Date of Award
Bachelor of Science
Paper Science and Engineering
The Ultra-Former is a new type of multi-ply board machine. It uses a cylinder mold without a vat and has a stock delivery system that uses a headbox similar to that found on a fourdrinier machine. The board made on the Ultra-Former has several improved qualities over the board made on the conventional type board machines. Of these several improved qualities formation is one of the most important.
Formation is important because it affects the physical properties of the finished product. One of the major physical properties affected is the tensile strength of the sheet. The tensile strength is reduced due to the higher probability of premature strain failure in areas of low fiber substance caused by poor formation.
Formation is change through the adjustment of five key machine variables found on the fourdrinier type headbox. The spouting jet to wire speed ratio and the consistency in the headbox are the most important of the five variables and the easiest to control.
This project involved the controlling of formation through fiber orientation as the most important variables, spouting jet to wire speed ratio and the consistency in the headbox are the most important of the five variables and the easiest to control.
This project involved the controlling of formation through fiber orientation as the most important variables, spouting jet to wire speed ratio and consistency in the headbox, are changed. The fiber orientation is deplicted by using a ratio between the machine direction (MD) tensile and cross machine direction (CM) tensile as determined using the zero span tensile test.
The results obtained indicate strongly that fiber orientation cannot be used for a formation control because the values are too random. At high degrees of fiber orientation the formation may be good one time and low at another time. Formation tended to be more dependent upon basis weight than fiber orientation.
Haw, Gerald R., "Fiber Orientation as a Means to Control Formation on the Ultra-Former Through Changes in the Spouting Jet to Wire Speed Ratio and Stock Consistency in the Headbox" (1972). Paper Engineering Senior Theses. 247.