| Author: | Zhang, Shichen |
| Title: | Design and development of age-friendly bras |
| Advisors: | Yick, Kit-lun (ITC) Yu, Winnie (ITC) Lau, Newman (SD) |
| Degree: | Ph.D. |
| Year: | 2020 |
| Subject: | Hong Kong Polytechnic University -- Dissertations Brassieres -- Design Brassieres -- Health aspects Aging |
| Department: | Institute of Textiles and Clothing |
| Pages: | xiii, 212 pages : color illustrations |
| Language: | English |
| Abstract: | Much like the rest of the developed world, Hong Kong is an aging society, which means that the older population is increasing dramatically. In comparison to younger adults, older adults are more financially comfortable and tend to invest more in themselves. One of the groups of older adults who are also a unique group of consumers are older women, particularly in terms of bras. They have specific needs and preferences for bras in response to their aging and changes in their physical body as well as how they perceive comfort. As commonly known, bras have an essential role in improving the shape of the body by lifting and gathering the breasts. An appropriate bra can thus provide pleasure to mature women by ensuring comfort, function, and aesthetics at the same time. Joint flexibility and range of movement of the body and limbs also decrease with aging. However, most of the bra closures are located at the centre of the back of the bra. Due to reduced flexibility and movement of the upper limbs and fingers, most older women find it very difficult to reach behind themselves and hence face serious difficulties when securing bra closures with hook-and-eyes at the centre of the back of the bra. In addition to physiological issues, the aging process also has psychological effects on women, and they cope with these challenges through beauty interventions such as a bra to mask the outward signs of increasing age. Therefore, the market for golden agers in terms of bras still needs further development. That is, when older women try to find a bra that meets their many needs, the choices are quite limited. The goal of this research work is to develop comfortable bras that would meet the potential needs of older women and also establish new design criteria and design methods for age-friendly bras. In order to achieve this goal, a thorough scientific basis is established to understand the age-related changes of older women and their needs and requirements in relation to bra features, the practical use of bras, and the difficulties of donning a bra. To examine the age-related changes in terms of physical features, comparisons are conducted between a younger group of twenty-eight Chinese females between 19 and 33 years old with an older group of twenty-six Chinese females between 54 and 69 years old. Physical measurements of the subjects are both manually taken and determined by using a three-dimensional scanning method. Body measurements including height, weight, body mass index (BMI), slope of the shoulders and curvature of the back are taken to determine the physical well-being of the subjects and their level of obesity. Measurements are also taken of the breasts, including breast prominence, bust and underbust girths, the difference between the bust and underbust girths, distance from clavicle to the nipples, nipple to nipple distance and breast ptosis, to evaluate their bra size, breast position and breast shape. The results show that compared to the younger females, the older women in this group are more obese, have more sloping shoulders, a forward bending back, larger bust and underbust girths, and more sagging breasts. The physical measurements therefore act as a reference for the development of the bra prototypes in this study. The bra wear problems and bra needs of the same group of subjects are then identified from a wear trial based on eight bra samples. In-depth interviews are carried out and then a content analysis is used to analyse the transcripts of the interviews. The shaping function of the bras is found to be associated with the self-acceptance and confidence of the older women. The concerns around social acceptance also affect bra preference. Five problematic areas are identified through the content analysis, including the shape, support, (wear) comfort, (wear) convenience and aesthetics. The design requirements for addressing these problems are then determined based on the performance of the bra samples in the wear trial and an analysis of the bra features. The list of design requirements provides specific and applicable guidance on the bra design which addresses the bra needs of older women and could comprise an essential part of the design process of new bra products for older women. Using a new set of criteria for assessing bra fit, the fitting problems are then quantified from the wear trial. The relationships between bra design features and related problems are systematically addressed. Bulging is considered to be the most common fitting problem in this study, which is affected by the rigidity of the bra band. The strap width, strap front width, straight vertical length of the bra cup, difference between the gore and underarm height, and gore height are also found to be related to bra fitting problems. The key characteristics of a bra that would fit older women properly include wide shoulder straps, wide straps at the front of the bra, adequate vertical cup length, higher gore, fabric strap at the back of the bra and a underband with high rigidity. The design recommendations formulated in this study can advance the design and development processes of bras for older women. A systematic design and development framework for age-friendly bras is formulated with a series of bra prototypes which have been evaluated for fit, wear comfort and functional performance. The result of the evaluation shows that the four prototypes meet the needs of five key aspects of shape, support, (wear) comfort, (wear) convenience and aesthetics, and improve the performance of bras with fitting problems. The simulation of the dynamic process of bra strap movement due to body motion has been successfully carried out based on a validated rigid-flexible coupled finite element model. The influence of the different design features of the bra straps (strap width, strap spacing, elongation, friction coefficient and Young's modulus) on the contact pressure between the bra and body, amount of displacement of the bra strap and the associated wear discomfort is evaluated through a full factorial analysis with the finite element model. It is found that elongation has the most significant influence while Young's modulus has the least influence on the displacement of the bra strap during movement. Material elongation is identified as the most significant factor that affects the contact pressure between the bra straps and body, followed by the Young's modulus and bra strap spacing, while the effect of material friction on wear pressure is the least significant. The proposed method is proven to be an effective and scientific approach to enhance bra design and eliminate the time-consuming "trial and error" testing in the design process and hence, provides an effective means for design modifications in today's ever-changing lingerie market. This study systematically characterises the bras needs of older women. The new design approach and guidelines that consider the needs of the wearer can be extended to designing other wearable products. The use of a finite element method in this project also provides the basis for future research on the dynamic aspects of human motion on the human body structure in that anatomic curvature and changes in posture during wear are taken into consideration to advance the design of stretch fit garments. |
| Rights: | All rights reserved |
| Access: | open access |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| 991022378659103411.pdf | For All Users | 8.2 MB | Adobe PDF | View/Open |
Copyright Undertaking
As a bona fide Library user, I declare that:
- I will abide by the rules and legal ordinances governing copyright regarding the use of the Database.
- I will use the Database for the purpose of my research or private study only and not for circulation or further reproduction or any other purpose.
- I agree to indemnify and hold the University harmless from and against any loss, damage, cost, liability or expenses arising from copyright infringement or unauthorized usage.
By downloading any item(s) listed above, you acknowledge that you have read and understood the copyright undertaking as stated above, and agree to be bound by all of its terms.
Please use this identifier to cite or link to this item:
https://theses.lib.polyu.edu.hk/handle/200/10405