Tappi method

TAPPI Method T-430 om-94 (1994)(Braidy) Zellcheming method IV/8/70 (Schwalbe-Sieber)... 

MEASUREMENTS OF properties. Water-leaf handsheets at a basis weight of about 75 g/m were prepared from the BP and UBP pulps using a Williams Standard Sheet Mould. Solubility in hot-l%-sodium hydroxide was determined by TAPPI method T212 om 83. Intrinsic viscosity in cuene (cupraethylenediamine solution) and, therefrom, the DPV were determined according to ASTM Standard D1795. 

TAPPI method T-453-ts-63, which uses only the dry oven, gives a satisfactory estimate of the stability of acid paper but has no value in predicting oxidative degradation or the life of a paper containing the oxidation catalysts. The humid oven will find both acid degradation and oxidative degradation. 

This study was part of a more extensive investigation conducted in 1967 and previously published (15). Since the object was to compare rankings of papers by multitemperature estimates of room temperature degradation rates with rankings by the Technical Association of the Pulp and Paper Industry (TAPPI) method of assessing retention of folding endurance (16), ovens at all temperatures were operated under arid conditions. Physical and chemical properties of the papers discussed are listed in Table III. 

Values for activation energies and the rate of change at room temperature calculated for these data and the values for retention of folding endurance obtained from the single-temperature (105°C), single-withdrawal time (72 hr) TAPPI method (16) are listed in Table V. 

The object of this study in 1971 was to assess the potential permanence characteristics of selected commercially available copy papers. Physical tests included folding endurance at 500-g tension (10) and reflective brightness (9). Sixty replicate measurements of folding endurance and 10 replicate measurements of reflective brightness were made on each paper in the fresh state and after each withdrawal time from each oven. Only three oven temperatures (60°, 70°, and 80°C) were used in this rate study with humidities adjusted as in Table II for moisture control. Comparison tests were also made using the TAPPI method (16), and the values obtained at 96 hr in the 80°C oven were used as a single-temperature, single-withdrawal moist oven comparison. 

TAPPI method, Reference 16. One withdrawal only (96 hr), 80°C moist oven. Activation energy. Estimated rate of change of °/o reflective brightness/hr X 10"5 Reference 16. Reference 20. at23.9°C. 

The maximum time in each oven was 1344 hr at 60°C, 864 hr at 70°C, 528 hr at 80°C, and 336 hr at 90°C. Comparison tests were also run using the 72-hr, 105°C TAPPI method (16). Data at the 384-hr withdrawal time at 80 °C were also used as a single-temperature, singlewithdrawal time moist-oven comparison. 

TAPPI method0 vs. 384 hr (moist) 80°C Estimated room temperature rate vs. TAPPI method Estimated room temperature vs. 384 hr (moist) 80°C... 

Folding endurance under tension (10) is a favorite physical property for research on paper permanence and is the basis for the TAPPI method (16). Application of the mechanism involved in this test procedure, however, is unknown in practical uses for paper. Comparisons among product choices and estimates of their useful life should be based upon tests that assess physical properties of practical interest. Retention of reflective brightness, tear strength, tensile energy absorption, and... 

A TAPPI method for pH was used (35), care being taken to prevent any of the paper from touching the electrodes during the measurement process (36). 

Stiffness (37), folding endurance (38), Sheffield smoothness (39), porosity (40), and internal tearing resistance (41) were determined by appropriate TAPPI methods. 

TAPPI method T 235 Alkali Solubility of Pulp (TAPPI methods are issued... 

TAPPI method T 451, Flexural Properties of Paper (Clark Stiffness). 

TAPPI method T 511, Folding Endurance of Paper (MIT Tester). 

TAPPI method T 414, Internal Tearing Resistance of Paper. 

TAPPI method T 417 OS-68, Proteinaceous Nitrogenous Materials in Paper... 

TAPPI method T 404, Tensile Breaking Strength of Paper and Paperboard. 

TAPPI Method T 200 Laboratory Processing of Pulp (Beater Method). 

TAPPI Method T 205 Forming Handsheets for Physical Tests of Pulp. 

A series of papers containing varying amounts of zinc oxide was selected from among those that had been treated with diethyl zinc in the development of the treatment process. The properties of these papers before and after treatment are shown in Table I. All papers were conditioned by TAPPI Method T-402 before testing. Samples of the treated papers and the untreated controls were exposed for 88 h to the light of... 

The TAPPI methods were designed for normal wood chemicals. A method of characterizing and quantifying degraded chemicals would seem more appropriate and may solve some of these problems. 

Tappi Method T 698 cm-91. Determination of Wetting Tension of Polyethylene and Polypropylene Films and Coatings (Modified Visking Analytical Technique), The Pulp and Paper Institute Atlanta, Georgia, 1983. 

Table I Lignin Content of Bark-Containing Willow Wood Chips (Lignin by TAPPI Method T-222 Original willow = 28.2 % lignin)...

TAPPI method T 222 om-88. In TAPPI Test Methods TAPPI Press Atlanta, GA, 1994. 

TAPPI method 411(4) (5 second wait) was used to map the front samples thickness. 

An Instron Table Model tensile tester with a 100 gram load cell B was used at Yi inch per minute strain rate with a 1 gap. TAPPI method 494 (4). 

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