(1) Hydroxypropyl methylcellulose (HPMC) is divided into ordinary type (hot-soluble type) and cold water instant type:
Ordinary type, clumps in cold water, but can quickly disperse in hot water and disappear in hot water. When the temperature drops to a certain temperature, the viscosity will slowly appear until it forms a transparent viscous colloid. The reason for encountering cold water clumps is: the outer cellulose powder encounters cold water, immediately becomes viscous, thickens into a transparent colloid, and the cellulose inside is surrounded by the colloid before it comes into contact with water, and it is still in powder form. , but slowly melts away. Ordinary products do not need to use hot water in practical applications, because the putty powder or mortar is a solid powder. After dry mixing, the cellulose is separated by other materials. When it encounters water, it will immediately become viscous and will not form a group.
The instant product disperses quickly when it encounters cold water and disappears in the water. At this time, the liquid has no viscosity, because HPMC is only dispersed in water without real dissolution. From about 2 minutes, the viscosity of the liquid gradually increases, forming a transparent viscous colloid.
(2) The scope of application of ordinary type and instant type: instant type is mainly used in liquid glue, cosmetics, and laundry detergent. Because the surface of instant cellulose has been treated with dialdehyde, the water retention and stability are not as good as ordinary products. Therefore, in dry powder such as putty powder and mortar, we recommend ordinary products.
How to choose the right viscosity of cellulose:
1. First of all, we need to understand the role of cellulose ether: water retention and thickening.
2. The industry can usually say 100,000 viscosity, 150,000 viscosity, and 200,000 viscosity. What do these measurements mean? What is the impact of different units of measurement on the product?
(1) For water retention
The water retention performance increases with the increase of viscosity, but according to market conditions, when the viscosity of cellulose exceeds 100,000, the water retention performance increases with the viscosity.
(2) For thickening
Generally speaking, when the effective content is normal, the larger the unit, the better the thickening performance. That is to say, high viscosity requires a large amount of water, and the water retention rate does not change much.
3. Many companies use differentiated ratios, that is, different mortars and cellulose ether specifications are different, but for small factories, it will increase the cost. Many small factories only use one fiber plastic ether for general use, that is, the dosage is different. ! Generally, 100,000 units are the most used.
4. Usually 200,000 viscosity is used for bonding mortar, and 100,000 is also used for self-leveling, 100,000 for self-leveling, and 80,000 for plastering. Of course, it is mainly determined by the quality of water retention. We do not recommend customers to use high viscosity. For example, for 200,000 units, the higher the viscosity of cellulose ether, the more unstable it is, and there are more counterfeit products. Some customers report that the 20W genuine product is too sticky and the construction is not very good.
5. The water retention of cellulose ether used in mortar is different from the water retention of cellulose ether in the experiment. Even if the water retention of cellulose ether itself is good, it does not mean that the effect in mortar is certain Well, it is mainly determined by the performance of the remaining additives in the formula, the amount of addition, and the mixing effect of the dry powder mortar equipment. It is best to use it on the wall to see the effect. This is the truth!