The Wool ComfortMeter and the Wool HandleMeter, new opportunities for wool

Two instruments have been developed by the Sheep CRC that provide the tools for a new standard in comfort and handle for the next generation of next-to-skin wool knitwear. The Wool ComfortMeter and Wool HandleMeter provide a rapid, accurate and objective measure of two important characteristics of wool knitwear that are currently determined by subjective assessment. The Wool HandleMeter allows the prediction of a set of handle attribute values that can quantify the hand feel of a lightweight jersey fabric. The instrument uses the principle of pushing a fabric sample through a ring. The force displacement curve associated with the fabric test is characterised and used to define each fabric. These values were then compared to the average handle values, as determined by a group of experts, of a large set of lightweight knitted fabrics. Algorithms were developed that enable the instrument to more accurately predict each of seven handle attributes than an individual expert. The Wool ComfortMeter provides a measure of the fibres that are protruding from the surface of the fabric that are responsible for the itchy sensation caused by some knitwear. The results from the instrument have been compared to the results from extensive wearer trials to provide an understanding of the relationship between the instrument value and the comfort perceptions of wearers. The results have shown a very clear relationship between the instrument and wearer trials.

Ultrafine wools: comfort and handle properties for next-to-skin knitwear and manufacturing performance

This study aimed to quantify the skin comfort and handle properties of a range of wool fabrics produced from ultrafine wool (13.7–15.1 µm) and in doing so determine if differences in fiber diameter and staple crimp frequency (5.3–7.1 crimps/cm) were important in these properties. The fabrics were evaluated using a range of subjective and objective measurement techniques, including the Wool ComfortMeter, the Wool HandleMeter and in wearer trials. This work indicated that single jersey fabrics made from ultrafine wool are approaching the limit of objective and subjective evaluation of next-to-skin comfort. The results from the Wool ComfortMeter, Wool HandleMeter and the wearer trial show that there were no significant effects that can be attributed to wool staple crimp (fiber curvature) in these ultrafine wool fabrics. The work also demonstrated a difference in the manufacturing response when knitted fabric made from wools of different fiber diameter (13.7–23.7 µm), and using yarns of the same count, resulted in a progressively higher fabric mass per unit area as mean fiber diameter was progressively reduced.

The influence of fiber diameter, fabric attributes and environmental conditions on wetness sensations of next-to-skin knitwear

This study investigated the relationships between the sensations of sweaty, damp, muggy and clingy, as assessed by human response from wearer trial garment assessment, and fiber type, fiber, yarn and fabric properties and instrumental fabric measurements of next-to-skin knitwear. Wearer trial assessment of 48 fabrics followed a strict 60 minute protocol including a range of environmental conditions and levels of exercise. Adjusted mean weighted scores were determined using linked garments. Instrumental fabric handle measurements were determined with the Wool HandleMeter (WHM) and Wool ComfortMeter. Data were analyzed using forward stepwise general linear modeling. Mean fiber diameter (MFD) affected the sweaty, damp, muggy and clingy sensation responses accounting for between 23.5% and 56.2% of the variance of these sensations. In all cases, finer fibers were associated with lower sensation scores (preferred). There were also effects of fiber type upon sweaty, muggy and clingy scores, with polyester fiber fabrics having higher scores (less preferred) compared with fabrics composed of wool, particularly for peak sweaty scores in hot and active environments. Attributes such as fabric density, yarn linear density, knitting structure and finishing treatments, but not fabric thickness, accounted for some further variance in these attributes once MFD had been taken into account. This is explained as finer fibers have a greater surface area for any given mass of fiber and so finer fibers can act as a more effective sink for moisture compared with coarser fibers. No fabric handle parameter or other attribute of fiber diameter distribution was significant in affecting these sensation scores.

Análise tribológica das malhas multifuncionais obtidas por multicamadas

The present work consists in the analysis of tribologycal properties of basic and multifunctional knitted fabrics. This knowledge has fundamental importance for the textile industry since it can quantify, in an objective way, the tactil. The fabrics used were characterized by friction and mechanical tests for determining the viscoelastic region, wear resistance and friction coefficient of the fabrics used. The stress-strain curve was obtained by the method Kawabata, KES-FB1. Wear tests performed with the aid of equipment Martindale. The measurement of friction coefficient, two methods were used and analyzed comparatively. The first was a method already established worldwide known as KES-FB4 and the second was an innovative method called FRICTORQ, developed by the University of Minho. These two methods were compared taking into account the relative motion between the tribologycal pairs are different from each method. While the first motion is translational, the second is rotational. It was formal that the knitted had a multifunctional fabrics tribologycal performance which was better than the basic knitted fabrics, as the viscoelastic region, was laager highlighting a multifunctional structure, with greater wear resistance mainly on the back side of the knitted fabrics and lower friction coefficient. Performing a comparative analysis between two methods used to measure the friction coefficient, it was formal that both methods were consistent in terms of results. In operational terms, the FRICTORQ showed ease of operation and increased reproducibility of results

