Clothing Biosensory Engineering

Yan Li, A S W Wong

• Publisher: Woodhead Publishing
• Year: 2006
• Print ISBN: 9781855739253
• eBook ISBN: 9781845691462
• Topic: Biological Sciences
• Subtopic: Biology
• Index: Biological Sciences

Human sensory perception of clothing involves a series of complex interactive processes, including physical responses to external stimuli, neurophysiological processes for decoding stimuli through the biosensory and nervous systems inside the body, neural responses to psychological sensations, and psychological processes for formulating preferences and making adaptive feedback reactions.Clothing biosensory engineering is a systematic and integrative way of translating consumers' biological and sensory responses, and psychological feelings and preferences about clothing, into the perceptual elements of design. It is a link between scientific experimentation and commercial application to develop economic solutions to practical technical problems.Clothing biosensory engineering quantifies the decision-making processes through which physics, mathematics, neurophysiological and engineering techniques are applied to optimally convert resources to meet various sensory requirements – visual/thermal/mechanical. It includes theoretical and experimental observations, computer simulations, test methods, illustrations and examples of actual product development. - Describes the process of Clothing biosensory engineering in detail - Quantifies the decision making processes applied to optimally convert resources to meet various sensory requirements - Includes theoretical and experimental observations and examples of actual product development

1

Introduction to clothing biosensory engineering

Y.I. Li¹; Anthony S.W. Wong^{2 1} Institute of Textiles and Clothing, The Hong Kong Polytechnic University, Kowloon, Hong Kong
² School of Nursing, The Hong Kong Polytechnic University, Kowloon, Hong Kong

1.1 Consumer trends

Modern consumers are interested in clothing that not only looks good, but also feels good. Silverman¹⁷ reported that, according to a major consumer survey conducted by the International Research Institute on social change, 81% of consumers (80 and 83% of women and men, respectively) selected comfort as the top attribute they seek in apparel, followed by easy care and durability. In a survey of the importance of ten different attributes (brand, colour, comfort, design, durability, easy care, fabric, fashion, fit and price) of tight-fit garments, Wong and Li²¹ found that comfort and garment fit were the two most important attributes. On the other hand, a garment’s brand and fashion were rated as the two least important attributes. Suppliers of both natural and synthetic fibers have identified an increasing trend for consumers to involve more than just vision in their purchasing decisions – touch, smell, intuition and emotion are increasingly involved. As a result, greater importance is being attributed to the shopping and wearing experience. Interest is growing in fabrics that feel better and comfort is being reinforced as a key parameter in clothing.¹

Fiber suppliers have identified comfort as one of the key attributes in consumers’ perception of the desirability of apparel products in all markets. However, retailers and processors feel some uncertainty with regard to consumer requirements. Under the heading comfort, the problem of prickle, especially in knitwear, is universally recognized, and light-weight, fluid fabrics are seen as highly desirable. Consumers find luxurious softness somewhat less appealing than processors and retailers do. Also, it has been shown that consumers’ requirements on comfort are changing along with products and wear situations. The underlying patterns and reasons behind this still await scientific investigation.

In the new century, the apparel market was highly competitive. To meet and even exceed consumers’ needs and expectations it becomes essential for enterprises in the textile and clothing industry to succeed in the market place. Synthetic fiber manufacturers have made a successful comeback through sportswear, where they have focused on comfort, movement and performance. By addressing consumers’ needs and using the growing interface between sportswear and fashion, synthetic fiber manufacturers have taken half of the fiber consumption market. Clearly, understanding and satisfying consumers’ needs and demands in relation to apparel products is crucial for the long-term survival of any enterprise in such a competitive market place.

Eisner² stated that Canadian apparel manufacturers have changed a lot in the past 20 years due to molded apparel, computerized manufacturing technology, microdenier fabrics and increased consumer demand for comfort. The number of apparel items with the Woolmark Total Easy Care label increased to two million in 2000, a 233% increase, indicating that apparel retailers are responding to greater consumer demand for apparel with increased comfort, high performance and low maintenance requirements.¹¹

Comfort is a fundamental and universal need for consumers. Fujiwara et al.⁶ examined consumer perception of apparel quality. Results of cluster analysis showed that there are six basic clusters – workmanship in sewing, physiological comfort, usefulness, physical and chemical properties, suitability to individual preference and fashion or branding. Of these, the first four clusters formed a higher order cluster that expressed the intrinsic attributes of the apparel and the last two expressed the extrinsic attributes of the apparel. Kwok et al.¹² investigated the major criteria which consumers coming from different age, gender, occupational, educational and income groups consider when purchasing denim apparel for their children. Results showed that comfort and fabric quality are the most important criteria in the selection of children’s denim apparel. Moisture comfort and pressure comfort are the most important considerations for denim apparel purchases in both summer and winter. As consumers, everything we do can be considered as an effort to improve our level of comfort in life. Clothing and textile products are the essential materials that we use every day to obtain physiological and psychological comfort and, more fundamentally, to ensure that the physical conditions around our bodies are suitable to sustain life. Therefore, research on clothing comfort has fundamental meaning for the survival of human beings and the improvement of our quality of life. From the viewpoint of business management of textile enterprises, clothing comfort research has substantial financial implications due to the effort to satisfy the needs and demands of consumers in order to obtain sustainable competitive advantages in modern consumer markets.

