Kraft paper was named after the German word kraft, meaning “strength,” which refers to a specific type of pulping process that ensures strong paper. Developed in 1879 by Carl F. Dahl, a patent was issued five years later, and the first kraft paper-making company opened its doors in Sweden in 1890. Combined with the invention of the recovery boiler in the early 1930s, kraft paper production entered a new, more efficient and environmentally-friendly stage.
With the recovery boiler, kraft paper manufacturers now reach a nearly closed-loop production cycle, meaning they recover and reuse almost all of the water and major chemicals used in the kraft pulping process. By the 1940s, kraft paper producers surpassed traditional sulfite process manufacturers, making them the dominant manufacturing type for wood pulp in the world.
Kraft paper is durable, a machine-made paper that’s made mostly from wood pulp. Unlike other papers, kraft can use all types of wood and non-wood for manufacture, including resinous pine, bamboo, and agri-residues.
Kraft paper products are known for their thickness and strength and, consequently, are coarse, have a high tear resistance and contain highly-oriented fibers. There are benefits to packaging with kraft paper. Since it is lightweight, kraft wrapping paper keeps shipping costs down. It also offers better protection than many other packing materials, thanks to its coarse texture, durability, and flexibility. Kraft papers used in multiple ways across the globe because of these including:
- Paper sacks for industrial materials such as cement and chemicals
- Flour and food bags at the grocery stores
- Multi wall sacks
- Envelopes
- Paper bags
- Corrugated layered cardboard
When unbleached, you can find it most often as a wrapper or packaging material. Kraft paper makers can make products that are watermarked, striped, or calendared and Kraft paper can be printed on as well.
Brown Kraft paper is normally made from unbleached Kraft pulp. A white Kraft paper, by contrast, is normally made from bleached kraft pulp.
Since bleaching weakens paper, Kraft paper making companies make their strongest products in the natural brown color.
Source:- https://www.paperindex.com/academy/paper-grades/kraft-paper-primer
