Discussion On The Method Of Improving The Air Permeability Of Wrapping Tissue

With the improvement of people's material living standards, household paper has quickly become one of the most closely related consumer goods in modern life. The production and consumption level of household paper is not only a symbol of the quality of life of a country and the technical level of the paper industry, but also a symbol of civilization. As a kind of household paper, wrapping tissue is currently mainly used in sanitary napkins, diapers, pet shops and as a composite core. It is mainly used to wrap fluff pulp, and the quality of fluff pulp wrapping mainly depends on the air permeability of the wrapping tissue. The air permeability affects the uniformity of fluff pulp distribution. The better the air permeability, the more uniform the distribution of fluff. This paper discusses the method of improving the air permeability of wrapped toilet paper from the three processes of beating, paper machine and slitting.

1. Beating section of wrapping tissue

(1) Slurry ratio

Long-fiber wood pulp has a longer fiber length, better inter-fiber interlacing ability, and better paper sheet strength, but the fibers are not tightly bonded and the fiber gap is larger, so the air permeability between fibers is better; short fibers have better air permeability. The fibers are shorter, the interweaving is relatively tight, and the gap is small. Although the short fibers can improve the evenness and softness of the paper sheet, the air permeability is poor. Therefore, when the ingredients are used, theoretically, when the proportion of long fibers is large, the paper sheet will be reduced. better air permeability. Keeping the beating method unchanged, only changing the proportion of the pulp, according to the actual production data, it can be concluded that properly increasing the proportion of long fiber content can indeed improve the air permeability of the absorbent paper.

(2) Beating degree

Beating is an indispensable process in papermaking, and its influence on the air permeability of paper sheets can be obtained through experiments: under the condition of the same paper quantification, using three disc mills for beating, the beating degree of the pulp is high, and the wet weight is small. The air permeability of the paper sheet is poor, the beating degree is low and the wet weight is high in the case of two disc mills, and the air permeability of the paper sheet is good. The reason is that the beating degree is high, the fiber is cut more thoroughly, the splitting is more obvious, and the specific surface area of the fiber increases greatly, so the combination between the fibers of the paper sheet is good, the tightness is high, and the friction between the paper layers is reduced. There are voids, and the bulk of the paper sheet is low, so the air permeability is poor. According to practical experience, when the pulp beating degree is 20-21°SR, it can not only ensure the required strength of the base paper, but also have good air permeability and reduce power consumption.

2. Paper machine section of wrapping tissue

(1) Elongation

The greater the elongation of the paper, the more fluffy, the better the air permeability. Therefore, in the actual production process, properly increasing the elongation of the paper can improve the air permeability. Compared with the steel knife, the ceramic knife can slightly improve the air permeability. elongation, thereby increasing air permeability. Therefore, the air permeability of the absorbent paper can be improved by changing the type of scraper.

(2) Slurry web speed difference

Changing the speed difference of the pulp web can change the forming characteristics of the paper sheet. Within a certain range, if it is appropriately increased, the paper sheets are combined better laterally, the fibers are tightly combined, the lateral tension is large, and the ventilation is poor. In the case of requirements, the speed difference between the pulp and the web can be appropriately reduced to improve a certain degree of air permeability.

(3) Squeeze specific pressure

In the pressing process, with the increase of the pressing specific pressure, the tightness of the paper sheet increases and the fiber gap becomes smaller, which will inevitably affect the air permeability. In the case of strict requirements on air permeability, it can be considered to reduce the specific pressing pressure and improve the drying efficiency to improve the air permeability.

3. Slitting section of wrapping tissue

In the process of slitting the coiled paper, the speed ratio of the slitting machine also has a certain influence on the air permeability of the paper. If the tension is too tight, the air permeability of the coiled paper will increase by 2-3 seconds compared with the base paper. During the cutting process, the speed ratio of the slitting machine should be reduced as much as possible to avoid affecting the air permeability of the absorbent paper.

In summary, in the production process of wrapping tissue, the amount of long fibers should be appropriately increased, and the pulp beating degree should be appropriately reduced on the premise of ensuring the strength of the paper sheet during the beating process, and 3 disc mills should be changed to 2 sets. ;In the production process of the paper machine, appropriately increase the elongation of the paper sheet, and replace it with a ceramic knife when the tension is satisfied; in the case of ensuring the transverse tension, appropriately reduce the speed difference of the pulp web; appropriately reduce the pressing specific pressure, etc., the above methods are all Can improve the breathability of wrapped toilet paper.