M4 - Non-metals, Pulp and Paper Flashcards
pulp mills
separate fibers of wood from other materials
paper mills
manufactures wood pulp into paper
how many properties of pulp?
13
ash content
residues from chemicals
Brightness of Pulp
paper brightness
coarseness of pulp
average weight of fiber per unit length
dirt content
suitability to make fine paper
dry content of pulp
describe SOLID CONTENT
Moisture Content of Market Pulp
Important for storage, transportation and handling point of view
extractive
pulp strength
Fiber Diameter
flexibility
Fiber Length of Pulp
Pulp strength
Fiber Strength
maximum strength obtainable from a given pulp
Fines Content
significantly impacts filtering or drainage operations
Hemicelluloses in Pulp
Indicator of chemical differences originating with the tree
Kappa Number of Pulp
hardness and bleach ability
pulp & paper production processes (12)
timber preparation de-barking chipping chemical pulping mechanical pulping hydrapulping blend chest Waste paper collection de-inking refining screening and cleaning paper making
timber preparation
Timber used for papermaking comes from well managed forests
de-barking
Removal of bark from the logs, manually or mechanically
chipping
Cutting of timber into small pieces
chemical pulping
Wood chips are then “cooked” to remove lignin
mechanical pulping
Production of fiber by forcing the logs and hot water between rotating steel disc that will tear the wood apart
hydrapulping
Wood fibers are brought into circular tank with water which will break the fiber into small pieces
Blend Chest
Adding of chemicals to obtain the desired characteristics
Waste Paper Collection
Waste paper is used as raw material again
de-inking
Removal of ink before recycling
Refining
Cellulose fibers pass through a refining process which is vital in the art of papermaking
Screening and Cleaning
Removal of undesirable materials using rotating screens and cleaners
paper making
Paper is drained to make paper web
