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Pitch control, additives

Retention and drainage additives are vital to the use of recycled fibers. Papermakers consider recycled fibers to behave like virgin fines, while recycled fines behave like filler. Drainage on the paper machine can be impeded and first-pass retention reduced by the use of recycled fiber (9). Additionally, the negative impact of contaminants found in recycled fibers can be minimized by the appropriate use of dispersants and other pitch-control additives. [Pg.15]

The most widely used pitch control method is the addition of pitch dispersants, which can be either organic, ie, typically anionic polymers such as naphthalene sulfonates, ligninsulfonates, and polyacrylates (33,34), or inorganic, ie, typically clay or talc. The polymers maintain the pitch as a fine dispersion in the pulp, preventing agglomeration and potential deposition on the paper machine or the sheet. When talc, clay, or other adsorbent fillers are added to the furnish, moderate amounts of pitch can adsorb on these materials, producing a nontacky soHd that can be retained in the sheet. [Pg.16]

In the paper industry, PEO is widely used as a retention aid and pitch control agent in the newsprint industry (118—135). Typically, a phenol formaldehyde-type resin is added to the substrate before the addition of PEO. The chemical that is added before PEO has been referred to as an enhancer. Recent pubHcations on designing enhancers that work with PEO have resulted in expanding the use of PEO in flocculation of several substrates (128,129). [Pg.344]

Until recently, the use of enzymes in the paper and pulp industry was not cortsidered technically or economically feasible. Quite simply, suitable enzymes were not readily available, except for the limited use of enzymes to modify starch for paper coatings. However, research by scientific institutions and enzyme producers has led to the development of new enzymes that offer significant benefits for the industry, particrrlarly from the environmental point of view. Two examples of applications, in addition to the starch modification, made possible by new enzyme developments are given here bleach boosting and pitch control. [Pg.68]

Pitch control - [URANIUMAND URANIUMCOMPOUNDS] (Vol24) - [URANIUMAND URANIUMCOMPOUNDS] (Vol24) -m papermaking [PAPERMAKING ADDITIVES] (Vol 18)... [Pg.767]

In addition to lubricating the engines, turbine lubricants are also required to lubricate a number of associated systems such as auxiliary power units and constant speed drive units and to act as hydraulic fluids, for instance, in the propeller pitch control units of some turbo-props. [Pg.354]

Today no chemical additives are used to modify the viscosity of the organic material of natural origin (wood pitch) to reduce deposition. Water-insoluble solvents, that would reduce the viscosity, can conceivably be used reducing the viscosity of the resin. The use of kerosene for pitch control, a method used half a century ago, worked by this mechanism. [Pg.30]

Conveyor chains are usually selected on the basis of working load and working load is related to chain pitch. In addition, carrier size or required attachment spacing may control chain pitch. Short-pitch chains (35-80) are normally used in short conveyors or where smooth operation is needed. Longer pitch chains (100-200, or C2040-C2160) are usually used in longer conveyors where speeds are slower. [Pg.271]

Back E 1956 Pitch control by combined alkali and aluminium sulfate addition. Some principles in controlling pitch problems. Svensk Papperstidn 59 319-325... [Pg.914]

Pelton R H, Allen L H, Nugent H M 1982 Additives for increased retention and pitch control in paper manufacture. Can Patent CA 1137710 (Cl D21H3/18)... [Pg.918]

In the case of the ship shown in Figure 1.3, the rudder and engines are the control inputs, whose values can be adjusted to control certain outputs, for example heading and forward velocity. The wind, waves and current are disturbance inputs and will induce errors in the outputs (called controlled variables) of position, heading and forward velocity. In addition, the disturbances will introduce increased ship motion (roll, pitch and heave) which again is not desirable. [Pg.4]

The Food and Drug Administration permits the use of diethanolamine as a component of adhesives in food packaging, as an indirect food additive, as a component of the uncoated or coated food contact surface of paper and paperboard for use with dry solid foods with no free fat or oil on the surface, and for use only as an adjuvant to control pulp absorbance and pitch content in the manufacture of paper and paperboard or for use only in paper mill boilers in the United States (Food and Drug Administration, 1999). [Pg.353]

Relatively small marine vessel motions have a significant effect on the process equipment design. For example, three degrees of pitch can cause a forty percent Increase in gas velocity due to the spirit level effect, combinations of pitch and heave can cause resonant waves, further reducing the dedicated phase areas and causing primary turbulence roll and sway motions, although of lesser conse quence, add to turbulent fluid conditions Inside the vessel. In addition all motion adversely affect level control and level safety systems. [Pg.114]

Conclusion. The development of low-complexity time-domain methods for time-scale or pitch-scale modifications has already made it possible to incorporate such systems in consumer products such as telephone answering systems, effect boxes and semi-professional CD players. They could easily be implemented in record or playback devices such as DAT or CD players, offering the user additional control over... [Pg.170]


See other pages where Pitch control, additives is mentioned: [Pg.15]    [Pg.16]    [Pg.158]    [Pg.110]    [Pg.174]    [Pg.308]    [Pg.8]    [Pg.36]    [Pg.2813]    [Pg.892]    [Pg.892]    [Pg.134]    [Pg.170]    [Pg.193]    [Pg.194]    [Pg.512]    [Pg.113]    [Pg.389]    [Pg.1913]    [Pg.1915]    [Pg.230]    [Pg.490]    [Pg.455]    [Pg.389]    [Pg.448]    [Pg.3]    [Pg.251]    [Pg.511]    [Pg.197]    [Pg.111]    [Pg.354]    [Pg.139]    [Pg.17]    [Pg.928]    [Pg.230]   
See also in sourсe #XX -- [ Pg.132 , Pg.133 , Pg.134 ]




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