First we have to start with pulp, unless you are recycling
From Gary Smook's excellent work, Handook for Paper & Pulp Technologists, published by Angus Wilde Publication, Vancouver, 1992
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All paper and board (which, for the sake of getting my head bitten off, is just thick paper made more slowly and with lots of layers pressed together), all paper & board is made from pulp, or 'pulp substitute' recycled materials (old newspapers & magazines, breakfast cereal boxes, boy scouts, office waste paper, etc.) Excluding recycled materials, pulp for paper making, regardless of it's raw material, is generally made in one of two ways, or a combination of both, at varying degrees of hybridisation of methods. I realize that is akin to saying that life is either black or white and the only other colour is a mixture of these two, but that's the truth of it. Actually the truth of it is that there are something like forty different ways of making pulp for paper, but really, they are all variations of one or the other common themes, or a mixture of both, i.e. MECHANICAL (U.S. = groundwood) or CHEMICAL pulping (U.K. = woodfree).
Both methods have a common first step, DEBARKING. Start with the 'logs' that go to the pulp mill. These are usually about a metre and a bit long (five feet?) and around 10 cms. across (4 inches) but they can be 'fatter' or 'thinner' it really doesn't matter too much. First the bark has to come off, a) because it is no good for making pulp, b) we can use it for fuel for the pulp mill instead of expensive electricity. Plus, using the bark for fuel is carbon neutral because we are only giving-off the carbon that the material sequestrated from the atmosphere during the trees lifetime. The bark separates quite easily from the wood at the cambium layer, especially in the presence of water. There are several ways of doing this, though a description of the various methods fall outside of the remit of this article and I can but refer you to the touchstone of paper and pulping knowledge, Gary Smook's excellent book 'Handbook For Paper And Pulp Technologists' if you wish to explore the matter further. Anyway, once de-barked the logs are ready for use in whichever pulping method you intend to use. |