Scoured Wool

Operating to International Wool and Textile Organization (IWTO) standards, SGS provides a range of independent laboratory tests on scoured wool to help verify quality and quantity.

Our scoured wool measurement services include certified tests for:

• Conditioned mass – wool absorbs up to 20 percent of its weight as moisture so invoicing is based on an agreed moisture content or regain (known as the conditioned mass)
• Yield – determining the amounts of clean wool (woolbase) and vegetable matter contamination in a sample
• Mean fiber diameter – the average fineness of the wool (fiber thickness), which is a primary determinant of wool value 
• Color – measured as tristimulus values, but normally used to assess clean color brightness (Y value) and yellowness (Y-Z value)

In addition, we certify a large proportion of scoured wool for length after carding. To do this, we adopt a standardized method of simulating semi-worsted processing to estimate mean fiber length after processing. We also test for:

• Residuals – the amount of mineral matter and residual grease left on the fibers after scouring, indicating scouring efficiency
• pH – the acidity or alkalinity of the wool after scouring affects the dyeing process, so it is important for processors to know the pH value 
• Alkali solubility and extent of bleaching – solubility is used to assess fiber damage, while the extent of bleaching is important in some processes 
• Medullation – refers to the hollow fibers in wool and other animal fibers, which causes uneven dye uptake and adversely affects appearance in apparel wools (but may be desirable for some carpet types)
• Bulk – this measures the fibers’ ability to fill space and also relates to resilience, which are important for applications such as carpets, futons and insulation 
• Fiber curvature – relates to bulk, compressibility and crimp and is cited as an influence on processing 
• Fiber diameter distribution – information about aspects of the diameter distribution may affect assessments of comfort and processing performance 
• Detergent residuals – wools intended for certain markets must be scoured with detergents that do not contain nonyl phenol ethoxylate (NPEO) 
• Mothproofing treatments – these must comply with the appropriate regulations
• Sanitary reports – shipments to certain destinations require an inspection report confirming that any residual vegetable matter is non-viable, while other places may require sanitization procedures to be verified 
• Exports to Iran – these shipments require conformity assessment involving specialized testing

To verify the quality and quantity of scoured wool across a range of criteria, contact SGS now to ask about our independent testing services.

• Wool Testing About Us

  Wool Testing Services has been operating in New Zealand as an independent wool quality certification body for over 40 years.
  Wool Testing About Us (166 KB)
• Conditioned Mass

  Conditioned mass is determined by sampling the consignment and determining the actual regain of the sample by oven-drying.
  Conditioned Mass (125 KB)
• Length After Carding

  The Length After Carding (LAC) test emulates the harshest aspects of commercial semi-worsted processing, and has proven extremely reliable.
  Length After Carding (135 KB)
• Wool Yield Testing

  Determination of wool yield and related components.
  Wool Yield Testing (204 KB)
• Mean Fibre Diameter Testing

  Mean fibre diameter is normally the most important determinant of raw wool price (Info-bulletin 3.1). Until recently, it was mostly certified using the airflow method detailed in IWTO-28.
  Mean Fibre (253 KB)

• Wool Colour

  Traditionally, the colour of wool has been expressed in terms of tristimulus values X, Y and Z. The numbers can be thought of in terms of the brightness of the red, green and blue components. In practice we talk of Y as representing brightness, and the difference between Y and Z (Y-Z) as yellowness.
  Wool Colour (558 KB)
• Residual Ash and Grease

  Scouring removes most of the unwanted material on greasy wool, but still leaves a very small percentage of dust and residual grease on the fibre.
  Residual Ash and Grease (244 KB)
• Chemical Residue Analysis

  Most chemical residue analyses arise from some form of environmental specification.
  Chemical Residue Analysis (216 KB)
• pH Testing

  The pH of the wool is often specified by dyers, since dying has to be carried out at a specific pH level. Whilst the pH can be easily altered by the addition of chemicals to the dye bath, having the correct pH to start with saves the dyer money.
  pH Testing (120 KB)
• Alkaline Solubility and Extent of Bleaching

  Occasionally users specify that alkali solubility, or some other test to determine the extent of bleaching, be carried out. Bleaching is sometimes carried out in the scour in order to bring the colour of the wool to specification.
  Alkaline Solubility (86 KB)

• Bulk

  Bulk is the ability of a fibre assembly to hold air, or its space-filling capability.
  Bulk (95 KB)
• Medullation

  Medullation is when an animal fibre has a hollow or partially-hollow core.
  Medullation (79 KB)
• Fibre Curvature

  Fibre curvature or crimp of a fibre has a second-order effect on spinning performance.
  Fibre Curvature (114 KB)
• Fibre Diameter Distribution

  There has been rapidly increasing interest in diameter distribution data, which is of potential interest to the quality of spinning, as well as indicating the comfort characteristics of apparel wools.
  Fibre Diameter Distribution (132 KB)
• Diameter Length Profile

  The average fibre diameter at increments along the length of wool staples may be important for managing sheep flocks, and in the future may assist in predicting processing performance.
  Diameter Length Profile (123 KB)

Info Bulletin IndexWool TestingWool Testing Info Bulletin IndexInfo-bulletins are concise summaries of information relating to specific tests or subjects related to wool testing. Check out our Info-bulletins now. ...

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All 16 resources

• 

  Wool Testing About Us

  published 02/28/12

  PDF

• 

  Conditioned Mass

  published 02/29/12

  PDF

• 

  Length After Carding

  published 02/29/12

  PDF

• 

  Wool Yield Testing

  published 02/29/12

  PDF

• 

  Mean Fibre

  published 02/29/12

  PDF

• 

  Wool Colour

  published 02/29/12

  PDF

• 

  Residual Ash and Grease

  published 02/29/12

  PDF

• 

  Chemical Residue Analysis

  published 02/29/12

  PDF

• 

  pH Testing

  published 08/17/12

  PDF

• 

  Alkaline Solubility

  published 02/29/12

  PDF

• 

  Bulk

  published 02/29/12

  PDF

• 

  Medullation

  published 02/29/12

  PDF

• 

  Fibre Curvature

  published 02/29/12

  PDF

• 

  Fibre Diameter Distribution

  published 02/29/12

  PDF

• 

  Diameter Length Profile

  published 02/29/12

  PDF

• 

  Info Bulletin Index

  published 04/03/12

  PDF