Paper production process is very easy to appear a lot of foam, which is mainly related to the paper pulp composition and process. Foam will affect the formation of paper, paper making paper of poor quality, encountered the problem of papermaking foam, can be eliminated by adding papermaking pulp defoamer to eliminate foam.
[ I ] Reasons for papermaking pulp foaming Increased content of these substances in the pulp, it will be easy to produce foam. There are generally the following main reasons: 1, The pulping part of the pulp is not clean, or bleached pulp washing is not clean, when the pulp remains a large number of surface-active substances, resulting in the paper machine feeding system to produce foam. 2, The amount of sizing is larger, so that the pulp contains more rosin acid salt, or pulp pH is higher, so that the gum is not well precipitated on the fibre, and the form of rosin acid soap present in the pulp, will lead to increased foam.
[ II ] paper making foam hazards 1, Foam for papermaking project has a greater impact. The presence of foam in the paper, will make the concentration of the pulp box fluctuations, so that the paper flow state is not stable. It can close the microporous surface of the wet paper web caused by the net part of the dewatering difficulties, so that the fibres and undispersed filler in the net part of the cohesion of the impact of the paper width of the uniformity. 2, The foam will also form a floating pulp so that the paper on the network appeared agglomerates in serious cases caused by the head break. Copying cardboard, foam exists between the cardboard layers, reducing its interlayer bond strength foam will also make the paper or cardboard produce foam holes, foam spots. Resin spots and other paper diseases. 3, In the process of coated paper if the storage tank and coating rollers have a large number of foam, so that the foam overflow which not only affects the normal operation of the coating caused by the flow of paint will also pollute the environment. Coated paper with foam drying, foam due to thermal expansion of the air within the rupture, the formation of a depression in the paper surface, thus destroying the paper surface of the glossy and smooth affecting the paper print map of the fine and complete. When the foam is serious, it will increase the viscosity of the paint, and make the paint flow performance deteriorate and bring difficulties to the production.
[Ⅲ] Anti-foaming programme Paper production foam is more difficult to avoid, and easy to cause negative impact. So paper production foam needs to be controlled as soon as possible, as soon as possible to deal with. Add defoamer is a very common method, defoamer is a chemical defoaming programme, will not change the original production process, does not affect the paper production process, the use of very convenient.
