A modern multi-layer hydraulic headbox is designed to deliver a uniform, low consistency stock stream to the forming section of a tissue machine. The stock inlet headers, dilution profiling header, turbulence elements, layering vanes, and headbox movements and adjustments must all be designed to create and maintain turbulence and deliver a well-distributed fiber suspension to the former at the correct angle and location. Proper design, operation, and maintenance are all critical factors in the optimal performance of a tissue machine headbox. Optimal performance of the headbox will produce a sheet with the desired attributes. Understanding how all of the headbox components function and interact will assist in both day-to-day operations and troubleshooting efforts.
Learning Objectives
At the end of this module, you will be able to:
- Describe the purpose and objectives of the headbox on a tissue machine
- Describe the advantages of a multi-layer headbox
- Identify and locate the major components of a multi- layer headbox
- Identify stock and recirculation flows
- Describe the available adjustments to the headbox
- Identify protection and care guidelines for the headbox and forming fabrics