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.