Leather and Textiles Physical Property Measurement

The textiles and leather industries employ millions of people worldwide, turning raw materials such as natural fibres (cotton and wool) and synthetic fibres (polyester) or treated, tanned hide into finished products such as clothes and footwear, using multiple complex processes.

Research and Development in the leather and textiles industries are now more important than ever before. Customers are driven to purchase eco-friendly alternatives to traditional materials, seeking out textiles that require a lower volume of water for growth (e.g. hemp as an alternative to cotton), recycled leather and textiles, textiles that consume a large amount of carbon dioxide during their growth (e.g. bamboo) and vegan alternatives to silk and leather. Vegan leathers were until recently made from PVC. However, novelty value and customers’ desire for reducing plastic manufacture, have caused plant-based leathers to become increasingly popular. These can be made from a wide variety of plant materials, including pineapples, apples and crop waste.¹

These alternative materials must still perform satisfactorily, in applications that cause them to be subjected to high and fluctuating stresses, and frequently harsh environmental conditions.

Why test textiles and leather?

Within the textiles industry, the use of mechanical testing with a Texture Analyser helps to ensure consistently high quality of products at every stage from raw materials, to dyed fabrics and through to the finished product. The same is applicable to the leather industry. There are many specific test methods for each industry, including International Standard methods. Although they are generally grouped separately, the basic methods used for each have a lot of overlap. Testing these materials allows product quality to be monitored, the product standard to be assessed, to aid the research and development process and to know the performance of the product at every stage of its manufacture.

Tests that are performed using a Texture Analyser are mechanical in nature, measuring physical properties. Most commonly, these are destructive, including tear resistance, compressive strength, tensile strength and puncture resistance, well-suited to the high precision of this type of instrument.

The majority of these tests are not expensive or time consuming, and they provide valuable data regarding the properties of components, materials and completed products for either product development / routine process testing or quality control. When used in a quality control capacity, these tests help prevent faulty products from reaching the market. Leather and textiles testing ensures the products live up to the high expectations on the market and that they are strong and flexible enough to do the job that they were designed for.

Standard methods are widely used in industry. They are not compulsory, acting instead as guidelines for materials that have to meet certain requirements and safety laws. Standards specify the conditioning processes, test instruments used and test atmosphere and conditions required for repeatability between laboratories.

Alternative methods to standards are possible whereby a test can be created that focusses on a particular property that needs to be measured or a quality issue that needs to be identified. Empirical or imitative methods can be developed easily and bespoke probes and fixtures created to support a material in a particular way that necessitates its successful testing.

Over the years we’ve worked with top scientists and companies in many industries to develop new fixtures to measure specific product properties. When the test solution doesn’t exist we go ahead and develop it and add it to our growing number of Community Registered Designs, testament to our leading innovative approach to finding the right solutions to a customer’s testing needs.

A wide range of leather and textiles test methods (including ASTM, ISO AND TAPPI Standards) is built into Exponent Texture Analyser software and will automatically load at the click of a button. We help make your testing quicker to access and the analysis of your product properties already prepared for you.

Typical measurements include: • Tensile Strength • Leather loop compression • Flexibility • Softness • Bagginess • Creep • Stitch tear resistance • Stitch line tear • Burst test • T-peel • Adhesive Peel Strength • Elongation • Modulus • Strength/Distension of Grain • Adhesion of finish • Baumann tear

A selection of special attachments and typical measurements which are commonly used in this application area are shown, although this does not necessarily include the complete range available for the testing of leather and textiles. Test procedures include: compression, puncture / penetration, tension, fracture / bending, extrusion, cutting / shearing. Any of the texture analyser range can be used for the product tests listed.