Paper Bleaching Chemicals : Paper Bleaching Auxiliaries

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Paper Bleaching Auxiliaries These products enable a more efficient bleaching of the chemical, mechanical and deinked pulps and lead to increased whiteness. They are generally based on sur¬face active agents, i. e. wetting agents (see Section 3.6.7.) which are resistant to bleaching chemicals as well as chelating (complexing) agents (see Section 3.6.3.). Some of the [...]

Paper Bleaching Chemicals : Bleaching Substances

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Bleaching Substances . • Chlorination (C) with chlorine, an effective, selective and inexpensive bleaching agent that reacts very fast with lignin. For environmental reasons during the last ten years chlorine is being substituted by chlorine dioxide, ozone and/or oxygen all over the world. In Europe substitution is already 100 %. In this particular case bleached [...]

Paper Functional Chemicals- Specialty Paper Additives

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Read the Beginning of this article... 3.6.8 Additives for Specialty Papers [13, 14] Specific functional chemicals are indispensable in the production of specialty pa¬per grades. Such grades are expected to display a very heterogeneous range of properties. Specialty paper grades account for only ca. 4 % of worldwide paper production, but the proportion of chemicals [...]

Paper Functional Chemicals- Recycled Paper Additives

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Read the Beginning of this article... 3.6.7 Additives for Recovered Fiber Processing For economic and environmental reasons the use of recovered paper as raw mate¬rial has already reached a high level and will grow further. For its preparation specific chemicals are required, depending on the quality of the recovered papers and the necessary properties of [...]

Paper Functional Chemicals- Wet Strength Resins

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Read the Beginning of this article... Wet Strength Resins (WSR) [2, 9–11, 21–24] Certain types of paper can only fulfil their purpose if they have adequate wet strength. Such papers include, for example, filter papers, hygienic papers, papers for bags, label papers, wallpapers, laminate base papers, packaging papers for moist goods and all papers which, [...]

Paper Functional Chemicals- Dry Strength Resins

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Read the Beginning of this article... Dry-Strength Resins (DSR) [3, 9–11, 22–24] Some of the specific mechanical properties important for paper are tensile strength, tearing resistance, folding endurance, bending resistance, burst and sur¬face strength, internal bond and compression resistance. It is generally accepted that the major factors contributing to dry strength development in paper manu¬facture [...]

Paper Functional Chemicals- Sized Paper Requirements

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Read the Beginning of this article... 3.6.4.4 Requirements and Measurements of Sized Papers The purpose of sizing is to modify the surface of the fibers to control penetration of aqueous liquids into the paper. The penetration usually correlates with the ab¬sorbency, repellency (hydrophobicity), and spreading of the aqueous liquid con¬cerned. Control of these important properties [...]

Paper Functional Chemicals : Sizing Advice

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Read the Beginning of this article... 3.6.4.3 Application Advice . • Rosin: The average addition rate is 1 % solid calculated on paper, the individual rate depending on the required degree of sizing. With these products this degree can be adjusted very precisely and is fully obtained directly after the paper has been dried. The [...]

Paper Functional Chemicals : Synthetic Sizing Agents

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Read the Beginning of this article... 3.6.4.2.2 Synthetic Sizing Materials These were only developed in the second half of the last century. Driving forces have been the increasing use of the cost and performance effective calcium carbonate as filler and coating pigment and also the need to produce paper with high and permanent paper strength. [...]

Paper Functional Chemicals : Rosin Sizing Agents

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 Read the Beginning of this article... 3.6.4.2.1 Rosin-based Sizing Agents These are still the most widely used of all wet-end sizes, because they are cheap to produce and are produced from regenerative raw materials. They are mainly used in acid and much less in pseudo-neutral pH conditions. They have the advantage that the degree of [...]