Office papers, paper grades

These estimations can be documented by the well-known example with the diisopropylnaphthalene (DIPN) contamination in mixed RCP (RCP grade 1.02). This chemical substance comes from NCR carbonless copy paper and is in this mentioned RCP grade on an average level of 23 mg/kg TS [13], despite the fact that since several years those papers tried to be separated in the RCP grade sorted office paper , coloured letters and carbonless copy paper to reduce the DIPN concentration in mixed papers and board. 

After the surface-sizing section, the paper is dried again by an array of steam-heated rolls (after-drying section) to a moisture content of 6-8%. After an additional smoothing step calendar grades like e.g. office papers and packaging papers are ready for use. 

In this way very pure products are obtainable the standard grade of white phosphorus is over 99 9 per cent pure and contains only the merest traces of sulphur and arsenic. It is extremely reactive chemically and it is said that an excise officer once found this out very much to his cost. When prowling round Albright s factory he wrapped a piece of the curious barley sugar or lemon rock in paper, and put it in his pocket and — lived to regret it. 

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