Wednesday, November 3, 2021
When a product is 3D printed, are the print layers always clearly visible? This is a common assumption among orientating customers in the field of 3D printing. It depends on the 3D printing technique you're using. Some techniques tend to leave more visible lines than others. For example, layers are beter visible with FDM 3D printing than with SLA 3D printing. Print lines do not always have to be bothersome. However, in some cases a smooth surface is required by the customer.
FDM 3D printing technology
SLA 3D printing technology
With the FDM 3D printing technique we use a heated nozzle. Through this nozzle a wire of the chosen material is pressed. This nozzle follows a path through which layers are created. Then the nozzle goes up a layer height thick (depending on the chosen quality), on which the next layer is 3D printed. Because the material is stacked on the previous layer, small grooves are visible. It is similar to bricklaying a wall, but very small.
This product is more suitable for FDM 3D printing because it needs to be cheap and produced in series.
With the SLA 3D printing technique, the process is completely different. We use a high-resolution LCD screen. The material we use is epoxy resin, this material is sensitive to UV. The build surface of the machine presses a layer of 0.035mm resin against the LCD screen. The pixels in the LCD screen form the layer to be 3D printed. The machine exposes this layer for a few seconds so that the material can be cured. Because the LCD screen has a very high resolution, the pixels are not visible in the 3D printed model. Therefore, the surface of an SLA 3D printed product is a lot smoother than an FDM 3D printed product.
This prototype is more suitable for SLA 3D printing because a smooth surface is required.