Calcium carbonate used in toothpaste usually comes in two specifications: 325 mesh (D97 about 45 μm) and 400 mesh (D97 about 38 μm). In recent years, with the development of toothpaste technology and the advancement of grinding technology, natural calcium carbonate with finer particle sizes has been used. Studies have shown that the particle size of calcium carbonate abrasives has an important impact on the pH value, total soluble fluorine retention rate, viscosity and friction value of fluoride toothpaste. As a manufacturer of calcium carbonate ultrafine vertical mills, Guilin Hongcheng will introduce to you today the impact of the production process of calcium carbonate for toothpaste on the toothpaste friction agent calcium carbonate.
1. The influence of the calcium carbonate particle size used in toothpaste on the pH value of toothpaste: the pH value of fluoride toothpaste basically increases with the decrease of the particle size of natural calcium carbonate abrasive D97, and the pH value of the same toothpaste increases with the aging time. The main tendency is to decrease and the pH fluctuation range is greater for those aged at 50°C than those aged at 40°C; this is related to the two main reactions that exist in toothpaste aging. The decrease in abrasive particle size (increase in specific surface area) causes the dissolution of calcium carbonate. Acceleration causes the pH value of toothpaste to increase, while SMFP gradually hydrolyzes hydrofluoric acid and reacts with calcium ions and phosphate to form insoluble fluoroapatite. At the same time, it releases hydrogen ions, which gradually decreases the pH value of toothpaste. Both reactions increase with the aging temperature. The increase and acceleration will lead to a wider range of pH value fluctuations in toothpaste.
2. The impact of the particle size of calcium carbonate used in toothpaste on the TSF retention rate of toothpaste: Generally speaking, the TSF retention rate of fluoride toothpaste decreases with the decrease in the particle size of natural calcium carbonate abrasive D97. The TSF retention rate of the same toothpaste is It decreases with the increase of aging temperature or the extension of aging time; this is due to the decrease of abrasive particle size (increase of specific surface area) and the increase of aging temperature, which increases the calcium ions or hydrofluoric acid in the liquid phase and generates insoluble fluoroapatite. It is caused by the accelerated reaction of stone, and the prolonged aging time causes the hydrolysis and precipitation of SMFP to continue.
3. The influence of the particle size of calcium carbonate used in toothpaste on the viscosity of toothpaste: The viscosity of fluoride toothpaste basically increases with the decrease of the particle size of natural calcium carbonate abrasive D97. The viscosity of the same toothpaste increases with the increase of aging temperature or aging time. The reasons can be attributed to two points:
(1) The decrease in abrasive particle size and the increase in aging temperature increase the calcium ions in the liquid phase, which intensifies the cross-linking effect of calcium ions on CMC. The prolongation of the aging time causes the cross-linking effect to continue to increase, resulting in paste Increase in viscosity.
(2) The decrease in abrasive particle size also increases the solid-liquid interface in toothpaste and increases the paste flow resistance, which also contributes to the increase in paste viscosity.
4. The influence of the particle size of calcium carbonate used in toothpaste on the friction value of toothpaste: the friction value Ra of fluoride toothpaste after aging at room temperature for 12 weeks showed an overall increasing trend with the decrease of the particle size of natural calcium carbonate abrasive D97; this is the proportion of particle size The decrease leads to an increase in the abrasive particles in the toothpaste, and more natural calcium carbonate abrasive particles are rubbing in the same groove during brushing. The superimposed effect makes the grooves easy to deepen, resulting in an increase in the friction value of the toothpaste. In addition, the particle size distribution width coefficient narrows as the particle size decreases, which also strengthens the superposition effect of the friction of natural calcium carbonate abrasive particles, that is, there are more natural calcium carbonate abrasive particles of similar size in the same groove for friction. It should also have a certain effect on increasing the friction value of toothpaste, which may be the reason why the friction value of D97 toothpaste with a particle size of 25.4 microns is relatively high.
The production process of calcium carbonate used in toothpaste determines the particle size distribution of calcium carbonate, the abrasive agent of toothpaste. As a manufacturer of calcium carbonate grinding mills, the ring roller mills, Raymond mills, ultrafine vertical mills we produce are all equipment for the production of toothpaste friction agent calcium carbonate. Among them, the ultrafine vertical mill is more suitable for the production process of calcium carbonate for toothpaste. The production process of ultra-fine vertical mill to produce calcium carbonate for toothpaste is as follows: the motor drives the reducer to drive the grinding disc to rotate, and the material is fed into the center of the rotating grinding disc by the air-locked feeding equipment. Under the action of centrifugal force, the material enters the grinding roller. The grinding roller continuously rotates and grinds, and the material is crushed by squeezing, grinding and shearing. At the same time, hot air is ejected upward at high speed and evenly from the air ring surrounding the grinding disc. The ground material is blown up and dried, and enters the classifier with the wind. The qualified fine powder passes smoothly and is collected by the dust collection equipment as the product. , the unqualified coarse powder falls back to the grinding disc under the action of the classifier blades, and is ground again together with the newly fed materials. This cycle completes the entire grinding process.
The roller sleeve and liner grinding curve of the calcium carbonate ultrafine vertical mill are specially designed for ultra-fine powder grinding, which makes it easier to form a material layer, has high grinding efficiency, and a high one-time grinding yield. The sorting fineness range is from 3um to 45um. It can produce products of different specifications with one vertical mill, and can also quickly and stably produce products of the same fineness. The finished product can better meet the particle size requirements of toothpaste abrasive calcium carbonate. If you have relevant purchasing needs, please leave us a message for details.