The project Design analysis and proposals of plastic screw caps in Australia was performed at Högskolan Dalarna in cooperation with University of Western Sydney, Australia. The Swedish company Tetra Pak, in Lund, were assigner for the project that was performed 2006-2007. The commission was to do a survey about the packages for non-carbonated drinks in Australia. The bottles had to be plastic, able to open in one step and with focus on the caps. The project has result in design analysis and a new proposal of a plastic screw cap for the Australian market. Six bottles were choosen and they were all testet on 20 consumers each with a Likert-scale test. The result from the test and the survey underlied the work with a proposal of a new design. The most important qualities for a optimal opening is: a tamper that is easy to break and also guarantee that is not been opened before, wide and soft grip, ergonomics, easy to close and that is good looking.