Ion-exchange resin particle size and the physical properties of its work and performance is greatly affected. (1) Resin particle size ion exchange resin beads are usually made of small particles, and its size is also important. By fine resin particles, the reaction rate is large, but the fine particles of the liquid through the greater resistance, require higher working pressure; especially sugar concentration of high viscosity, this effect is more pronounced. Therefore, the resin particle size should be selected. If the resin particle diameter of 0.2mm (about 70 mesh) or less, will be significantly increased fluid flow through the resistance and reduce flow and production capacity. Determination of the resin particle size is usually wet sieving method, swelling of the resin after the full sieved accumulated in 20,30,40,50 stay ...... mesh sieve stock to 90% of the particles by their corresponding The sieve diameter, known as the resin of the "effective diameter." Most general-purpose resins effective particle size between 0.4 ~ 0.6mm. Resin particles is uniform to uniform coefficient expressed. It is the determination of the resin of the "effective diameter" take stock of 40% cumulative particle left, and the corresponding sieve opening size ratio of the effective diameter. Such as a resin (IR-120) The effective size of 0.4 ~ 0.6mm, it is a 20 mesh sieve and 30 mesh sieve and retained on a 40 mesh sieve particles were: 18.3%, 41.1% and 31.3%, the calculated uniformity coefficient of 2.0. (2) drying the resin density of the density of the resin is called true density. Wet resin per unit volume (even the voids between particles) is called the weight of apparent density. Resin crosslinking density and its degree and the nature of the exchange group. Typically, the high degree of crosslinking density of the resin is high, strongly acidic or alkaline resin has a density higher by acidic or weakly alkaline, and a large hole density of the resin is lower. (3) ion exchange resin solubility of the resin should be insoluble matter. However, the resin mixture during the synthesis of the material of lower degree of polymerization, decomposition of the material and the resin will be dissolved out in the working operation. Low degree of crosslinking and containing more reactive groups of the resin, dissolution tend to be larger. (4) The degree of swelling the resin contains a large number of ion exchange resin hydrophilic groups, swelling upon contact with water. When the resin in the ion-transform, such as cationic resins into the H + Na +, Cl-anion resin is converted to the OH-, ions are due to the increase in diameter swell, increasing the volume of the resin. Typically, a low degree of crosslinking greater degree of resin swelling. In the design of the ion exchange device, the degree of swelling the resin must be considered in order to adapt to the production run of the ion-exchange resin, the resin volume change occurs.