Redispersible polymer powder (RDP) is an important building material additive, mainly used in dry powder building materials, such as dry mortar, putty powder, tile adhesive, exterior wall insulation system, etc. It can improve the adhesion, flexibility, crack resistance and water resistance of materials, and is widely used in modern building construction.

1. Material selection

Before using redispersible?polymer powder, you first need to choose the right variety. Choose different types of latex powder according to the specific needs of the construction. For example:

Polyethylene vinyl acetate copolymer (EVA): widely used in tile adhesive, plaster mortar, etc., with excellent adhesion and flexibility.

Ethylene-acrylic acid copolymer (VAE): commonly used in floor mortar and insulation system to enhance wear resistance and crack resistance.

Acrylic copolymer: used in high-strength occasions, such as exterior wall insulation mortar, with excellent water resistance and weather resistance.

2. Formula design

When using redispersible?polymer powder, the formula needs to be adjusted according to the project requirements. Generally, the amount of latex powder added is between 2% and 5% of the total weight of cement mortar, depending on the product requirements. The specific steps are as follows:

Preparation of dry mix: Mix cement, fine aggregate (such as quartz sand), filler (such as heavy calcium powder) and other dry powders according to the formula ratio.

Adding redispersible?polymer powder: Sprinkle the latex powder evenly into the mixed dry powder, and continue to stir to ensure that the latex powder and other dry powders are fully mixed.

Adding cellulose ether: In order to improve the water retention and construction performance of the mortar, a certain amount of cellulose ether (such as hydroxypropyl methylcellulose) is usually added to the formula.

3. Construction preparation

Before construction, ensure that all raw materials and tools are ready, and mix the dry powder evenly according to the formula. During the construction process, the redispersible?polymer powder is redispersed after contact with water to form a stable polymer film, thereby enhancing the adhesion and water resistance of the mortar.

Mixing: Add an appropriate amount of water to the prepared dry powder, and stir evenly with a mechanical stirrer until a uniform, lump-free slurry is formed. The stirring time is generally 3-5 minutes to ensure that all powders are fully wetted.

Standing and maturation: After stirring, the slurry should be left for a few minutes to fully mature to improve the construction performance. Then stir it lightly again before use.

4. Application method

Apply the mixed slurry to the construction surface according to the specific requirements of the construction. Common application methods include:

Plastering mortar: Use a scraper or trowel to evenly apply the mortar to the wall surface, which is suitable for internal and external wall plastering.

Tile adhesive: Use a toothed scraper to apply tile adhesive to the base surface, and then press the tile on the adhesive layer.

Self-leveling mortar: Pour the mixed self-leveling mortar on the ground and use its self-leveling properties to form a flat ground layer.

5. Precautions

When using redispersible?polymer powder, pay attention to the following points:

Environmental conditions: The construction environment should maintain a suitable temperature and humidity to avoid the influence of too high or too low temperature on the performance of the mortar. The general construction temperature should be between 5°C and 35°C.

Mixing water: Use clean, unpolluted water for mixing to avoid water quality problems affecting mortar performance.

Storage conditions: Unused redispersible?polymer powder should be stored in a dry, cool environment to avoid moisture and high temperature.

Proportion adjustment: According to the actual situation, flexibly adjust the amount of redispersible?polymer powder added to achieve the best construction effect.

6. Performance testing and maintenance

After the construction is completed, the finished mortar should be tested for performance, such as bonding strength, compressive strength, water resistance, etc., to ensure that it meets the engineering requirements. At the same time, the surface after construction should be maintained as necessary, especially in high temperature or dry environment, to prevent early water loss and mortar cracking.

As an important building additive, redispersible?polymer powder plays an important role in improving the adhesion, flexibility and durability of mortar. The correct selection and use of redispersible?polymer powder can not only improve the construction quality, but also extend the service life of the building. In actual application, construction personnel should strictly follow the formula design and construction requirements to ensure the stability and reliability of engineering quality.