Application of Industrial Bactericidal Preservatives in Paper making
Due to the high development of paper making industry, In the process of pulping and papermaking, due to the abundant nutrients (protein, carbohydrates, hydrolyzed sugars, etc.) for bacterial growth in the slurry, bacteria will multiply rapidly under appropriate temperature and humidity conditions. In the various equipment and pipeline systems through which the paper material and white water flow, if the machine is not shut down frequently to clean and keep clean, various bacteria are likely to multiply and become a disaster, forming a large amount of sludge. If the pulp is mixed into the pulp of papermaking, it will cause paper problems such as paper breaks or voids, which will increase the dustiness of the paper and increase the waste rate. Therefore, sufficient attention should be paid to the anti-corrosion control in the production of paper industry.In addition to doing a good job of cleaning during production, adding preservatives to pulp and coatings to inhibit or kill microorganisms is an effective measure to improve paper performance and ensure normal production.
The main function of preservatives is to ensure that materials do not deteriorate during use by killing bacteria or making them lose their ability to grow and reproduce. Preservatives can denature the proteins in microorganisms, eliminate the activity of cells and cause cell death; preservatives can also mutate the genetic genes of microorganisms or interfere with the activity of enzymes inside cells to make it difficult to reproduce and grow, thereby inhibiting microorganisms effect. The bactericidal and antibacterial effects of preservatives are often related to their concentration and action time. For the same preservative, high concentration or long action time can kill bacteria, while low concentration or short action time can only inhibit bacteria. In addition, the same preservative has completely different effects on different microorganisms. A preservative that can kill a certain microorganism may only inhibit another microorganism.
The ideal preservative used in the paper industry should have the following properties:
(l) Efficient, fast, broad-spectrum bactericidal and antibacterial ability, so that bacteria can be killed in a short time or make their cells lose their ability to grow and reproduce;
(2) No irritating odor, no serious pollution to the environment or no adverse effects on the operator;
(3) It has a long-term effect on microorganisms, and bacteria will not develop drug resistance in a short period of time and lose their effect on them.
(4) It should have low toxicity, easy to decompose and certain solubility, and it will decompose itself under certain conditions after use, causing little or no pollution to the environment and no harm to product users.
The preservatives used in the paper industry are mainly organic preservatives and inorganic preservatives.
1) Inorganic preservatives (chloramine, sulfurous acid and its salts, hypochlorite, chlorine dioxide, etc.) have bactericidal effects due to their oxidizing or reducing properties, but their chemical properties are relatively unstable, easy to decompose, and their effects cannot last long. It has a peculiar smell, so it is mostly used for disinfection and sterilization of equipment, containers, semi-finished products and water;
2) Organic bactericidal preservatives (surfactants, organic smelling bactericidal preservatives, etc.) have the advantages of high efficiency, low toxicity, and good biodegradability. Most of the bactericidal preservatives used are organic bactericidal preservatives. In China, many manufacturers have also begun to pay attention to the development and use of organic bactericidal preservatives.
The selection of bactericidal preservative should be determined according to factors such as production conditions, the properties of the slurry, and the pH value. A bactericidal preservative with a broad bactericidal spectrum should be selected as much as possible; if it is used for a long time, two or more bactericidal preservatives should be used alternately to avoid microbial resistance; if adding paper and cardboard that is in contact with food, consideration should be given to Its toxicity and maximum allowable dosage; pay attention to the influence of pH value. Generally, for basophilic bacteria, acidic bactericidal preservatives should be used, and for acidophilic bacteria, alkaline bactericidal preservatives should be used.
