Putty powder is a popular building material used to coat and refinish walls, ceilings and other surfaces. It is a mixture of various materials such as cement, filler and binder. Hydroxypropylmethylcellulose (HPMC) is one of the binders used in putty powder. HPMC is a non-toxic, odorless polymer that improves the workability of putty powders. It is used in cracks in various types of putty to enhance its performance. This article will discuss the four types of putty cracks and how to use HPMC in each type.
The four types of putty cracks are as follows:
1. Shrinkage cracks
Shrinkage cracks due to dry putty. As the putty dries, it shrinks, causing cracks to appear on the surface. The severity of these cracks depends on the composition of the putty. HPMC can be added to putty to reduce shrinkage cracks. HPMC acts as a water retaining agent, slowing down the drying process and allowing the putty to dry more evenly. It also reduces the amount of water needed to mix the putty, which helps reduce shrinkage during drying.
2. Hot crack
Hot cracks are caused by the expansion and contraction of the material as the temperature changes. They are common in buildings with large temperature fluctuations, such as in areas with extreme weather conditions. HPMC can help reduce thermal cracking by increasing the water retention properties of putties. The polymer acts as a binder that helps hold the other components of the putty together. This in turn reduces the risk of cracking due to thermal expansion and contraction.
3. Hardening cracks
Hardening cracks are caused by the hardening of putty. As putty hardens, it loses some of its flexibility, causing it to crack. HPMC can help reduce hardening cracks by increasing the flexibility of the putty. This polymer acts as a plasticizer, making the putty more flexible. This allows it to withstand movement of the surface it is painted on, reducing the risk of cracking.
4. Structural cracks
Structural cracks occur due to movement of the structure or underlying surface. They can be caused by a variety of factors, such as subsidence, earthquakes, or changes in surface moisture. HPMC can help reduce structural cracks by improving the adhesive properties of putties. The polymer acts as a binder, helping the putty to adhere more effectively to the surface. This in turn reduces the risk of cracking due to movement of the underlying surface.
HPMC is a valuable ingredient in putty powders because it can help improve the performance of various types of putty cracks. By reducing the risk of shrinkage, heat, hardening and structural cracking, HPMC can help ensure putties last longer and retain their beauty. As the construction industry continues to evolve, HPMC remains an important ingredient in putties for all construction applications.