how to solve HPMC problem
The problem of the construction glue layer is a larger problem encountered by customers. First of all, the problem of raw materials should be considered for the construction glue layer. The main reason for the construction glue layer is polyvinyl alcohol (PVA) and hydroxypropyl methyl cellulose ( HPMC) is caused by incompatibility; secondly, because the mixing time is not enough; and the thickening performance of the construction glue is not good.
In the construction glue, the instant hydroxypropyl methyl cellulose (HPMC) must be used, because the hydroxypropyl methyl cellulose (HPMC) is only dispersed in water without real dissolution. About 2 minutes, the viscosity of the liquid gradually increased, forming a transparent viscous colloid. The hot-melt product, when it meets cold water, it can disperse quickly in hot water and disappear in hot water. When the temperature drops to a certain temperature, the viscosity slowly appears until a transparent viscous colloid is formed. The recommended dosage of hydroxypropyl methyl cellulose (HPMC) in construction glue is 2-4kg.
Hydroxypropyl methylcellulose (HPMC) has stable chemical properties, mildew-proof and water-retaining effects in construction glue, and is not affected by pH changes. The viscosity can be used from 100,000S to 200,000S. However, in production, the higher the viscosity, the better. The viscosity is inversely proportional to the bonding strength. The higher the viscosity, the lower the strength. Generally, the viscosity of 100,000 S is better.