As a key connecting component of production equipment in the food, pharmaceutical and other industries, the attachment of microorganisms on the surface of sanitary clamp is directly related to product quality and production safety. Microorganisms can easily form biofilms on the surface of the clamp, which is not only difficult to clean, but also causes cross contamination, threatening product quality and consumer health. Therefore, inhibiting microbial attachment through advanced surface treatment processes has become a focus of industry attention. Common surface treatment processes include mechanical polishing, electrolytic polishing, passivation treatment, coating technology, nano-surface treatment, plasma treatment, and antibacterial metal alloying treatment, which act on the surface of the clamp from different angles to effectively inhibit the attachment of microorganisms.
Mechanical polishing is one of the basic processes for surface treatment of sanitary clamps. The surface of the clamp is polished by using tools such as polishing wheels and sandpaper to reduce the surface roughness and reduce the pores and depressions where microorganisms can attach. When the surface roughness of the clamp is reduced, it is difficult for microorganisms to find stable attachment sites and they are more likely to be carried away by fluid flushing. Studies have shown that when the surface roughness of the clamp is reduced from Ra 1.6μm to Ra 0.8μm, the initial attachment of microorganisms can be reduced by about 30%. However, mechanical polishing has certain limitations. It is difficult to process fixtures with complex shapes, and it is easy to leave tiny scratches on the surface, which may become new attachment points for microorganisms. Therefore, it is often used in combination with other processes.
As a more refined surface treatment process, electrolytic polishing uses electrochemical principles to treat the surface of the fixture. During the electrolytic polishing process, the raised parts of the fixture surface preferentially undergo anodic dissolution, making the surface smoother and forming a dense passivation film. Compared with mechanical polishing, the surface roughness after electrolytic polishing can be further reduced to Ra 0.2 - 0.4μm, and there are no scratches on the surface, which can greatly reduce the attachment area of microorganisms. In addition, the passivation film formed by electrolytic polishing has good chemical stability, which can prevent microorganisms from directly contacting the fixture matrix, thereby inhibiting the growth and reproduction of microorganisms. In practical applications in the pharmaceutical industry, the number of microorganisms on the surface of sanitary clamps treated with electrolytic polishing is significantly lower than that of untreated or mechanically polished fixtures.
Passivation treatment is to react chemical reagents with the metal on the surface of the fixture to form a dense oxide film, which can effectively isolate the external environment and prevent the attachment and erosion of microorganisms. For sanitary clamps made of stainless steel, strong oxidants such as nitric acid are often used for passivation treatment. Passivation treatment can not only improve the corrosion resistance of the fixture, but also change the physical and chemical properties of the surface, reduce the surface energy, and thus reduce the affinity between microorganisms and the surface. Experimental data show that the microbial attachment rate of the fixture surface after passivation treatment is reduced by about 40% - 50%. At the same time, the passivation treatment operation is relatively simple and low in cost. It is suitable for sanitary clamps of various specifications and shapes and is a more commonly used surface treatment process.
Coating technology provides a new idea for sanitary clamps to inhibit microbial attachment. By coating the surface of the fixture with antibacterial coating materials, such as coatings containing metal ions such as silver and copper, antibacterial ions can be continuously released to destroy the cell structure of microorganisms and inhibit their growth and reproduction. In addition, some super-hydrophobic and super-hydrophilic coatings can also reduce the attachment of microorganisms on the surface by changing the wettability of the surface. The super-hydrophobic coating creates a water droplet rolling effect on the surface, which can carry away the attached microorganisms; the super-hydrophilic coating keeps the surface covered with a water film, which prevents direct contact between the microorganisms and the surface. In the application of the food processing industry, the number of microorganisms on the surface of the sanitary clamp coated with an antibacterial coating is significantly lower than that of the uncoated clamp, and it can still maintain good antibacterial properties during long-term use and cleaning.
Nano-surface treatment technology uses nano-level structural design to micro-modify the surface of the clamp. By constructing nano-level protrusions, grooves or porous structures on the surface, the physical morphology and chemical properties of the surface are changed. On the one hand, the nano-scale structure can reduce the contact area between the microorganism and the surface and reduce the adhesion of the microorganism; on the other hand, the special nano-structure can also affect the metabolic activity of the microorganism and the formation of the biofilm. For example, a surface with a nano-level rough structure may destroy the cell membrane of the microorganism, making it difficult for it to survive. Studies have found that the amount of microbial attachment on the surface of the sanitary clamp treated with nano-surface can be reduced by more than 60%, showing a strong microbial inhibition ability.
Plasma treatment uses high-energy plasma to react physically and chemically with the surface of the fixture to improve the hydrophilicity, surface energy and chemical composition of the surface. The active particles in the plasma can etch the surface, remove pollutants and impurities, and introduce new functional groups to change the chemical properties of the surface. After plasma treatment, the fixture surface becomes more hydrophilic and the surface energy increases, which makes it difficult for microorganisms to stably attach to the surface. In addition, plasma treatment can kill microorganisms on the surface to a certain extent. In practical applications, the sanitary clamp after plasma treatment not only significantly reduces the amount of microbial attachment, but also significantly improves the cleanliness and corrosion resistance of the surface, providing a strong guarantee for the safe production of food, pharmaceutical and other industries.
Different sanitary clamp surface treatment processes play an important role in inhibiting microbial attachment through their own unique mechanisms of action. In actual production, according to the specific application scenarios and needs, the appropriate surface treatment process can be selected or a combination of multiple processes can be adopted to achieve the best microbial inhibition effect and ensure product quality and production safety.