Fabric and greasy wool handle, their importance to the Australian wool industry: a review

Handle-related properties of woollen fabrics have been demonstrated to be major factors affecting consumer buying attitudes. Handle is the combination of both textural and compressional attributes. Compressional handle has demonstrated processing advantages in woven and knitted fabrics. The handle of processing lots can be manipulated using a variety of technologies but direct manipulation of textural greasy wool handle pre-processing is still crude. On-farm, there is documented evidence that including handle assessment in a selection index provides additional improvements in genetic gain. However, the assessment of greasy wool handle is based on a tactile evaluation of the wool staple by sheep and wool classers, and its application is affected by a lack of framework that instructs assessors on a standard method of assessment. Once a reliable and repeatable protocol is developed, further understanding of the effect greasy wool handle has on final garment quality will be possible.

Bifacial fabric structures and properties.

Novel bifacial fabrics, with a woven structure on one face and a knitted structure on the other, were developed and produced on a purpose-built machine using conventional fibres. Bifacial fabrics have two breakages in warp and weft directions, and better thermal comfort properties than traditional woven and knitted fabrics.

Controlling and predicting the pilling propensity of knitted wool fabrics

This thesis tackles an important quality issue in the wool industry - the pilling of wool knitwear. Through artificial neural network modelling, the important fibre, yarn and fabric attributes that affect fabric pilling have been identified. A predictive model on fabric pilling has been developed, which will assist the wool industry in the management and control of fabric pilling.

Evolution of moisture management behavior of high-wicking 3D warp knitted spacer fabrics

Moisture management behavior is a vital factor in evaluating thermal and physiological comfort of functional textiles. This research work studies functional 3 dimensional (3D) warp knitted spacer fabrics containing high-wicking materials characterized by their profiled cross section. These spacer fabrics can be used for protective vest to absorb a user’s sweat, to reduce the humidity and improve user’s thermal comfort. For this reason, different 3D warp knitted spacer fabrics were produced with functional fiber yarns in the back layer of the fabric (close to the body) and polyester in the front and middle layers (outer surface). Comfort properties such as air and water vapor permeability and wicking and other moisture management properties (MMP) of different fabric samples were measured. It is demonstrated that by using profiled fibers such as Coolmax fiber, moisture management properties of spacer fabrics can be improved, enabling them to be use as a snug-fitting shirt worn under protective vests with improved comfort.

Relationships between wearer assessment and the instrumental measurement of the handle and prickle of knitted wool fabrics

The relationships between wearer-assessed comfort and objectively measured comfort and handle parameters were investigated using 19 pure wool single jersey garments made of single ply yarns. Wearer trials were used to determine prickle discomfort, and whether wearers “liked” the garments. Fabrics then were objectively evaluated using the Wool HandleMeter, which measures seven primary handle attributes; and the Wool ComfortMeter (WCM), to predict a wearer's perception of fabric-evoked prickle. Wearer responses and the relationships within and between objective measurements and the effect of fibre, yarn and fabrics attributes were analysed by general linear modelling. Mean fibre diameter, fibre diameter coefficient of variation, yarn count, fabric thickness, fabric density, fabric mass per unit area and decatising affected one or more handle parameters. The best model for predicting wearer prickle discomfort accounted for 90.9% of the variance and included only terms for the WCM and WCM2. The WCM was a good predictor whereas mean fibre diameter was a poor predictor of whether wearers “liked” garments. Wearer assessment of prickle and whether or not wearers “liked” fabrics were independent of fabric handle assessment. The results indicate that the handle and comfort properties of lightweight, wool jersey fabrics can be quantified accurately using the Wool HandleMeter and the Wool ComfortMeter. For fabric handle, fibre and yarn characteristics were less important than changes in the properties of the fabric.

Objective pilling evaluation of wool fabrics

An objective pilling evaluation method based on the multi-scale two-dimensional dual-tree complex wavelet transform and linear discriminant function of Bayes' Rule was developed. The surface fuzz and pills are identified from the high-frequency noise, fabric textures, fabric surface unevenness, and illuminative variation of a pilled fabric image by the two-dimensional dual-tree complex wavelet decomposition and reconstruction. The energies of the reconstructed subimages in six spatial orientations (±15º, ±45º, ±75º) are calculated as the elements of the pilling feature vector, whose dimension is reduced by principal component analysis. A linear discriminant function of Bayes' Rule was used as a classifier to establish classification rules among the five pilling grades. A new pilled sample with the same physical construction can then be automatically assigned to one of the five pilling grades by the classification rules. A general evaluation of the proposed method was conducted using the SM50 woven, non-woven, and SM54 knitted standard pilling test image sets. The results suggest that the new method can successfully establish classification rules among the five pilling grade groups for each of the three standard pilling test image sets and should be applicable to practical objective pilling evaluation.

