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The objective of this research was to determine the effect of multiple layers of materials typical of those used in air pneumatic compression devices (which require air impermeable layers to function) on thermal and water vapor resistance. The experimental set-up included: (a) single layers of two next-to-skin knit fabrics in both relaxed and extended conditions, (b) two layers of silicone, and (c) a multi-layered assembly comprised of a next-to-skin fabric and two layers of silicone. Structural properties (thickness, mass) dominated thermal resistance of the multi-layered assembly, and the silicone layers rendered this assembly impermeable to water vapor as expected. Results confirmed the need for some form of 'ventilation' to facilitate water vapor transfer from a potential user’s skin to the environment. By creating 18 circular vents across the silicone layers (each vent 314 mm2), which formed ventilation of ∼2% of total surface area, the water vapor resistance of the multi-layered assembly dropped significantly from very high (but non-measurable) to below ∼300 m2Pa/W, although ventilation did not improve the thermal resistance of the multi-layer arrangements. Results of this research will enable manufacturers of pneumatic compression devices to develop devices comprised of a multiple layer arrangements i.e. a knit fabric next-to-skin layer and silicone layers with optimized vents across the silicone layers, so that the user can continue the compression treatment with an acceptable microenvironment.

Understanding odor volatiles known to constitute those emanating from the human body and how these interact with textiles is relevant to diverse interested parties because of changing fiber use, a better understanding of apparel life cycles including cleaning and the potential for fiber/textile re-use. This paper extends the application of our proton transfer reaction-mass spectrometry model system on adsorption and release behavior of fiber types typical of next-to-skin uses to include both viscose and other volatile organic compounds in body odor for which release has not previously been studied (hexanoic acid, acetone, cyclohexanone, hexanal, methyl butanoate, ethyl benzene, 1-octanol, decanal, butanoic acid). The current findings confirmed release patterns of different fiber types found in our earlier studies – low release of volatile organic compounds from cotton and wool, but higher release from polyester – and made a new finding of low release from viscose. Adsorption characteristics were different given the different volatile organic compounds analyzed. Viscose showed better adsorption characteristics for primarily polar volatile organic compounds, but was otherwise very similar to cotton.

Bandages are common in many health-related treatments, including management of edema of the lower limb where they may remain in place for several days. The behavior of 2 bandage fabrics was investigated after exposure for up to 5 days to a multiaxial extension laboratory setup on a tensile tester in compression mode. The fabrics were extended 20% and remained under that machine setting. Stress-relaxation over time was determined by analyzing the rate of change over 24 hours and over 5 days. Most change, a rapid drop in force, occurred during the first 15 minutes; thereafter, for the next 12-hour period, a slower rate of decrease was observed. Both fabrics continued to relax gradually during the next 12 hours and continued to do so for up to 5 days. Little further change was evident during the last 12 hours or so. This phenomenon suggests that rewrapping may be appropriate (albeit not practical) after 12 hours of compression therapy to optimize the compression given to the lower leg. Relaxation behavior of these 2 fabrics can be explained using the generalized Maxwell-Wiechert model.

Electrically conductive fabrics are achieved by functionalizing with treatments such as graphene, however, these change conventional fabric properties and the treatments are typically not durable. Encapsulation may provide a solution for this, and the present work aims to address these challenges. Next-to-skin wool and cotton knit fabrics functionalized using graphene ink were encapsulated with three poly(dimethylsiloxane)-based products. Properties known to be critical in a next-to-skin application were investigated (fabric structure, moisture transfer, electrical conductivity, exposure to transient ambient conditions, wash, abrasion, and storage). Wool and cotton fabrics performed similarly. Electrical conductivity was conferred with the graphene treatment but decreased with encapsulation. Wetting and high humidity/low temperature resulted in an increase in electrical conductivity, while decreases in electrical conductivity were evident with wash, abrasion, and storage. Each encapsulant mitigated effects of exposures but these effects differed slightly. Moisture transfer changed with graphene and encapsulants. As key performance properties of the wool and cotton fabrics following treatment with graphene and an encapsulant differed from their initial state, use as a patch integrated as part of an upper body apparel item would be acceptable.

