Dry-mix mortar is a mixture of cement, sand, and other additives used to glue tiles, fill gaps, and smooth surfaces. The right combination of ingredients is critical to making high-performance mortars with excellent bond, strength and durability. Manufacturers therefore use hydroxypropyl methylcellulose (HPMC) as an important ingredient in dry-mix mortar formulations. HPMC is a cellulose-derived polymer that is soluble in water and widely used in the construction industry due to its unique rheological properties.
HPMC grade test
There are a variety of HPMC grades on the market, each with unique properties and capabilities that affect end product performance. Therefore, dry-mix mortar manufacturers need to test various HPMC grades to choose the one that is most suitable for their product formulation.
The following are key attributes that manufacturers evaluate when testing HPMC grades in dry-mix mortar formulations:
1. Water retention
Water retention is the ability of HPMC to hold water and prevent evaporation during the curing process. Maintaining the hydration level of your mortar and ensuring it cures properly is critical, especially in hot, dry climates. Higher water holding capacity results in longer curing times, which leads to lower productivity. Manufacturers therefore seek to strike the right balance between water retention and cure time when selecting HPMC grades.
2. Thickening power
The thickening capacity of HPMC is a measure of its ability to increase the viscosity of mortar. High viscosity mortars have better cohesion and bonding properties, making them ideal for construction applications. However, over thickening can cause the product to clump, which makes mixing and spreading difficult. Manufacturers therefore need to test HPMC grades extensively to ensure optimum thickening power with balanced viscosity and ease of use.
3. Set the time
The setting time of dry-mix mortars is a key factor affecting productivity and the quality of the final product. Longer setting times lead to lower productivity, higher labor costs, and lower customer satisfaction. Therefore, manufacturers need to choose the HPMC grade that will provide the best setting time while ensuring that the product is properly cured.
4. Film formation
Film-forming property is the ability of HPMC to form a protective layer on the surface of cured mortar. This layer provides protection against various environmental elements such as wind, rain and humidity and helps to extend the life of the final product. Manufacturers therefore aim to select HPMC grades that provide high film buildability with minimal side effects such as fading, discolouration or peeling.
5. Compatibility with other adhesives
Dry-mix mortars use a combination of binders to achieve optimum performance. However, not all adhesives are compatible with HPMC, which can lead to reduced cohesion, adhesion and bond strength. Therefore, manufacturers test HPMC grades extensively to determine their compatibility with other adhesives and choose the one that gives the best results.
HPMC is a key ingredient in dry-mix mortar formulations, affecting its performance and durability. Therefore, manufacturers need to evaluate various HPMC grades to select one that provides the best water retention, thickening power, setting time, film formation, and compatibility with other adhesives. Testing HPMC grades is a critical step in creating high-performance dry-mix mortars that deliver long-lasting performance, customer satisfaction and increased profitability. With the right combination of HPMC grades and ingredients, dry-mix mortars can provide excellent bond strength, durability and ease of use, making them ideal for a variety of construction applications.