Towards Better Understanding of Void Volume in Press Nips Webinar

The sheet dryness out of a press nip or press section can be relatively independent of how much water is in the sheet and felts IF there is enough void volume in the nip.  It is difficult to calculate how much void volume is “enough” because the usable void volume is a variable throughout the lives of felts, roll covers and shoe press belts, and is quite different from their theoretical void volumes.   Creating void volume, also known as “venting”, in roll covers and shoe press belts increases press dryness and reduces dryness and sheet property variation.  We will discuss usable void volume, how it is created, and why getting it right optimizes not only press dryness but also runnability.  Case studies will be presented.

Learning Outcomes:

1. Understand the importance of Felt, Roll Cover & Shoe Press Belt Void Volume in Press Nips
2. Understand the difference between Theoretical and Usable Void Volume
3. Understand how Void Volume Variation affects Sheet Properties and Runnability

Keywords:

Press Nips, Nip Venting, Void Volume, Nip Rejection, Nip Saturation, Press Dryness, Press Optimization  

Who Should Attend:

Job Titles

• Production Managers
• Superintendents
• Papermakers

Companies

• Tissue
• Paper and Board Producers

Committees

• Paper & Board
• Engineering
• Pulp Manufacture  

I got my start in the paper industry as an intern with Beloit Corporation while earning a Bachelor of Mechanical Engineering at the Georgia Institute of Technology.

In 1981, I began working full-time at Beloit’s Rockton Research Center under the mentorship of Mr. Dennis Cronin - principal developer of the Venta Nip grooved press roll and the Extended Nip Press.  For the next 20 years I worked on the mechanical development of shoe presses, assisted suppliers with their shoe press belt and felt developments, and studied the effects of shoe pressing on paper and board grades. 

In 2001, I joined Küsters (now Andritz) to continue shoe press development and expand understanding of how press dryness and sheet properties from tissue to market pulp react differently to the many variables of wet pressing.