Corrugated papers, paper grades

In case that corrugated base papers are not any more produced from recycled paper, as it is typical for testliner and medium in Germany, virgin fibres would have to be used. The corresponding paper grades as kraftliner would be produced from kraft pulp and fluting from semi-chemical pulp. For the simplified calculation of the required wood demand for the fibres, an average process yield of 60% (kraft pulp = 50%, semi-chemical pulp = 70%) is used. The substitution of the... 

Kraftliner as well as fluting are not manufactured in Germany. Corresponding paper grades would have to be imported or at least the necessary raw materials. The required pulp volume for the production of 3.6 Mio t corrugated base papers would exceed the current total chemical pulp import of 3.4 Mio t of the German paper industry. 

Corrugated boxboard is made by gluing sheets of linerboard to each side of a fluted sheet of the corrugating medium. Papers for packing may be laminated to polyethylene film or aluminum foil, or coated with waxes and hot-melt resins. The printing and bag- and box-making industries depend on the production of many mills that produce the several hundred grades of paper used in the United States, and each user may require special paper characteristics to match its process. 

In the production of corrugating medium, linerboard and other unbleached (Kraft) paperboard grades, starch is added as a slurry spray to the fiber mat on the paper-maker s wire.205 This procedure provides better starch retention in the sheet than the addition of dispersed starch to the stock. According to the position of the spray boom, starch can be forced into the sheet for strength gain or held on the surface for improved surface quality. 

Adhesives for paper tubes, paperboard, corrugated paperboard, and laminated fiber board are made from dispersions of days suspended with fully hydrolyzed poly(vinyl alcohol). Addition of boric acid improves wet tack and reduces penetration into porous surfaces (312,313). The taddfied grades have higher solution viscosity than unmodified PVA and must be maintained at pH 4.6—4.9 for optimum wet adhesion. 

The number of dryers and the auxiliary equipment used in a dryer section depend on the particular grade to be produced and the speed of the machine. Up to 70 cylinders may be used in a Kraft dryer section 50-55 would be adequate for a typical newsprint or fine paper dryer section. On the other hand, although the breaker stack and size press are necessary for Kraft bag and the hot press, size press, and intercalender dryers for linerboard, none of these is used for corrugating medium [4],... 

Uses Extrusion coating grade for use with paper, films, and other base stocks for flexible pkg., milk cartons, single-ply bags, board trays, fiber drums, corrugated boxes, fiberboard containers, food-contact paper Regulatory FDA 21 CFR 176.170,177.1520 compliant Properties Sp.gr. 0.923 melt index 10.0 g/10 min Vicat soften, pt. 95 C tens. str. 1700 psi elong. 226% hardness (Shore D) 51 Petrothene NA 220-000 [Equistar]... 

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