Global ETD Search

1	Advances on Geometrical Limits in the Deep Drawing Process of Paperboard Hauptmann, Marek, Kaulfürst, Sebastian, Majschak, Jens-Peter 06 September 2018 (has links) The geometrical limits of the deep drawing process of paper to advanced shapes are not known. This report examines the technological limits of convex elements of the base shape in relation to the drawing height and shows the material behavior in the bottom radius of 3D shapes with regard to special material properties. In the bottom radius, non-compressed wrinkles occurred due to the in-plane compression, but wrinkles were reduced by an increased blank holder force or tool temperatures and improved extensibility or in-plane compressive strain. The forming ratio during deep drawing (drawing height related to base diameter) was increased to a value of more than 1 by a blank holder force, which increased with the drawing height such that the initial blank holder force was reduced concurrently. Straight sections in the base shape reduced the risk for ruptures in the edge radii of rectangular shapes, producing a forming ratio in these radii of 2.5. The forming ratio was further supported by a pattern of creasing lines at the blanks with a radial orientation and a number near the expected maximum number of wrinkles. The spring-back at rectangular shapes mainly depended on the drawing height and edge radius. info:eu-repo/classification/ddc/500 ddc:500
2	Evaluating the Factors Influencing the Friction Behavior of Paperboard during the Deep Drawing Process Lenske, Alexander, Müller, Tobias, Penter, Lars, Schneider, Matti, Hauptmann, Marek, Majschak, Jens-Peter 28 June 2018 (has links) (PDF) Deep drawing of paperboard with rigid tools and immediate compression has only a small presence in the market for secondary packaging solutions due to a lack of understanding of the physical relations that occur during the forming process. As with other processes that deal with interactions between two solids in contact, the control of the factors that affect friction is important due to friction’s impact on runnability and process reliability. A new friction measurement device was developed to evaluate the factors influencing the friction behavior of paperboard such as under the specific conditions of the deep drawing process, which differ from the standard friction testing methods. The tribocharging of the contacting surfaces, generated during sliding friction, was determined to be a major influence on the dynamic coefficient of friction between paperboard and metal. The same effect could be examined during the deep drawing process. With increased contact temperature due to the heating of the tools, the coefficient of friction decreased significantly, but it remained constant after reaching a certain charging state after several repetitions. Consequently, to avoid ruptures of the wall during the forming process, tools that are in contact with the paperboard should be heated. Reibverhalten Reibungsmessung Karton Tribokontrolle Kontaktelektrifizierung Triboelektrifizierung Tiefziehprozess 3D-Umformung TU Dresden Publikationsfond Friction behavior Friction measurement Paperboard Tribocharging Contact electrification Triboelectrification Deep drawing process 3D-forming TU Dresden Publishing Fund ddc:500 rvk:TA 1000
3	Evaluating the Factors Influencing the Friction Behavior of Paperboard during the Deep Drawing Process Lenske, Alexander, Müller, Tobias, Penter, Lars, Schneider, Matti, Hauptmann, Marek, Majschak, Jens-Peter 28 June 2018 (has links) Deep drawing of paperboard with rigid tools and immediate compression has only a small presence in the market for secondary packaging solutions due to a lack of understanding of the physical relations that occur during the forming process. As with other processes that deal with interactions between two solids in contact, the control of the factors that affect friction is important due to friction’s impact on runnability and process reliability. A new friction measurement device was developed to evaluate the factors influencing the friction behavior of paperboard such as under the specific conditions of the deep drawing process, which differ from the standard friction testing methods. The tribocharging of the contacting surfaces, generated during sliding friction, was determined to be a major influence on the dynamic coefficient of friction between paperboard and metal. The same effect could be examined during the deep drawing process. With increased contact temperature due to the heating of the tools, the coefficient of friction decreased significantly, but it remained constant after reaching a certain charging state after several repetitions. Consequently, to avoid ruptures of the wall during the forming process, tools that are in contact with the paperboard should be heated. info:eu-repo/classification/ddc/500 ddc:500

1

Page generated in 0.0503 seconds