The objective was to determine whether changes in indicators of skin health among participants suffering from diabetes mellitus could be attributable to the type of sock worn (fiber content, structure). Changes in skin health over time (e.g. temperature, skin hardness, transepidermal water loss, stratum corneum hydration) can indicate improvement or deterioration, and these may be related to socks worn. Socks of different structure (single jersey, terry), and of fiber content (merino wool, cotton) were worn over a period of 22 weeks by participants suffering from diabetes mellitus. Each participant was their own control: change over time in skin hardness, stratum corneum hydration, transepidermal water loss and temperatures were monitored. Properties of the sock fabrics were measured as new and after use to determine effects of wear. Limited evidence of improved skin health was attributable to socks composed primarily of wool.

Low-energy impact testing of hockey shin guards was carried out using a drop test impact rig and a new physical setup protocol. Two brands of shin guards were impacted once (2.6 J, 3.3 J; without and with a sock), and impacted three times (3.3 J; with a sock). The peak force and impulse of a single impact increased with increasing impact energy (by approximately 30 and 7%, respectively) whilst repeated impacts increased the peak force and decreased the impulse (by approximately 70 and 3–9%, respectively, between one and three impact events). The presence of a sock attenuated impact force to a greater extent than the guards alone, at both impact energies. As a sock is usually worn over hockey shin guards, its presence contributes to enhanced protection to the lower limb.

Properties critical to the structure of apparel and apparel fabrics (thermal and moisture transfer, elasticity, and flexural rigidity), those related to performance (durability to abrasion, cleaning, and storage), and environmental effects have not been consistently addressed in the research on fabric sensors designed to interact with the human body. These fabric properties need to be acceptable for functionalized fabrics to be effectively used in apparel. Measures of performance such as electrical conductivity, impedance, and/or capacitance have been quantified. That the apparel/human body system involves continuous transient conditions needs to be taken into account when considering performance. This review highlights gaps concerning fabric-related aspects for functionalized apparel and includes information on increasing the inclusion of such aspects. A multidisciplinary approach including experts in chemistry, electronics, textiles, and standard test methods, and the intended end use is key to widespread development and adoption.

Branded blends of wool and cotton for high-end apparel fabrics were established in Britain and later exported to many English-speaking countries during the 19 th century (e.g. woven fabrics Viyella™, 55% wool, 45% cotton; Clydella™, 81% cotton, 19% wool). During the late 20 th century, cotton and wool blend yarns for high-end apparel applications were developed in Australia (Colana®, 70% cotton, 30% wool). None of these branded blends of wool and cotton has a current market presence, yet there is evidence of relevance and interest in such blends for the high-end apparel market. How can we account for this disappearance and for the renewed interest?

The mechanism of dry heat flow through lofty nonwoven structures (i.e. thermal resistance) as occurs in quilts has been established. By contrast, there is a scarcity of published information on the water vapor transport properties. This work explores the thermal and water vapor transport properties of a number of different quilt samples with a focus on identifying fiber type effects. Both commercial product and matched laboratory samples were examined. Steady-state thermal resistance and water vapor resistance measurements confirmed that both properties are primarily determined by sample thickness and are largely independent of fiber type. Experiments were also undertaken to observe transient effects. Test samples were initially equilibrated on a ‘dry’ guarded hotplate (35 ± 0.1℃) in a low relative humidity environment (45%). The relative humidity was then rapidly increased to 85%. Compared to polyester, wool samples exhibited a large reduction in the heat flux required to maintain the hotplate temperature. This transient peak lasted for in excess of 1000 seconds. The magnitude of this transient peak in heat flux was proportional to the quantity of wool in the sample and is believed to be associated with the known exothermic nature of water vapor absorption by wool as relative humidity increases. Based on the published values of the heat of water absorption of wool it is estimated that this additional transient heat source is significant relative to a typical human resting metabolic rate and so the effect may be of practical relevance in the bedding environment.

A method for collecting axillary odor on nine knit fabrics was developed and odor intensity determined using a panel of assessors. Two methods, one involving paired-comparisons in the quad analysis method and the other a line scale, were investigated to determine if differences in intensity of odor retained on the fabrics varying by fiber and fabric structure could be detected. Both methods allowed detection of differences. However, the line scale method was more time-efficient and enabled a greater number of assessors on the panel, an advantage for reducing the effect of individual differences in sensitivity to axillary odorants. Recommendations for a collection method, handling and assessment method are raised.

