For particle size, the finer the particle, the better the water retention. When large particles of cellulose ether come into contact with water, the surface immediately dissolves and forms a gel to wrap the material and prevent water molecules from continuing to penetrate. Sometimes it is not evenly dispersed and dissolved even after long time stirring, forming a turbid flocculent solution or lump. It greatly affects the water retention of cellulose ether, and the solubility is one of the elements for choosing cellulose ether.
Fineness is also an important performance index of methyl cellulose ether. MC for dry mortar requires powder with low water content, and fineness also requires 20%~60% particle size less than 63um. fineness affects the solubility of hydroxypropyl methyl cellulose ether. The coarser MC is usually granular, which can be easily fractionally dissolved in water without lumping, but the dissolution speed is very slow and not suitable for use in dry mortar.
In the dry mortar, MC is dispersed between the aggregate, fine filler and cement and other cementitious materials, and only a fine enough powder can avoid the clumping of methyl cellulose ether when mixing with water. When MC is dissolved with water and clumped, it is very difficult to dissolve in dispersion. The coarser fineness of MC not only wastes, but also reduces the local strength of mortar, so that when the dry mortar is constructed in a large area, it shows that the curing speed of local dry mortar is obviously reduced and cracks appear due to the different curing time. For shotcrete mortar with mechanical construction, the requirement for fineness is higher due to the shorter mixing time.
Landcel has developed HPMC with high purity and quality, and has many years of experience in R&D and production of hpmc in dry mortar for adding measurement and performance. We have customers all over the world and look forward to your visit.