Common questions
(1) Excessive pulping causes excessive fiber cutting.
(2) The adsorption time is too short. As a result, the moisture content of the wet press pulp tray is too high, and it is difficult to remove the mold of the product.
(3) The degree of vacuum is too low. If the degree of vacuum is too low, the pressure difference between the inner cavity of the mold and the suction cover outside the mold will be reduced. Therefore, there is no enough pressure difference to suction the mold, resulting in a large amount of moisture remaining in the wet press pulp tray at the end of adsorption.
(4) The backwash time is too long. If the backwash time is too long, it will not only affect the adsorption effect but also make the molded wet and bad. The increased water in the tray will even prevent the demoulding of the post-process from proceeding normally.
Solution
(1) When handling waste paper, you should try to maintain the strength of the fiber. On the basis of complete deflake, do not excessively improve the pulping concentration and avoid excessive fiber cutting to ensure pulp molding the smooth water filtration and demolding.
(2) Moderately extend the absorbed time. Long absorbed time will reduce production efficiency and lead to a decrease in the degree of vacuum. In addition, it will also waste a lot of energy, because after adsorption to a certain extent, the moisture content of the wet press pulp tray will no longer decrease, and it must rely on the later production process to further reduce the water content.
(3) Appropriately increase the degree of vacuum. If the vacuum is too high, the pressure difference between the inner cavity of the mold and the outer suction cover of the mold will get large. At this time, although there is enough pressure to absorb the moisture in the mold, it makes the moisture content of the wet press pulp tray much lower and affects the hot pressing process, therefore, the quality of the product after hot pressing is too light and the strength is poor.
(4) Appropriately shorten the backwash time. If the backwash time is short, the slurry in the pulp tank cannot be stirred well. Besides, the uneven slurry will lead to uneven fiber deposition on the surface of the mold and reduce the product qualification rate.
