Kraft paper

Fully bleached kraft pulp is used to make high quality paper where strength, whiteness, and resistance to yellowing are important.

Wood pulp for sack paper is made from softwood by the kraft process.

[1] Machine direction elongation can be further improved by pressing between very elastic cylinders causing more microcrepping.

[1] The paper may be coated with polyethylene (PE) to ensure an effective barrier against moisture, grease and bacteria, although recyclability is hindered.

Maintaining a high effective sulfur ratio or sulfidity is important for the highest possible strength using the kraft process.