Rapid Prototyping SLA & SLS
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  • Rapid Prototyping SLA & SLS

Rapid Prototyping SLA & SLS

WayKen's rapid prototyping project group can guide you through many 3D printing processes to achieve exactly what you are looking for. We pride ourselves on craftsmanship, for which will be able to establish the best blend of traditional CNC machining techniques, combined with the latest rapid prototyping technologies to construct each model in the most cost-effective manner.

MAKE YOUR INVENTION A REALITY WITH 3D PRINTING

3D Printing is a broad term used to describe additive manufacturing which encapsulates a range of rapid prototyping technologies. Rapid prototyping with 3D printing is the quick, easy and cost-effective way to turn great ideas into successful products. These print rapid prototype parts not only can help verify a design, but also express an idea issues early in the development process and feedback directly on design fix, preventing costly changes to the hard tool once the product is in full production. Creating a physical model also helps potential investors and customers better visualize the product at hand to direct further investment in the product before it goes to market.

WayKen is an expert of rapid prototyping in China, providing multi-faceted 3D printing services including Stereolithography (SLA), Selective Laser Sintering (SLS). At WayKen, We have a full team of dedicated engineers and project managers that will work with you to verify your designs, tolerances, function, etc. We deeply understand the time significance for any business; we prototype maker strive to meet all specified times to deliver products in the highest standard to our clients worldwide at affordable prices. We would embrace any opportunity and challenge to assist all prototype model making.

What Is Stereolithography?

Stereolithography (SLA) is regarded as the original 3D printing process still widely used today for creating concept models, master patterns for urethane casting, one-off presentation models, and complex parts with intricate geometries. SLA uses an ultraviolet laser that draws on the surface of liquid thermoset resin to create thousands of thin layers until final parts are formed. A wide selection of materials, extremely high feature resolutions, and quality surface finishes are possible with SLA.

What Is Stereo Laser Sintering?

Stereo Laser Sintering (SLS) is very similar to the SLA process in that it makes use of a high power optic laser that fuses small powder particles layer by layer to produce complex and durable geometric parts. SLS builds robust parts with nylon materials as well as glass filled nylon materials, making it an ideal process for applications such as duct work, fuel tanks and brackets, as well as functional prototyping. The SLS process can be used for testing products and short run production under the proper conditions.

SHOULD YOU CHOOSE SLA AND SLS FOR YOUR PROTOTYPE?

WayKen’s rapid prototyping services are ideal for speeding up your product development process. From a CAD design to a physical part in your hands and finally in front of your team, it is faster than ever. If you are looking for rapid prototyping services, our team of project managers can guide you through the many rapid prototyping processes, including 3D printing to achieve exactly what you are looking for. When thinking about additive manufacturing for your prototype, if you're not sure whether using SLA or SLS, this article will give you more information.

How Does SLA Work?

  • Data processing, the 3D Model is imported into a slicing program of proprietary software, with support structures added as necessary.
  • The STL file is then sent to print on the SLA machine, with a tank filled with liquid photosensitive resin.
  • A building platform is lowered into the tank. The UV laser beam focused through the lens scans contour of the cross-section along liquid surface according to the instructions of the machine.
  • The resin in the scanning area solidifies quickly to form a single layer of material. Once the first layer has been completed the platform is lowered by 0.05–0.15mm (dependent on building mode selected) with a fresh layer of resin covering the build surface.
  • The next layer is then traced out, curing and bonding the resin to the layer below. This process repeats layer by layer until the model and any support structures are “fully grown” in the resin.
  • Once the completed platform is raised, excess resin will be drained away before the model is removed from the platform.

How Does SLS Work?

  • Powder is dispersed in a thin layer on top of a platform inside of the shaped chamber.
  • When heated to a certain temperature just below the point of powder sintering, laser beam scans the powder according to cross-section contour of the layer to rise the powder temperature to melting point and sinter the power and implement the bond with shaped parts beneath. The unsintered powder supports the cavity and cantilever of the model.
  • When the sintering of a cross-section is completed, the thickness of the platform decreases by one layer, and the laying roller spreads a layer of uniformly dense powder on it for the sintering of a new cross-section.
  • The process is repeated until all layers are sintered to obtain the solid model.

Compare the Following Application of SLA and SLS to Find Your Focus:

Q1: Material properties

SLS is rich in materials and can be made of plastic, metal, ceramic, or glass powders with good performance. WayKen machines can produce parts in white Nylon-12 PA650, PA 625-MF (Mineral Filled) or PA615-GS (Glass Filled). However, SLA can only be liquid photosensitive polymer, and its performance is not as good as thermoplastic or thermosetting plastic.

Q2: Surface finish

In the sintering process of SLS, the temperature of powder materials (or the binder) reaches melting point, but they can’t flow well and fill the space among the powder particles. As a result, the surface of the prototype is loose and rough. Assuming your prototype needs to be displayed, then naturally surface smoothness is important. In this case, you can choose SLA providing high-definition to make the surface of the parts smoother and the details clearer.

