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Volume 28, Issue 9
Displaying 1-8 of 8 articles from this issue
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Hirovnu Nakamichi, Keiroku Fuchino1972 Volume 28 Issue 9 Pages 329-335
Published: September 10, 1972
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSHeat distortion test is similar to that of tensile creep test except that the temperature increases at uniform rate.
Under some range of loads and a constant heating rate, the textile fiber(e. g. hot drawn P. P. monofilament) shortens its length because the thermal shrinkage overcomes the creep. At the softening or heat distortion temperature, the textile fiber begins to stretch at a rapid rate over a narrow range of temperature.
The maximum shrinkage and the load of heat distortion tests are similar to those of the thermal stress measurements, when the load under which the extension begines and this heat distortion temperature is equal to the maximum stress (fmax) and temperature (Tmax) of the thermal stress measurement.
Comparing these two sorts of test, we obtained the following results:
1. The relation between the load (P) and temperature under which the extension begins (T) satisfies the experimental formula: P=A•T+B, where both A and B are constants.
This formula is similar in shape to that of thermal stress; i.e. fmax=K•Tmax+C, where both K and C are constants.
2. Under the load equivalent to the value of fmax and the same heating rate as on thermal stress measurement, the fibers never shrink by heating until the maximum temperature in the thermal stress measurement.
It is therefore, assumed that free thermal shrinkage and the creep under this load are just in equilibrium until the maximum temperature of thermal stress, and the free thermal shrinkage may be equivalent to the creep recovery introduced by A. Ribnick3).
3. Four-parameter model (Fig. 10 can be applied to explain these phenomena, but the viscosity of dashpot η_??_ follows Bingham flow: η_??_={fe(Tmax-fmax)}/D, where fe(Tmax) is the equilibrium thermal stress at Tmax and D is the rate of shear.View full abstractDownload PDF (440K) -
Kozo Kataoka, Toshisada Takahashi, Ishio Tsujimoto1972 Volume 28 Issue 9 Pages 336-342
Published: September 10, 1972
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSThe deformation behavior of polyethylene spherulite composed of spherical shells (extinction bands) was studied by polarized microscope. The spherulitic films were drawn with various ratios at 20°C and 100°C, and the elongation ratios of each shell were evaluated.
The results obtained are as follows;
(1) The elongation ratio of the outermost shell, being the same as that of spherulite, is less than that of the sample. This indicates that the relative motion occurs between spherulites. The deviation from affine deformation is less for the hot drawn film than for the cold drawn film.
(2) The thickness of each elemental shell is almost uniform for the homogeneously deformed two-dimensional spherulite. Consequently the elongation ratios of outer shells are less than that of inner shells.
(3) Similarly a spherical shell in three-dimensional spherulite deform to an ellipsoidal shell, though the thickness of an elemental shell is not uniform. The crystal lamellae constituting these deformed shells must be disrupted to fullfil the geometric requirement.
(4) Deformation modes within a three-dimensional spherulite, which are generally deviated from affine deformation, depend on elongation ratios and deformation temperatures.View full abstractDownload PDF (1343K) -
Kimihiro Suzuki, Iichiro Kido, Naoto Tanabe1972 Volume 28 Issue 9 Pages 343-352
Published: September 10, 1972
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSIn order to modify the hydrophobic property of polyethylene terephthalate (polyester) fiber, some hydrophilic monomers such as acrylic acid, acrylamide and the like were graft-polymerized onto the fiber using ceric salt as an initiator. As the commercial polyester fiber was previously drawn and heat-treated, its fine structure becomes so compact and impenetrable that its graftreactivity is very small. Various pretreatments of the fiber were tried in order to increase its reactivity and was found that treatment with benzyl alcohol (150°C, 1_??_2 hr) was effective though accompanied with about 20% shrinkage of the fiber.
The grafting medium consisted of a hydrophilic monomer, acetic acid, water and ceric salt and the pretreated fiber was allowed to react in the medium under nitrogen atmosphere and with constant shaking. Influence of conditions upon the grafting was investigated and some properties of grafted fibers were measured.
Grafting percent of acrylic acid was more than 30%, while that of acrylamid was less than 20%. The moisture regain of the fiber could be increased to more than 10% at RH 65%, when the grafted polyacrylic acid was converted to Na or Ca salt. Also, the dyeability of the fiber could be increased towards cationic, basic or acid dyes.View full abstractDownload PDF (678K) -
Mikio Karasawa, Noriko Choji, Minoru Sekido1972 Volume 28 Issue 9 Pages 353-358
Published: September 10, 1972
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSIn order to estimate the diffusion coefficient Dc depending on the concentration, the graphical method proposed by Matano1) has been widely used, but the accuracy is not always satisfactory.
In this paper, a method is presented to evaluate Dc more accurately using an empirical formula (a) and equation (b).
The procedure to calculate Dc from concentration distributions is as follows:
1. Approximate values of β, γ and C0 in formula (a) are caldulated using concentration distributions.
2. Most probable values of β, γ and C0 are determined by a least squares method using the approximate values of β, γ and C0 obtained in procedure 1. and concentration distributions. And then the empirical formula (a) is determined.
3. Differential and integral numericals of formula (a) are calculated.
4. Dc's are calculated by substituting the differentials and integrals obtained in procedure 3. into equation (b).
The application of this method to some theoretical Fickian, non-Fickian distributions and some experimental distributions shows that Dc calculated by this method are more accurate compared to that obtained by the graphical method.View full abstractDownload PDF (339K) -
Kiyoshi Ishii, Tatsuo Sekiguchi, Tatsuo Takaya1972 Volume 28 Issue 9 Pages 359-367
Published: September 10, 1972
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSThe flammability of various fibers was investigated by the vertical test, APEX test, 45° coil test and LOI (limiting oxygen index) test. The flash point and the ignition behavior were also studied with an electric furnace. The LOI value of the fiber was the most valuable for evaluating the flammability of the fiber.
