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.

Orchid makes use of the print-and-fill technique to make parts by 3D printing a mold for the intended part and injecting it with relevant material.

This articles discusses Collider’s flagship product, Orchid, which uses 3D printing and programmable tooling technology to manufacture parts.

Collider Orchid – In-depth

Size

Orchid has a footprint of 31″ x 34″ and a build area of 14″ x 12″ x 8″. In other words, It has a build volume of 1344 in³ or 5.81gal.

It has a tower-type design and has a height of about 71″ (6′).

Material Capability

Collider’s Orchid can work on materials like rubber, silicone, plastic, and metals.

Orchid prints at a vertical target speed of 36 cm/hr, and its XY resolution is 150 μm.

A lower resolution value gives prints with high levels of detail, and with higher values, the prints may have visible print lines.

Orchid has an extensive catalog with over hundreds of materials. Some of the supported varieties of materials are:

Manufacturing Process

The current methods for making production parts are injection molding and 3D printing.

Injection molding is slow and time-consuming, while 3D printing is comparatively faster, but it compromises on building strong parts.

Shifting away from these contemporary methods, Orchid processes materials in a different setup called “Programmable Tooling”.

First, Orchid uses continuous DLP (Digital Light Processing) to print a hollow shell. As a result, the designed mold shell is entirely smooth with no visible print lines.

Once the shell is ready, Orchid then injects the shell with an off-the-shelf manufacturing material that chemically converts into a solid part.

After the build cycle is complete, you can remove the build platform from the machine and dunk it in hot water, and the shell material will dissolve away.

All these processes can be completed in a time frame of hours.

Controller and Electronics

Orchid has a standard 110V/AC input power rating, so you can plug it into regular wall outlets.

At the front part of the machine, there is a touchscreen that you can use to handle some of the major functions of the machine.

It has connectivity features like USB, Wi-Fi, Bluetooth, SD card, and ethernet, which you can use to connect to a computer or import a design file.

Software

The software part of Collider is pretty simple. You can access Collider’s proprietary software through a web browser.

You do not need to have an internet connection for running the software, and the software can be accessed using the machine’s IP address.

Since it is not connected to any external server, you don’t have to worry about your designs getting into the wrong hands. Every design you use will stay within the Orchid machine and your computer.

Once you upload the design file, the Collider’s software takes over to design a mold for the part.

For the CAD phase, you can use any 3D design software like unity, blender, etc., to export files in STL format, which Orchid accepts. It is also a standard industrial-level three-dimensional design format.

Final Thoughts

3D printing mold and then injecting it with the desired material from a single machine was the world’s first endeavor, and Collider succeeded in doing it.

It dramatically increases the customizability of parts and reduces the production cost by about 80%.

Orchid’s technology is quite promising for making custom prosthetics by going away from the one-size-fits-all technique that most prosthetic manufacturers follow.

The custom mold-and-print technique of Orchid is also faster than other such techniques, which usually takes days to prepare a mold and then finally make the part.

Collider was acquired by Essentium, a US-based 3D printer manufacturer.

Frequently Asked Questions

What is injection molding?

Injection molding is a manufacturing technique used to produce parts in large quantities. It uses a mold of a specific shape depending on the part to be made, then materials in its molten form are injected into the mold to fill all the space tightly and make out the inside shape of the mold.

What is 3D printing?

3D printing is an additive manufacturing process that produces parts by continuously printing materials layer-by-layer to reach a three-dimensional shape.

What is DLP in 3D printing?

DLP or Digital Light Processing in 3D printing is used to produce photopolymer parts at a faster rate. It uses a light source to treat the whole layer in a single go. It is a type of vat polymerization which uses a combination of resin and light to build parts.