Newsprint paper

Pulps from recovered paper or paperboard using a chemical or solvent process to remove contaminants such as inks, coatings, and pigments used to produce fine, tissue, and newsprint papers... 

Newspaper inks, 74 313 Newspaper printing, 74 320 Newsprint paper, 78 128... 

The processes occurring in a high-speed newsprint paper machine have been discussed above. There are several additional considerations of note in the overall process picture. Paper for the most part is a commodity item (i.e., production costs are more economical per unit when large tonnages of uniform specifications are produced). Most mills have a break-even point at an 85% capacity so it is vital to operate mills at design capacity. Economies of scale are also found for pulp and paper mills at levels of about 1000 tonnes of paper per day for full chemical mills and 200—400 tonnes of paper per day for semichemical or mechanical mills. Thus, the outputs of paper mills are... 

While individuals able to attract national attention continued to speak to the paper problem, a collective voice was still to be heard. Seeking an improvement in newsprint, the American Library Association (ALA) formed a Committee on the Deterioration of Newsprint Paper in 1911 (3). The committee worked with the American Newspaper Publishers Association in surveying publishers concerning the possibility of special library editions. Some positive responses were received, but when the ALA committee surveyed libraries, they found most were interested only in permanent files of local papers. The committee concluded that special newspaper editions were possible, if libraries were willing to pay for such editions. Perhaps as a result of the consciousness raising of this... 

Table II shows the calcium content in paper from the chemical feeder process. With the addition of 9.2 ppm Ca in DI water, the treated newsprint papers calcium content doubled in comparison with the control. The treated Foldur Kraft paper contained three times more calcium than did the unwashed paper. The more calcium that was added in the DI water, the higher the amounts of calcium absorbed in the papers during the washing and deacidification process. However, the absorption of calcium in the paper reached a saturation point. This is the reason why newsprint and Foldur Kraft papers that are treated with 36.4 ppm Ca in the Dl-Ca water imbibed the same amount of calcium as the papers washed with 112.8 ppm Ca in the Dl-Ca water.

Figure 4. Newsprint paper washed for 1 h in chemical feeder process...

Table VI. Aging Tests an Washed Paper, Effect on Brightness, Newsprint Paper...

In this chapter, empirical rate constants were determined by following the loss of tensile strength and the decrease in diffuse reflectance of a rag and a newsprint paper buffered over a range of pH values. From the results of these experiments, the influence of acidity on both the atmospheric oxidation process and the oxygen-independent process was determined. Before describing the results of these experiments, the methodology employed to obtain the empirical rate constants will be discussed. 

Figure 6. Relative rate of (O) tensile strength change and (X) yellowing vs. relative acid concentration for newsprint paper degradation at 90°C, 100% RH, in an air atmosphere...

The above experiments also were conducted on buffered rag and newsprint papers sealed under nitrogen atmospheres. As before, relative rates were determined at 90°C and 100% relative humidity by comparison with the data taken on the papers at pH 4.00 exposed in an atmosphere of air. At every pH, the rate under nitrogen was slower than the rate in air, as shown in Figures 7 and 8. Moreover, in the absence of oxygen, as... 

In the experiments described above, accelerated degradation occurred at 90°C in an atmosphere maintained at 100% relative humidity. Under this condition, both the oxygen-independent and the atmospheric oxidation processes contributed about equally to the degradation of the rag and newsprint papers. The 100% relative humidity condition allowed an examination of the influence of acidity on both processes, but whether... 

Table IV. Average Number of Folds (MIT 1/2 kg Tension) for Aged Newsprint Paper Samples Subjected to Varying Humidity Conditions...

Materials. All test papers were obtained from a single roll or were made from pulp. The following test papers were used (1) Foldur kraft paper, a bleached kraft paper made from 90% southern pine and 10% hardwood pulps, with 0.5% rosin size and 3% titanium filler (2) newsprint paper made from 80% groundwood and 20% unbleached sulfite pulp and (3) handsheets prepared from a 1 1 furnish of Weyerhaeuser New Bern softwood (NBS) and New Bern hardwood (NBH) bleached kraft pulps. 

Treatment of Papers. Foldur kraft and newsprint papers were prewet with 1 1 solution of denatured alcohol and distilled water before further treatment to facilitate their penetration. Test papers were treated with sodium borohydride by immersion in the appropriate solution for 30 min. The treated samples and untreated controls were then washed for 1 h in either a wash solution composed of dilute calcium hydroxide or in deionized water, or they were left unwashed. 

Table IV shows brightness retention of newsprint papers. Borohy-dride treatment increased initial brightness by as much as 10 brightness units. A decrease in brightness is generally observed when newsprint is subjected to a Ca(OH)2 wash. Treatment with either 0.1 or 1.0 NaBH4 followed by 0.002 calcium hydroxide washing also increased the brightness of newsprint. For the newsprint samples, the borohydride treatment did not produce a significantly greater improvement in brightness retention than the calcium hydroxide wash alone.

Monthly data on newsprint paper, chemicals, and power generation, including production, consumption, foreign trade, foreign tariffs, foreign markets, and new products, processes and equipment, are assembled by the Newsprint Service Bureau, Inc., of New York. In addition, information on production facilities is issued annually. 

The action spectrum for surface yellowing of a mechanical pulp newsprint paper sample at ambient temperature in the wavelength region of X = 280-600 nm is shown in Fig. 2. Mechanical pulps, being unbleached, have about the same composition as the pine wood from which it was derived. The... 

Fig. 2. Action spectrum for change in yellowness index of newsprint paper (mechanical pulp from PInus taeda species) [59]...

Figure 3 shows the activation spectrum for yellowing of newsprint paper (unbleached mechanical pulp) exposed to a borosilicate-filtered xenon source. 

Newsprint Paper (mechanical pulp) xenon source... 

Fig. 3. The activation spectrum for change in yellowness index of mechanical pulp newsprint paper exposed to a borosilicate-filtered xenon source, for 13.8 h at 69 °C, determined by the cut-on filter technique [44]...

The activation spectrum for yellowing and decrease in brightness of newsprint paper exposed to xenon radiation has been obtained using the cut-on filter technique [44]. As seen in Fig. 4, the wavelength interval 335 to 380 nm was mostly responsible for both yellowing and brightness reversion of paper. 

---