Tissue machines

The bases for hygienic products are tissue grades with basis weights of 5 to 35 g m . Consumer demands drive the tissue industry to ever more softness and absorbency of the tissue grades used e. g. in the bathroom (toilet, facial) or in the kitchen (towels). Softness can be increased by the proper selection of fiber furnish and chemical additives or the proper machine concept and operation e. g. by low or no wet pressing. On the other hand sufficient paper strength and economy of production have to be regarded. 

The dryer section in tissue machines consists of either 

Finally the web is calendered off hne for web caliper control and for surface smoothness. The line load is low in order not to lose too much bulk. 

Compared to other paper machines tissue machines are compact as regards their widths (maximum 7.9 m) and lengths which are about 45 m for conventional machines and about 60 m for a machine equipped with a through air dryer. Tissue 

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Crepetrol . [Hercules] Cationic polymer cieping and adhesion aid for tissue machines. 

Paper/board produced Fine paper machines generally have a greater need for retention than drainage, whereas board machines are the opposite. Newsprint/LWC/ SC machines require both retention and drainage. Tissue machines are notoriously difficult in terms of applying retention aids due to the low basis weights produced and effects on cylinder adhesion etc. 

FIGURE 39.14 (a) Tissue machine with a creping dryer (h) Yankee dryer in machine for MG papers. (Courtesy of JM. Voith GmbH,... 

What about the fact of making aerosols with highly contaminated water near machine showers, high speed machine wet end or around tissue machines ... 

Process control with advanced measuring techniques and control strategies allowing the operators to continuously monitor the operation, see trends in paper quality and machine condition and take appropriate action Machine speed five decades ago the typical paper machine ran at a speed of about 300-350 mmirnh Today maximum machine speeds are above 2100 m mim for tissue machines, more than 1900 m min in newsprint production and above 1550 m mim for woodfree grades ( Fig. 6.1)... 

Fig. 6.85 Tissue machine with through air dryer for extra soft tissue production (source Andritz).

Uses Defoamer, rewetting agent for toweling and tissue machines and tor other types of paper inci. food-contact papers Features Water-based Regulatory FDA compliant... 

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