Testing Natural Easy Care fabrics
Natural Easy Care (NEC) fabrics are designed to retain all their aesthetic and functional properties after machine washing and tumble drying. Performance testing provides assurance they are fit for this purpose.
NEC fabrics, developed at AgResearch in Christchurch for Australian Wool Innovation Ltd. (AWI), are tested using the Woolmark Company test specifications. The Woolmark is an internationally recognised brand that gives consumers a guarantee of quality.
Woolmark symbol
The Woolmark symbol indicates a product has met the Woolmark quality standards – these standards are internationally recognised.
Testing NEC fabric properties
Traditional wool fabrics are likely to shrink, mat and pill when they are machine washed and show signs of fibre breakage with wear over time. NEC fabrics are designed to be more durable and easy care, so scientists use standard tests to ensure they meet the performance standards specified for these fabrics. The main properties they test are machine washability, shrinkage, abrasion and pilling resistance, stretch and recovery, and tensile and tear strength.
Shrink testing on NEC fabric
When AgResearch transfer the NEC technology, the companies producing the fabric send them a sample for testing. AgResearch use a Woolmark Company test to test the fabric. Research Associate Carolyn Piper explains the test performed for shrinkage. NEC fabrics are designed to shrink no more than 3% so the fabric sample is measured, given the equivalent of 50 machine washes and remeasured.
Questions to consider:
The Woolmark Company test is a ‘standard’ test that is internationally recognised. What are the advantages of using an internationally recognised test such as this?
Why would a standard test have been set up initially?
What may be involved in establishing a standard test method?
Tensile strength testing on NEC fabric
Fabric samples are tested in the warp (lengthwise) and weft (crosswise) direction. They are clamped in a machine and extended until they break. The breaking load and extension are measured. The extensibility of the fabric contributes to its comfort.
Questions to consider:
Why is it an advantage to have natural stretch in the fabric?
Fabric testing a stage-by-stage process
Testing is fundamental to the research, and researchers test NEC fabrics at many stages throughout their development, not just in their finished state.
From early in the development, researchers trial many different parameters. Each time something is changed, they carry out testing and analyse the results to decide how they will refine and improve the fabrics.
Martindale machine
The Martindale machine at AgResearch is used for carrying out standard tests for abrasion and pilling resistance in fabrics.
Testing of the finished fabric is also carried out at a number of stages:
Prototype fabrics: Smaller quantities of fabric are produced first until the required performance properties are met.
Pilot plant trials: When they are ready to trial a larger production run, they do this in the AgResearch Pilot Plant, and the fabric is tested again.
Mill trials: When the technology is transferred to a company for commercial production, the final fabric produced is also tested. Sometimes processing adjustments are necessary to ensure the fabric meets the specifications.
Final fabrics: Ongoing testing of final fabric is carried out as required.
Abrasion and pilling testing on NEC fabric
Testing for abrasion is done on a Martindale machine. The sample fabric is rubbed against a standard abrasion fabric using a standard weight until it reaches an unacceptable end point. Testing for pilling is done on the same machine but without using weights or abrasion fabric – two samples of the same fabric are rubbed against one another for a thousand rubs and compared to a standard photograph.
Question to consider:
Can you design a method for testing abrasion and pilling resistance of fabrics in the classroom?
Find out more in this aricle, Developing Natural Easy Care fabrics.
Related content
This article is a handy curation of our resources looking at some of the innovative wool textiles being developed at AgResearch.
