The elastic recovery behavior of a solid obeying the power law has bee predicted by the linear and nonlinear models. The relaxation modulus of the solid is assumed to be proportional to some power of time, if the solid is extended at a constant rate to a given strain ε₁ and then held constant for a fixed time t_r. The Boltzmann and Schapery equations of a time-strain reduced type are used for the linear and nonlinear models respectively. The predicted results from both models have experimentally been discussed by two kinds of polyethylene films at a room temperature.
The fractional elastic recovery (U.E.R.) of the linear model, which is recovered during the unloading to the zero level of a stress, is constant regardless of the initial strain ε₁ when t_r=0, and increases with the initial strain when t_r>0. The U.E.R. of the nonlinear model is smaller than that of the linear model and the difference between both values of the U.E.R. is larger at higher strain ε₁. The U.E.R. of the model decreases exponentially with the time of stress relaxation t_r. If the solid shows the more stress relaxation and the stronger nonlinearity, the U.E.R. of the solid is smaller. The experimental results of the U.E.R. are qualitatively similar to the U.E.R. predicted by using the nonlinear model.
The fractional delayed elastic recovery (D.E.R.), which is recovered after ceasing of unloading, can only be calculated from the linear model. The D.E.R. of the model is constant regardless of ε₁ when t_r=0, and decreases with ε₁ when t_r>0. The solid exhibiting a remarkable stress relaxation has higher rate of delayed recovery and then larger D.E.R. Contrary to the above predictions from the linear model, the experimental results of the D.E.R. give the considerable nonlinear effects and are inconsistent with the linear theory.

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The labor cost and energy cost account for 5060% and 1015% of the total cost of dyeing and finishing process respectively . The sum of the two costs amounts to 6075%. Because an increase of the labor and petroleum cost reluctantly raise the dyeing and finishing cost, it is more needed for an advanced production systems to save both labor and energy . An attempt has been made to develope an unattended and energy-saving system in the dyeing process.
The results obtained in the plant of 8, 000 Kg/day, i.e., about 60 batches per day in productivity are :
(1) Labor saving :
i) The number of operators attending to 10 sets of dyeing machines and weighing dyestuffs was reduced from 24 to 4.
ii) Labor productivity of dyeing process including an auxiliary process was increased by about 3 times.
(2) Energy and resources saving :
i) The consumption of steam was reduced to about 1/3.
ii) The consumption of water was reduced also to about 1/3.
iii) The consumption of dyestuffs and chemicals was reduced by about 10%.

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The diffusion coefficients of C.I. Disperse Red 17 into poly (ethylene terephthalate) films were measured in the mixture of solvents by the film-roll method. Following results were obtained.
(1) The relations of the diffusion coefficients and the molar fraction were remarkably dependent on the combination of the solvents, and were divided into two types, i.e., . (a) the diffusion coefficients which decrease or increase with increasing the molar fraction of a component, and (b) the diffusion coefficients which increase with increasing the molar fraction to a maximum and then decrease.
(2) The diffussion coefficients correlate to the values of T₁ and increase with decreasing the values, T₁.

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The distribution of the life of girdles has been found to be well simulated to the Weibull's curve. The shape factor m and scale parameter t'₀ of the curves in the different cases under some conditions of tests are shown in the following table.
(1) Column 1 shows that the samples tend to deteriorate their performances even at the beginning of the utilization.
(2) Column 2 shows that hard type samples are more deteriorated than soft ones.
(3) Column 3 shows that the samples washed in a weak alkaline detergent solution are more deteriorated than those washed in the neutral detergent solution.
(4) A machine washing tends to rather deteriorate girdles than a hand washing does.
The results of the survey have revealed the parts likely to be deteriorated and reasons of a disuse of girdles

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