acid (PLA)

PLA is a bio-degradable thermoplastic monomer made from organic resources like sugarcane and corn starch.

These materials generally have a low printing temperature (190 – 220ºC), which eliminates the need for a hot base plate.

However, using a hot base plate with a temperature of around 60ºC improves the quality of the print.

It is one of the easiest materials to print, which does not warp easily and produces excellent prints with good precision.

Being an organic-based polymer, PLA does not produce any harmful or unpleasant odors when melted.

This makes it an excellent filament material for domestic desktop 3D printers that are ideal for beginners and hobbyists.

Although the objects printed with PLA have a good surface finish and precision, it is not suitable for objects that require high strength.

It is comparatively less durable than other thermoplastic (ABS and PETG) and is not recommended for printing objects that are susceptible to high heat and wear conditions.

Acrylonitrile Butadiene Styrene (ABS)

ABS is a type of thermoplastic that consist of acrylonitrile, butadiene, and styrene.

It is the most commonly used filament material in industrial and commercial 3D printing applications.

ABS has high mechanical strength and good resistance to extreme temperatures, making it ideal for applications prone to wear.

These plastics tend to warp during printing and require an enclosed heated chamber to avoid warping.

This makes ABS comparatively more difficult material to print than PLA and is not commonly used in hobbyist 3D printers.

However, ABS provides high strength at an affordable price and is available in various colors, making it ideal filament material for printing items, such as lego bricks, hand tools, automobile parts, etc.

Polyethylene Terephthalate Glycol (PETG)

PETG is a durable thermoplastic polyester that provides good resistance to environmental factors.

It is generally a transparent material similar to acrylic with impact resistance comparable to polycarbonate.

PETG has good heat-formability characteristics, making it easy to 3D print compared to ABS.

Overall, it is an excellent 3D printing material that is easy to print and offers better strength than PLA.

Composite Filaments

Materials like stones, woods, etc., cannot be melted and therefore cannot be used for 3D printing.

However, with recent developments, manufacturers have introduced a new type of filament called composite filaments.

These filaments enable printing objects with texture and finish similar to that of natural wood or stone.

Furthermore, it also enables to the production of metal composite filaments that can be used for 3D printing metal objects by FDM 3D printers.

Metallic Composite

A metal composite filament consists of a mixture of PLA and powdered metal.

These filaments generally consist of a very small amount of powdered metal, enabling the printed object to have a metallic finish.

However, some manufacturers have made composite filaments with high metal concentrations.

Performing a sintering process on the parts printed with these filaments will help achieve a pure metal part even by an FDM 3D printer.

Wood Composite

Like metal composite, wood composite enables 3D printing of objects with texture and finish similar to that of natural wood.

Depending upon the type of wood used, there are various wooden composites that offer different finishes.

Some of the most common woods used in wood composite filaments are Bamboo, timber, cork, plywood, etc.

Stone Composite

Stone composite filaments can be used to 3D print objects with a stone-like texture and finish.

These filaments generally consist of 60% stone and 40% PLA, making the 3D printed object resemble a natural stone.

However, regular use of filaments with a high concentration of stone or metal can damage the nozzle of the 3D printer.

Advanced Materials

Apart from all the materials discussed above, some advanced engineered materials are also used for special 3D printing applications.

3D Printing Concrete

The 3D printing concrete is a special mixture used to print rigid structures.

It has properties similar to concrete and can even be used for 3D printing houses.

Generally, a large-sized 3D printer is used for applications involving 3D printing concrete.

Living Tissues

The ability to 3D print living tissues can be life-saving.

Research is being done to use biomaterial, like stem cells, to print a complete tissue layer-by-layer.

Furthermore, scientists have successfully used 3D printing to print plant tissues and even some human organs.

Frequently Asked Questions (FAQ)

Is 3D printing titanium possible?

Yes, 3D printing of titanium is possible.
Titanium is a lightweight metal with high strength and corrosion resistance, which can be 3D printed using the powder bed fusion process. One of the most popular examples of 3D printing titanium is NASA’s Perseverance Rover, which has most of its titanium components manufactured by 3D printing.

Can we 3D print diamonds?

Yes, you can 3D print diamonds.
Although natural diamonds cannot melt and therefore cannot be 3D printed, Sandvik Additive Manufacturing has successfully manufactured a diamond composite that does not shine like a diamond but can be used for 3D printing cutting tools.

Can we 3D print Polyvinyl Chloride (PVC)?

Yes, you can 3D print Polyvinyl Chloride (PVC).
However, melting PVC produces toxic fumes of chloride and hydrochloric acid, which can be harmful to humans and corrode the 3D printing equipment. Therefore, it is not recommended to use PVC for 3D printing.