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Volume 35, Issue 6
Displaying 1-9 of 9 articles from this issue
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The Seven Wonders of WoolRYO UMEHARA1979 Volume 35 Issue 6 Pages P155-P168
Published: June 10, 1979
Released on J-STAGE: November 28, 2008
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SEINOSUKE KAKIAGE1979 Volume 35 Issue 6 Pages P169-P172
Published: June 10, 1979
Released on J-STAGE: November 28, 2008
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Juzo Takahashi1979 Volume 35 Issue 6 Pages T221-T226
Published: June 10, 1979
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSThe phase transition of PSLG in the optically anisotropic state was studied in terms of the thermal behaviors examined by DTA, DSC and TGA.
A fraction of water in the solution containing PSLG of less than 48% freezed, whereas the rest water did not freeze. Water in the solution containing more than 48% PSLG did not freeze at all, indicating that the water is associated closely with PSLG molecule.
The structure of the solution of PSLG below 60% was regarded as a liquid crystal, and that of the solution above 70% was regarded as a crystal. These conclusions agreed closely with those obtained by X-ray analysis.
Phase diagrams were obtained referring to the PSLG concentration and the molecular weight. The anisotropic to isotropic transition temperature for the PSLG solution of below 60% was lower than 100°C, and the temperature for the solution of above 70% was higher than 200°C. The relationship between the transition temperature (T) and degree of polymerization (DP) of PSLG was represented by the following relation (1), where K and C are constant. Also the relationship between the transition concentration and the molecular weight of PSLG at 20°C agreed with Flory's prediction as, where v*2 is the concentration in the volume fraction at which anisotropic phase appears, and x is the axial ratio of PSLG helix.View full abstractDownload PDF (427K) -
Akira Watanabe, Shinya Kurosaki, Fujio Konda, Hiroshi Kondo1979 Volume 35 Issue 6 Pages T227-T236
Published: June 10, 1979
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSIn order to investigate the bending mechanism of twistless yarn fabric, which is related closely to the hand properties, the deformation of yarn in the fabric by bending were observed in detail on both twistless and twisted fabrics.
Materials and yarn making method are the same as those used in the previous reports. Yarn density in fabrics is shown in Table 1, in which No.1_??_No.7 are twistless yarn fabrics, and No.8_??_No.14 are twisted yarn fabrics.
Some microscopic photographs are demonstrated in Fig. 1 and Fig. 2. From these results, yarn deformation in bending can be fully observed.
The changes of yarn packing factor by bending are shown in Fig. 11_??_Fig. 14. These figures show that the yarn packing factors of twistless yarn fabrics change more drastically in slight bending stages to ρ=5cm-1 (ρ: curvature) than those of the twisted yarn fabrics. In final stages where ρ=20cm-1, however, the packing factors in both fabrics become almost the same value. In twistless yarn fabric, the packing factor change in the lower yarn density is larger than that in the higher yarn density. Generally, inside yarns have larger changes in the yarn packing factor than outside yarns. Comparing with the conventional twisted yarn fabrics, the twistless yarn fabrics have a characteristic to respond easily to the external force. This characteristic is due to the movable property of constituting fibers, and is closely related to “softness” or “fullness” of twistless yarn fabrics.View full abstractDownload PDF (2599K) -
Jiro Shimizu, Norimasa Okui, Koichiro Toriumi, Kazuo Oshima, Hisayoshi ...1979 Volume 35 Issue 6 Pages T237-T244
Published: June 10, 1979
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSFilaments of isotactic polypropylene and high density polyethylene have been produced by melt spinning in the presence of torsional shear, which is achieved by an air-jet false twister. The twister can rotate by air vortex the running filament without any contact and give the filament set-twist before coming the point of complete solidification of the threadline.
The twist number is increased as the applied air pressure to the twister is increased and it reaches the maximum value at the take-up velocity near to 250m/min. The maximum twist number is discussed as a result of the interrelation between the filament diameter and the speed of running filament. The set-twist number is also discussed from the standpoint of false twist mechanism under various spinning conditions.
Molten polymer filaments are affected by elongational and torsional strains along the spinning line and thus the physical properties of the spun twisted filaments are similar to those of the filaments spun at higher take-up velocities without torsional shear.View full abstractDownload PDF (528K) -
Teruo Hori, Tadaaki Hayashi, Masato Sekiguchi, Toru Shimizu1979 Volume 35 Issue 6 Pages T245-T251
Published: June 10, 1979
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSThe generally accepted model for diffusion of ionic dyes into cellulosic substrate is based on a heterogeneous system in which dye anions diffuse through the liquid in the pore of the substrate and are simultaneously adsorbed on the pore walls. By use of this model investigations were carried out to study the diffusion of Orange II through cellophanes containing carboxyl groups in the presence of various electrolytes (NaCl, Na2SO4, CH3COONa, C2H5COONa, C6H5COONa, CH3C (CH3) CH2SO3Na and C6H5SO3Na) at 50°C.