The tested fibers are classified as follows (in the parensis are shown the LOI or the LOI and the flash point, °C):
(1) The most flammable fibers (LOI, <20): Acetate [17, 363], Exlan (PAN) [17, 331], Cotton [18, 361], Rayon [19, 327], Chinon (PAN/casein) [18, >650].
Acetate, cotton and rayon have the low flash and ignition points. Chinon has a higher flash and ignition points than the other and less flammable.
(2) Flammable fibers (LOI, 20-25): Nylon 6 [20, 459], Nylon 66 [21, 461], PP [20, 448], PET [22, 448], MXD-6 [23, >650], Silk [23, 622], Wool [24, >650].
MXD-6, silk and wool have higher flash points than the others. Silk and wool have a higher ignition point than MXD-6.
(3) Flame-resistant fibers (LOI, 26-30. Flash point >650): Kanekalon (PVC/PVA) [26], Cordelan (PVC/PVA) [30], Nomex (aromatic polyamide) [30].
(4) Highly flame-resistant fibers (LOI 31-50: Flash points, >650°C): Teviron (PVC) [35], FR cotton (treated with N-methyl dimethylphosphonopropionamide; P, 2%) [35], Krehalon (polyvinylidene chloride) [50], Kynol (crosslinked phenol formaldehyde resin) [35].
Kynol shows the highest ignition point in this group of fibers.
(5) Non-flammable fibers: Carbon, Glass.
The thermogravimetric behaviors of fibers were studied and discussed in relation to the flammability of the fibers. Cotton, rayon and acetate show almost the same TGA curves with two rapid weight-decreasing temperature ranges. Nylons, PP, and PET show higher weight-decreasing temperature ranges than cotton, while Cordelan, Teviron, and Krehalon show lower weight-decreasing temperature ranges where non-flammable gases seem to be evolved. The TGA curves of Kanekalon, Exlan, and Chinon show three rapid weight-decreasing temperature ranges and those of carbon and Kynol have only one range.
The amount of the residue at 600°C was in the order; Carbon (76.5%), Exlan (58.5%), Chinon (48.5%), Kanekalon (34.5%), Kynol (30.0%), Nomex (21.4%), MXD-6 (17.0%).View full abstractDownload PDF (499K) -
Mieko Tagawa, Yasuko Tujii, Seibe Yoshikawa1972 Volume 28 Issue 9 Pages 368-373
Published: September 10, 1972
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSIn order to investigate the phenomena of soil redeposition to fabric in the process of detergency, the soiling bath composed of 0.2% SDS solution containing dirt material (carbon black) and various builders, Na2SO4, Na5P3O10, Na2CO3, sodium carboxy-methyl cellulose (CMC), was prepared and each fabric such as cotton, nylon, acryl, polyester was soiled in this soiling bath.
First, the effect of each builder above mentioned on the soiling to these fabrics was examind. It was generally shown that the addition of Na2SO4, Na3P3O10, Na2CO3 in the soiling bath promoted the soiling and the addition of CMC prevented the fabrics from soiling.
Next, the ξ-potentials of fabric (by streaming potential method) and of carbon black (by electrophoresis method) in 0.2% SDS solution were measured to discuss the soiling properties.
The results showed that there was decreasing tendency in -ξ of fabrics and carbon black when Na2SO4, Na5P3O10, Na2CO3 were added in 0.2% SDS solution except in the case of nylon fabric-Na2SO4 system. While the addition of CMC showed the increase in -ξ of fabrics and carbon black. As far as our experiments are concerned, it was made clear that the change of soiling property of fabrics with the addition of builders is due to the change of ξ-potential of fabrics and carbon black. Thus, it is confirmed that the ξ-potential was one of the inportant factors in the soil redeposition to fabrics in the process of detergency.View full abstractDownload PDF (416K) -
Mieko Tagawa, Yasuko Tsujii, Seibe Yoshikawa1972 Volume 28 Issue 9 Pages 374-378
Published: September 10, 1972
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSThe anti-redeposition action of sodium carboxy-methyl cellulose (CMC) and polyvinyl alcohol (PVA) in washing process was investigated. CMC having various degree of polymerization (70_??_1, 000) or PVA (_??_=500_??_1, 800) with various degrees of substitution of acethyl group prepared by hydrolysis of polyvinyl acetate (78.5_??_99.4mol%) was added as a builder to the model soiling bath in which carbon black was dispersed in sodium dodecyl sulfate aqueous solution. The degrees of anti-redeposition effect of cotton and nylon fabrics and nylon film were measured by optical reflctance method after the treatment in the soiling bath.
The addition of CMC to the soiling bath prevents soil deposition on cotton fabric at the concentrations more than 1×10-3%, while it shows no obvious effect on nylon fabric.
When PVA is used, soil deposition on cotton and nylon fabrics and nylon film is prevented. By the addition of any PVA more than 1×10-4%, the cotton fabric is slightly soiled. In the case of nylon fabric, the soil prevention effect becomes more remarkable with the increased degree of hydrolysis of PVA. In the degrees of hydrolysis from 78.5% to 81.5%, low molecular weight PVA is more effective for the prevention of soil deposition on nylon fabric than high molecular weight PVA.
It is concluded from above results that PVA is effective as an anti-redeposition agent for cotton and nylon, and that.PVA highly hydrolyzed has a remarkable effect for soil prevention.View full abstractDownload PDF (305K) -
1972 Volume 28 Issue 9 Pages 379
Published: 1972
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSDownload PDF (55K)
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