Packaging material-load-limits during webforming

Statement of the Problem

The global trend towards an economic use of resources has become a very serious issue within the packaging industry. This development, asking for a reduction of packaging material, is accompanied by a great demand for increased turnout. To meet the requirements, materials of very low thickness have gained great recognition and are applied increasingly. As generally known packaging films show astir permeation characteristics. For a solid product quality however, contact with oxygen and hydrogen as well as a decrease of flavor need to be avoided by any means. To cure this cause, numerous compound materials with various barrier characteristics have been developed. Against the background of material reduction metalized films are used increasingly. Unfortunately, these films prove to be rather sensitive towards mechanical stresses which occur regularly during processing and packaging. Already minor mechanical stress may cause damages and severe deterioration of the permeation characteristics. Conclusively, product safety can’t be guaranteed.

Project Aim

The aim of the research project is to systematize damage symptoms and researching damage causing mechanisms during the processing of web shaped packaging materials (film in particular) under dynamic processing and testing conditions. Further, the project is aimed at generating a theoretical basis that will put on view the cooperation of all relevant influencing variables containing the following key aspects:

• predicting the withdrawal force that is to be expected, in order to dimension the packaging materials accordingly,
• defining withdrawal force ranges by considering all relevant influencing variables to ensure a low level of damaging disruptions during processing and
• acquiring knowledge to derivate working tool adjustments will also be central to the research.

Approach

Based on detailed examination of all relevant influencing variables, a classification will be created. In case of damage this classification will allow to draw conclusions as to what the origin of the problem is. Furthermore it will offer support in localizing the occurrence of the disturbance within the processing and packaging. The process inherent mechanisms of the damage causing points of action will be researched experimentally and theoretically. The gained knowledge will be integrated in a simulation model and verified through experimental testing. As a result, the simulation model will offer an estimation of the damage in advance to its occurrence. Consequently, to permit a reasonable verification, the development of a measuring system constitutes one more key aspect of the project. Using the mentioned measuring system a determination of web-tensions and web-tension profiles according to authentic process conditions will be made possible.