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

Butler²

2016

animal

The mean fibre diameter (MFD) of wool is the primary determinant of price, processing performance and textile quality. This study determines the primary influences on MFD as Saxon Merino sheep age, by allometrically relating MFD to fleece-free liveweight (FFLwt). In total, 79 sheep were grazed in combinations of three stocking rates and two grazing systems (GS: sheep only; mixed with Angora goats) and studied over 3 years. Measurements were made over 14 consecutive periods (Segments), including segments of FFLwt gain or FFLwt loss. Using shearing and liveweight records and dye-bands on wool, the FFLwt and average daily gain (ADG) of each sheep were determined for each segment. The mean and range in key measurements were as follows: FFLwt, 40.1 (23.1 to 64.1) kg; MFD, 18.8 (12.7 is a random animal effect, γ(Segment.Plot) a random effect associated with Segment.plot combinations, and κ a constant that depends on GS, random animal effects, random Segment.plot combination effects, Segment and ADG. Thus, MFD was allometrically related to the cube root of FFLwt over seasons and years for sheep, but to the square root of FFLwt for sheep grazed with goats. The result for sheep grazed alone accords with a primary response being that the allocation of nutrients towards the cross-sectional growth of wool follicles is proportional to the changes in the skin surface area arising from changes in the size of the sheep. The proportionality constant varied systematically with ADG, and in sheep only grazing, was about 5 when sheep lost 100 g/day and about 6 when sheep gained 100 g/day. The proportionality constant did not systematically change with chronological age. The variation in the allometric coefficient between individual sheep indicates that some sheep were more sensitive to changes in FFLwt than other sheep. Key practical implications include the following: (a) the reporting of systematic increases in MFD with age is likely to be a consequence of allowing sheep to increase in size during shearing intervals as they age; (b) comparisons of MFD between sheep are more likely to have a biological basis when standardised to a common FFLwt and not just to a common age; (c) wool quality (MFD, staple strength) are most likely to be optimised in management systems that maintain constant FFLwt of adult sheep within and between years.Keywords: allometric coefficient, sheep, scaling, wool, skin follicles ImplicationsResponses in mean fibre diameter (MFD) of Merino wool to changes in fleece-free liveweight (FFLwt) were in accord with the primary response of MFD being proportional to the changes in the skin surface area arising from changes in animal size. However, this response can change with individual sheep and nutritional environment. Comparisons of MFD between sheep are more likely to have a biological basis when standardised to a common FFLwt than when standardised to a common age. Wool quality (MFD and staple strength) will be optimised in management systems that maintain constant FFLwt of adult sheep within and between years...

Section: Introductionmentioning

confidence: 99%

Coarser wool is not a necessary consequence of sheep aging: allometric relationship between fibre diameter and fleece-free liveweight of Saxon Merino sheep

Butler²

2016

animal

“…The Wool ComfortMeter values ranged from 13 to 855, the upper value exceeding the target range for comfortable fabrics. 11,17,31 Generally there was a range in Wool HandleMeter parameters of 3 to 5 units. For sleeve trial assessments, the range was about 27 to 50 units, with the largest range and variation in skin feel.…”

Section: Resultsmentioning

confidence: 99%

“…17,24,25 While the WCM gives the value which is related to the perception of prickle in next to skin garments, the Wool HandleMeter quantifies the mechanical properties of knitted fabrics relevant to fabric handle. As with the evaluation of single jersey single ply wool fabrics assessed with the wearer trial, 17 the present investigation has shown that the Wool HandleMeter is a poor predictor of sleeve trial comfort attributes. In other words, a good fabric handle does not guarantee that wearers will not detect prickle discomfort during sleeve trial assessment.…”

Section: Resultsmentioning

confidence: 99%

“…Recent investigations using single jersey garments constructed with single ply wool yarns have shown wearer assessment of prickle and whether or not wearers 'liked' fabrics after wearing them during the wearer trial period were independent of objective Wool HandleMeter fabric handle assessment. 17 While this may be true for the single jersey fabrics evaluated in that study it remains to be determined if objective handle assessment of a wider range of fabrics assessed using the sleeve protocol will provide additional explanatory power in describing wearer prickle discomfort. The aims of this study are to investigate: a) the relationship between the sleeve trial assessments of fabrics with the wearer trial assessment of fabric prickle and uncomfortable scores; b) the association between the Wool ComfortMeter and Wool HandleMeter assessments of fabrics and the sleeve trial assessments of those fabrics; and c) to quantify the additional value of sleeve trial assessments in predicting wearer trial fabric scores when additional measurements are available, including Wool ComfortMeter, Wool HandleMeter, and fabric mean fiber diameter (MFD).…”

mentioning

confidence: 93%

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Relationships between sleeve trial and wearer trial assessment of discomfort and objective measurements

Textile Research Journal

Doyle

Thompson³

et al. 2014

Self Cite

The relationships were investigated between the prickle discomfort scores, assessed by human response from wearer trial garment assessment, and sleeve trial, Wool ComfortMeter (WCM) and Wool HandleMeter (WHM) assessments of fabrics, and fiber diameter characteristics including mean fiber diameter (MFD). Sleeve trial assessment followed exercise, the use of a control sleeve to reduce participant variance and four sensory traits. WHM provides eight handle parameters calibrated against a panel of experts. Four scenarios were evaluated: sleeve trial assessment with MFD; sleeve trial assessment with MFD and WCM; sleeve trial assessment with MFD, WCM and WHM parameters; and sleeve trial assessment with WCM and WHM parameters. Data were analyzed using correlation and forward stepwise general linear modeling. There was no evidence that the incidence of fibers coarser than 30 mm aided the prediction of prickle discomfort once MFD had been accounted for in the models. There were significant correlations between the WCM measurement and each sleeve trial attribute. There was no significant correlation between WHM parameters and sleeve trial assessments. The sleeve trial attribute of 'skin feel' offers potential to improve the predictions made of wearer trial prickle discomfort when used in association of the WCM with or without data on fabric MFD. There was little evidence to support using WHM parameters with or without the WCM in predicting wearer assessed prickle discomfort of fabrics. These results indicate that the rapid evaluation of fabrics using sleeve trial assessment can provide cost effective ranking of consumer preferences.

“…Recent investigations with next-to-skin wool knitwear have shown that prickle discomfort is not associated with the handle of wool fabrics (McGregor, Naebe, Wang, Tester, & Rowe, 2015), as comfort is basically a more complex phenomena. Comfort involves physical interaction between the human body, the fabric and the external environment, while handle is the reaction to the mechanical interactions between human skin and the fabric, where both the fabric surface and the material bulk are being spontaneously evaluated by external body movement.…”

Section: Introductionmentioning

confidence: 99%

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

The Journal of The Textile Institute

Naebe

2015

Self Cite

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.