Why do we heat the Smart Dispenser?
NOVA’s smart dispenser module is much more than just a motor. The smart dispenser has its own onboard computer that communicates with NOVA, and handles everything required to measure and maintain a dispensing pressure in real time. A critical element of this equation is the dispenser temperature.
- Holding the dispenser at a stable temperature guarantees that the viscosity of the material will be stable as well. This allows us to confidently control the print quality using the smart dispenser’s pressure sensing capabilities.
- A temperature of 35°C/95°F is high enough to minimize impact from room temperature fluctuations and passive heating from the on-board electronics, but low enough to avoid chemical reactions in the ink.
The smart dispenser heating function creates consistency with the viscosity () of your materials, and the effect that it has on flow rate (Q).
- Viscosity (n): A measure of the force required to make a fluid flow. You can think of it as the ‘internal friction’ of the material. Thicker materials (like honey) have higher viscosity, while thinner materials (like water) have lower viscosity.
- Flow Rate (Q): The volume or amount of fluid that flows out per unit time — usually measured in milliliters per second.
To get a consistent print, ultimately that means getting a consistent flow rate. If an ink’s viscosity is higher, you need a higher pressure to get it to flow. Intuitively, this makes sense — it’s harder to squeeze toothpaste (high viscosity) from a tube than it is to pour soy sauce (low viscosity) from a bottle.
Viscosity is strongly dependent on temperature. How much so? Well, we conducted a study, and we found that changing the room temperature by 10°C could lead to a 70% change in viscosity — which could lead to a 50% change in flow rate.
While a 10°C temperature change might seem extreme, local temperatures in an office environment are much less stable than you might think. The AC turning off or on, the amount of sunlight, and the location of HVAC vents can all lead to rapid changes in the temperature around the dispenser, which in turn will affect the pressure reading. By precisely and actively heating the dispenser to a temperature well above your typical room temperature, we can minimize the impact of these room fluctuations.
However, too high of a temperature could start to initiate curing in an ink (along with introducing safety issues), so we typically recommend heating to 35°C/95°F.
There are very few instances where you would need to change this temperature. 35°C/95°F is our recommended temperature for the dispenser, so unless your material is extremely sensitive, or your environment well outside of room temperature, you should be fine.