Produce &Technology

In building construction and material applications, the phenomenon of sand removal refers to the appearance of powdery substances on the surface of concrete, mortar or other building materials, and gradually falling off. This phenomenon can affect the strength and durability of the material and is often related to a number of factors, including the use of cellulose (HPMC). The following are some of the conditions related to cellulose that can lead to sand and powder removal:

The addition of cellulose (HPMC) is too high:

Cellulose ether (HPMC) is often used as a thickener, water retaining agent and binder in building materials. If the amount of cellulose (HPMC) added is too high, it may affect the solidification and hardening process of the material, resulting in a surface that is not hard enough, resulting in sand removal.

As a thickening agent and water retaining agent, cellulose ether (HPMC) can delay the solidification and hardening process of materials. If the amount is too high, the hardening rate of the material will slow down, resulting in the surface being affected by external influences when it is not fully hardened.

The excessive addition of cellulose (HPMC) will change the internal structure of the material, resulting in a decrease in the strength and compticity of the material. On the surface, that is, the material is not hard enough, and it is easy to drop powder in friction and use.

The excessive addition of cellulose (HPMC) also affects the hydration reaction of cement. Excessive cellulose (HPMC) will adsorb a lot of water, making the hydration reaction of the cement inadequate. This will lead to incomplete hardening of the material, especially the surface layer, which is prone to loose and sand.

The addition of high amount of cellulose (HPMC) may form a weak layer on the surface of the material, which is easy to fall off during use because of the weak bond, showing the phenomenon of powder dropping.

Different types of cellulose ether (HPMC) have different properties, and the appropriate cellulose type should be selected according to the specific needs to avoid material problems caused by the inappropriate performance of cellulose (HPMC).

The use of low-quality or unsuitable cellulose (HPMC) products can result in poor building material performance. For example, the purity, viscosity and particle size of cellulose ether (HPMC) do not meet the requirements, which may lead to insufficient strength of the material, and then the powder loss problem.

The compatibility of cellulose (HPMC) with other additives or raw materials can also affect the performance of the final material. If the cellulose (HPMC) is not compatible with cement, sand or other chemical additives, it may cause the internal structure of the material to be unstable, and the surface is prone to sand and powder.

Low-quality cellulose (HPMC) may contain impurities that can interfere with the setting and hardening process of the material, resulting in insufficient surface strength and prone to sand removal.

The viscosity of cellulose (HPMC) is one of its key performance indicators, and the viscosity of low-quality cellulose (HPMC) is unstable, which will affect the uniformity and stability of the material, making the material appear uneven structure during the hardening process, resulting in the surface easy to drop powder.

The inconsistent particle size of cellulose (HPMC) will lead to uneven mixing, reduce the strength and compactness of the material, and the surface is prone to loose and powder drop.

Low-quality cellulose (HPMC) has poor solubility and cannot be fully dispersed in the material, resulting in local concentrations that are too high or too low, making the material properties inconsistent and easy to drop powder on the surface during use.

In the material mixing process, if the cellulose (HPMC) is not evenly distributed, it will lead to inconsistent performance in local areas. In some places, the concentration of cellulose (HPMC) may be too high, resulting in insufficient strength of the material, resulting in powder dropping.

High or low water retention properties of cellulose (HPMC) will affect the curing process of the material. If the water retention performance of cellulose (HPMC) is too high, the water in the material is not volatile, and the curing process is slow, resulting in insufficient surface strength; On the contrary, the water retention performance is too low, which may cause the material to lose water too quickly, and the surface cracks and powder drop phenomenon.

When dealing with the problem of sand and powder removal, the quality of cellulose, the amount of addition, the compatibility with other materials and the construction process should be considered comprehensively to ensure that the performance indicators of the material meet the requirements to avoid the occurrence of the above phenomenon.

How to do prevention and solution measures?

Control the amount of cellulose (HPMC) in strict accordance with the material ratio requirements to avoid excessive use. The optimal amount of cellulose can be adjusted experimentally to ensure that it can play its role of thickening and retaining water without affecting the strength and hardness of the material.

Different types of cellulose ether (HPMC) have different properties, and the appropriate type of cellulose (HPMC) should be selected according to the specific needs to avoid material problems caused by the inappropriate performance of cellulose (HPMC).

During the material mixing process, ensure that the cellulose (HPMC) is evenly distributed with other components to avoid excessive local concentrations. Methods such as mechanical stirring can be used to improve the uniformity of materials.

