Making paper by machine

This page does not dwell on the process of making paper. That is covered on [113003].

Most people nowadays are using machine-made paper. In a paper-making machine a huge quantitiy of the runny sludge-mix is held in a large tank. This is then allowed to trickle out in a wide river onto a slowly moving mesh belt ~ which acts as a seive. As the belt draws out the sludge so the finres tend to lie out in the direction of the movement of the belt. Once dried this directionalit of the fibresy ~ called the grain ~ causes the paper to have some interesting properties. Craftworkers need to know about these ~ failure to allow for the grain can spoil a project. The grain direction is that from head-to foot of the fibres ~ called with the grain. The direction at right angles to the fibres is called across the grain.

It takes a long time to drain the water away, leaving the thickening fibrous sludge. In a paper machine this involves a long length of moving belt. As the fibrous mix starts to dry so it can be wrapped around hot cylinders ~ and also gently rolled to press the fibres together. By long belt ~ think in terms of the length of a football pitch. The machine minders use bicycles to go from end to end of the factory. I once read that the paper being produced was as wide as a three-lane motorway. A car, on this imaginary motorway, could pull the paper out of the machine at about 50km per hour. At the 'dry end' the paper is wound onto great steel rollers, which require huge cranes to remove them from the machine.

The paper mill needs a large site. A lot of space is needed to collect and prepare the fibres ~ timber from trees to form the sludge ~ tanks to hold it in readiness at the 'wet end'. A warehouse at the 'dry end' to store the rolls ~ then chop them into useful sizes ~ then store them ~ and finally a loading-bay to keep the lorries moving. Paper mills need lots of water ~ and a purification plant in order to return it to a river or lake in an environmentally clean condition. Finally ~ it should be initially ~ an abundant supply of suitable trees ~ and a timber mill to saw up and sell the good bits of wood and leave the offcuts for the paper-mill. Most mill owners these days have huge tree-replanting schemes ~ they tend to pride themselves by planting two or three trees for every one they cut down. Their forests cover land areas comparable to that of small countries. In Portugal there is a large mill thatprodcues fine office papers by using eucalyptus trees ~ a very fast growing wood. Their forests are planted on poor and otherwise unproductive soil.

As a final note it is worth pointing out that tropical hardwoods are not suitable for making paper. Species of spruce and larch ~ which grow in temperate and cool climates ~ are best. The 'paperless office' that was forecast some decades ago has not yet arrived.

You may wish to browse on related topics, although some are still in preparation.

~ Why knowing about grain is important [127784].

~ Ways of finding the direction of paper's grain (0) check the length ~ [122082].

~ Ways of finding the direction of paper's grain (1) tear it ~ [122082].

~ Ways of finding the direction of paper's grain (2) wet it ~ [122092].

~ Ways of finding the direction of paper's grain (3) ~ cheat it [123382].

~ Ways of finding the direction of paper's grain (4) ~ paste it [124341].

~ Ways of not finding the direction of paper's grain (5) ~ guess it [117509]


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