New Generation Nip Equipment

Abstract: In the laminator there are three laminator stations where protective layers are applied to the paperboard. In each station there are several rollers which help perform the lamination process, the most important rollers to be considered in this thesis are the nip roller and the chill roller. The nip roller is pushed towards the chill roller using hydraulic cylinders , thus creating a narrow contact surface between these rollers called "the nip". It is in the nip that the different additives are applied onto the paperboard (or rather the 'web' which is the printed paperboard when loaded into the laminator). Some additives are melted onto the paperboard while others are applied in a solid state (foil or film). When the additives are applied onto the web they are cooled while in contact with the chill roller and then fed to the next laminator section. Even though the hydraulic cylinders satisfies the specifications for today they will probably not be able to handle the demands for future operation. With increased need for precision the hydraulics simply cannot reach the same level of precision as a servomotor operated solution. To help clarify the project mission the problem is decomposed into three sub problems: linear motion, elasticity and motion guiding. By searching for concept solutions to these problems both externally and internally a number of concepts are created, the existing motion guiding system is kept. From these the most potent concepts are chosen using target specifications and a rating system. After further evaluation the final concepts are selected; for the solution to the linear motion problem the electromechanical cylinder is chosen and the elasticity problem is best solved with a disc spring package. Performing the necessary analysis and calculations on these solutions concludes the concept selection phase.