What Is 3D Printing?

Three-dimensional printing is an additive process in which a mechanical device can make a 3D object out of digital information, such as photos or image layers.

The sophistication of the printing software and printer will determine the number of layers the item will require to be printed. Some printers can print thousands of micro layers creating unbelievable detail.

Credit: ©iStockphoto.com/hopsalka

Three-dimensional manufacturing is typically done in a subtractive process, especially when the item needs to be made out of one solid piece. For example, a wooden baseball bat is made out of a single chunk of wood, often ash or maple. The wood is placed in a lathe (manufacturing tool) and essentially scraped and sanded down to the exact size and shape needed. This process often leaves a ton of waste material behind.

After the introduction of mold casting, materials such as metal, plaster, plastic, and wood particles were then liquefied and poured to fit inside a specific shape, called a mold, and then re-solidified. This process is not 100 percent accurate due to air bubbles and material expansion/contraction, so most casted materials then need to be worked on with different tools to grind and smooth the imperfections out — saving on materials but increasing the time to create a finished product.

Even in a more modern process called die-casting, a traditional mold is still used, but pressure is applied to minimize on imperfections. However, detail work still needs to be performed on the pieces to remove the surface imperfections often left behind in the area where the die-cast mold’s seams fit together as well as the area where the material is pumped into the mold.

This is where 3D printing technology comes to the rescue. Three-dimensional printing is done in a series of layers. Since products can be created in layers, more accurate manufacturing can be done. 3D printers have cheaper overhead costs, fewer needed materials, and a decreased production time (depending on the speed of the printer, of course)

There are a few different types of three-dimensional printing options available, and these 3D printing processes include:

• Bio-printing

• Binding/sintering

• Extrusion

• Lamination

• Photo-polymerization

Bio-printing

Bio printing involves a process in which skin, bone, cartilage, and organ tissue is created by adding live cells to a growth medium (usually stem cells) while also using an organic polymer base to hold the cells together.

While not really able to do 3D limb reconstruction like in the movies, research and development is in the works with successful creation of several different kinds of tissues, including replacement heart valves and dental devices.

Binding/sintering 3D printing

Binding or sintering is a process in which printing is done with fine grains of material. Often heated by laser, the granules then are melted together in a series of movements made by the printer. The laser/printing head heat can be concentrated and moved in any direction; therefore, printing can be done in fewer layers, making a more time-efficient printer.

The material used is a plastic polymer mix as with other 3D printers, however, since the printing is done in an enclosed area filled with material, the unused granules act as a support for the laser-heated printed areas inside the printer. Any unused granules then can be removed and reused on the next printing job.

Extrusion process of 3D printing

3D printing using extrusion processes involve a printing material that starts as a solid, can be heated and shaped while warm, and after cooling turns back into a sturdy solid. The material is usually shaped in long coils and fed into the printer where the printing head heats and pushes the material through onto the printing surface.

While printing, the device’s printing head will extrude the 3D object in thin layers until the desired item is complete.

The extrusion process can also be used in the cooking world where moldable foods can be heated and extruded from the printer creating food sculptures. Chocolate is a great example of a printable food.

In extrusion, compare the printer’s printing head to a hot-glue-gun where the heated material used instead of glue is a plastic polymer or even food!

These printers often use plastic-based polymers typically mixed with other stabilizers. For instance, the 2015 CES (consumer electronics show) recently announced new printing polymers such as plastics mixed with wood, limestone, iron, or bronze.

Lamination 3D printing

Lamination 3D printing does not use polymers. Instead the process uses a die-cut laser and adhesive to cut and glue together cross sections of material, creating 3D items out of whatever flat, easy-to-cut material you can think of.

Examples of materials capable of lamination printing are as follows:

• Fabrics

• Papers

• Plastics

• Thin sheet metals

• Thin wood veneers

Photo-polymerization

Also known as stereolithography, photo-polymerization printing involves a light-based process in which photo- or light-sensitive liquid is exposed to controlled light, and a solid is formed from the liquid inside the printing chamber.

Many different angled photos of the original item or computer-generated item are taken. The duplicate item being printed has these photos projected from the same angles as the original onto the sensitive fluid to create a three-dimensional object. After the object is solidified, the remaining liquid can be stored and used again for future stereolithography creations.

What 3D printing means to consumers

While there are many different kinds of 3D printing options, the mainstream printers available to the public today are either an extrusion printer or 3D lamination printer.

Three-dimensional printing capable of outputting items that are useable will continue to evolve and improve to the point where you will be able to create items you need for home usage. You will likely purchase the polymer material and printing blueprints and make and customize your own products!

Because consumers will be able to do much of their own manufacturing rather than buying products from corporations, 3D printing will change the world as you know it.