MSLA (RESIN) 3D PRINTING VS FDM 3D PRINTING
Since the beginning of 3D printing technologies in the 1980s, the purpose has stayed the same to produce a digital model designed on a computer to be made in physical form. With 3D printing evolving new methods of printing have come about. Today we will take a look at FDM & MSLA (RESIN 3D PRINTING) techniques of printing how they compare, but first, let us learn how FDM and MSLA work.
How does FDM 3D printing work?
FDM stands for fused deposition modeling. This method of printing works in both directions horizontally and vertically, where an extrusion nozzle moves over a heated build platform. The printer uses thermoplastic material, otherwise known as printer filaments. These materials reach a melting point between 180 to 270 degrees, to produce a 3D model in layers. As the object takes its form, the layers can be seen clearly horizontally on the model. Once a layer is complete, the nozzle of the printer pauses for a moment and the build platform is lowered along the z-axis, for the next layer of filament to be heated and extruded to make the rest of the model.
How does MSLA 3D printing work?
MSLA stands for masked stereolithography apparatus. MSLA uses a LED array, which is closely packaged LEDs as its light source. The U3DS 3D Printers LEDs array is combined with a 4K monochrome LCD. The 4k monochrome LCD is composed of square pixels. These pixels are used to define each unique layer of a 2D image whilst the LED array shines UV purple light through the 4K screen. Each layer is stacked and cured on top of one another during the printing process. The build platform is lifting up and down per layer on the Z-axis to create a 3D model.
Materials (Filaments & Resins)
FDM technology offers many materials starting first from PLA and ABS in early 2011. Over the last 10 years, we have seen other filaments appearing on the market such as nylon, carbon fiber, and a mixture of different variations of PLA and ABS. With new materials also came a large choice of colours to be printed with. The filament diameter depends on the machine the user decides to buy, two options are available 1.75mm or 2.85mm. The 2.85mm filament is not as popular as the 1.75mm diameter however in some cases produces better results of printing especially out of Nylon filament.
FDM Filament 1.75mm
In MSLA technology, resin liquid-based materials are used. The resin materials come in various colours just like the filament materials pink, green, black, and many others. The major difference between the two printing techniques materials is heat. With MSLA technology no heat is required to produce the 3D object only UV light. For example, resin material Emerald Green can withstand temperatures of 900 degrees before melting for jewel casting. FDM prints on a desktop machine cannot produce a part that will be able to withstand such heat as the primary procedure to print a model is done by melting the plastic between 180 to 270 degrees on desktop machines.
Printed part in MSLA Resin
Print quality
One of the major differences between FDM and MSLA is print quality. MSLA is known to be of a significantly higher quality print than FDM. In MSLA the monochrome 4k LCD screen determines the resolution of the model. MSLA technology does not physically print the object; it merely exposes each layer to UV light. It is because of this process each layer is almost invisible to the naked eye as each layer is 0.05mm thick.
Drill bits
Jewellery
Origami
Lower jaw
FDM resolution is related to the size of the nozzle and the extruder movements on the X and Y-axis. The nozzle fitting can vary from 0.1mm to 1mm. Each nozzle size, however, proposes its own challenges of printing for example getting the print to stick to the build platform. FDM machine quality of print varies in the machine precision and softness of stepper motor, belt pulleys and linear guides.
FDM print quality
Post-processing
Once the printer finishes printing the process of creating the model is complete. However, the process of taking it off the build platform and taking off supports is next.
For FDM printing we remove the print from the build platform once the plate is at room temperature and we remove the supports with little pliers or by hand wearing gloves. The finish of the model once the supports are removed is not always its best. Additional sanding can be done to improve the model further or a vapor smoother with isopropanol alcohol could be used, these machines can come at a large cost though more than the FDM printer.
Applications in industry
Both technologies FDM and MSLA have a purpose in multiple industries however, they are divided by quality, strengths, and printing speed.
With the FDM technique, its primary benefit is low-cost materials therefore it’s good for the education sector. The higher-end desktop machines offer the development of fixings or brackets from more robust materials like carbon fiber. The technology is accessible for testing designs but not so much as delivering high-quality consumer-worthy products. It is, however, improving rapidly and high-quality FDM printers are progressing onto the market.
FDM Supports
With MSLA printing the post process has 3 stages. The first is to remove the print from the build platform same as the FDM but we do not need to wait for the machine to cool down. The second stage is to place the print for a bath to remove any excess resin sticking to the model. The last stage is to cure the model one last time so that there are no layers that have not been cured properly during the printing process.
MSLA Supports
MSLA technology is used by jewellery makers, the automotive industry, and individual designers. The dental industry has also taken advantage of the MSLA technique of printing due to its high-quality, precise detailing, and quick printing times.
Summary – Pros & Cons:
FDM
Pros
The most widespread desktop technology
It is much simpler to tell if the print is failing or not than MSLA as you can see the nozzle and build platform.
Changing material can be done during printing
A large number of materials available
Minimal knowledge is required in setting up the print file.
Cons
Requires a thorough calibration to print quality models
Printing details in models are often less than in other technologies
Successful print relies on having one flat surface to print the model on.
The printer is noisy
The machine has multiple moving parts during printing
Brass nozzles are worn off quickly
Making filament stick to the build platform can be difficult
Some filaments have a lot of moisture after being stored in warehouses. They need to be heated up to print without moisture.
Calibrations of the machine are necessary per print.
SLA
Pros
The quality is significantly better, therefore, this technology can be used in multiple sectors
Low power consumption
The different types of resins allow the creation of models with different properties, such as castable resins.
Models created with the MSLA printing process offer greater precision and in some cases the strength of the part
The final model’s quality is worthy of being used as a part of a product, not just a prototype
The machines have resins that produce no odor, unlike FDM machines which have the smell of burnt plastic from the heated extruder.
Minimal to no noise at all
A material change is quick simply change the resin tank.
Cons
Technical knowledge is required for the use of 3D printers.
Technical knowledge is required in setting up the print file.