Polyacrylamide used in paper mills has good flocculation properties and can reduce frictional resistance between liquids. Polyacrylamide used in the papermaking industry is widely used as a retention agent, filter aid, leveling agent, water treatment agent, etc. in the papermaking field. Its function is to improve the quality of paper, improve the dewatering performance of the slurry, increase the retention rate of fine fibers and fillers, and reduce the consumption of raw materials and environmental pollution.
Polyacrylamide for paper industry
The effect used in papermaking depends on its average molecular weight, ionic properties, ionic strength and the activity of other copolymers. Non-ionic PAM is mainly used to improve the filterability of pulp, increase the strength of dry paper, and increase the retention of fibers and fillers; anionic copolymers are mainly used as dry and wet strengthening agents and retention agents for paper; cationic copolymers are mainly used It is used for papermaking wastewater treatment and filter aid. In addition, it also has a good effect on increasing the retention rate of fillers. In addition, polyacrylamide is also used in papermaking wastewater treatment and fiber recycling.
Anionic polyacrylamide for paper mills:
There are two types of polyacrylamide used in paper mills. One is anionic polyacrylamide. The main reason is that it should have the characteristics of pyrolysis and its viscosity will decrease quickly with the increase of temperature, so as to ensure that the original fiber in the dry paper is not affected Performance. Anionic polyacrylamide is a water-soluble organic polymer, which is easily soluble in water and forms a high-viscosity liquid. It can promote good dispersion of papermaking fibers and excellent paper forming effects at low addition levels, and improve the uniformity of pulp and paper Softness can also increase the strength of paper. In the use of papermaking coating, the papermaking dispersant has high dispersion efficiency, stable coating viscosity, less foam, non-toxic, non-corrosive, can increase the solid content of the coating, and has good fluidity and scrub resistance, and can maintain paper gloss Degree, not easy to become moldy. Papermaking dispersants can also increase the speed of papermaking, save beating time, reduce energy consumption, and have significant economic benefits.
Cationic polyacrylamide for water treatment in paper mills:
If you want to know which polyacrylamide is used in a paper mill, you must first understand the water quality characteristics of the paper mill. The following will introduce Capitel Chemical in detail.
Water quality characteristics of paper mills: Papermaking wastewater contains high COD and suspended solids (SS) content and serious color. The concentration of SS and COD in papermaking wastewater is relatively high. COD consists of two parts: insoluble COD and soluble COD. Generally, insoluble COD accounts for most of the total COD composition. When SS in wastewater is removed, most Insoluble COD is removed at the same time. Therefore, the main problem to be solved in waste paper and papermaking wastewater treatment is to remove SS and COD.
Using air flotation or precipitation method, by adding cationic polyacrylamide, most of SS can be removed, while most of insoluble COD and partially soluble COD and BOD can be removed. The typical treatment process is as follows:
Wastewater → Screen → Cistern → Air flotation or sedimentation → Discharge
Air flotation and sedimentation are both physical and chemical treatment methods, and the treatment effect is related to the selected equipment, process parameters, coagulant, etc. The COD removal rate is generally higher than that of the middle stage water of pulping, usually reaching 70%-85% . For small and medium-sized waste paper paper-making enterprises with a discharge volume of more than 150 m3 of paper waste water and a low concentration, through air flotation or precipitation treatment, the effluent water quality index can meet or approach the national discharge standard.
Polyacrylamide for wastewater treatment in paper mills
1. Dissolution temperature. A certain temperature is required for dissolution to speed up the dissolution. However, if the temperature is too high, the molecular chain of the polymer will be broken and the use effect will be reduced. The most suitable dissolution temperature is below 60℃.
2. Stirring conditions. Dissolution should avoid excessive shearing force stirring, excessive stirring will break the molecular chain, thereby reducing the use effect. Low-speed paddles should be used for mixing, such as anchor type, frame type, multi-layer paddle type, etc. The stirring speed is about 60 rpm. High-speed centrifugal pumps should also be avoided during transportation, and piston pumps or diaphragm pumps are more suitable.
3. Disperse and feed evenly. The key link in the dissolution of polyacrylamide is the uniform dispersion of the feed. After starting the mixer, use a mechanical vibrating screen for feeding (the screen mesh is 10 meshes), try to avoid the production of "large clumps" and "fisheye" insoluble particles, so that the polyacrylamide can be fully dissolved and used well effect. Polyacrylamide for paper industry.
4. Avoid connecting with iron. In the dissolving stirring and conveying dosing system, materials such as plastic, enamel, aluminum, and stainless steel are used.
5. Product selection. When purchasing polyacrylamide products, users should provide sewage/sludge to the flocculant manufacturers as much as possible for polyacrylamide product selection tests. Due to the different raw materials and sewage treatment processes used in the papermaking process of various paper mills, the water quality is still very different. , I still firmly believe that choosing the right flocculant products can help companies save a lot of pharmaceutical costs, and also solve the problem of manufacturers’ drainage compliance as much as possible.
Packaging and storage:
25kg/bag (plastic kraft paper bag lined with plastic bag outside). This product is non-toxic, pay attention to moisture, rain, and avoid sun exposure.
Dongguan Shouxin Chemical Co., Ltd. is a professional polyacrylamide supply chain resource integration company, mainly including cationic polyacrylamide, anionic polyacrylamide, non-ionic polyacrylamide, zwitterionic polyacrylamide, four major products, free on-site sampling , Experimental selection, to provide you with solutions with better effects and lower prices, welcome to consult.