Recently, the twistless yarns and their fabrics have been developed. In previous paper, it was shown that the rupture forces of the twistless yarn fabrics were as same as those of the conventional twist yarn fabrics. The considerations were based upon the compressive forces working at the intersecting points of the yarns in the fabrics and inter-fiber frictional forces which increase with tension. In this paper, the initial extensional properties of the twistless yarn fabrics (T0F) and the twist yarn fabrics (T2.6F) are comparatively discussed, concerning the changes of yarn cross-section shapes and sizes (Fig. 8), yarn packing factors (Fig. 9) and yarn crimp angles (Fig. 10) during extension. The aspects of the fabric crosssections are shown in Fig. 7. The various factors of equation (7) are obtained by above experimental results. (Table 2) Fig. 12, the initial regions of load-elongation curves both twistless and twist yarn fabric, are calculated from the equation (7). The calculated and experimental results are compared in Fig. 13. The difference between the twistless and twist yarn fabrics are remarkably characterized by the aspects of initial regions of loadelongation curves. That seems to depend on the differences of mobility of fibers in both fabrics.
To clarify the relationship between ways of building up fabrics from silk and fabric structures, it was investigated by means of Fraunhofer diffraction on the silk plain fabrics having the basic organization of cloths. The following results were obtained: 1) Fraunhofer patterns of silk fabric are indicated the frequency of thread spacing as the principal diffraction maximum. 2) The patterns were shown the period for the structure of fabric as some kinds of principal maxima. 3) It was shown the diffuse patterns corresponding with the fine structure of fabrics. In comparison with the reeds, the method could be deduced that the fabric structures correspond to some silk assembly. 4) This instrument is found to be effective for the spacing (thread spacing is 0.4-0.15mm) to obtain quantitative measurement.
The micro structure of commercially pure iron filament which was manufactured by the method of vycor glass conjugated melt spinning with various winding speeds was investigated and the following results were obtained: 1) The residual stress in iron filament manufactured by winding speed more than 100 m/min is observed to be compressive one of a few kg/mm2. 2) On a scanning electron microscope after the electrolytic polishing the etch pits are found on the surface of iron filament, and the strain figures are found on the iron filament spun at 146.4 m/min winding speed, but those are not observed on the iron filament spun at 61.2 m/min winding speed. The etch pit density (ρ) is related to the deformation on the winding (ε), by ρ=Cεα, where C and α are found to be 3×109/cm2 and 8, respectively. 3) The line broadening and the peak shift on X-ray line profile of iron filament are measured by means of the X-ray diffractometer method. The line-broadening of iron filament is considered to be due to the distribution of lattice strain, and the slight distribution of lattice strain is found on the iron filament spun at more than 100 m/min winding speed. The peak shift increases with increasing winding speed, which is considered due to the combined effects of tensile stress and rapid cooling treatment on spinning.
For the purpose of improvement of pilling tendency of acritic fiber, many studies have been reported. However they seem not to be successful due to poor testing method at the stage of staple fiber. In this work the new pill-testing method of staple fiber (SF-pill-test) is proposed as a useful technique to estimate the pilling tendency of woven and knitted fabrics. If pill formation and wearing-off process proceeds as shown below, theoretical equation may be introduced. k1: rate constant of pill formation k2: rate constant of pill wearing-off By application of the data from SF-pill-test to the equation, k2 and HWT can be calculated. Improvement of pilling tendency will be expected from larger k2 and smaller HWT.
The present paper gives a method to evaluate fold-content, Cf in polyethylene (PE) from IR measurement (1200-1400cm-1). Solution-grown crystals of n-paraffin and PE were adopted as standard specimen containing no fold (Cf=0) and 100% fold (Cf=1.0), respectively and mixtures of these substances were used for the determination of constants, k and K, in Koenig's equation. The values of Cf obtained from two pair of absorption bands (from each sample) showed good agreement for various PE samples.
A new crosslinking agent for cellulose, bis-isocyanatomethyl disulfide (BIMD), was synthesized from dithiodiacetyl dihydrazide. Both O-methyl and ethyl urethanes produced by the reaction of BIMD with methanol and ethanol showed a C-H absorption peak at unusually high wave length (3060cm-1) in their infrared spectra.
In order to improve the wet fastness of nylon dyed with acid dyes, after-treatment by tannic acid (T. acid) and antimony potassium tartrate (APT) have often been carried out. The mechanism of fixation of T. acid with APT is still unknown. In this paper the interaction between T. acid and APT in aqueous solution was investigated spectrophotometrically. Results obtained are as follows: (1) Two isosbestic points (254nm, 290nm) were found in absorption spectra of aqueous solution of T. acid and APT mixture. (2) It was found that 1:1 complex was formed by reaction of two components in aqueous solution. (3) The values of free energy (ΔF°), entalpy (ΔH°) and entropy (ΔS°) change for the complex formation were respectively-8.1_??_-8.4 kcal/mol (5_??_40°C), -13.3 kcal/mol and -17.4 e. u.