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Pulp is a fibrous lignocellulosic material prepared by chemically, semi-chemically or mechanically producing cellulosic fibers from wood, fiber crops, waste paper, or rags. Mixed with water and other chemicals or plant-based additives, pulp is the major raw material used in papermaking and the industrial production of other paper products .
The raw material is long fibered softwood fluff pulp in roll form. The pulp are defibrized in a hammermill. Defibration is the process of freeing the fibres from each other before entering the papermachine. Important parameters for dry defibration are shredding energy and knot content. Normally an air-laid paper consists of about 85% fibre.
From a heritage perspective, the field encompasses the design and analysis of a wide variety of thermal, chemical and biochemical unit operations employed in the manufacture of pulp and paper, and addresses the preparation of its raw materials from trees or other natural resources via a pulping process, chemical and mechanical pretreatment of ...
Mechanical pulp can also be bleached to increase the brightness, but retaining the lignin in the pulp. [1] Industrial mechanical pulping started in the 1840s with groundwood pulping, producing the pulp from grinding. This made wood fibers the main raw material in paper, instead of textile fibers.
The machine itself is a thermo mechanical pulping refiner in which the pulp material, such as wood chips, is ground in an environment of steam between a rotating grinding disc (rotor) and a stationary disc (stator) each with radial grooves that provides the grinding surface.
A special grade of bleached sulfite pulp is known as dissolving pulp [12] which is the raw material for a wide variety of cellulose derivatives, for example rayon, cellophane, cellulose acetate and methylcellulose. Rayon is a reconstituted cellulose fiber used to make many fabrics.
Molded pulp or molded fiber (also spelled as moulded pulp or moulded fibre) is a packaging material, that is typically made from recycled paperboard and/or newsprint. It is used for protective packaging or for food service trays and beverage carriers. Other typical uses are end caps, trays, plates, bowls and clamshell containers. [1]
Molded pulp Pulp can be molded into shapes suitable for cushioning and for immobilizing products in a package. Molded pulp is made from recycled newsprint and is recyclable. Inflated products Bubble wrap consists of sheets of plastic film with enclosed “bubbles” of air. These sheets can be layered or wrapped around items to be shipped.