Method of polyvinyl alcohol dissolution
I. Dissolving device:
1. Stainless steel is generally recommended as a material for dissolving tanks.
2. The speed of blender is 100-200r.p.m. suitable. If the stirring is weak, the PVA particles will settle and tend to form clumps at the bottom of the dissolution tank, so be careful.If the stirring is too strong, it tends to bubble.
Ii. Dissolution method:
1. Add water whose temperature is lower than room temperature into the solution tank;
2. Start stirring and slowly put PVA into the water while stirring, so that it can be fully dispersed in the water;
3. Stir to 95℃;
4. Keep warm for about 1 hour;
5. PVA completely dissolved, stir and cool to room temperature.
Notes for dissolution:
PVA is a product of cold expansion and hot dissolution. It is easy to produce clumps during feeding, so please note the following:
1. Water temperature should be as low as possible below 25℃ when feeding.
2. Feeding speed of PVA should be as slow as possible.
3. After feeding, stir fully at the original temperature for 10-30 minutes before starting to heat up, and continue stirring during the heating process;
Iii. Solution storage:
PVA solution will not change its chemical properties even if stored for a long time, but it may become moldy with the change of water quality. In addition, viscosity may increase with time.
1. For mildew: add 0.01-0.05% of organic nitrogen, organic iodine, cationic interfacial surfactant and other fungicides to PVA.
2. Countermeasures for viscosification: For those easy to be viscosified, such as high concentration aqueous solution of fully alcoholized PVA, storage at 50-70℃ is recommended.
Safekeeping • Attention on use:
*PVA should avoid the high temperature and wet place and keep it in the place that is not wet by rain.
* Since the powder is easy to slip and may cause a fall, please take it back in time.