How to dissolve PVA
The dissolution of polyvinyl alcohol is a very delicate operation, and micelles or even hard clumps will appear if the dissolution is not good, which directly affects the subsequent operation and product quality.
PVA is dissolved in three step.
First of all, PVA is dispersed into cool water, which means that the particles are dispersed in the water, rather than a large mass. The feed must be dispersed and added to allow PVA to enter the room temperature water grain by grain.In industrial production, the bulk cone is often placed in the feeding port and the adding speed is controlled.
Secondly, it is placed under slow stirring or rest for a period of time to make the PVA swell in cold water. The swelling time is determined according to the specific PVA model.
Finally,heat at a slow and constant speed to the specified temperature, while stirring slowly to dissolve the PVA and hold it for a certain amount of time. The dissolution temperature ranges from the high 80s to the low 90s depending on the model.
The principle of slow mixing is to stir the system without bubbles.
Dissolved PVA is a clear viscous liquid with a slight blue light.