Foldur Kraft paper

Of the two test papers employed in this study, the wood pulp waterleaf better represents natural cellulose, while Foldur Kraft paper, which is sized with alum-rosin, is fifteen years old and also fairly acidic, more closely resembles average library book paper. Both the papers were aged as sheets freely suspended on a rack, as... 

Effect of relative humidity on pH of Foldur Kraft paper... 

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 2. Foldur Kraft paper washed for 1 h in chemical feeder process...

Table V. Aging Tests on Washed Paper, Effect on Brightness, Foldur Kraft Paper...

After magnesium bicarbonate washing, the pH of the Foldur Kraft paper was 9.2 with a 1.69 alkaline reserve value. 

Two different sets of Foldur Kraft papers were used. One set was prewet with a solution of 1 1 denatured alcohol to distilled water and then treated with a wash of 10 g/L (1% ) magnesium bicarbonate solution for thirty minutes. The other set of Foldur Kraft papers was left untreated. 

The data in Table II show that the Foldur Kraft paper that was treated with a magnesium bicarbonate solution con-... 

Table II. Comparison of Aged Foldur Kraft Paper Treated with Magnesium Bicarbonate Solution with Aged Untreated Foldur Kraft Paper Under Various Relative Humidity Conditions, Average Number of Folds (MIT 1/2 kg Tension)...

Table III. Number of Times Folding Endurance Increased for Foldur Kraft Paper Samples for the Relative Humidity Range of 20% to 80%...

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. 

Table V. Effect of Calcium Hydroxide Wash Concentration on Aging of Foldur Kraft Paper ...

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