Wool blended with cotton, polyester and acrylic can be spun on MVS for a large range of end products.  However, it is reasonably well established that blends with nylon do not spin well on MVS and therefore fibre blends with nylon are not recommended.

 

Input sliver to MVS needs to have U% less than 3.0%, which is achievable by following the draw-frame recommendations described.  Sliver U% values less than 2.5% produce significantly better yarn quality and spinning efficiency.  Values less than 2% are achievable for cotton rich/wool blends.  Conditions (heat & RH) should be maintained around the MVS creel and air turbulence needs to be kept to a minimum to prevent sliver damage and ensure regain of the wool component is maintained at or above 16%.   

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The diameter and length of the component fibres in the blend play critical roles in determining the quality and spinning stability of MVS yarn.  The number of fibres in a MVS yarn must exceed 70 fibres in yarn cross-section for stable spinning.    Furthermore, as much as possible, the average lengths of the blend fibres should be similar and not exceed 50 mm staple length.  For softer handle yarn, lower the N1 pressure and increase the delivery speed.  The workable N1 range is between 0.4 and 0.6 MPa with the range between 0.45 and 0.55 MPa being selected in trials at CSIRO for optimum spinning stability and handle properties.  

 

The softness of handle and pilling properties of MVS knitted fabrics are also affected by fibre length and diameter.  Trials have shown that the properties of MVS yarns and fabrics are comparable to those of ring spun yarn, eg MVS fabric can be as smooth and soft as ring spun fabrics, with the addition of enhanced wear properties.  However, MVS requires good quality fibre and preparation to achieve ring spun benchmarks.  It has been demonstrated that wool gives MVS yarns additional softness.  

 

“Drawing” lists the critical fibre properties required for MVS yarns.