1. lotion freezing and demulsification
Phenomenon: Frozen into ice cubes in winter, tofu residue particles and layers appear after melting. Reason: When the temperature is below 0 ℃, the latex particles are frozen and broken.
Solution: 1) The storage environment should be maintained at 5-30 ℃, and insulation should be done well in winter; It has severely clumped and can only be scrapped; After slight clumping and low-speed stirring, there is still a chance for filtration.
To solve the problem of low-temperature storage, our company has developed HD501 which can be frozen three times in a -15 ° C cycle and can be restored to its original state after thawing.
2. Let it stand and separate into layers, with clear water on the upper layer and thick water on the lower layer
Causes: too long storage, too large particle size of lotion, and insufficient additives.
Countermeasure: Only stir evenly at a low speed of 300-500 rpm, and high-speed stirring is strictly prohibited.
3. lotion is moldy and smelly
Phenomenon: Odor and mold growth on the liquid surface.
Reason: Insufficient addition of preservatives, prolonged storage after opening the lid, and high temperature environment. Treatment: discarded deteriorated lotion; Source solution: Add BIT preservative during production.
For cases where corruption has already occurred, reducing agents can be added. If the deterioration is severe and cannot be resolved by adding reducing agents, it should be scrapped.
2、 Common problems when mixing paint ingredients
1. Demulsification and agglomeration after adding lotion incentive
1) High speed mixing of lotion after powder grinding;
2) The pH of the system is too low (less than 7);
3) Excessive use of strong acid additives, or inorganic powder with too strong acidity;
4) Defoamer is poured into lotion in large quantities at one time.
Solution:
1. After powder grinding, reduce the rotating speed to 300-600r/min, and then put in lotion;
2. Use AMP-95 to adjust the overall pH to 8.0-8.8;
3. The silicone defoamer is added in two times, 40% in the grinding stage, and 60% after the addition of lotion.
2. Finished paint separates water, sediment, and bottom hard slag
Reason: Insufficient amount of hydroxyethyl cellulose added; Lack of low shear associative thickening agents; Excessive filling material; The electrolyte in the system is relatively high.
Solution:
1. Increase the amount of hydroxyethyl cellulose added;
2. Add low shear aggregation and thickening agent (HD-60);
3. HEC combined with polyurethane thickener for use;
4. Reduce the usage of ultrafine heavy calcium;
5. Add a small amount of dispersant in moderation.
6. If it cannot be solved, the dispersant can be investigated separately. Different types of dispersants may also cause water splitting.
7. Check for fungicides, which may also cause water splitting, and make parallel comparisons.
3. A lot of foam appears in paint mixing
Reason: The stirring speed is too fast; Excessive dispersant; The hardness of the water quality is too high. Treatment: Use polyether defoamers; Replace hard water with deionized water; Control the stirring speed.
3、 Common defects in paint film after construction painting
Problem 1: The paint film falls off and turns white when touched
Reason:
① Insufficient dosage of film-forming aids;
② The construction temperature is below 5 ℃;
③ The addition ratio of lotion is low; Mixing too much water.
solve:
1. According to the high and low temperature, the alcohol ester -12 is usually added to the lotion with a solid content of 3-8%;
2. Internal wall water mixing ≤ 20%, external wall water mixing ≤ 12%;
3. Increase the proportion of lotion and reduce the amount of talcum powder.
Question 2: Shrinkage, pinholes, volcanic craters
Cause: Excessive use of silicone defoamers; The substrate has oil stains; There is a lot of dust on the wall; The compatibility between lotion and defoamer is poor; Silicone acrylic lotion is most prone to shrinkage cavity. The bubbles have not dissipated, forming pores.
improvement:
1. Reduce the use of organic silicon defoamers and switch to polyether defoamers;
2. Clean the wall thoroughly and apply a sealing primer first;
3. Silicone acrylic lotion shall use as few organosilicon products as possible.
Problem 3: Cracking of paint film
Divided into surface fine cracks and deep cracks:
1) The one-time brushing is too thick; Tg is relatively high; Insufficient film-forming aids;
2) The cracking of the putty layer is accompanied by the cracking of the topcoat.
Countermeasure: Apply 2-3 thin coats; Increase film-forming agents during low temperature seasons; Low Tg elastic lotion is selected as the exterior wall.
Problem 4: Poor water resistance, whitening and foaming when exposed to rain
Reason: The proportion of fillers is too large; Excessive dilution of water; The quality of styrene acrylic lotion is poor; The moisture content of the wall is too high.
solve:
1. Pure acrylic or modified styrene acrylic lotion is preferred for exterior wall;
2. The moisture content of the cement wall should be controlled within 10% before construction;
3. Add a small amount of silane additive appropriately to improve water resistance.
Problem 5: yellowing of paint film in later stage (high incidence of styrene acrylic lotion)
Reason: Styrene components are subject to UV aging; Excessive addition of ammonia water; Poor quality additives.
Solution:
1. For outdoor projects, the common styrene acrylic lotion is abandoned and the core shell modified styrene acrylic lotion or pure acrylic lotion is used instead;
2. Use less ammonia water and prioritize adjusting pH with AMP-95.
3. Titanium dioxide is of the rutile type.
Problem 6: Paint hangs and drips down the wall
Reason: Excessive water mixing; Insufficient addition of low shear thickener; The construction coating is too thick.
Handling: Strictly control the amount of water added; Cellulose combined with low shear alkali swelling thickener; Apply multiple thin coats.
Question 7: The paint film sticks and does not dry for a long time
Cause: Excessive addition of film-forming agents; The environmental humidity is too high; The Tg of lotion is too low.
Solution: Reduce the amount of film-forming agents used; Avoid construction in humid weather; High ambient humidity selects Tg high lotion.
4、 Common faults when making real stone paint and waterproof mortar
1. Stone like paint turns white after rain: ordinary styrene acrylic has poor water resistance, so choose lotion with good water resistance, or replace pure acrylic lotion with silicone acrylic lotion.
2. The tensile strength of waterproof coating is not enough: too much water is added, the content of lotion is low, and the water is controlled within 5%.
5、 Summary of Key Points to Note (Key Points)
1. Add lotion and stir at low speed throughout the process;
2. The pH of the finished product system is stable at 8.0-8.8;
3. The dosage of film-forming agents is adjusted with temperature;
4. Try to avoid ordinary styrene acrylic lotion on the exterior wall;
5. Do not use excessive amounts of organic silicon additives;
6. Construction can only be carried out when the ambient temperature exceeds 5 ℃.
Post time: Jul-15-2026