1. What are the ingredients in wall putty formula?
Wall putty formula includes adhesive, fillers, and Auxiliaries.
|Reference for exterior wall putty formula|
|300||White or gray potland cement 42.5|
|220||Silica flour (160-200mesh)|
|450||Heavy calcium powder (0.045mm)|
|6-10||Re-dispersible polymer powder (RDP) ET3080|
|4.5-5||HPMC MP45000 or HEMC ME45000|
|3||White wood fiber|
|1||Polypropylene fiber (thickness 3 mm)|
Wall putty includes interior wall putty and exterior wall putty. Its main function is to fix uneven to make walls smooth.
1.1 The adhesive
The adhesive in the wall putty formula is cement, polymer powder with high viscosity, and slaked lime. Cement is widely used in construction. It is famous for good adhesion, high hardness, and cost-effectiveness. But tensile strength and cracking strength are poor. Powder powder is a kind of re-dispersible polymer powder. It can play a binding role in the wall putty formula.
1.2 The filler
The filler in the wall putty formula refers to ground calcium carbonate, double fly powder, gray calcium powder, and talcum powder. The fineness of ground calcium carbonate is around 200 mesh. Don’t use too big particles of filler in the wall putty formula. This will cause an uneven flat. Fineness is an important element in the wall putty formula. Sometimes also add bentonite to increase the catchability.
Auxiliaries in wall putty formula include cellulose ether and VAE dispersible polymer powder. This kind of auxiliaries plays the role of thickening and water retention. The main cellulose ether includes HPMC, MHEC, CMC. The dosage of cellulose ether is important for formulation workable.
In the HPMC structure, one chemical is hydroxypropoyl. The higher the content of hydroxypropoxy, the better the water retention effect. Another chemical is Methoxy. The gel temperature depends on it. In a hot environment, workers pay more attention to this index. Because if the environmental temperature exceeds the HPMC gel temperature, cellulose will precipitate out of the water and lose its water retention. For MHEC, its gel temperature is high than HPMC. So MHEC water retention is better. Our MELACOLL™ MHEC is around 75 to 100 ℃. And MELACOLL™ HPMC is 55-75 ℃. The marketing price of MHEC is high than HPMC. But, HPMC is enough for wall putty formula.
HPMC will not undergo chemical reactions. It has good water retention, thickness, and good workability.
1. Thickness: cellulose ether can thicken, keeping the solution uniform up and down. It gives wall putty good anti-sagging.
2. Water retention: reduce the drying speed of putty powder. And help the chemical reaction between ash calcium and water.
3. Good workability: cellulose ether has a lubricated function. This can give wall putty good workability.
Redispersible polymer powder refers to VAE RDP. Its dosage is low. Some workers maybe don’t add it in wall putty formulation for money saving. RDP can make wall putty light, waterproofing, and flexible. Adding redispersible polymer powder can speed up construction and improve smoothness.
Sometimes wall putty formulations include fiber, like pp fiber, or wood fiber. PP fiber concrete is an effective way to stop crack. FibeRego™ PP fibers (also known as Polypropylene fibers or PPF) are made of 100% Virgin polypropylene. It will prevent wall putty cracks.
Tips: 1. Although cellulose ether is an important element in the formula of putty powder. But the amount of cellulose ether should also be strictly controlled. This is because cellulose ethers, such as HPMC, can emulsify. If the dosage is too much, the cellulose ether emulsifies and entrains air. At this time, the putty will absorb a lot of water and air. After the water has evaporated, the putty layer will leave a lot of space. Eventually it will lead to a decrease in strength.
2. Only rubber powder is added to the wall putty formula, and cellulose is not added, which will cause the putty to powder.
2. Wall putty types
Wall putty includes interior wall putty and exterior wall putty. Exterior wall putty will suffer wind, sand, and hot weather. So it contains more polymer and has high strength. But its environmental index is lower. But the overall index of interior wall putty is better. Interior wall putty formulations don’t have harmful elements.
Main Wall putty formulations are gypsum-based wall putty and cement-based wall putty. These formulations are easy to bind with bases. There is a wall putty formulation as follows:
2.1 White cement-based wall putty formulation
Interior walls and exterior walls can use white cement-based wall putty. Gray walls and concrete walls can use it. This putty regards white cement as its main material. And then add filler and auxiliaries. After drying, do not cause an embarrassing smell. Cement-based formulations have high strength and hardness.
2.2 Acrylic wall putty formulation
Acrylic putty is made from a special acrylic adhesive. It has good thickness like peanut butter. That can be used to fill cracks and patch holes in walls
What is the difference between cement based wall putty and acrylic wall putty？
Acrylic putty is better for interior walls and costs more than cement-based putty. Its alkali resistance and whiteness are also better than cement-based putty. Plus, it dries faster than white cement, so jobs need to be done quickly.
2.3 Flexible wall putty formulation
The flexible putty is composed of high-quality cement, fillers, synthetic polymers and additives. And the sun exposure does not affect the construction of the putty. Flexible putty has high bonding strength, flat and smooth surface, water and moisture resistance.
When choosing a suitable putty formula, it is often impossible to talk about the starting formula. The formula should combine with environment, such as regional characteristics, raw material quality... The most perfect putty formula is to scrape the putty according to the local conditions. Change the formula of putty by batch scraping effect.
If you want to know interior wall putty problem, please click on it.