How 3D Printing Works & How Leasing One Saves You Time & Money

To create a 3D printable model, a blueprint must first be made. This is accomplished using Computer-Aided Design software, commonly known as CAD. The software produces the image after a 3D scanner has scanned the object from end to end.

Additionally, custom CAD models can be created by individuals using the appropriate software. CAD generated models can be stored in the stereolithography file format, or STL, a file format native to CAD software that is specifically used by 3D systems for rapid prototyping, 3D printing, and computer-aided manufacturing.

A newer CAD file format, Additive Manufacturing File Format (AMF) was created to correct errors that STL can commonly cause, such as surface inconsistencies. CAD has improved the quality of design and reduced the number of errors in printing while providing a digital database for 3D models.

Once the model has been generated, it is inspected for issues like holes or self-intersections that can be repaired. After this, printing can begin.

 

Once the materials are chosen for the object, a method like material extrusion, which works similarly to a glue gun, is employed. This is the most common method of 3D printing.

The printing material, in some cases a plastic filament, is heated until it can be extruded through a type of dye, also called the print nozzle.

Using the digital CAD file, the nozzle deposits the heated plastic filament exactly where it needs to go, generating two-dimensional cross-sections on top of one another, layer by layer. The polymer solidifies quickly, fusing to the layer below it on the build platform before another layer is generated.

Depending on the type of object being printed, this process can take several minutes to a few days. Although that may not sound too quick, conventional methods of manufacturing can take weeks to create a similar object.

 

After a 3D model has been successfully created, it goes through a few steps of post-processing.

This can include removing the object from the build platform and any excess supporting structures it is attached to, brushing off residual powders, filling in small holes or crevices using an epoxy resin, sanding the object, or even additional subtractive manufacturing, in order to fine-tune the object and ensure quality control.

 

3DP is used to create a variety of medical devices. It includes both standard, identical design as well as unique, patient-matched design, and the implant types can range from hip joints, cranial plates and jawbones, to external prosthetics including hand replacements, and general instrumentation such as guides that help with proper surgical placement of devices.

Patient-matched devices are created using medical imaging, where a technique such as computerized tomography generates an image of an individual’s specific anatomy and sends the file to a 3D printer system to be printed.

 

This technology has created new horizons in research and development of printed materials and devices in the pharmaceutical industry. Some applications include the production of small batches of medicine that can be tailored for specific dosages, shapes, and sizes, while including specific release characteristics of a drug.

Pharmaceutical companies have begun to apply fused filament fabrication techniques to create multi-layered pills, or polypills, that contain a mixture of drugs separated through layering that assists dosage control within each layer. Another capability is the printing of microneedles, needles that provide a non-invasive method of tissue penetration and drug delivery.

 

Aside from material extrusion, there are several distinct technologies used in 3D printing and additive manufacturing. Some of the technologies include material and binder jetting, vat photopolymerization, sheet lamination, powder bed fusion, and directed energy deposition.

But what’s the best 3D printer? Each technology can also be considered a type, and each type has different specifications, such as build volume, speed, quality, and materials used. Let’s quickly review below.

Material Jetting
Similar to how an inkjet printer works, this process is used to create an object by depositing a material onto a build platform in either a continuous or Drop on Demand (DOD) approach.

Binder Jetting
This involves a powder-based material and a binder, usually in liquid form. A print head moves horizontally across the machine while alternatively depositing the build material and binder material.

Vat Photopolymerization
Also known as resin 3D printing, vat photopolymerization involves liquid resins that are used to create a model layer by layer. Ultraviolet light (UV) can be used to cure or harden the model as it moves downwards on the build platform. There are three distinct types of resin printer technologies, including stereolithography (SLA), digital light processing (DLP), and liquid crystal display (LCD).

SLA 3D printing uses UV lasers as a light source to selectively cure a polymer resin, layer by layer, using a UV laser beam. During SLA, photosensitive thermoset polymers that come in a liquid form are typically used as the printing material.

Similar to SLA, DLP 3D printing selectively cure a resin using a light source. However, DLP printers use a digital light projector screen, instead of a UV laser beam, to flash an image of an object’s layer across the entire 3D printer platform, or build plate, curing all points simultaneously. The light is reflected using a digital micromirror device (DMD), a micro-electrical-mechanical system consisting of highly reflective mirrors laid out in a matrix on a semiconductor chip.

LCD 3D printing is similar to DLP in that it flashes an entire layer across the 3D printer’s build platform. However, LCD relies on UV light coming from an array of LED lights shining through an liquid crystal display, rather than a projector. A screen is used to mask the entire image, only revealing the current layer for curing in the resin tank.

Sheet Lamination

This includes ultrasonic additive manufacturing, or UAM, and laminated object manufacturing, or LOM. They differ in that UAM uses sheets or ribbons of metal that are bound together using ultrasonic welding, while LOM uses paper and adhesive in place of these materials.

Powder Bed Fusion
Powder bed fusion 3D printing technology includes multiple techniques: Electron Beam Melting (EBM), Selective Heat Sintering (SHS), Selective Laser Melting (SLM), Selective Laser Sintering (SLS), and Direct Metal Laser Sintering (DMLS).

Regardless of specific technique, powder bed fusion involves an electron or laser beam to melt down and fuse powder material and spread the powder over each previous layer as construction proceeds. Different processes may involve different mechanisms to enable the layering.

For example, SLS use a high-powered laser to compact and form small particles of polymer powder into a solid structure. The unfused powder supports the part during printing and eliminates the need for a dedicated support structure. SLS is useful for creating complex geometries and interior features. Parts produced with SLS printing are known for having very good mechanical characteristics.

Directed Energy Deposition
This is a more involved and complex printing process that aims to either add to or repair an existing component of a 3D printed model.