Know everything about Paper - 1

Know everything about Paper - 1
(Written by : N.R. Jayaraman)  
 

Making of Paper-  Brief summary

Paper is made from mainly plant fibers called cellulose, which are found in wood. The cellulose from the wood or plants are converted into pulp and processed with some chemicals including bleaching solution etc before manufacturing paper using the processed pulp. Besides cellulose from wood and other plants the already manufactured waste paper is also re pulped and used as recycled pulp for making cheaper varieties of paper. For high quality paper the cotton rag is used as pulp for making paper as paper manufactured with cotton fibers are strongest and durable . Both good quality longer fibers cotton and cotton linters with short length are used. Most of the security document paper belongs to this group.
The wood is chipped to fine layers of shred and mixed with water to make pulp fo0r paper. The pulp thus prepared is thoroughly washed to remove impurities and hard particles, refined, cleaned and then put in a beater to crush them to so that it forms fibrous pulp. Depending upon the Color of paper manufactured the coloring agents and dyes, fillers and other additives are mixed before the shushed pulp is pumped onto a large moving web of finely porous steel mesh screen where the excess water is drained away to form a layer of paper.
The resultant layer of sheet is passed through special rollers to further squeeze away the remaining water and to ensure uniform smoothness and thickness of the web of sheet that lay over the mesh or screen. Sometimes the layer thus formed is also passed through heated rollers to dry the web of paper before they are wound. Where the requirement is in sheet form, the wound paper web is slit on a separate slitter to specified size and packed as reams of paper.
Paper is medium for printing or writing and prepared out of several material like bamboo, cotton Rag, esparto grass, wooden and other such fibrous material. The Paper used for Printing and writing has several characteristics. All the Papers are not the same. Each variety is meant for some specific purpose and each one is made with specific qualities.
Broadly two varieties of paper are manufactured  - One  for printing security documents of several varieties and the second is for non security use such as general writing, for printed books and forms etc, etc.  The Paper manufactured for the security documents are embedded with security features some of which are overt or covert (visible and invisible) features and are not available in other varieties of paper.


Various varieties of paper is manufactured some of which are:


a) Writing Paper
b) Kraft Paper
c) Packing Paper
d) Paper for Security Printing
e) Bond Paper
f) Cream Wove Paper
g) Parchment Paper
h) Granite Paper
i) Linen Paper
j) Acid free Paper
k) Laser Printing Paper
l) Art paper
m) Antique Paper
n) Azure laid Paper
o) Tissue paper
p) Chromo Paper
q) News Print Paper etc


..............to be continued