Mitsuo Matsudaira

Regional microclimate humidity of clothing during light work as a result of the interaction between local sweat production and ventilation

Purpose – The aim of this study is to explore the influence of the clothing ventilation in three body regions on the humidity of the local clothing microclimates under five work‐shirts immediately after the onset of sweating in light exercise.Design/methodology/approach – The clothing microclimate ventilations were measured at chest, back and upper arm using a manikin. Separate wear trials were performed to determine the sweat production and the humidity of the clothing microclimate at the same locations as where the ventilation was measured during light exercise.Findings – Every shirt shows the greatest value of ventilation index (VI) for the chest and the smallest one for the upper arm. The values of VI differ remarkably at the chest among the five shirts. Comfort sensation became gradually worse as the time passed after starting exercise. There was no significant difference among the clothing conditions in mean values of rectal temperature, local skin temperatures, microclimate temperatures, microclima...

The Effect of Fibre Cross-sectional Shape on Fabric Mechanical Properties and Handle

In order to clarify the effects of different fibre cross-sectional shapes on fabric mechanical properties and handle, polyester ‘Shingosen’ fabrics of different fibre cross-sections were investigated using the KES-FB system. The results were discussed by comparing them with typical womens fine dress fabrics and the following conclusions were obtained. Polyester fabric becomes soft and deformable with an increase in the space ratio in the fibre cross-section, however, it does become inelastic and unrecoverable. FUKURAMI (fullness and softness) and SHINAYAKASA (flexibility with a soft feel) of polyester fabrics is greater with higher space ratios, but, KOSHI (stiffness) and HARI (and-drape stiffness), however, is lowered. Fabric bending rigidity is in proportion to fibre bending rigidity if all other conditions such as yarn density, count and finishing conditions remain the same. However, in general, the fabric mechanical properties and handle are controlled by the fibre assembly structure rather than fibr...

Predicting mechanical properties and hand values from the parameters of weave structures

In this study, mechanical properties and hand values are predicted from the parameters of weave structures. To promote the design of woven fabrics, we can define the crossing-over firmness factor (CFF) and the floating yarn factor (FYF) as the parameters of the weave structures for predicting mechanical properties and hand values. Both the CFF and FYF are related to some mechanical parameters and primary hand. Multiple regression equations of mechanical parameters and hand values are derived from those parameters of weave structures, and the predicted values almost exactly agree with the measured values from the KES-FB system.

Polyester "Shingosen" Fabrics Characterized by Dynamic Drape Coefficient with Swinging Motion

The static and dynamic drape behavior of polyester Shingosen fabrics is investigated using the new mechanical parameter of dynamic drapability, that is, the dynamic drape coefficient with swinging motion Dd. The Dd of the Peach Face fabric is small and that of the New Worsted fabric is large. On the other hand, there are almost no differences between each group of Shingosen fabrics in node numbers and conventional static drape coefficients. In classifying production characteristics, yam-processing fabrics show larger values of Dd than other fiber-production and fabric-finishing samples. In classifying fiber characteristics contractile fiber and ultra-fine fiber Shingosen fabrics show smaller values of Dd than irregular fiber fabrics.

The Effect of a Grooved Hollow in a Fibre on Fabric Moisture- and Heat-transport Properties

It is shown that polyester fibres are able to absorb water more easily by making a grooved and/or a non-grooved hollow in a fibre. The effect of water absorbency becomes larger with an increase in the ratio of space to polymer in the fibre cross-section if the yarn and fabric structures are the same. The effect is especially large under high-humidity conditions. The retention of warmth by polyester-fibre fabrics is increased by making a grooved and/or non-grooved hollow in a fibre in dry conditions, but the effect is reversed in wet conditions. The thermal conductivity of polyester-fibre fabrics is reduced by making a grooved and/or a non-grooved hollow in a fibre, and the trend agrees well with the ratio of space to polymer in the fibre cross-section. The parameter q-max for polyester-fibre fabrics increases with relative humidity if the fabrics absorb water. However, the effect of the surface-contact area is more important for the measurement of q-max.

