Types of Paper, Board and Cardboard

Paper and board are planar products made essentially from fibers that are mostly of plant origin, and different portions of fillers. Fillers are mainly inorganic substances, their content in the product may vary from zero to about 40%. Paper and board are formed by draining a fiber suspension through a sieve. The resulting fiber web is subsequently compacted and dried. 

There are approximately 3000 kinds of paper and board products [11]. Most products with a basis weight up to 225 g m are defined as paper. Above 225 g m, these products are usually called board, but the naming overlaps. 

Depending on their use the paper and board grades can be divided into four main groups  

This classification has also been largely adopted by the Statistisches Bundesamt (Federal Statistical Office) of Germany in Chapter 48 of the Commodity index for foreign trade statistics [12]. The basis of this systematology is a harmonized system for the marking and coding of merchandise of the council for tariff cooperation . 

The term graphic papers refers to a large range of different papers that are suitable for printing and writing and are made from virgin or recycled fibers or mixtures of 

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Flush doors are produced by bonding skins of plywood, hardboard, or particle board to the vertical and horizontal frames (the stiles and rails), which are usually either a soft wood such as fir or a man-made product comprising layers of pressed board. Hollow core doors utilize an accordion-type paper core, while a solid core door is constructed with a core of pieces of scrap wood edge-glued with an inexpensive casein-soy glue. Some of these cores are held to shape by corrugated cardboard, which is bonded to their surfaces with the same type of protein blend glue. 

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