In the use of waste paper, in order to keep the paper tensile strength, good performance, to meet the needs of modern offset printing, use the cationic polyacrylamide (CPAM) paper strengthening agent, the molecular length provides a good adsorption performance and position combined with chlorine bond, the integration between the fibers increased with enhanced, help a variety of functions, such as filter aid, especially the tearing index increased, which can effectively improve the paper emphasis; used as dispersing agent, can improve the paper.

The acrylamide solution adding cationic modifier PAM, sodium hypochlorite and alkali made mainly used as paper strengthening agent. Enhanced heat resistance paper manufacturing agent PAM. For example, fatty acid sizing agent 0.5, PAM paper strengthening agent in 0.2 copies, 1 copies of aluminum sulfate and epoxy reinforced agent 0.7 and joined the paper pulp, the paper soaked in water after 1h 200C, the tear strength is up to 183g, good printing performance. Adding acrylamide, acrylic acid and hydroxyethyl acrylate grafted onto cassava starch and Yang ion copolymer into the Canadian standard 560ml pulp beating, then add Al2 (SO4) 3, make quantitative 74.2g/m2 paper, the breaking length is 8950m, the middle layer strength 148g, tear factor is 135.

In the 800m/min Internet speed, concentration of 0.6%, paper ash content is 20%, the first stage of PAM retention agent can reach 80% of the retention rate of ash and 50% first pass retention. As a unit USA retention agent, BAYER RETAMINOLC0.1, composition of CPAM, the general dosage is 0.05%-0.3%, the concentration of 0.1%-1.0% is preferred; dual retention agent, the composition of PEI + PAM, dosage of 0.2%-1.0%, concentration of 0.5%-1.5% was added. Adding method for both pre mixed adding flocculation; series of Sweden Akzo Noble company production of retention agent is mainly composed of CPAM + colloidal silicon. Suitable for low weight coated paper, including waste paper recycling slurry system.

The particle flocculation system, first joined the CPAM forming larger flocs, under the action of shear stress, dispersed into small floc, and then add the negative particles of colloidal silica, can react with smaller flocs, with more intensive, more fine flocculation dewatering system, can achieve higher retention rate. Good uniformity and filtration performance. The use of cationic PAM as retention agent, retention rate was 98%, and the tiny fiber and lignin Cation Anion in PAM is better than that of mechanical pulping, exhibit a strong retention and use of rosin glue, gelatin, modified PAM filler such as titanium dioxide, can be used as wet end additive.

To improve the properties of PAM pulp dewatering. In the production process, has used the alum, ionic PAM and cationic starch to improve the result of retention and dewatering performance. The use of PAM in the coating base paper printing leave agent can improve the retention of fillers and fines, accelerate the dehydration speed, can be settled sewage, pollution reduction, therefore it is very important to strengthen environmental protection and improve the economic benefit. PAM is a kind of amphoteric flocculant, especially suitable for wastewater treatment. Join the 0.25%-0.5% PAM in the pulp, the pulp settling velocity can be increased by 60 times, the solid content of white water is reduced by 60%, ash of pulp increased, white pigment retention rate increased by 10%-15%, and greatly reduce the water turbidity, suspended solids below 50mg/1.