Breast sizing and development of three-dimensional seamless bra.

摘要

In intimate apparel, sizing and fit are two most important issues. The bra sizing system has been based on bust girth and underbust girth since 1935. Woman's breast is however a very complex 3D geometry, the existing sizing system was found inappropriate to categorize the breast sizes. One of the purposes of this project is to develop a new bra sizing system to fit Chinese women's breast shapes and sizes.; Based on the 3D nude breast measurements of 456 Chinese women subjects aged between 20 and 39, an improved bra sizing system was developed through principal components factor analysis and K-means cluster analysis of the data. The new system uses "underbust girth" and "breast depth width ratio" as the classifying parameters, which were identified as the two most critical parameters out of 103 measurements. Compared with the existing bra system, the new bra sizing system covers higher percentage population, provides better fit to the accommodated individuals, while maintaining a clear structure and keeping the same number of size categories.; Another objective of the project is to develop seamless knitted bras with improved fitting. Based on the understanding of the breast shapes, fifteen testing bra samples with three new styles were developed using two key knitting parameters---loop density and elastic yarn tension. To hold the breast shape in a natural manner, a soft 3D supporting wire prototype was designed based on the average shape of breast root of the 49 women subjects sized 75B* in the new bra sizing system.; To test the fitting performances of the newly developed seamless knitted bras and four commercial bras, the evaluations included objective pressure value, subjective comfort & pressure sensation and 3D breast shape were assessed by six subjects of bra size 75B*. The results indicated that the 3D supporting wires could provide definite support to the breasts and improve the breast vertical-sectional profiles, especially for the seamless knitted bras which have relatively larger value of loop density.; The research results build up our knowledge for the development of a bra sizing system and its application for seamless knitted bras development.