The objective of this work was to determine the drying time of a range of apparel fabrics simulating both during and after wear and in doing so, develop: (1) a laboratory method for wetting specimens in a reproducible manner, applicable to a wide variety of apparel fabrics and a large number of specimen; and (2) a method for determining drying time, including a practical laboratory definition for the end-point `dry'. The methods were applied to seventeen fabrics varying in fiber content and in fabric structure. Fabric specimens can be wetted by machine, can be line dried, and can be dried using a simulated on-skin method. A workable laboratory definition of `dry' is provided.

Nine apparel fabrics varying in fiber (cotton, wool, polyester) and knit structure (1 × 1 rib, interlock, single jersey) were investigated for their retention of axillary odor following wear. As axillary odor results from bacterial metabolism of apocrine and sebaceous secretions, counts of total aerobic bacteria and corynebacteria on the fabrics were carried out. Odor intensity was strongly associated with the fiber type, with polyester fabrics rating high in odor intensity and cotton and wool mid-low odor intensity. A structure effect was apparent for polyester fabrics, with the lightweight single jersey fabric rated less odorous than the heavier-weight interlock and 1 × 1 rib structures. The relationship between fiber type and odor was not influenced by bacterial numbers present, with counts after one day similar for all fabrics. However, the number of bacteria declined more rapidly on polyester fabrics than on either the cotton or wool fabrics. Counts of odor-associated corynebacteria subgroup (A) remained largely unchanged on wool fabrics for 28 days.

A range of wool knit fabrics designed to be used in garments worn next to or near the skin was examined to establish if differences in responses to water vapor and to water were detectable. The three-block experimental design involved six fabrics (non-dyed), and fabric responses on the dynamic sweating hotplate and on the gravimetric absorbency testing system (GATS) were determined. Some differences among the fabrics were detectable (e.g. %RH at the initial rise and at equilibrium, %RH rate of rise, temperature differences in the initial phase and at equilibrium, specific maximum absorbent capacity, flow rate) but many were not. For this set of wool knit fabrics, mass and thickness were typically linked to the temperature variables from the dynamic sweating hotplate, and bulk density linked to a few variables from the GATS.

The microscopic structure of muka (fiber aggregate extracted from harakeke) (observed using light microscopy and scanning electron microscopy) from six selected cultivars of harakeke varied, and this may explain the differences perceived by weavers, and that different end uses are preferred for various cultivars. The dimensions of ultimate fibers ranged from 10.1 μm (Takaiapu) to 12.8 μm (Paretaniwha) in average-transverse-width and 3735 μm (Takirikau) to 4751 μm (Makaweroa) in length. The cultivars prized for muka (e.g. Arawa, Makaweroa) had the longest and finest ultimate fibers. The transverse-section shapes of fiber aggregate bundles varied among the cultivars. Tapamangu and Takaiapu had fiber bundles that were more uniformly shaped than the other cultivars studied, and Takirikau had a high yield of fiber aggregate bundles. Paretaniwha differed from the other five cultivars studied having an average number of narrow, non-uniformly shaped fiber aggregate bundles per unit width.

The objective of this work was to develop a pre-treatment (cleaning) procedure for a wide range of apparel fabrics and to determine whether differences observed in the properties of fabrics which had and had not been pre-treated were significant. Properties relevant to the manufacture and/or performance of apparel included mass per unit area, thickness, bending length, flex-ural rigidity, drape coefficient, air permeability, water vapor permeability, liquid absorptive capacity, drying time, ‘dry’ thermal resistance, ultra-violet transmission. Results for the same property on the same fabric measured when the fabrics had and had not been pre-treated generally differed significantly, confirming the importance of pre-treatment prior to measuring these properties, particularly when claiming in-use attributes of fabrics. A procedure for pre-treatment is recommended: six consecutive cleaning cycles following procedure 8A of British Standard EN ISO 6330: 2001 (i.e. not dried between cycles), and dried flat following procedure C of this standard.

