By using the theoretical equations on tubular film extrusion, we presented a scale-up rule for setting the conditions which make the stretch stress constant both in MD (machine direction) and in TD (transverse direction). The rule originated from a concept of the maximum stretch stresses at the frost-line level. The rule was applied to HDPE tubular film extrusion under the different film thickness and width. The melt behavior in tubular process, the orientation factors of films, and the physical properties of films were independent on film width and thickness under the scale-up conditions. That is, the scale-up rule worked well.
We are able to predict the film processability and film physical properties for the large scale tubular film process, once the tubular film extrusion is carried out by using the small scale machine and a small amount of resin.

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A composite rubber foam for high-hydraulic-pressure wet suites was prepared by orderly filling small cylinders of a rigid foam in an ordinary flexible foam. Under a pressure of 100m depth in water, this composite foam showed much better heat insulation and flexibility than either the original foam or a composite foam containing small spheres of the same rigid foam.

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Wilson's equation, a theoretical expression for rate-of-dyeing, was numerically evaluated with a BASIC program. The program allows to calculate M_t/M∞ to six decimal places from (Dt/r²)^1/2 and vice versa. The evaluation using this program required 2-12min for roots (q_n's) finding, 1-30 sec for M_t/M∞ from (Dt/r²)^1/2 and 0.2-12min for (Dt/r²)_1/2 from M_t/M∞ when an NEC PC-9801 personal computer was used. The easy evaluation of the equation using the program will facilitate detailed kinetic studies of dyeing.

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Electrically heated platinum wires of 0.1 or 0.2mm diameter were longitudinally vibrated in air and water. Heat transfer coefficient obtained at RePr^1/3 value ranging from 20 to 300 was expressed by an experimental formula:
Heat transfer coefficient of sewing needles for air derived from the above formula is as follows;where h, N, D and T_m are heat transfer coefficient (kcal/m²h°C), sewing speed (spm), blade diameter (mm) and film temperature (°C) respectively.
The heat transfer coefficient of the blade part of a sewing needle (#16) determined by Newton's cooling law in a previous paper²⁾ agreed well with the result calculated from the above formula.

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The static and kinetic coefficients of friction of various fibers were systematically measured by Roeder's method at the velocity ranging from 0 to 20m/min. Fibers tested were viscose rayon, cupra, polynosic, acetate, nylon 4, nylon 6, nylon 11, Nomex, Kevlar, polyester, alkali treated polyester, polyethylene, polypropylene, vinylon having cocoon-like or circular cross-section, silk, and wool, respectively. In order to confirm the effect of shape of cross-section, the coefficients of friction of polyester and nylon filaments having various shapes such as circular, trilobal, pentagonal, pentalobal and octalobal were also measured. All fibers tested except wool moved in scale direction, showed similar relation of the coefficient of friction with the circumferential velocity of the cylinder, i.e. the value decreased with increasing velocity at the initial stage and showed a minimum at the velocity 1m/min., gradually increased and levelled off at around 10 to 20m/min. Wool gave different values depending on the direction of rubbing. The effect of alkali treatment of polyester fiber was also examined.

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