3D printing technique from light-cured resins is gaining a growing group of supporters due to the differences and advantages over the popular 3D printing technology from thermoplastics – FDM / FFF, as well as increasingly affordable prices of devices and consumables (3-4 years ago, the average entry level for photopolymer technology stood at couple of thousand USD). Nevertheless, it is still a problematic technological process, and one of its key features is the complex post-processing stage.
Light-curing resin can be photopolymerized in several ways – by a laser beam (SLA technique), by light emitted by a projector (DLP technique), or by an LCD screen (UV LCD technique). However, regardless of how the resin is exposed, the end result is the same – the printed model has resin residues on its surface that we must remove.
The most popular solution is 3D print bath in isopropyl alcohol (IPA). This is an activity that requires compliance with appropriate conditions and procedures. IPA is flammable and has an irritating odor which, when exposed to high vapors, can lead to poisoning. Requires the use of protective gloves because it irritates the skin. However, bathing prints in isopropyl alcohol brings with it one more significant challenge – where to do it…?
In autumn 2018, Zortrax presented its first photopolymer 3D printer – Inkspire. Along with it, a dedicated 3D printing washer – Zortrax Ultrasonic Cleaner went on sale. This very simple device significantly simplifies the work with the 3D printer. Below I present the specifics of working with a washer, and in particular its most demanding fragment in the form of cleaning the resin container.
The washer comes in a small cardboard box. It is very small – ideally suited to the dimensions of individual Inkspire elements that we will bathe in IPA. On the back there is a power switch, and on the front there is an activation button and a time counter.
Models can be bathed in two ways – we either dip the table with prints or detach them, put them directly into the washer. In the latter case, make sure that the print that falls into the washer does not “splash” us unintentionally outside the IPA… It’s best to remove the models outside the washer – I do not recommend doing it above it (the “splashing effect” mentioned).
After starting the washer, it starts vibrating and heats the alcohol to a temperature of about 40°C. After the bath, the printout should be removed (only with gloves!) And dried (preferably on paper towels or tissues).
IMPORTANT! Long exposure of the 3D printed model to isopropyl alcohol can cause it to deform! If the bath lasts 10 minutes, the detail should be removed from the washer after 10 minutes. Leaving it for a few hours may result in damage to the model.
Cleaning models is trivial – cleaning the resin tank is more problematic. We do it when we change the resin to a different color or type. You will need a bottle of resin, a funnel supplied by Zortrax with a 3D printer, and a filter through which you will pour it. We have to wear gloves on our hands! It is also good to lay a substrate on which we will pour the resin with paper or other disposable material (in case the resin or isopropyl alcohol spill out, which we will clean the tank with).
We remove the cover of the 3D printer and unscrew the two screws securing the resin tank to the housing. We pour the resin into the bottle and put the container in the washer.
After rinsing the resin, we clean (GENTLY!) the film at the bottom of the tank. First, wipes or a paper towel soaked in IPA, and after drying the tank with a cloth. Later, we repeat the process with the table.
When the tank and table are clean (and dried with IPA!), We mount them back to the 3D printer. We pour resin (I replaced gray with white).
In the previous article I described the calibration of the 3D printer – we repeat this process according to the instructions on the display. When everything is ready – we can start another print…