Botanists recognize only two kinds of New Zealand flax ( Phormium tenax and Phormium colensoi), while Māori weavers recognise over fifty different cultivars that have specific end-uses. Selected properties of muka4 (sclerenchyma fiber aggregates extracted from harakeke ( P. tenax)) from three of these cultivars (Arawa, Tapamangu, Makaweroa) are examined. Māori consider these three cultivars to provide excellent fibers that are easy to process. Tapamangu and Arawa are similar in terms of muka length, linear density, tenacity, extension at maximum load, and maximum extension, and the ultimate fibers of these cultivars have similar dimensions (width, length). Muka from Makaweroa is longer, not as tough, but with a linear density similar to the other cultivars. The ultimate fiber length of Makaweroa is greater, but the width is similar to Tapamangu and Arawa. Muka from the keel is longer, of higher linear density, and tougher (similar tenacity, higher maximum extension) compared to margin muka. The side of the leaf from which muka is extracted does not affect the properties measured.

Selection of a suture material typically depends on its tensile properties, but in the absence of an international standard test method, a comparison of properties is problem atic. A series of experiments is conducted to determine the tensile performance of non-knotted and knotted non-sterile suture monofilaments, and the effect of test conditions on this performance. Using the ear and cut loop technique, the factorial experiment includes three gauge lengths, three crosshead speeds, three non-sterile suture monofila ments, and five knot configurations. Each combination of variables is replicated five times. Different test conditions affect the ultimate strain and tenacity of both knotted and non-knotted monofilaments. Ultimate strain values are lower with increasing gauge length (when tested at the same crosshead speed) and crosshead speed (when tested at the same gauge length). All monofilaments are characterized by higher tenacity values with in creasing gauge length (at the same crosshead speed) and lower tenacity values with increasing crosshead speed (at the same gauge length). Load-extension curves and visual images of selected monofilament sutures are provided.

Samples of opossum fibers are examined using scanning electron microscopy to describe their appearance, including any visible damage that may have resulted from early processing. Variations in the surface morphology among individual fibers and along the length of a single fiber are observed. Even tile-like, rounded tile-like, wave-like, and cornet-like scales are present, most with smooth surfaces and smooth scale margins. The mean fiber length and diameter are 29 mm and 19.89 μm, respectively, and neither fiber length nor diameter seems related to scale type. Breaks accompanied by transverse and longitudinal cracking, fibrillar failure, buckling, and peeling back of scales are evident in fibers extracted by machine. No damage is visible on bleached fibers.

A theoretical viscoelastic model based on the four-element Burgers model is devel oped to predict changes in load with time of ISO-301 stitched seams under longitudinal loading subjected to extension/recovery cycling at a constant rate of extension. Param eters calculated from experimental stress relaxation curves are used to determine the theoretical relationship between load and time for tensile cycling. The model gives good agreement with experimental stress relaxation behavior of seams over the range 0-30 seconds. Theoretical predictions of load versus time give the best agreement with experimentally derived tensile cycling curves for seams cycled between the lowest extension limits. The exact solution of the theoretical model consists of a double ex ponential expression, suggesting that two processes are responsible for the change in load of seams with tensile cycling, a result consistent with the statistical model for seam ageing and with visual observations described in Part I of this series.

In order to examine the mechanisms by which seams age and fail under loads typical of those in use, factors and interactions among factors influencing the change in load required to extend an ISO-301 stitched seam (type ISO 1.01.01) during repeated lon gitudinal extension/recovery cycles at low loads are identified. Fabric type and exten sion limit have the greatest effect on the load required to reach maximum extension of the seam between 0-100 cycles, while fabric type is important over the range 100- 5000 cycles. Variables depending on inclusion of the seam (thread type, linear stitch density) have the most influence during the initial extension. Visual aspects of seam ageing are examined with optical and scanning electron microscopes, and two distinct processes occurring during tensile cycling are identified. Fabric type and thread type are the most important variables affecting the breaking load and breaking extension of cycled seams. Although interactions among variables are not important individually, together they account for 13% of the total variance in breaking extension.