Q3: Which is more accurate?

For SLA, Minimum Wall Thickness = 0.02” (0.5mm); Tolerances = +/- 0.006” (0.15mm) to +/- 0.002” (0.05mm).
For SLS, Minimum Wall Thickness = 0.04” (1.0mm); Tolerances = +/- 0.008” (0.20mm) to +/- 0.004” (0.10mm).
SLA can build in high resolution with a finer laser beam diameter and finer layer slices to improve details, small features and accuracy.

Q4: Mechanical processing performance

Although prototypes of SLS and SLA can be machined, you should be carefully for their points during the process. SLS uses actual thermoplastic materials to produce parts with good mechanical properties. And its final component can be used to test the final purpose component of a future injection mold design or function in end-use. This indicates that SLS are more easily processed, and can be easily milling, drilling and tapping, while machining SLA prototypes should be handled with care in case the part is broken.

Q5: Resistance to the environment

The resistance of SLS prototype to the environment (temperature, humidity and chemical corrosion) is similar to that of thermoplastic materials; while SLA prototype resistance is poor, for example, molding SLA artifacts made of epoxy resin are susceptible to moisture and chemical erosion, and in more than 38 ℃ environment they will become soft and deform.

Q6: Which is stronger with glue?

3D printing can usually output a piece directly from CAD, but when the size of part making is too large, this time we can process them separately into several pieces by 3D model segmentation method and then glue together as a whole. However, the SLS binding strength is better than that of SLA, for which there are many pores on the surface of SLS binding contributes to the infiltration of viscose.

Q7: Master patterns for casting

The rapid prototyping can be used as the master pattern to copy the silicone rubber mold for vacuum casting. SLA prototype is suitable for the reproduction of the prototype master pattern, because it has a smooth surface, good dimensional stability and fine features.

WHEN TO CHOOSE 3D PRINTING OR CNC MACHINING?

Subtractive & Additive Manufacturing

3D printing is also known as additive manufacturing with many advantages over traditional manufacturing methods however it has its problems. Another manufacturing technique is CNC machining, a fairly common subtractive technique for part creation. We know that you have a lot of options in front of you when it comes to determining who to partner with for your manufacturing and prototyping needs. So, how to make the more appropriate choice for your project?

Materials & Availability

3D printing process involves parts being created layer by layer using materials such as liquid photopolymer resins (SLA), drops of photopolymer (PolyJet), plastic or metal powders (SLS/DMLS), and plastic filaments (FDM). Using a source of energy such as a laser or heated extruder, layers of these materials are solidified to form the finished part, so it has a great advantage over minimal material wastage. However, the part made by 3D printing is weak in intensity and resistance.

For CNC machining, the parts are cut from the whole piece of material and the utilization of the material is relatively low. One of the main advantages of this process is material availability as virtually any material can be CNC machined, including various grades of production plastics (ABS, Acrylic, PP, PC, POM, Nylon, PEEK, etc.), and a variety of metal materials (Aluminum, Steel, Stainless Steel, Magnesium Alloy, Zinc Alloy, Titanium Alloy, and Copper or Brass, etc.). This means CNC machining might be the most viable technique for prototypes that need to be highly functional and will undergo immense stress or strain, as well as mass production components for end-use.

Accuracy, Surface Quality & Geometric Complexity

3D printing can create parts with highly complex geometries even hollow shape that no traditional manufacturing method can replicate, such as jewelry, crafts, etc. However, with minimum layer thicknesses the superiority is not so profound.

Generally speaking, CNC machining offers greater dimensional accuracy and much better surface finishes than 3D printing. Tight tolerance accuracy ranges from +/-0.001" (0.025mm) to +/-0.0002" (0.005mm). The advanced 5-axis CNC milling machines can perform high-precision machining of more complex parts that will help you meet your most difficult manufacturing challenges.

Cost, Quantity & Delivery Time

3D printing typically produces low quantities of parts without tooling, and without human intervention, so that fast turnaround and low cost is possible. The manufacturing cost of 3D printing is priced based on the amount of materials, which means that the larger parts or more quantity cost more.

While the process of CNC machining is complex, it requires specially trained engineers to pre-program the processing parameters and processing path of parts, and then machining according to the programs. Manufacturing costs are therefore quoted taking the extra labor into account. However, CNC machines can continuously run without human supervision, making it perfect for larger volumes.

So, judging from the cost, it is very difficult to get a standard answer which one is cheaper between 3D printing and CNC machining. In fact, technology should be selected based on application of prototype.

Conclusion

In some cases, it may even be beneficial to combine both 3D printing and CNC machining manufacturing process to complete an end goal according to your application on the material, geometric complexity, manufacturing volume, and budget. We encourage you to visit us for more website pages, so we can show our full range of services and answer any questions you may have about your next project.

Rapid Prototyping SLA & SLS Gallery