A Study of the Mechanical Properties of Woven Silk Fabrics. Part I: Fabric Mechanical Properties and Handle Characterizing Woven Silk Fabrics

In order to investigate the soft handle of woven silk fabrics, their basic tensile, bending, shearing, compressional, and surface properties were measured on the KESF system. Fabric shear, compressional, and tensile properties distinguish continuous-filament silk fabrics from fabrics of other fibres. Shear stiffness and hysteresis in shear force are very small, and these fabrics are very deformable in their compressional and tensile properties at small strain levels. High values of FUKURAMI are a characteristic of continuous-filament woven silk fabrics.

The Mechanical Properties and Fabric Handle of Polyester-fibre ‘Shingosen’ Fabrics

Features of the mechanical properties and fabric handle of polyester-fibre ‘Shingosen’ fabrics are studied precisely by the objective-evaluation method of fabric handle. The distinctive features are clearly shown for each ‘Shingosen’ type, classified conventionally as: New Silky, Peach Face, Rayon Touch, and New Worsted fabrics, which were produced more recently (1991–92). A new classification based on the main technique for producing ‘Shingosen’ fabrics is proposed as: Contractile Fibers, Irregular Shapes, Yarn Processing, and Ultra-fine Fibres groups. It is shown clearly that the Irregular Shapes group corresponds well lo the New Silky type and that the Yarn Processing group corresponds to the New Worsted type. Three independent types of primary handle, FUKURAMI, HARI, and SHARI, were selected for ‘Shingosen’ fabrics by cluster analysis, and the corresponding three fabric groups, FUKURAMI group (high FUKURAMI), HARI group (high HARI), and SIHNAYAKASA group (low SHARI), are defined. ‘Shin-Shingosen’ fabr...

Changes in the Mechanical Properties and Fabric Handle of Polyester-fibre Fabrics Through the Finishing Stages

The basic mechanical properties and fabric handle of the polyester-fibre fabric called ‘Shingosen’ were pursued through the finishing stages by an objective-evaluation method developed by Kawabata and Niwa, using the KES-FB system. The effects of the finishing stages were clarified as follows. The polyester-fibre fabric is remarkably softened in all its mechanical properties and fabric handle by the stage of relaxing, which includes desizing, shrinking of fibres, and relaxing of the internal residual stress of the fabric. The polyester-fibre fabric becomes increasingly soft at the following weight-reduction stage because of the ‘effective gap’ between fibres and/or yarns and the splitting of fibres. However, the effects of dyeing and raising are small. By using discriminant analysis with the primary hand values as variables, it is considered that bere is a distinctive zone of fabric handle for silk-like and peach-skin-type polyester-fibre ‘Shingosen’ fabric.

Features and Characteristic Values of Fabric Compressional Curves

A compressional model of fabric was proposed and its validity was investigated precisely. The following conclusions were obtained. The compressional and recovering curves are considered to consist of three steps, respectively. Characteristic values proposed here are strongly related to features of the shapes of fabric compressional curves. According to the principal component analysis, the first and second principal components can explain almost all the information about fabric compressional property.

Some Features of the Static and Dynamic Drape Behaviour of Polyester-fibre Shingosen Fabrics

The static and dynamic drape behaviour of polyester-fibre shingosen fabrics was investigated precisely and analyzed by using the new mechanical parameters of the dynamic drapability of fabrics, such as the revolving drape-increase coefficient, D r, and the revolving drape coefficient at 200 r/min, D 200. It is shown that the value of D r of Peach Face type was small and that of New Worsted type was large. The value of D 200 of New Worsted type was larger than that for other shingosen types. On the other hand, there was no difference between each group of shingosen fabrics in node numbers and conventional static drape coefficients. In the classification by production characteristics, yarn-processing-type fabrics showed larger values of D r and D 200 than fibre-production- and fabric-finishing-type fabrics. In the classification by fibre characteristics, contractile-fibre-type shingosen fabrics showed the smallest values of D r and D 200. These features of shingosen fabrics in static and dynamic drape behaviour became more distinct by means of discriminant analysis using the parameters of the revolving drape coefficients and also the conventional static drape coefficient and node number as variables.