IWTO is the global authority for wool quality standards in the wool textile industry. Since 1930, IWTO has represented the collective interests of international wool trade, representing members from all stages of the wool textile pipeline – from farm to retail. Through continued scientific research, wool textile education and knowledge sharing, IWTO is working hard to ensure a sustainable future for the wool industry.
In major wool producing countries, national bodies typically exist to represent the interests of the various industry players. In New Zealand, this is the National Council of Wool Interests Incorporated (NZNCWII).
The New Zealand industry consists of farmers who shear every 8-12 months, wool stores (operated by merchants and brokers), exporters (who coordinate sales, usually international), scours (for cleaning the wool) and test houses (providing integrity in wool quality standards). Many of these groups have associations or bodies that make up the membership of the NZNCWII, who are in turn, members of IWTO.
New Zealand is the third largest wool producing nation in the world, behind Australia and China. Our environmental conditions suit sturdy sheep that can tolerate wet feet, which typically trends our production to strong wools (30-40um), with limited amount of Merino (<20um) and mid micron (2-30um) wool.
Sheep (Ovis aries) are domestic animals raised on farms for their wool, meat and milk. Wool is the most ancient fibre and is synonymous with human civilisation, helping to enable the survival of many populations and cultures for generations.
Globally today, there are around 1.2 billion sheep, with China having the most of any country at 162 million. Wool production is the major driver for farming sheep, with Australia producing 400,000 ton of primarily Merino wool, and a global production (all breeds) of 1.9 million ton.
New Zealand has 13.7 million hectares of farming land – approximately half is grassland – and approximately 25 million sheep. Of these, roughly half are Romney breed, and collectively the flock produces 136,000 ton of wool and 350,000 ton of meat per year. Along with their animals, New Zealand farmers care for around 25% of New Zealand’s total native vegetation on farms.
Wool is 100% natural, renewable, sustainable, compostable and good for the planet and its people. Wool products and garments are biodegradable at the end of their lifecycle, unlike other garments made from fossil fuels, such as polyester or acrylic.
For further information general information on sheep and wool, click here.
For further information on New Zealand farming, click here.
For further information on the benefits and attributes of wool, click here.
Raw wool is scoured to remove wool grease, soil and as many other impurities as possible before going through a series of processes designed to open up and align the fibres and remove the vegetable matter. Once cleaned and aligned, wool is then processed into a yarn for further processing and end-product manufacturing – such as apparel, carpets, upholstery or other textiles.
For further information on wool processing, click here.
There are a number of ethical standards within the New Zealand and international wool industry to ensure wool farming, processing and production is both authentic, genuine and safe. The standards also provide assurances around integrity, traceability, animal health and welfare, natural resources and biosecurity.
Ethical standards are administered by various organisations, all with the intent to provide confidence and assurance within the wool industry.
For further information on New Zealand ethical standards, click here.
For further information on global ethical standards, click here.
In New Zealand, wool is shorn and processed throughout the year. However, depending on breed and animal health requirements, usually the busiest periods run from February to April, and September to November. Directly after shearing, it is important to objectively test and measure the wool quality standards, collate data, and to inform the wider industry.
Below is an overview of the wool testing process, with video demonstrations. Click on the testing process stage to expand and view more.
As an IWTO certified test house, NZWTA provides the option of a Certificate or a Report for results of wool that we test. A certificate comes with guarantees and to achieve these guarantees, the whole process of sampling, processing and testing must be regulated to ensure result authenticity and integrity. NZWTA appoint, train and audit sites and sampling officers to oversee the process. Sampling of greasy wool can be manual or by machine. It is vital that a good representative sample is taken to provide an accurate result to the customer.
Once collected, samples are then packaged and sent to NZWTA for testing. On arrival in the lab, the sample is written up according to the required test. Several test types are available, the principle ones being:
For all wool that requires Yield, Colour, Micron, Residual Grease and Conditioning, the first few steps follow similar paths. After the write up step, the process moves to Blending and Sub-Sampling – the homogenisation step.
For an accurate result, the wool sample must be well blended to ensure it is a good representation of the whole line or batch of wool. The sample is then sub-sampled, with one part following the Yield pathway, another following the Colour and Micron path, and a final sub-sample kept for any future check testing needs. The two sub-samples for testing then go through our mini scouring process, intended to replicate commercial scouring.
Several steps are involved in attaining the yield measurement. After sub-sampling, the wool is weighed and recorded. The sample is then scoured and dried in ovens at 105 degrees Celsius for about an hour. This results in the oven dry mass. After this process, the sample contains absolutely no water – only wool, some residual grease, the Vegetable Matter (VM) and a mineral component. All of these factors are key to unlocking the yield calculation.
Wool samples pass through a Near InfraRed Spectrometer (NIR). Calibrated accurately through thousands of samples, the NIR allows a much accelerated and efficient cost method, providing a reading of Ash (mineral content) and residual grease in the wool, post scouring.
Sub-samples are then prepared for Vegetable Matter quantification and calibration work, for both the Ash Content and Residual Grease. These factors are then fed into the appropriate yield calculation.
Wool for colour and micron testing is scoured, dried and then sent to the Shirley’s. Shirleying involves a machine that pulls the wool fibres apart in order to remove any final pieces of vegetable matter and open the fibres completely from one another. This allows a more accurate measurement of both colour and the micron.
Wool is conditioned, and then measured a minimum of four times using the colorimeters. The values of X, Y and Z are taken and often presented with the Y-Z value, as this is a key measurement for wool buyers contracts.
Micron measurements may be completed by Laser, Airflow, OFDA or Electron microscope. Commercially, Airflow is preferred for coarse wools and Laser is used for the fine wool sector. The video below explains both Laser and Airflow in detail.
Throughout the entire scouring process, three LAC test samples are randomly drawn using specially-designed sampling equipment. One of the three samples is randomly selected as the test sample. The sample is carded and gilled to remove the vegetable matter and align the fibres. Sliver samples are twisted into hanks in preparation for measurement. A series of fibre draws are prepared from the slivers and read on an almeter.
The LAC test provides a certified measurement of Barbe length for the scoured delivery. Additional data on Hauteur length and length distribution, and an estimate of the card waste (percentage) is also available.
Staple Length, Staple Strength and Position of Break are important measurements that assist in the prediction of processing performance. NZWTA test most of the Merino wool in New Zealand and have also developed the test to be applicable for crossbred wool.
The Length and Strength test begins with extensive sampling involving mechanical grab and tuft sampling equipment to obtain a representative specimen. The samples are prepared and conditioned before being tested by NZWTA using the industry-leading ATLAS (Automatic Tester of Length And Strength) instruments. Samples are tested with a minimum of four instruments, used to test at least 60 staples, for the certification of each sale lot.
All certified results will be presented to the buyer as an IWTO Certificate. If the sampling was not conducted by a registered sampler, then results can only be provided as a report. This is due to the lack of chain of custody or independence in the sampling process.