Heatset

Web Heat-Set Publication and Commercial Inks. Almost all heat-set inks are now printed on web offset presses, and are based on vehicles containing synthetic resins and/or some natural resins. These are dissolved in hydrocarbon solvent fractions which are specially fractionated for use in the ink industry. They vary in boiling range between 180 and 300 °C. Small percentages of alkyd resins (qv) may be contained in these inks. They dry in less than one second by means of solvent evaporation in a heatset oven. These ovens utilize high velocity hot air to raise the web temperature to 120-150 °C. 

Vegetable oil-based inks today offered in Germany are mainly for the heatset printing colours cyan, magenta, yellow and to a lesser extent black. The use of fatty acid alkyl esters as high-boiling solvents in offset inks as substitution of mineral oils is also practised [23]. 

In this context, the question has to be raised about the contribution offset heatset inks make to the mineral oil problem in RCP. The inks themselves can contain a significant mineral oil content even when mineral oil-free inks are available on the market. During the drying process, the majority of the oils evaporate. Nevertheless, in RCP from offset heatset printed magazines, mineral oil constituents will exist even though on a much lower level than in recovered newspapers and despite the... 

Experimentally, a 0.3. The value of K is a measure of inherent fiber strength and will depend on the molecular weight of the polymer. This parameter will also increase if post-draw heatsetting is used to crystallize the oriented structure. 

Figure 12.11 Schematic of a modern staple drawline for PET fibers 1, spun yarn supply cans 2, lubricating bath 3, two-stage drawing 4, heatsetting 5, cooling 6, reheating 7, crimping 8, dyeing 9, cutting 10, baling...

The inks can contain drying oil alkyds along with hydrocarbon resins and high boiling (200—370 °C) hydrocarbon solvents. Business form inks closely resemble the lithographic heatset or quickset inks. Business forms have also been printed by the ink jet method. These inks are usually based on water, glycols, and dyes. 

Temptation to do-it-yourself, however, is always present library materials needing repair grow more numerous every day, and at the same time the market offers increasing numbers of tempting proprietary products that are advertised as being of archival quality—as indeed some are. The list includes dry mounting film and tissues, heatset tissues, pressure-sensitive tapes, rag boards (which may be made from cotton and/or wood fiber), storage containers, and nonaqueous deacidification solutions. 

Volatility Some softeners are volatile or contain volatile components. During drying, heatsetting or curing these volatile components can condense on cooler areas of the ovens and then drop back onto the fabric, causing spots. Heating the top of the ovens can help prevent this problem. 

Wet winding lubricant for nylon and polyester carpet yarns. Enhances moisture regain after heatsetting. 

Thermally stable, antistatic lubricant for synthetic and natural fibers and blends. Effective on carpet yarns processed on continuous heatset systems. 

In this investigation, a set of six experimental heatset lithographic inks were subjected to a variety of rheological measurements both as a dry ink, as well as after being emulsified with a commercial fountain solution. Determinations of apparent viscosity at 2500 secs l and yield stress at 2.5 secs l were made 25°C from 5 point shear rate/stress curves, and inkometer tacks at 1200 RPM/90°F were also measured. 

Materials from starch crosslinked with melamine-formaldehyde, methylated melamine-formaldehyde, and other amine-aldehyde resins were patented as binders for filter paper,1336 milk filter sheet materials,1338 and aqueous papercoating compositions containing clay, titanium(IV) oxide, butadiene-styrene latex, and calcium octadecanoate.1396,1397 Foams for filters were developed.1398 A heatsetting adhesive was one of the first applications reported for starch crosslinked by urea-formaldehyde and phenol-formaldehyde resins.1331,1340-1342,1347,1372,1399... 

Erhan, S.Z. T.C. Nelsen. Comparisons of volatile organic chemical content of news, sheetfed, and heatset ink formulations./. Am. Oil Chem. Soc. 2001, 78, 419-422. 

Retarders n. (1) In flexography, gravure and heatset printing high boiling solvents added to ink to slow the evaporation rate. (2) In letterpress and offset. 

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