The quality of woven fabrics is deeply affected by the regularity of warp and weft density, which is one of the fundarnental fabric pararneters determining the physical properties of fabrics. In particular the regularity of weft density can be easily destroyed in a transient or unstable processing state, for example: when weaving process is interrupted by a disturbance or in the case of article change. In most cases, a reruning of the weaving machine leaves a fabric fault in the form of streaks which caused by the irregularity of weft density. This fault is called "stop mark" and is nowadays one of the most frequently occurring errors in fabrics. In this study, it was tried to analyze the mechanism how a stop mark takes place and to obtain a theoretical model. During modelling, it was proposed that the latest pickspacing can be affected by the beating motion which build up a new pickspacing as a result of new weft insertion. The mathematical model has shown a nonlinear simultaneous difference equation system which consists of equations about the pickspacing and clothfell position. The results of simulation revealed that forward movement of dothfell position has a sensitive effect on occurrence of dense weft streaks. The backward movement of clothfell position, however, brought about a broad and thick weft streaks.t streaks.

The polyurethane/polystyrene interpenetrating polymer network (PU/Ps IPN) was prepared by simultaneous polymerization method. The effects of preparation conditions on the reaction rates of each component, domain size, effective crosslinking density, Tg, mechanical properties were investigated by SAXS, DSC and mechanical analysis. The increase of reaction rate of PU component caused the decrease of Tg of PS component even in the constant composition on PU/PS IPN. This result is considered that the increase of reaction rate of one component changes the matrix phase in IPN to its own phase. The notched impact strength of PU/PS IPN increased with the increase of reaction rate and molecular weight of PU component, but decreased with the increase of reaction rate and crosslinking density of PS component.

In the dyebath consisting of acid- and cationic-dyes, properties of the dye solution and behavior of a non-ionic dispersing agent were investigated by the measurements of particle size of the dye aggregates and absorption spectra. Acid dyes and cationic dyes in the solution without non-ionic dispersing agent were precipitated a lot. As the non-ionic dispersing agent increased, the degree of precipitation was highly decreased. The effect of adding non-ionic dispersing agent in the dye bath was also investigated. The non-ionic dispersing agent made complex with acid dye, but not with cationic dye.

The interfacial electrokinetic potentials were measured by streaming potential method which was generally used in the electrochemical study of interface of fiber and dye solution. The results were transformed into ζ potential by Helmholtz-Smoluchowski formular, into surface charge density by Suzawa formular and into surface dye adsorption of fibers. The ζ potential of wool or acrylic fiber in dye mixture solution showed similar trend as was found in single dye solution, but the total dye up-take of wool fiber increased at higher pH value. It is postulated that the increase in dyeing sites by the dissociation of carboxyl groups of wool fiber at higher pH is responsible for the increased dye up-take.

The effect of drying temperature on the morphology and mechanical properties of acrylic fibers was studied. It was found that the porous fiber was contracted in both the axial and radial directions during drying, and internal microvoids between fibrils within fiber were eliminated. This pheno-menon has frequently been termed collapse. The collapsed fiber was lustrous and transparent. The degree of crystallinty and crystallite size of dried fiber increased with increasing drying temperature and the fiber structure apparently became denser and more homogeneous. On the other hand, the mechanical properties of drawn fibers were discussed in relation to the morphology of tensile failure. The fibers dried at room temperature or 70˚C, which contained many flaws due to the trace of voids, exhibited tensile fracture with axial splits, whereas the collapsed fiber dried at 130˚C exhibited tensile failure perpendicular to the fiber axis. These morphological difference in tensile failure resulted in a difference in mechanical properties. The higher mechanical properties of the collapsed fiber might be attributed to an increase in the degree of bonding between fibrils.

To increase the moisture content of polyacrylonitrile (PAN), thin layer surface photo-grafting of 2-hydroxyethyl methacrylate(2-HEMA) onto PAN fiber by using benzophenone as an initiator with a mixture solvent was carried. The effects of reaction conditions such as monomer and initiator concentration, UV irradiation time, composition of mixed solvent and immersion time of fiber on grafting were investigated. The percent grafting increased with increasing monomer concentration, benzophenone concentration, immersion time and UV irradiation time up to limiting value and thereafter decreased or leveled off. Using suitable mixed solvent significantly increased the percent grafting.