Bleached Hardwood Kraft Pulp (BHKP) is a southern bleached kraft pulp manufactured from a mix of hardwoods. The primary wood species are oak and gum, along with a small amount of Southern pine. The pulp is clean and exhibits high bulking. Pulp is a dry fibrous material prepared chemically or mechanically which involves separating fibres from wood, fibre crops or waste paper. Pulp can be either fluffy or formed into thick sheets. The latter form is used if the pulp must be transported from the pulp mill to a paper mill. When suspended in water the fibres disperse and become more pliable. This pulp suspension can be laid down on a screen to form a sheet of paper, and this is the primary use for wood pulp.
The pulping process converts raw materials into a fibrous mass that can be formed into paper or cardboard. Wood contains both cellulose fibers and lignin; the objective of the kraft pulping process is to dissolve the lignin and leave most of the cellulose fibers intact.
The main operations performed in the kraft pulping process are:
1. Digestion of wood to form pulp.
2. Pulp processing to recover spent cooking chemicals and to remove impurities and uncooked wood chips (deknotting, pulp washing, pulp screening).
3. Concentration of used pulping liquor for chemical recovery
Hardwood fibers are especially suited for producing smooth papers for printing and writing due to their stiffness and bulking ability. Hardwood pulps also tend to produce paper products with more uniform formation, compared to softwood fibers. Papermakers are well aware that different blends of fiber types produce different grades of paper.
Wood packaging material (WPM) is also called Non-Manufactured Wood Packing (NMWP) or Solid Wood Packing Material (SWPM). It is defined as hardwood and softwood packaging that comprised wholly of wood-based products such as plywood, particle board, oriented strand board, veneer, wood wool, etc. They are created using glue, heat, and pressure or a combination and thereof used for supporting, protecting, or carrying a commodity.