Fused Deposition Modeling (FDM) and PolyJet are the two most advanced and effective 3D printing technologies. They range from economical desktop model equipment to large-scale factory equipment with a good budget. And it can produce durable goods through precise and detailed models. Although these two technology platforms have cross-cutting applications and advantages, these two technology platforms remain independent and can bring different benefits. Understanding the difference between the two is a benchmark for choosing the right technology for the application.
technology
Fused Deposition Modeling (FDM):
The heating head heats the thermoplastic material (ABS resin, nylon, wax, etc.) to a critical state, presenting semi-fluid properties. Under computer control, along the two-dimensional geometric information trajectory determined by CAD, the nozzle squeezes out the semi-fluid material. , Solidified to form a thin layer of contour shape. When the first layer is completed, the new cambium is lowered through the vertical lifting system for curing. In this way, the layers are stacked and bonded to form a three-dimensional entity of a part from bottom to top.
Polyjet 3D printing:
PolyJet's jet printing head moves back and forth along the X axis to jet photopolymer. When the photosensitive polymer material is sprayed on the workbench, the UV lamp will emit UV ultraviolet light along the working direction of the nozzle to cure the photosensitive polymer material. After completing the jet printing and curing of one layer, this process will be repeated, layer by layer, until the entire 3D object is formed.
These mature technologies can create models or finished products for the jewelry and construction industries as well as the aerospace and consumer electronics manufacturing industries. To complete the installation of a system that uses these technologies, it will cost between 99 and 600,000 U.S. dollars. It is true that there are things that are useful for everyone and every application in these technologies, so that many companies use FDM and Polyjet machines at the same time to take advantage of the strength of each system. However, for those whose budget is so limited that they can only choose one of the systems, then the operation, component characteristics, and material selection must be considered.
Compared
The comparison between the three categories of FDM and Polyjet will be based on common decision-making criteria. "Operation" will be compared with operating environment, workflow and time; component characteristics will cover the output quality of the item; and material selection will consider the physical properties derived from FDM and Polyjet processing.
Operating speed
Although performance can be flawed, speed is often a priority. Sometimes, Polyjet will be faster, but this is not always the case. When we evaluate the time from document preparation to delivery of finished parts, we will find that, on average, the total time consumed by FDM and Polyjet is about the same.
For the preprocessing step, both technologies provide a very simple front-end file processing, just a few clicks of the mouse, a ready-made print file can be generated within five minutes. One of the differences is that the 3D printer used by FDM adds an advanced user controller that can adjust the part building program to meet the needs of the application. All construction parameters are open to users.
In post-processing, when it comes to supporting disassembly and cleaning of parts, the similarities between FDM and Polyjet begin to disappear. Polyjet uses water jets to remove jelly-like printing materials through a quick manual step; while for FDM, users either choose to fully automate the step of removing the soluble stent by soaking in the water tank, which takes longer; or using simple manual methods. Tool to remove the bracket.
When choosing a technology, it is necessary to evaluate the operational requirements for the business. For example, if the level of employees is not high, it is best to choose FDM's full automation. If quick turnaround is the most important, choose Polyjet.
Office environment
Unlike some other AM technologies, FDM and Polyjet do not require a closed laboratory or wearing respiratory protectors. During use, there will be no powder that can spread through the air and is sensitive to humidity and temperature, and all systems require only minimal pipes or electrical power. Electricity, water supply and drainage pipelines (required for post-processing work) have already met their needs.
Easy to use
In addition to the simplicity of file settings, there are other factors that make FDM and Polyjet easy to use.
● Material conversion: Just remove one material and insert the new material box into the 3D printer.
● Setup setting: Insert a construction sheet (FDM only), let the system reach the working temperature, and press "Start".
● After completion: After a job is completed, open the door/cover and remove the parts.
Operating cost
Polyjet's operating costs are slightly higher than FDM, so if budget is your primary consideration, FDM may be a better choice.
The main factor that determines the operating cost is the consumables, whether it is hardware or materials. With FDM, you will frequently change the build plate (or sheet) and extrusion nozzle. However, these are cheaper than the complex nozzles that Polyjet has to replace.
In addition, the total material cost per cubic inch of FDM components costs less. If you calculate the cost based on the weight of the material, in fact, the cost of the two technologies is almost the same. However, the cost of each part of FDM is lower because it requires minimal support materials. The Polyjet system requires more support material to limit tiny droplets.
Part characteristics:
1. Surface finish
Polyjet is able to produce smooth, shiny surfaces, even minor defects on the surface will show up. FDM is not the case. The extrusion process of FDM produces visible layer lines on the sidewalls or top and bottom surfaces. These lines can be eliminated, but additional post-processing is required. 2. Resolution and detail
High resolution and fine details are the hallmarks of the Polyjet process. Polyjet prints in layers of 16 to 32 microns at 600x 600 dpi to reproduce complex details and fine textures. So, if resolution is your main consideration, then PolyJet is the best choice.
3. Accuracy
Regarding dimensional accuracy, the published specifications indicate that the results obtained by the FDM and PolyJet platforms are similar when the parts are removed from the system. However, with the passage of time and the load relationship, the dimensions of FDM materials are more stable, which is crucial for the production of parts.
size
(Note: The following specifications have been rounded for simplicity.) PolyJet and FDM machines can print from 5×5×5 inches (127×127×127 mm) to 39×31×20 inches (1000×800×500 mm). Objects, they all have similar medium and large size options. The only difference is the small size category. The entry-level FDM has a size of 5×5×5 inches, which is small enough to fit on a desktop. The smallest PolyJet is 9×8×6 inches (240×200×150 mm).
Material
For many people, the biggest difference between FDM and PolyJet comes from the material. There are nearly 600 kinds of materials in total, ranging from thermoplastics to thermoplastic resins, rigid to flexible, and opaque to transparent.
PolyJet combines different 3D printing materials into the same model by jetting multiple materials at the same time. This means you can selectively place multiple materials in a printed prototype, or even combine two or three materials to create composite digital materials with different, predictable properties. Combine rigid and rubber-like materials to simulate multiple Shore A hardness values; mix cyan, magenta, and yellow to produce a variety of mixed tones; even combine rubber-like materials with colors to create bright and flexible prototypes that look closer to future products. If the breadth of material performance is what you need, PolyJet is your best platform.
On the other hand, if your application requires functional and durable thermoplastics, FDM is the right choice. The materials used in FDM range from the commonly used plastic ABS to the extremely advanced ULTEM ™ 9085 resin. FDM materials have a variety of specialized characteristics, such as static dissipation, translucency, biocompatibility, VO flammability, and FST rating, making them ideal for demanding designers and engineers in the aerospace, automotive, and medical industries.
Both FDM and PolyJet provide biocompatible materials from USP plastic VI to ISO10993. They can be used in hearing aids, dental and surgical guides and fixtures, and food and medication handling.
Additive manufacturing (AM) covers a range of products from medical applications to industrial products. Each application has the same requirements as well as different requirements. It is these application-specific requirements that determine which technology is the best tool for manufacturing applications, FDM or PolyJet 3D printing.
As for medical applications, both technologies can provide biocompatible materials, so the scalability and integration capabilities of 3D printing can be fully utilized for patient care and advanced experiments. In the medical field, 3D printing will greatly improve the work efficiency of doctors, researchers and medical equipment manufacturers, and become an ideal platform for creating innovative medical products. (end)