The use of toothpaste increases the effect of mechanical tooth cleaning. Toothpaste consists of a soft paste or a gel. Its main ingredients are cleaning agents, foaming agents, moisturisers and wetting agents, flavourings and aromas, preservatives, as well as colorants and additives. In addition, toothpastes also contain active substances for dental prophylaxis, especially for the prevention of periodontitis and caries (fluoride).
Toothpaste is produced by both batch and continuous process.
As a rule, toothpaste is produced by batch process, as follows:
First, the moisturising agents glycerin and sorbitol are put in a process plant equipped with a scraper agitator, a high performance homogeniser and a vacuum unit. The binders, such as sodium carboxymethyl are sucked into the mixer in stages under liquid level.
This takes place under intensive agitation and homogenisation in circulation. One after the other, demineralized water, saccharin, MEP and preservative are added to this mixture. To swell the binding agent, the mixture is further agitated and homogenized to support the swelling of the binders. After the binding agents have been solubilized, the cleaning bodies (e.g. chalk), the pyrogenic silica and the tenside (sodium laury sulphate) are sucked in by vacuum under liquid level in successive stages.
The tenside should, if possible, be added in the last stage, so that the procedure of the production step is not hindered by foaming. The mass is then deaerated under agitation and homogenisation by vacuum until it has a smooth, even appearance. Finally, the aromatic oils are sucked in under liquid level and homogenised. Care must be taken that the aromas do not evaporate during the venting process.
After incorporation of the aromas, a sample is taken for quality control. After the batch has been released by the laboratory, the mixer is cleaned.
The following should be taken into account when designing the mixer for the production of toothpaste:
- A high-performance scraper agitator with excellent vertical mixing, as well as operation with change of rotational direction
- A high-performance homogeniser with good conveying properties, also in vacuum operation
- Rotor/Stator system equipped with wear protection.
- Particular attention should be paid to the addition of powders and aromatic compounds, as these process steps are decisive for the function of the system.
- GMP–compliant design, no rough edges, no dead space behind the agitators.
- GMP-compliant CIP-cleaning, e.g. by means of rotating jet cleaner