Tissue paper grades

Principal Uses. Groundwood pulp contains a considerable proportion (70—80 wt %) of fiber bundles, broken fibers, and fines in addition to the individual fibers. Principal uses of paper-grade pulps are in newsprint, magazine papers including coated pubHcation grades, board for folding and molded cartons, wallpapers, tissue, and other similar products. 

Woodfree recovered paper, such as MOW, CWF and/or UWF, is used as raw material to produce woodfree DIP grades for tissue, woodfree graphic paper grades or market DIP as a chemical pulp substitute. Table 4.4 shows the raw material quality parameters and the quahty demands on woodfree DIPs for named applications. 

The same styrene acrylic emulsions used for sizing tissue paper to provide wet strength are used in the ink. The colorants used are mostly dyes or pigments that are not dermatological irritants. The resin should give a waterproof bond and be low cost. The components of a towel and tissue ink are re-pulpable for ease in recovery of waste and/or off-grade material to achieve satisfactory economies of paper towel tissue converting. 

Paper is made in a wide variety of types and grades to serve many functions. Writing and printing papers constitute ca 30% of the total production. The balance, except for tissue and toweling, is used primarily for packaging (qv). Paperboard differs from paper in that it generally is thicker, heavier, and less dexible than conventional paper. 

The cahper is the thickness in p.m of a single sheet measured under specified conditions (TAPPI T411). CaUpers for a number of common paper and board grades are capacitor tissue, 7.6 p.m facial tissue, 65 p.m newsprint, 85 p.m offset bond, 100 p.m linerboard, 230—640 p.m and book cover, 770-7600 pm. 

Spray appHcations to the surface of the sheet have been useful, especially for appHcation of creping aids and release agents in towel and tissue miUs. The spray appHcation of functional chemicals has not been used widely. Generally, the uniformity of appHcation is mote difficult to control when functional chemicals are sprayed than when they are appHed by a size press. Eunctional chemicals also can be appHed to heavier grades of paper or paperboard at the calender stack. 

The pulp and paper industry produces primary products—commodity grades of wood pulp, printing and writing papers, sanitary tissue, industrial-type papers, containerboard, and boxboard— using cellulose fiber. The two steps involved are pulping and paper or paperboard manufacturing. 

---