一. The prone problems of putty powder

1. Dry fast. This is mainly due to the excessive addition of gray calcium, and the excessive addition of gray calcium will greatly increase the water absorption, causing the finished putty powder to dry quickly. It can appropriately reduce the amount of gray calcium powder in the putty formula, and it is also related to the dryness of the wall.

2. Peeling and rolling. This is related to the low viscosity of the hydroxypropyl methylcellulose , which is prone to this situation or the amount added is small.

3. Depowdering and powdering of putty powder. The purity of the ash calcium powder in the putty powder formula is too low, the ash content is too high, and the fly ash content is too high. At the same time, it is also related to the amount and quality of hydroxypropyl methylcellulose, which is reflected in the water retention rate of the product, and low water retention rate can easily cause this problem.

4. Foaming. This is related to the dry humidity and flatness of the wall, and also related to the construction.

5. Needle points appear. This is related to hydroxypropyl methylcellulose. The impurities in the cellulose react slightly with gray calcium. If the reaction is violent, the putty powder will be in the state of tofu. It cannot be wall-mounted, and there is no adhesive force. In addition, hydroxypropyl methyl cellulose is mixed with carboxymethyl and other products.

6. Volcanic caves and pinholes appear. This is obviously related to the water surface tension of the hydroxypropyl methylcellulose aqueous solution. The surface tension of the hydroxyethyl aqueous solution is not obvious. It will be fine to carry out the finishing treatment.

7. The putty powder is easy to crack and turn yellow after drying. This is related to the large amount of gray calcium powder. The added amount of gray calcium powder increases the hardness of the putty powder after drying. Only the hardness is not flexible and it is easy to crack, especially when it is exposed to external force. It is also related to the high content of calcium oxide in gray calcium powder.

二. Why is putty powder added to hydroxypropyl methylcellulose after adding water, the more it is stirred, the thinner it becomes

Hydroxypropyl methyl cellulose is used as a thickening and water retention agent. Due to the thixotropy of hydroxypropyl methyl cellulose itself, the addition of hydroxypropyl methyl cellulose in the putty powder also causes the putty to produce thixotropy after adding water. . This thixotropy is caused by the destruction of the loosely combined structure of the components in the putty powder. This structure is produced at rest and disassembled under stress. That is to say, the viscosity decreases under stirring, and the viscosity recovers at rest.

三. Why is the putty powder heavier in the scraping process?

In this case, the viscosity of the hydroxypropyl methyl cellulose selected by the manufacturer is generally too high. Some manufacturers use cellulose with a viscosity of 200,000 to make the putty. The putty made in this way has a high viscosity, so it will appear heavy during scraping. a feeling of. Shandong Gomez Chemical recommends that the viscosity of internal wall putty is 80,000-100,000.

四. Why does it feel that the viscosity is different when using the same viscosity hydroxypropyl methylcellulose in winter and summer?

Hydroxypropyl methylcellulose has thermal gelling properties, so that the viscosity of putty and mortar will gradually decrease as the temperature rises, and the room temperature in summer is generally above 30 degrees, which is much different from the temperature in winter. Therefore, the viscosity is lower than usual in summer. It is recommended to choose a product with a higher product viscosity or increase the amount of cellulose during product application in summer, and then choose a product with a higher gel temperature.

We produce high-quality hydroxypropyl methylcellulose with stable quality and suitable viscosity. Major putty powder manufacturers can call for consultation.

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