1.2 Definition of sensory comfort

Comfort, however, is a very complex and nebulous subject and one that is very difficult to define. Fourt and Hollies⁴ surveyed literature and found that comfort involves thermal and non-thermal components and is related to wear situations such as working conditions, non-critical and critical conditions. The physiological responses of the human body to a given combination of clothing and environmental conditions are predictable when the system reaches steady state. It can be calculated from knowledge of easily measured factors such as the thermal and moisture resistance of clothing, the climate conditions and the level of physical activity. This is the traditional area for clothing comfort study, and one in which a large amount of research has been published and applied to solve practical problems. For instance, the thermal insulation value clo has been widely used for designing and classifying military uniforms¹⁰ and calculating thermal comfort indices for indoor air conditioning.^3,7,8

As clothing is in direct contact with the human body, it interacts with the body continuously and dynamically during wear, which stimulates mechanical, thermal and visual sensations. This has been termed sensory comfort, and it is a relatively new area in clothing comfort research.

Smith¹⁹ defined comfort as well-being and freedom from pain. Slater¹⁸ defined comfort as ‘a pleasant state of physiological, psychological, and physical harmony between a human being and the environment’. Slater identified the importance of environment to comfort and defined three types of comfort: physiological, psychological and physical. Physiological comfort is related to the human body’s ability to maintain life, psychological comfort to the mind’s ability to keep itself functioning satisfactorily with external help, and physical comfort to the effect of the external environment on the body. Fris⁵ stated that apparel comfort results from a balanced process of heat exchange between the wearer’s environment and apparel, specifically the ability of apparel to convey heat and moisture from the skin to the environment. Li¹³ stated that comfort depends on subjective perceptions of visual, thermal and tactile sensations, psychological processes, body–apparel interaction and external environmental effect. Tarafder and Chatterjee²⁰ stated that comfort is a subjective quality that comprises a range of physiological, psychological and physical variables.

It has long been recognized that it is difficult to describe comfort positively, but discomfort can be easily described with terms such as prickle, itch, hot and cold. Therefore, a widely accepted definition for comfort is ‘freedom from pain and from discomfort as a neutral state’.⁹ Further, comfort has been considered to be both psychological and physiological and has a number of aspects.

• Thermophysiological comfort – attainment of a comfortable thermal and wetness state, involves transport of heat and moisture through a fabric;

• Sensorial comfort – the elicitation of various neural sensations when a textile comes into contact with skin;

• Body movement comfort – ability of a textile to allow freedom of movement, reduced burden, and body shaping, as required;

• Aesthetic appeal – subjective perception of clothing to the eye, hand, ear and nose, which contributes to overall feelings of well being and pleasantness on the part of the wearer.⁹

In all these definitions, there are a number of essential components.

1. Comfort is related to subjective perception of various sensations.

2. Comfort involves many aspects of human senses such as visual (aesthetic comfort), thermal (cold and warm), pain (prickle and itch) and touch (smooth, rough, soft and stiff).

3. The subjective perceptions involve a psychological process in which all relevant sensory perceptions are formulated, weighed, combined and evaluated against past experiences and present desires to form an overall assessment of comfort status.

4. The body–clothing interactions (both thermal and mechanical) play important roles in determining the comfort status of a wearer.

5. External environm...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright page
• Editor contact details
• Preface
• 1: Introduction to clothing biosensory engineering
• 2: Psychology and sensory comfort
• 3: Neurophysiology of sensory perceptions
• 4: Physiology of thermal comfort
• 5: Physics of thermal comfort
• 6: Thermal and moisture sensations
• 7: Tactile sensations
• 8: Dimensions of sensory comfort perceptions
• 9: Overall comfort perception and preferences
• 10: Prediction of clothing sensory comfort
• 11: Thermal properties
• 12: Water vapor transfer
• 13: Liquid moisture transfer
• 14: Coupled heat and moisture transfer
• 15: Air permeability
• 16: Mechanical tactile properties
• 17: In vivo physiological measurements
• 18: Application of clothing biosensory engineering
• 19: Mechanical and thermal sensory engineering design
• 20: Sensory comfort of denim product
• 21: Sensory comfort of tennis wear
• 22: Sensory comfort of aerobic wear
• Index