Folding endurance of paper

Book ASTM Stand., Folding Endurance of Paper by the MIT Tester, ... 

Retention of "strength is also an important consideration in assessing suitability of papers for historical purposes, but strength of paper can be measured by a variety of techniques. Folding endurance of paper (10)... 

TAPPI Suggested Method T-511su-69, Folding Endurance of Paper... 

Some previous work is shown in Table I R. D. Smith (2) impregnated the paper in a book with acrylic resin and ethyl hydroxyl-ethyl cellulose solutions to increase fold. Salz and Skrivanek (2) patented solutions of polyvinyl butyral and formal for the purpose these materials have been supplied under the name of Regnal. Baer, Indictor, and Joel (3) compared the folding endurance of papers impregnated with Regnal,... 

Figure 2. The effect of beating on folding endurance of paper, with paper embrittlement on aging indicated...

Folding Endurance of Paper by the M.I.T. Tester. Primary Film Test Method ASTM D2176. The folding endurance test is used for determining the folding endurance of paper and plastic by use of the M.I.T. tester. It is recommended for papers/films less than 0.25 mm. This test method is the technical equivalent of TAPPI T511. 

Chitosan and chitin derivatives have been shown to increase the breaking strength and folding endurance of paper, without affecting its brightness. The water resistance of paper, as well as its sorption capacity for dyes, is also improved together with its electrical resistance [206]. 

Life Expectancy Estimates. If the end of the useful life of a paper is arbitrarily defined as a folding endurance of one double fold, rate-of-fold-loss lines such as those in Figure 4 can be extrapolated until they reach one double fold, and the corresponding accelerated-aging intercepts on the time axis can be compared directly. This gives a measure of the extent of improvement resulting from treatment. 

The extended data points (50 days) at elevated temperatures all lie above the extrapolated rate line. As the glue deteriorates, the paper may play a greater role in the fold endurance of the system. 

The Effect of Humectant and Wet Strength Resin on the Folding Endurance of Alkalized Paper... 

Paper may be deacidified to make it more permanent. Since the paper often has become brittle before it is treated, methods are needed for increasing folding endurance that may be applied in conjunction with deacidification. In this study, the effects of sorbitol and Hercules Kymene 557H on the folding endurance of three papers alkalized with magnesium carbonate are explored. A synergistic action of the reagents is apparent. 

The Effects of Varying Relative Humidity Conditions on the Folding Endurance of Aged Paper Samples... 

Folding endurance refers to the number of folds a paper can withstand before failure when tested (TAPPI T423). 

One of the most industrially important characteristics of papers is their chemical stability, which enables them to withstand degradation with its consequential loss of tensile and tear strength and fold endurance under normal conditions of use. However, this stability is not absolute. Cellulose is susceptible to oxidation and the glycosidic linkage is susceptible to hydrolysis. In order to protect book papers from acid degradation, they must not be exposed to acid. Acids are generated from the alum-rosin size as well as from such... 

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