15. Measurements of Yarn and Fabric Errol Wood Learning objectives At the completion of this trial the student will have and understanding of: Explain how the constructional parameters, evenness and tensile properties of yarn are measured and interpreted Describe the features of a software system for predicting the properties and spinning performance of worsted yarn Outline the principles by which the tensile, dimensional stability, serviceability, drape and other mechanical properties of fabrics are determined Describe and compare the two instrument systems for objectively measuring the handle and related properties of fabrics Key and concepts Yarn twist and count, evenness, periodicity, yarn strength and elongation, bulk, bundle strength, prediction software, fabric burst strength, dimensional stability, pilling, snagging, abrasion resistance, drape, crease recovery, shear, Kawabata Evaluation System, SiroFAST system Introduction to the trial Fibre assemblies relevant to wool include slivers, tops, yarn and fabrics. The kinds of measurements relevant to these structures can be grouped as follows: Constituent properties e.g. diameter, fibre length – Construction e.g. linear density, twist – Mechanical tests e.g. strength, flexibility, bulk – Contamination tests e.g. residual grease, vegetable matter faults, neps, moisture – content. In this topic tests for wool fibre assemblies are considered, for yarns and fabrics. The principle references for this topic are the texts by Saville (1999) and Booth (1976). 15.1 Yarn tests Yarn Constructional Parameters 1. Linear density (or count) A (1) (2) , A = 1000 / = 1000 /
15. Measurements of Yarn and Fabric Errol Wood Learning objectives At the completion of this the student will have and understanding of: Explain how the constructional parameters, evenness and tensile properties of yarn are measured and interpreted Describe the features of a software system for predicting the properties and spinning performance of worsted yarn Outline the principles by which the tensile, dimensional stability, serviceability, drape and other mechanical properties of fabrics are determined Describe and compare the two instrument systems for objectively measuring the handle and related properties of fabrics Key and concepts Yarn twist and count, evenness, periodicity, yarn strength and elongation, bulk, bundle strength, prediction software, fabric burst strength, dimensional stability, pilling, snagging, abrasion resistance, drape, crease recovery, shear, Kawabata Evaluation System, SiroFAST system Introduction to the Fibre assemblies relevant to wool include slivers, tops, yarn and fabrics. The kinds of measurements relevant to these structures can be grouped as follows: Constituent properties – e.g. diameter, fibre length Construction – e.g. linear density, twist Mechanical tests – e.g. strength, flexibility, bulk Contamination tests – e.g. residual grease, vegetable matter faults, neps, moisture content. In this topic tests for wool fibre assemblies are considered, for yarns and fabrics. The principle references for this topic are the texts by Saville (1999) and Booth (1976). 15.1 Yarn tests Yarn Constructional Parameters 1. Linear density (or count) (1) (2) , = 1000 / = 1000 / A A trial trial
WOOL-472-572-14-T-15.docx