| Why does a little HPMC need to be added in thermal insulation mortar? This is because thermal insulation mortar needs a certain water retention function. Hydroxypropyl methyl cellulose (HPMC) is mainly used to keep the cement in mortar hydrated sufficiently before hardening, so that the cement does not get enough water to solidify because of the rapid loss of water. Only when the hydration reaction of cement is complete, the strength of insulation mortar itself and the bond with base materials can be guaranteed. Strength. According to the experimental theory, the free water required in the process of complete hydration of cement is 26% of the quality of cement. The water consumption of thermal insulation mortar is much more than that of cement hydration in thermal insulation mortar. The excess water is to meet the needs of construction. But if the water-holding capacity of HPMC is too high, or the amount of water added in thermal insulation mortar is too large, what will be the impact? The strength of thermal insulation mortar is mainly related to water-cement ratio. The larger the water-cement ratio, the larger the porosity of thermal insulation mortar will be, and the strength of thermal insulation mortar will be affected to a certain extent. If the water-holding capacity is too high, the water-cement ratio of mortar will be affected. High, not only can affect the bond between mortar and matrix, but also prolong the setting time of insulation mortar, affect the construction speed and increase the difficulty of construction. Therefore, the water retention of HPMC is not the higher the better, as long as the water retention of thermal insulation mortar ensures the amount of water required for cement hydration and the operability of mortar. Of course, if the water retention is not enough, the moisture in mortar is easily absorbed by other materials, resulting in inadequate hydration of cement and reducing the mortar's performance. Bond strength and self-strength are also one of the reasons for cracking of insulation mortar. Shanghai Longou Chemical Co., Ltd. reminds you that the amount of hydroxypropyl methyl cellulose has a suitable range of dosage. Putty lubricants and putty hardeners also have their own suitable range of dosage. |
