How to Choose the Viscosity of HPMC

Hydroxypropyl methylcellulose (HPMC) is a commonly used functional additive in building materials such as mortar, putty powder, water-based coatings, and tile adhesives. The appropriate selection of its viscosity significantly impacts product performance. To help manufacturers make informed and efficient choices, the following professional guidance provides guidance on selecting the viscosity of HPMC for various application scenarios.

In cement mortar, it is generally recommended to choose HPMC products with a viscosity range of 100,000 to 200,000 mPa·s. HPMC in this viscosity range effectively retains water and retardes setting, ensuring good pumpability of the mortar. Simultaneously, it slows down water evaporation during cement hydration, preventing premature drying and cracking, thereby improving the overall strength after hardening.

For putty powder systems, a viscosity of approximately 100,000 mPa·s is recommended. This type of product maintains good water retention while also providing suitable bonding and lubrication effects. It significantly reduces moisture loss during construction, preventing cracking and powdering of the putty layer, and enhances the adhesion between the putty and the substrate, improving application smoothness, effectively mitigating sagging, and resulting in a smoother coating.

In tile adhesives, hydroxypropyl methylcellulose with a viscosity of approximately 100,000 mPa·s is recommended. This viscosity grade significantly improves the adhesive's bond strength and water retention, extends workability, and ensures a fine and uniform system for easy application. Furthermore, it imparts superior anti-slip and moisture-proof properties to the adhesive.

When preparing adhesives (such as 107 and 108 adhesives), fast-dissolving hydroxypropyl methylcellulose with a viscosity of approximately 100,000 mPa·s is generally recommended. This type of product rapidly thickens and maintains system stability, enhancing the adhesive's workability and adhesion.

In conclusion, appropriately selecting hydroxypropyl methylcellulose within the corresponding viscosity range to meet the functional requirements of different building material systems is a crucial step in optimizing product processing performance and final application results. It is recommended to verify its compatibility through system testing before practical application in order to achieve the best application performance.