Effect of fibre, yarn and knitted fabric attributes associated with wool comfort properties

In this replicated experiment, we investigated the comfort properties of single jersey fabrics composed of cashmere in blends with superfine wools of different fibre curvature (crimp) where the fibre diameter of the wool and cashmere were tightly controlled. The 81 fabrics were evaluated using the Wool ComfortMeter (WCM) which has been calibrated using wearer trials of wool knitwear. General linear modelling determined the best prediction models for log10 transformed fabric WCM values using 27 fibre, 16 yarn and 30 fabric attributes. Tighter fabrics were less comfortable. Progressively blending cashmere with wool progressively increased comfort assessment. The WCM was able to detect differences between fabrics which were more supple and springy, thinner and lighter, and were composed of more elastic, uniform and stronger yarns. Together these attributes explained 82% of the variance in WCM value.

Effect of surface treatment and knit structure on comfort properties of wool fabrics

The comfort properties of the pique and single jersey knitted wool fabrics were investigated using the Wool ComfortMeter (WCM). The fabrics were knitted in three cover factors and treated with either plasma or a silicone softening agent and were compared with untreated fabrics. Plasma treatment did not show significant effects on the comfort value. However, silicone polymer significantly reduced WCM values suggesting that the silicone coating reduced the number of protruding fibres on the fabric surface. Regardless of treatment used, pique fabrics showed a lower WCM value, and therefore were perceived to be more comfortable than the single jersey structure. While the effect of cover factor was not significant, in fitted model to predict the WCM value of fabrics, mass/unit area and fabric thickness were significant predictors along with fabric structure and finishing treatment.

Reducing photoyellowing of wool fabrics with silica coated ZnO nanoparticles

Though ZnO nanoparticles (NPs) are an excellent UV absorber, their photocatalytic activity greatly limits the application areas of these particles. Under sunlight exposure, ZnO NPs used as a UV absorber can accelerate the wool yellowing process by generating free radicals. To reduce this photocatalysis effect, a physical barrier has been fabricated by coating the ZnO NPs with a silica layer (ZnO@SiO2), hence providing good UV-shielding with low photocatalytic activity. The structure and optical properties of ZnO and ZnO@SiO2 NPs were characterized by transmission electron microscope (TEM) and UV–Vis spectrum. The photocatalytic activity of ZnO and ZnO@SiO2 NPs was evaluated by photo-degradation of Rhodamine B. The ZnO and ZnO@SiO2 NPs were applied to knitted wool fabrics using the dip coating method. The treated wool fabrics were characterized by a scanning electron microscope (SEM) and the photoyellowing level of treated fabrics after exposure under simulated sunlight was evaluated by a Datacolor Spectraflash spectrophotometer. The ZnO@SiO2 NPs demonstrated excellent protection of wool against photoyellowing.

Fabric handle properties of superfine wool fabrics with different fibre curvature, cashmere content and knitting tightness

The handle properties of single jersey fabrics composed of superfine wools (17 μm) of different fibre curvature (114 vs. 74 °/mm) in blends with cashmere (fibre curvature 49 °/mm) were investigated. There were four blend ratios of cashmere (0, 25, 50, 75%) plus 100% cashmere. Each of the nine fibre blend combinations were replicated three times, and each was knitted into three tightness factors. The 81 fabrics were evaluated using the Wool HandleMeter, which measures seven primary handle attributes and Overall handle, and have been calibrated using a panel of experts and a wide variety of commercial fabrics. Results were analysed by ANOVA and general linear modelling. Tightness factor significantly affected all Wool HandleMeter attribute values, with the effect of tightness factor varying according to handle attribute. The Wool HandleMeter was able to detect differences between fabrics composed of superfine wool differing in fibre curvature, with lower fibre curvature wool fabrics having more preferred Overall handle and softer, looser, cooler, lighter and less dry handle attributes at some or all tightness factors compared with fabrics composed of higher fibre curvature superfine wool. Progressively blending cashmere with wool significantly improved Overall handle, increased soft and smooth handle, reduced dry, heavy and tight handle. Linear regression modelling indicated that fabric mass per unit area explained more than 50% of the variance in overall fabric handle and in combination with variations in fabric thickness and yarn elongation could explain 71% of the variance in Overall handle.