Hysteresis in the equibrium moisture content and differences in the paper strength caused hereby, were measured and at the same time the error variances were calculated.
The results were summarized as follows ;
(1) The air circulated over the sample for 6 hours at the rate of not less than 1.8m/sec.. it is sufficient to conditioning except highly moisture-resistant paper such as hard-sized paper and paperboard.
(2) The greatest difference between the equiribrium moisture contents was observed in groundwood as much as 2 %.
(3) Consequently, the tensile strength differs not less than 10% in newsprint.
(4) The differences in strength as well as in equiribrium moisture content were reduced according to the degree of pulping process.
(5) Almost all papers were signified the variance in strength at 5 % level except the folding endurance.
(6) The coefficient of variation was grown up in proportion to the difference in strength caused by hysteresis.
(7) Increased the measuring area of a test piece decided by tester type (such as folding endurance, tearing strength, bursting strength and tensile strength.) decreased the coefficient of variation.
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