A linear relationship was found between the square root of the obtained diffusion coefficient through the liquid in the pore and the reciprocal of the square root of the ionic strength of each electrolyte. These results could be explained by means of the equation by Warwicker and other investigators.
However, the diffusion coefficients didn't depend only on the ionic strength, but also on the kind of electrolyte; i.e. the electrolytes having SO-3 group increased the diffusion coefficient more markedly than those having COO- group. The same effect was observed also in the diffusion coefficient in the bulk liquid, which was measured by the capillary method.
Such variation of diffusion coefficient with the kind of electrolyte was explained by the generally accepted suggestion that water structure around SO3- group is broken and that around COO- group is enhanced.View full abstractDownload PDF (486K) -
Mamoru Nango, Masako Maekawa, Akira Katayama, Nobuhiko Kuroki1979 Volume 35 Issue 6 Pages T252-T256
Published: June 10, 1979
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSDyeing of Cotton by Chrysophenine G (C. I. Direct Yellow 12) in aqueous sodium alginate solution has been studied. The results show the increasing dye absorption with increasing sodium alginate as described before. In this report, the results have been interpreted by reference to the parameters affecting the free energy of the dyeing and the relevant model available for explaining this dyeing system. The effect of sodium alginate (polyelectrolyte) on the absorption equilibrium of dye by cotton has been compared with that of sodium chloride (inorganic salt) in terms of the Donnan membrane equilibrium theory, assuming that sodium alginate is present only in the “bulk solution” defined in the unimolecular absorption model of cellulose. We have considered that dyeing of cotton by direct dye in aqueous sodium alginate solution is similar to the dyeing in the absence of foreign electrolyte and that by the membrane equilibrium the dye has been concentrated into the internal solution of cotton for the presence of sodium alginate in the bulk solution.View full abstractDownload PDF (281K) -
Itsuro Tanaka, Kazuo Watanabe1979 Volume 35 Issue 6 Pages T257-T263
Published: June 10, 1979
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSThe purpose of the present investigation is to obtain the relationship between the flammability of various aromatic polymers and their structures. The polymers prepared by the polycondensation reaction in organic polar solvents were examined for their flammability and thermal stability.
Limiting Oxygen Index (LOI) test using a conventional filter paper sample was very useful in examining the flammability. Filter paper samples were prepared by the filteration of the precipitants of feathery polymer.
Aromatic polyhydrazide, polyurea and poly acyloxyoxalicbisamidrazone did not show selfextinguishingness and good thermal stability. In the case of polyamide, incorporation of methylene groups in the polymer main chain decreased both flammability and thermal stability. So the aromatic polyamide containing aliphatic methylene units did not show self-extinguishingness.
On the other hand, wholly aromatic polyamide exhibited much higher thermal stability and flammability. But there was no clear relationship between these two properties. It was verified that iso-oriented polymer is superior in flammability to all-para oriented polymer and generally inferior in thermal stability. The reason may be that the iso-oriented structure is easy to change into crosslinking structure.View full abstractDownload PDF (555K) -
Itsuro Tanaka, Yasuo Kato, Kazuo Watanabe1979 Volume 35 Issue 6 Pages T264-T272
Published: June 10, 1979
Released on J-STAGE: November 28, 2008
JOURNAL FREE ACCESSAromatic polyamide fibers were modified by phosphorous and halogen compounds and their flammability and related properties were examined.
Because of the good durability and reproducibility, we adopted the method of blending. In order to evaluate the flammability of fibers and fabrics, we have established a Limiting Oxygen Index test ignited from the bottom of samples (LOI-B), in addition to the standard method in which the samples were ignited from the top (LOI-T). Mechanical resistances to very hot flame and iron were also estimated. The following results were obtained.
1) Flame-retardant Halogen compounds increased the LOI-T value but not the LOI-B one. Phosphorous compounds were found to be effective for the flammability and especially aliphatic phosphonate was superior to others.
2) Flammability By the addition of 1 wt.% Phosphorous to wholly aromatic polyamide, the values of LOI-T and LOI-B became 38.0 and 26_??_27, respectively and mechanical resistances to very hot flame and iron were also greatly improved.
3) Spinning Modified polyamide containing 10 wt. % polyphosphonate could be spun in an ordinary way and the properties of fibers such as tenacity and elongation were well good enough for garments.
4) Durability After 20 times home washing, phosphorous content did not decrease and the flammabilities were maintained.View full abstractDownload PDF (604K)
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