Paper
Essay by review • November 8, 2010 • Essay • 839 Words (4 Pages) • 1,223 Views
Paper has a long history, beginning with the ancient Egyptians and continuing to the present day. For thousands of years, hand-made methods dominated and then, during the 19th century, paper production became industrialised. Originally intended purely for writing and printing purposes, a wide variety of paper grades and uses are now available to the consumer
Of all the writing and drawing materials that people have employed down the ages, paper is the most widely used around the world. Its name derives from papyrus the material used by the ancient Egyptians, Greeks and Romans. Papyrus, however, is only one of the predecessors of paper that together are known by the generic term Ð''tapa' and are mostly made from the inner bark of paper mulberry, fig and daphne.
Tapa has been found extensively in nearly all cultures along the Equatorial belt and is made by what is possibly the oldest papermaking technique Ð'- one still practised in some parts of the Himalayas and South East Asia. Indeed, recent archaeological excavations in China have revealed some of the oldest Ð''tapa' paper ever found which shows that paper was being produced in China before western records began.
The tapa technique involves cooked bast, which is flattened with a wooden hammer to form a thin, fibrous layer and then dissolved in a vat with water to make a pulp. A screen consisting of a wooden frame with a fabric base is then laid in a puddle or big basin and floats with the fabric just under the surface of the water. The papermaker then pours the quantity of pulp needed to make one sheet into this Ð''floating mould' and spreads it evenly, by hand, across the surface. The screen is then carefully lifted out of the water, allowed to drain off and a sheet of paper forms on the wire. Once the water has dripped off, the screen is placed in the sun or near a fire to dry. When dry, the sheet easily peels off and, apart from possible smoothing, requires no further treatment. This technique has two basic drawbacks. Firstly, a separate screen is needed for each new sheet, and is only available for use again after the last sheet has dried. And secondly, an increase in production can soon lead to a shortage of raw material, since fresh bast is not always available everywhere in the required quantity.
The fibres normally used for textiles, like flax and hemp, also served as substitutes for bast. In later times, the fabric was replaced by fine bamboo sticks, which freed the papermaker of the need to let the paper dry naturally in the mould, since the poured or ladled sheet could be Ð''couched' off.
The history of the paper industry in the 19th and 20th centuries can be broken down into five partly overlapping periods, each marked by definite trends.
In the first stage (from about 1800 to 1860), all work sequences previously performed by hand were mechanised. This included the rag preparation, the use of fillers, pulp beating, the paper machine with its various parts, and the machines required for finishing the paper (the headbox, wire section, press section, dryer section, units for reeling, smoothing and packaging).
During
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