HPMC, which stands for Hydroxypropyl Methylcellulose, is added to putty powder for several important reasons:
Water retention: HPMC acts as a water-retaining agent in putty powder. When mixed with water, it forms a stable gel that helps to retain moisture within the mixture. This property is crucial because it prevents the putty from drying out too quickly during application, allowing the user more time to work with the material.
Improved workability: The addition of HPMC enhances the workability of the putty. It helps to create a smooth and easily spreadable consistency, making it easier for the user to apply the putty evenly onto surfaces such as walls, ceilings, or other substrates.
Reduced sagging and shrinkage: HPMC helps to reduce sagging and shrinkage during the drying process. This is especially important when applying putty on vertical surfaces, as it prevents the putty from slumping or running down the wall before it sets.
Adhesion: HPMC improves the adhesion of the putty to various surfaces, ensuring better bonding and longevity of the application.
Crack resistance: By incorporating HPMC, the putty becomes more flexible and less prone to cracking once it dries. This is particularly important for maintaining a smooth and crack-free surface finish.
Enhanced durability: HPMC contributes to the overall durability of the putty, making it more resistant to wear, abrasion, and weathering over time.
Reduced dust generation: When dry, putty with HPMC tends to produce less dust, which is beneficial during sanding or finishing work.
It's important to note that the specific formulation and amount of HPMC cellulose added to putty powder can vary depending on the manufacturer and the intended application. The addition of HPMC is just one of many additives used in putty production to achieve desired properties and performance characteristics.
