This paper describes the results of the laboratory test to investigate the effects of the fluorescent brightners contained in the detergents for domestic laundry on the visual appearance of dyed fabrics. Cotton shirtings, dyed with disperse dyes in red, yellow and blue of three different levels in saturation and lightness, were treated with the fluorescent brightners of 0.1, 0, 5 and 1.0% owf. They were then exposured under carbon-arc light of a weather-O-meter. Such treatment/exposure cycles were repeated by eight times. The degree of saturation, reflectance of fluorescent light and visual appearance were determined after each treatment/exposure cycle. The following two results have been obtained : (1) The reflectance of fluorescent light depends on the concentration of the fluorescent brightners and spectral reflectance of wave-length where fluorescent light were emitted. (2) The fluorescent brightening treatment decreases itse effect with repeating treatment/exposure cycle. The lowering of saturation injures the visual appearance of dyed fabrics.
The mechanism of drape formation has been investigated by using a flare-skirt type model. This model is an applied example of the rubber ring model which is the most simplified model of an umbrella type. The testing conditions were that : the diameter of a supporting disc was 20cm and the hanging length of a skirt model was varied from 35cm to 90cm in five levels. The shape and the number of buckling wave (node) were observed. With decreasing the hanging length, the shape of wave becomes more clear and the number of nodes increases. Buckling wave of a thick material is more clear than that of a thin one. Comparing observed number of nodes with theoretical one, it is found that the equation to calculate the number of nodes can nearly be applied to this model.
Hitherto, it has usually been considered that the seam strength is dependent on the loop strength of a sewing thread and the stitch density. However, our experimental findings revealed that the seam strength might also be affected by the kind of fabrics to be sewn. The following results have been obtained: (1) The seam strength depends upon not only the loop strength of the sewing thread and the stitch density but also the kind of fabrics to be sewn. By taking account of the effect of the kind of fabrics, the seam strength can be experessed by : F=kT (N+α), 10≤N≤30 where, F : seam strength, T: loop strength of the sewing thread, N: number of stitches, α : constant depending on the kind of fabrics k: linear constant. (2) Some effects of the stress-strain curve of fabrics on the seam strength have been analyzed.