Strengthen the quality control of raw materials to ensure that the cellulose used (HPMC) meets the quality standards. The purity and stability of cellulose (HPMC) can be ensured through incoming inspection and quality inspection.

Through the above measures, can effectively prevent the addition of cellulose (HPMC) caused by too high sand powder problems, to ensure the quality of building materials and service life.

When purchasing, select certified high quality cellulose (HPMC) products to ensure that their purity, viscosity and particle size meet standards. Reputable suppliers can be selected through market research and supplier evaluation.

The sourced cellulose (HPMC) is subjected to rigorous quality testing, including testing key indicators such as purity, viscosity, particle size and solubility. Ensure that the cellulose used meets the material ratio requirements.

Optimize the material mixing process to ensure that the cellulose is evenly mixed with other components. Efficient mixing equipment can be used to ensure that the cellulose is fully dissolved and dispersed.

According to the specific application scenario, a reasonable cellulose (HPMC) adding ratio scheme is formulated to ensure the best performance and use effect of the material. The optimum ratio can be determined through laboratory tests and field tests.

In the production process, regular quality monitoring and performance testing are carried out to discover and solve the quality problems of cellulose (HPMC) in a timely manner. Ensure that the material performance indicators meet the design requirements.

The use of high-efficiency mixing equipment to ensure that the material can be fully and evenly mixed during the mixing process. Especially in large-scale construction, it is very important to choose the right equipment.

According to the characteristics of the material, determine the appropriate mixing time and speed. Too short stirring time or too slow stirring speed will lead to uneven mixing, which needs to be adjusted according to the type and amount of materials.

For materials that need to add a variety of components, a step-by-step mixing method can be used to first mix cellulose (HPMC) with some materials, and then add other components for secondary mixing to ensure that the components are evenly distributed.

During the mixing process, quality monitoring and inspection are carried out to ensure the uniformity of the material. The mixing process can be adjusted in time by sampling inspection to check the uniformity and performance of the mixture.

Conduct professional training for operators to ensure that they understand the critical control points in the mixing process and master the correct operation methods to ensure the uniformity of the mixing process.

If possible, pre-mixed materials can be used, which have already been evenly mixed during the production process, reducing the risk of uneven mixing on site.

Improper water retention of cellulose (HPMC) may also lead to sand removal of powder from building materials. Cellulose ether materials (HPMC) are often used to improve the water retention, bonding and constructability of mortar and concrete. However, too high or too low water retention will affect the performance of the material, resulting in sand removal.

The reason why the water retention of cellulose (HPMC) is too high will cause the water in the material to be less volatile, delaying the hardening process of cement or other gelling materials. The surface of the material with insufficient hardening is soft, and it is easy to sand off the powder after construction. Too much moisture will affect the early strength development of the material, making the surface layer insufficient strength, resulting in surface flour.

Insufficient water retention will cause the moisture in the material to volatilize too quickly, so that cement and other cementified materials can not be fully hydrated, and the surface is prone to cracks and powders. The poor water retaining cellulose (HPMC) can not effectively maintain the wetness of mortar, reduce the adhesion of mortar, and easily lead to sand on the surface.

Choose cellulose (HPMC) products with moderate water retention properties to ensure that their water retention properties match the requirements of the mortar or concrete used. The water retention performance of cellulose (HPMC) is verified by laboratory tests before use to ensure that it can meet the requirements of construction and use.

According to the specific construction conditions and material characteristics, determine the reasonable amount of cellulose (HPMC) to avoid too much or too little addition. By adjusting the amount of cellulose (HPMC) in a small scale experiment, the best water retention effect was found to ensure that the material properties met the requirements. Ensure that the cellulose (HPMC) is well mixed with other materials and evenly distributed to exert its optimal water retention properties. In the construction of extreme environments such as high temperature and low humidity, necessary moisturizing measures are taken, such as covering, spraying, etc., to prevent the material from losing water too quickly. In addition to cellulose (HPMC), other water-retaining agents, thickeners, etc., can be added to improve the overall performance of the material and ensure the balance of water retention and strength. In the construction process, the water retention performance and hardening progress of mortar or concrete are regularly tested, and the construction parameters are adjusted in time to ensure the final quality.

Through these measures, the water retention of cellulose (HPMC) can be effectively controlled, and the sand and powder phenomenon caused by improper water retention can be prevented, and the quality and durability of building materials can be ensured.