A method for digital simulation of unsteady process in melt spinning is described. The method is developed on the basis of methods to solve nonlinear partial differential equations by orthogonal collocation. Computation is illustrated for both steady and unsteady conditions. In the former case the results are compared with those from finite difference method and experimental data.
Obtained results are as follows;
(1) Good agreement is obtained between the solutions obtained from orthogonal collocation method and those from finite difference method. In the case of steady state, the number of collocation above 12 is needed to get good accuracy.
(2) Transient solutions converge very rapidly to one curve for each spinning condition with increasing of number of collocations. And above 12, each solution is closely coincident. Whereas computation time needed is proportional to the square or cube of number of collocations. Therefor we concluded that a numerical model having 12 collocations is usable for simulation of unsteady melt spinning process.

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PVA compounds plasticized by various amounts of glycerin were spun into fibers by melt process and followed by the extraction with methanol and the drawing in a hot air. The structure and properties of the fibers were studied by a x-ray instrument, a polarizing light microscope, a density gradient column, a differential thermal analyser and a tensile tester. The best spinnability was found for the compound containing 27 wt% glycerin. However, the exact glycerin content of the as-spun fiber prepared from this compound was 11 wt%. The drastic decrease in glycerin content might be attributed to the vaporization during the melt spinning and the bleeding after the melt spinning. The extracted fiber could be drawn by around 7 times at 220°C, while the plasticized as-spun fiber was drawable up to 6 times. The drawn extracted fiber had the higher anisotropy evaluated by polarized microscopy but the lower crystalline orientation by x-ray analysis than those of the extracted fiber. This may be responsible to the mobility and the orientation of amorphous chains in both plasticized and extracted fibers.

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An attempt has been made to develop a new laminated material with light weight and high impact toughness. Drawn film of low density polyethylene was multi-layered and heat-treated to give an accurate adhesion between films. The best condition of heat treatment temperature for the mechanical properties of the product was found to be 108°C. The impact toughness of the product was over 5 times greater than that of polyvinyl-chloride or high density polyethylene pipes, which are manufactured by injection molding.

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On the alkali saponification of ethylene-vinyl acetate copolymer (EVAc) in heterogeneous system, the effect of preliminary partial saponification (p-EVAc) was examined. p-EVAc membrane was saponified with a sharp moving boundary in it, giving a linear rate curve as in the case of EVAc reported previously. The reaction rate of p-EVAc presaponified to 33.0% of the acetyl group became 40 times of that EVAc at 30°C and 24 times at 35°C, despite of the increased zero-shearing viscosity by the partial presaponification. The reaction rate and the accerelation effect caused by the presaponification increased with an increase of acetyl group content of the polymer. These results were explained as follows. The saponification of p-EVAc proceeded with a rate determining step of boundary reaction whose phenomenon resembled “Case II type diffusion” The acceleration effect of the resaponification in this reaction was caused by the adsorption of alkali ion on hydroxyl groups near the acetyl groups in the reacting boundary.

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The modified pore model for diffusion, which was proposed in our previous paper by taking into account the reduction of pore radius by the bulkiness of diffusants, has been applied to the diffusion of small simple compounds having -SO^-₃, -COO^- or -OH group through water-swollen cellophane. Diffusion coefficient, D'_p (0), of each compound in the water-filled pore in cellophane has been obtained from the data of steady state permeation, on this model. By comparison of D'_p (0) with the diffusion coefficient, D_b, in the bulk water, obtained by capillary method, the following information has been obtained:
1) D'_p (0) of small inorganic compounds, such as HCl and KCl, depends on the larger size of the component ions, while that of the other organic, relatively long compounds, depends on the slightly larger length than the radius of minimum cross-section of the diffusant molecule as was found for the diffusion of several dyes.
2) For the compounds having -COO^- group, D'_p (0) is generally smaller than D_b, while for the compounds having -SO^-₃, D'_p (0) is considerably larger than D_b. These facts were explained by invoking to the difference in the effects of -COO^- and -SO^-₃ on the water structure: the former acts as structure maker and the latter as structure breaker.
3) For alkyl sulfonic acids, an additional flux due to the considerably large amount of the diffusant adsorbed weakly on the pore wall has been observed.
4) Alcohols and phenols are considered to behave as molecular aggregates of two or three molecules in water. D'_p (0) of these compounds seems to depend on the radius of these aggregates.

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The dynamic modulus of the polyester film in the several concentrations of phenol solution was measured in the temperature range of 0 to 90°C at the equilibrium condition.
The moduli of polyester films in the several concentrations of phenol solution were found to decrease as the concentration of phenol increases, at the same time, the apparent glass transition temperature (T_g), determined from the peak temperature of E″ curve, was also observed to shift to low temperature. The dynamic modulus of amorphous region (E_A′) could be separated from that of crystalline region applying the theory of mixed bicomponents polymer system. The linear relationship between log E_A′ and concentration of sorbed phenol was induced in the temperature range above T_g.

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A new technique to prepare ultra thin laminate of CA on cellulose membrane (cellophane) for reverse osmosis was exploited by use of surface tension of water film formed on the swollen cellophane. Droplets of acetone or methyl acetate (conditioning solvent) were spread on the swollen cellophane, and CA solution with the same solvent was spread on it simultaneously. By this operation, the ultra thin and antipeeling laminate of CA was formed on cellophane. The mechanism of this lamination is explained as follows. Substitution of water in swollen cellophane by the foregoing solvent facilitates the anchoring of CA in the membrane to form thin laminate. The rejection of glucose by this laminate from its aqueous solution was about 60%.

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