To facilitate appropriate selection of fiber, fabric and product variables (fiber content, fabric structure and product design) during manufacture it is desirable to know what, if any, relationships exist among the fiber, fabric, tactile and thermal properties and acceptability of fabrics. This information would allow targeting of products towards specific end-uses such as upholstery. Possible interrelationships among selected objective (temperature, humidity) and subjective factors (tactility, thermal acceptability, satisfaction), product acceptability and subject preferences for a range of upholstery fabrics were examined Upholstery samples in seat cover form were assessed in a controlled environment of 23 ± 2°C, 55 ± 2% R.H. Tactile assessment was performed before and after controlled environment testing. Some small differences in tactile rankings before and after controlled environment testing did occur in the case of the wool/polyester samples. Distinct thermal acceptability, temperature and humidity profiles (both objective and subjective) were identified although these differences were not statistically significant. Significant differentiation among fabrics on the basis of thermal acceptability, temperature and humidity alone was not possible. Lack of significant differences among fabrics perceived temperature and wetness profiles suggested other variables influence consumer judgment of thermal acceptability over time. This was confirmed by subjects overall assessment of fabrics, which differed significantly among samples.

This work examined the extent to which wool fiber variables (fiber diameter, length and bulk) influence the tactile characteristics of otherwise homogeneous fabrics, i.e., fabrics constructed from standardized fiber content, yarn structure, dye, and finishing treatment. Subjects were 24 female students enrolled in advanced Clothing and Textiles courses at the University of Otago and 20 male Textile Scientists. Results showed that structurally homogeneous fabrics (but with differing wool fiber variables) could be distinguished as having different tactile characteristics. Significant differences in the ranking of roughness (F (5,42) = 11.29, p < .001) and prickliness (F (5,42) = 12.84, p < .001) occurred among these fabrics. Smooth and less prickly perceptions were associated with fiber diameter of less than 23 microns and fiber bulk greater than 31 cm3/g; rougher and more prickly perceptions occurred when fiber diameter was greater than 34 microns and fiber bulk less than 21 cm3/g. No significant difference was found among fabrics on the basis of warmth to the touch (F (5,35) = 1.52, ns).

Although interest in the tensile behavior of the lockstitch seam dates back fifty years, analysis so far has been restricted to load and elongation at the first thread break. Information on events up to the first break, and on work, would earlier have had to be extracted manually, a time-consuming and error-prone process. With increased availability of microprocessors, continuous rapid retrieval of data can occur during the testing sequence and can be stored for subsequent analysis. The development of a computer program and its application in isolating critical factors in seam tensile behavior are outlined. This approach has wide applicability in clothing and textile research organizations and in clothing quality control laboratories.

Tactile perceptions of five fabrics commonly used for protective clothing were made by four subjects from specimens using the hand and from garments using selected body sites. Results indicated there was considerable agreement among subjects on ratings of prickly-smooth, stiff-limp, cool-warm, thick-thin, and the five fabrics being assessed did not differ significantly. Regional variations in perception were not demonstrated.

The criteria for selection and use of protective clothing, particularly with respect to protection from high radiant heat, are both objective and subjective. Part 1 of this study examines objective responses to clothing. Five fabrics commonly used in protective workwear were made into overalls of identical design and were evaluated by adult males in a simulated work environment. Microclimate humidity differences occurring during exercise and rest were significant with respect to subjects and times but not with respect to overalls. There was, however, a significant overall/time interaction. Skin temperature differences occurring during exercise and rest were significant only with respect to time and regions of the body. Thus, despite physical differences in the five overalls, particularly mass, statistically significant objective data allowing discrimination among overalls was not demonstrated.

The criteria for selection and use of protective clothing, particularly with respect to protection from high radiant heat, are both objective and subjective. Part 2 of this study examines subjective responses to clothing. Five fabrics commonly used in protective workwear were made into overalls of identical design and evaluated by adult males in a simulated work environment. Subjective evaluations of humidity sensation in the leg microclimate at set times during the exercise/rest protocol did not differ significantly with respect to the five overalls and differed significantly among subjects only after the full exercise period had elapsed. High positive correlations were found between subjective humidity sensations and objective measurements. Subjective thermal sensations taken at three different body regions did not enable discrimination among overalls. Subjects tended to rank garments similarly. Subjective thermal sensations did not pattern objective thermal data; thus when measuring two parameters (humidity and thermal responses) subjectively and objectively, discrimination among overalls was not possible.