Polyjet’s Superior Surface Finish


Polyjet’s Superior Surface Finish

Stratasys has two main technologies under its umbrella and each has its own advantages, Polyjet and FDM. Depending on what you need from your prototype, or end use part, you can narrow down which technology you might need. Let’s say you are looking for a nice aesthetic part to emulate the end product. This could be for showing investors what you will be making or to convey ideas to the sales team or even for the marketing department to start using in the promotional material before the actual product is finished. All of these can help you get to market faster and with a better result that you might get with a less detailed and in-depth part.

The polyjet technology can achieve this by making parts that look like finished, injection molded plastic parts. Depending on which level polyjet printer you are using you can print parts anywhere from 28-14 microns thick per layer. This is an amazing level of surface finish right out of the printer considering that a human hair is ~100 microns thick. So you can print ~4-5 layers in the Z axis to achieve the same thickness of a human hair.

This impressive resolution in the Z axis is the main driver for creating parts that look and feel so smooth right off of the machine. One of the issues other printers have is that when the Z height is thicker you notice the layer lines more. On surfaces in the Z axis you will even notice a ‘wash board’ texture to it on other machines and also see and feel the layer lines more and more prominently when there are gently curves going across the Z axis. But on the Polyjet machines, with such high resolution Z axis layers, you can hardly tell the difference between parts right off the printer an injection molded part.

Now combine the high surface smoothness and resolution the printers ability to print multiple materials at the same time and you can get to the high quality, ready to show, full color parts right out of the printer. When you make the leap into the largest and most versatile of the Polyjet machines, the J750, you can eliminate the need for lots of high man power machines that used to be needed to get to real product realism. You no longer need to use sand and finishing machines, paint booths, water printing, glue multiple parts together, or over molding machines. Being able to remove all of these machines and man hours saves money and time to market.

Another advantage to having such a high surface finish and detailed part is that you can now print your part in an orientation that works best for you. You are no longer a slave to having to orient the parts worried about maximizing the surface quality by sacrificing other aspects. On some printers worrying about orienting the parts just to get the print job to finish and issues of aesthetics or strength come in a distant second. With the Polyjet printers you can orient it in any direction and achieve a superior surface finish.