Definition of a Shive:

 

The FQA detects a shive based on a user defined minimum width and length.  If a fiber image has both a width and a length greater than those defined by the user the fiber image will be classified as a shive.  The user can enter into the FQA   shive width values greater or equal to 0.177mm and shive length values greater or equal to 0.353 mm.  If values smaller than these are input into the FQA the FQA will default back to a width of 0.177mm and a length of 0.353 mm.  

 

 

The Shive Analysis Results:

 

Our shive analysis software provides three results:

 

1. Effective Length:

 

When shive is detected a box is placed around the extreme edges of the shive.  The box can either be rectangular or square depending on the shape of the shive, Figure I.   Due to the very complex shape of most shives it is very difficult to track the exact length of a shive, especially when there are many long branches extending of the shive, Figure II.  In this case the tracker can not determine which branch to travel down and use as the true length of the shive.  To avoid this problem the software takes the diagonal of the box that is placed around the shive.  This diagonal is called the effective length, Le.

                                  

      

Figure I: Simple Shive                               Figure II:   Branched Shive

 

 

 

 

 

2. Area of the Shive:

 

The area of the shive is a measurement of its size and likely a strong indicator of the degree of impact the shive will have on the paper making process.  When used in combination with the length measurement it can be an indicator of the compactness of the shive.

 

 

3. Shive Branch Index:

 

The FQA  captures and stores the images of the shives.  The area and perimeter of the shive image is then determined.   Next the software generates a model of a stick which has the same perimeter and area as the shive image, Figure III.

 

             

      Figure III: Shive Branch Index determination

 

 

The shive analysis software first calculates the moment of inertia of the shive image, Iactual.  Next the software calculates the moment of inertia of the the stick, the ideal moment of inertia,  I ideal.  Finally the Shive Branch Index is determined by taking the ratio of the Iideal /  I actual 

 

Shive Branch Index =  I ideal /  I actual   

 

The Shive Branch Index will increase as a shive becomes more branched.  This is because as a shive becomes more branched its perimeter increases and when its perimeter increases, the stick generated to determine  Iideal becomes longer.   A longer stick causes the  Iideal  value to become larger.   

 

 

Caution:   The shive analysis routine is intended for shive morphology research and as a result is only available to qualified customers.  When shive analysis is active very intensive image storage, tracking and analysis is performed.  Consequently, some "non-shive" fibers may be missed.  This means that the fiber (i.e. non shive) Ln, Lw, Lww, Curl, Kink and Coarseness results for the sample analyzed may not be representative.  The shive analysis routine can only provide detailed information about the shive images which were stored.  The shive analysis also enables the user to look at images of shive.