In order to verify the relation of the two following functions, some observations on cross section of the yarn of the distributed fibers were made. The function (1) is obtained by the optical method previously proposed, and this function is correlated with the fiber distribution in each vertical division of a cross section. The function (2) is derived theoretically from the function (1), it means the fiber distribution located within a area of circular ring with Δr width, situated at distance r from the center in the cross section. The fiber distribution in each vertical division of the cross section showed normal distribution and conformity with the above function f (r), and the function p (r), with circular divisions of the cross section was also satisfied experimentally.
In order to clarify the morphological characteristics of textured yarn, the individual crimped single filament was separated from the parent textured yarn, and the crimping amplitude and wave-length distribution along a single filament was measured. The following results were obtained: (1) The amplitude and wave-length distribution of crimped filament are similar to that observable in the parent textured yarn, and this distribution discloses diagrammatically the morphological characteristics of the crimp caused by the texturing process. (2) The distribution of amplitude vector along a crimped single filament is identified with the fiber distribution in a cross section of it's parent yarn, and the function of r, which is the accumlation of each amplitude from the outside to r along a radius, is correlated with the fiber distribution f (r) derived in the previous report1). Thus, the fiber distribution f (r) was verified also experimentally by the analisis on the wave distribution in a crimped single filament.
For investigation of the mechanism of cold drawing of vinylidene chloride-vinyl chloride copolymer undrawn fibers which contain plasticizer, the birefringence, stress-strain curve of fibers drawn at room temperature in the air, and change of birefringence for various time held at stretched states have been measured. Changes of the foregoing physical properties have also been compared with those by drawing of films which does not contain plasticizer. 1. Results; the facts that the birefringence of aggregate parts of unisotropic micelles and molecular chains is negative, and the positive form-birefringence arises by addition of plasticizer in the copolymer substance were clearly proved. By increase of the molecular and micellar orientation, the formbirefringence increases and the birefringence of copolymer fibers which contain plasticizer approaches from negative maximum value to zero by cold drawing. 2. In both cases, the cold drawing process of undrawn fibers and films may be divided into the following three parts. The orientation increases rapidly at the early stage, and then at the middle stage crystallization is accompanied with the increase in degree of orientation. Both the orientation and crystallization remains nearly unchanged at the last stage.
Crimped yarn is an assembly of crimped fibers, and when the yarn is stretched, the crimp of fiber is at first stretched and then the fiber itself is to be stretched. Because the load elongation curve can be considered as made of a few regions and of course at first region the crimp of fiber is stretched. The purpose of this paper is to determine the mechanical behavior of crimped yarn at the first region. A few results are obtained from the theoretical study and experiments. The results are as follows: (1) As the hysteresis loop is obtained from cyclic deformation, the mechanical hehavior of crimped yarn has a characteristic including elastic after effect and is not a perfect elastic behabior. (2) Studying the experiments of stress relaxation, the crimped yarn may be considered as that of a linear characteristics. (3) By the results of the above-mentioned (1) & (2), the mechanical behavior of crimped yarn may be considered to have been explained by the mechanical model including slider mechanism as shown in Fig. 2.
The shrinkage of high tenacity rayon (I) during fibrous acetylation in acetic anhydride-kerosene, the drawing of the acetylated rayon (II) and the crimping process of the drawn (II) were studied. The shrinkage of (I) during this acetylation process is generally greater than that during the acetylation in vaporized acetic anhydride. Stretch during acetylation to prevent (I) from shrinking, retards the acetylation rate. Draw or stretch either hot or wet, given to (II) improves its mechanical properties; tensile strength, Young's modulus and elastic recovery increase. Optimum draw ratio is 20_??_30% for (II) of acetic acid content of 50%. At a certain draw ratio, hot draw shows a greater improvement in tensile strength than wet one. Increase in degree of acetylation inevitably causes reduction in strength even if (II) is drawn at optimum condition. (II) drawn at optimum draw ratio can have higher mechanical properties, in particular higher Young's modulus than Alon, acetylated in vaporized acetic anhydride. Sufficient crimps are given with a conventional crimper with a stuffing box only when (II) is heated with steam just before passing the crimping rollers. It was noted that the drawn (II) reduces its Young's modulus when it is sufficiently crimped. This series of processing, however, brings about little change in chemical properties of (II). (II) is dyed with disperse dyestuff at a higher rate with higher exhaustion in comparison with Alon. In general (II) is slightly less resistant to chemicals than Alon.
Soap solution is generally used as degumming agent on raw silk, but the papain enzyme also can be used. We have studied under various conditions the controlling effects of the solution on the degree of appearance of lousiness fibers and obtained the following results: 1) In the case of papain enzyme solution treatment, classification results of exfoliation test shows 7_??_10% higher. 2) Sodium bisulphite, hydrosulphite and sodium sulphite are effective agent as an activator, especially hydrosulphite brings forth better results than the others.
Using polyvinyl alcohol as an adhesive agent, paper making with synthetic fiber and viscose rayon by hand process was studied. The effects of the amount of fibrous polyvinyl alcohol and powder on paper strength is almost the same. But the fibrous polyvinyl alcohol is less effective than the powder for the paper making with long fiber. The effects of the polyvinyl alcohol on the strength of Vinylon paper is more clear than that of viscose rayon paper. Adhesion mechanism of the polyvinyl alcohol is discussed.