The overall goal of this procedure is to manufacture polyvinyl alcohol multilayers using inkjet printing methods. Inkjet printing is a flexible and efficient, free printing technology that enables us to manufacture complex 3D structures in multiple materials. The main advantages of this technique are the efficiency in material use, digital and additive partnering, noncontact process, compatibility with many materials in substrate, room temperature deposition, high speed and low cost fabrication.
To begin this procedure, heat a beaker of purified water to 60 degrees Celsius. Add polyvinyl alcohol such that the final weight percentage of polyvinyl alcohol in solution is 8%Then add monopropylene glycol such that its final weight percentage in solution is 10%Stir the solution for six to eight hours to ensure homogeneity. After this, filter the solution through a five micrometer filter.
Visually assess the ink for homogeneity and signs of sedimentation. Characterize the ink as outlined in the text protocol. Next, thoroughly clean the glass substrate, first with acetone and then with deionized water.
Using a nitrogen spray gun, dry the wash substrate. Load the substrate onto the print bed and secure it firmly. Flush ink through the print head to remove any air or cleaning solution from the reservoir and nozzles.
After this, load the cartridge into the printer. Connect the print head to the GIS print manager via the head personality board. Load the ink solution into the 150 milliliter syringe situated above the cartridge.
Seal the syringe with an air tight cap. Next, press the purge button to purge the ink through the nozzle. After setting up the wave form and printing parameters, load the desired image for printing.
Start the digital process and print the image pattern onto the substrate. Then, analyze the printed pattern as outlined in the text protocol. In this study, the physical properties of PVOH water based ink are investigated.
The reological behavior is examined by measuring the viscosity as a function of shear rate. The viscosity is seen to decrease with increasing shear rate, which suggests the ink displays pseudoplastic shear thinning behavior. The ink's stability is then tested by measuring the viscosity and pH as a function of time over 30 days.
The average viscosity is 7.76 centipoys while the average pH is 6.71, which reveals that the ink is very stable over time. The wetting behavior of the ink is then investigated. As can be seen, the PVOH ink demonstrates a good level of wettability with the first contact contact angle of 54.5 degrees.
A slight decrease in the contact angle is then observed for the first 25 seconds after which it stabilizes. An optical micrograph of the inkjet printing with 10 layers of printing passes shows a number of defects generated by the ring coffee stain effect. However, the quality is seen to improve significantly with 75 layers of printing passes.
This may be the result of a shift in solvent evaporation rate and the change in interface interaction between the additional overlapping layers. After watching this video, you should have a good understanding of how to formulate an ink and about all steps required to paint the pot in using an additive layer manufacturing method called ink jet printing. Overall, our goal was to explore the potential of ink jet printing technology to provide another platform for producing polyvinyl alcohol multilayers.
The interest for many industry sectors has gained momentum for this technology. We now have the ability to dose actives in a precise multilayer structure while protecting the consumer or the active with a soluble protective eight of barrier layer.
