If you want your company to thrive and stay competitive, you need the best tools for the job. This is an undeniable truth.
This applies to any job, any industry.
If your goal is to leverage new technologies, you must use cutting-edge machines that ensure you stay ahead of others.
The same applies to 3D printing. Now imagine if you could complete tasks faster and more efficiently, while also avoiding a lot of hassle. That would be
great, right? This convenience is achievable simply by choosing the right 3D printing technology.
To choose the right 3D printing technology, you must evaluate the pros and cons of various techniques.
What are FDM, SLA, and SLS?
These are different technologies, different 3D printing methods. FDM stands for Fused Deposition Modeling – in this process, models are made by extruding molten material in flat layers, which hardens immediately upon extrusion.
SLA is short for Stereolithography. It uses photopolymerization, utilizing light to connect molecular chains, forming 3D polymer structures. Both can be considered forms of micro-sculpting, but they use different methods to bind the structures together.
Finally, there's SLS - Selective Laser Sintering, a completely different technology. It uses powder (most commonly polyamide - a type of nylon), which is then heated, and then melted in specific places with a laser beam, sintering continuous layers into a durable model.
How does it form? You can imagine a miniature sandbox, where layers of polyamide "sand" are melted in a few places, then a new layer of powder coating is applied, allowing the laser to reach another layer - again melting in carefully selected spots. After this, the structure will slowly emerge from the powder.
Accuracy and the Importance of Support Structures
Many people tend to think: the more objects you can print, the better. But in reality, the opposite is often true. If you print a seemingly clumsy, inaccurate object, what's the point of printing huge objects?
As they say, the devil is in the details; to create objects, you need precision.
The higher the precision you need - the narrower the layers you can print - the more complex your model can become. This is why SLS technology is gaining prominence. Due to the use of polyamide powder with an average particle size of 38 micrometers, layers as thin as 0.075 [mm] or even thinner can be produced. Compared to SLS: FDM printers can usually only achieve a layer thickness of about 0.100 [mm], and while SLA performs well in this regard, it can still only produce layers twice as thick as SLS (thinnest at 0.15mm).
But it's not all about accuracy. There's also the factor of using support structures.
When you print a model, it needs support, otherwise it will collapse. After all, gravity is quite unforgiving. If printing with FDM or SLA, special supports are needed to allow the model to stand or hang.
These support structures must be manually or chemically removed after printing to smooth the surface. This all takes time, but most importantly, using support structures limits your choices when printing. Some things simply cannot be printed. SLS is not subject to these limitations, offering unparalleled model freedom.
It all comes down to a very clever idea: the support structure is made up of spare powder, which is not used during the printing process but is located in the printer's build chamber. Remember the sandbox? It sinters in selected places during each printing layer. When the model is finished, you simply remove the spare powder, and it's ready to use.
Time and Cost Efficiency
Okay, it's great to be able to print models with a lot of detail, but what if you need quantity rather than complexity and quality?
This is another common question, why not have both?
With SLS, this becomes entirely possible, thanks to a process called "nesting." This is very simple - because you need to use more powder than is actually required to print a specific structure (the actual amount will be defined by the height of your model), you can put more models into the printer's build chamber, allowing them to be printed at once. The laser will sinter more points, which extends the printing process, but the workflow is exactly the same. Even if it takes more time, it's still faster than printing each structure one by one, not to mention the fact that an entire complex model can be completed at once.
If you also consider the time required to remove support structures and assemble models – which is absolutely necessary for FDM and SLA printing – a little thought reveals that SLS is undoubtedly the fastest 3D printing technology currently available.
However, a question might arise: if you have to use so much powder every time you print something, how cost-effective is SLS? It depends, but overall it's much better than it sounds. SLS printers are optimized for large-volume printing, but this doesn't mean printing a single model is a bad idea. The most important thing to make it feasible is that you can recycle the unused (unsintered) powder from the printing process. You have to mix it with some fresh material for it to work - for the Sinterit Lisa printer, the ratio is 7/3 - but ultimately, the cost of using the printer won't be as high as you might imagine.
Durability and Resistance, Without Cutting Corners
The materials used in SLS printing offer high durability for printed structures. When measured during Charpy impact testing, PA 12 smooth material, one of two commonly used types, reached a maximum fracture energy of 5.23 [KJ/m²] with U-notch samples and 3.28 [KJ/m²] with V-notch samples. It is also worth noting that this durability is achieved without sacrificing the option to print movable parts within the model.
On the other hand, if you choose to use TPU Flexa Black material, you can achieve impressive chemical resistance, temperature resistance, and UV resistance, all while maintaining great flexibility. Flexa Black has a melting temperature of 150 - 160 degrees Celsius and can withstand UV radiation, not to mention chemicals like acetone, glycerol, gasoline, methanol, etc.
Groundbreaking Technology
As you can see, there is currently a 3D printing technology on the market with clear advantages over others - Selective Laser Sintering. You might wonder why SLS isn't used everywhere, as it still has its drawbacks - it requires a lot of space and is quite expensive.
Due to these issues, it has only been used in large manufacturing-sized printers. But technology is constantly advancing, and the world is still changing. With 3D printers like the Sinterit Lisa mentioned above, SLS additive manufacturing technology is now suitable for all medium-sized desktops and affordable accessories.
Original link: https://www.sinterit.com/sls-the-cutting-edge-in-3d-printing/