1. Solubility and viscosity of HPMC
As a water-soluble cellulose derivative, HPMC is widely used in building materials, especially in putty powder, where it plays the role of thickening, water retention, and improving construction performance. During the stirring process of putty powder, the stirring speed and duration may affect the solubility and final viscosity of HPMC. If the stirring is too intense or the stirring time is too long, the solubility of HPMC may decrease, thereby affecting its thickening effect and water retention. In this case, the construction performance of putty powder may be affected, such as cracking, powder loss and other problems.

On the other hand, the quality of the diluent will also affect the performance of HPMC. If the water quality of the diluent is poor, contains too many impurities or has a high salt content, it may react adversely with HPMC, resulting in incomplete dissolution of HPMC or reduced gelation effect, which ultimately affects the construction quality of putty powder.

2. Uniformity of stirring
The uniformity of the stirring process is crucial to the final quality of putty powder. If the stirring is not sufficient, HPMC and other ingredients (such as gypsum, titanium dioxide, calcium carbonate, etc.) cannot be evenly mixed, which may cause the HPMC concentration in some areas of the putty powder to be too high or too low, thus affecting the overall viscosity and use effect. For example, too high HPMC content in a local area may cause the putty powder to be too viscous, affecting the spreadability; while too low HPMC content may cause the putty powder to have poor adhesion and easy to fall off during construction.

3. The influence of dilution water
Dilution water is an important factor in the production process of putty powder. The hardness, pH, dissolved salts, etc. of water will affect the solubility and performance of HPMC. For example, calcium and magnesium ions in hard water will react with HPMC to form precipitation, reduce the solubility of HPMC, and thus affect the final effect of putty powder. If soft water or relatively pure water is used, HPMC can play a better role, so that the construction and adhesion of putty powder are guaranteed.

4. The proportion of HPMC
The addition ratio of HPMC directly affects the final quality of putty powder. During the mixing and dilution process, if the proportion of HPMC is not appropriate, whether it is too much or too little, it will affect the performance of putty powder. For example, if HPMC is added too much, the viscosity of the putty powder will be too high, which may lead to uneven application; while if HPMC is added too little, it may lead to insufficient adhesion of the putty powder and fall off during construction.

5. Effect of temperature
Temperature changes during mixing and dilution will also affect the quality and performance of HPMC. Under high temperature conditions, HPMC is usually more soluble, but when the temperature is too high, it may also accelerate the degradation of HPMC, thereby reducing its performance. Conversely, the solubility of HPMC will decrease under low temperature conditions, affecting its thickening effect. Therefore, during the mixing and dilution process, it is necessary to ensure that the temperature is appropriate to ensure that HPMC can be completely dissolved and perform at its best.

6. Effect of mechanical stirring on HPMC
The method and speed of mechanical stirring are also a factor that needs attention. If the stirring speed is too fast, especially violent high-shear stirring, it may cause the molecular structure of HPMC to be destroyed, reducing its thickening and water retention functions. In addition, too intense stirring may cause the water to evaporate too quickly, resulting in incomplete dissolution of HPMC and affecting the final use effect of putty powder.

The stirring and dilution process of putty powder does affect the quality and performance of HPMC. In order to ensure the quality of putty powder, it is necessary to control the uniformity and temperature of stirring, select appropriate dilution water, and add HPMC strictly according to the proportion. At the same time, avoid excessive stirring speed and inappropriate diluent to ensure that HPMC can fully play its role in thickening, water retention and improving construction performance.