Vidareutveckling av serveringskanna i plast avsedd för varm dryck

Sammanfattning: ABSTRACT This thesis work consists of a case study, where August Lund AB assigned the further development of an ergonomically designed plastic serving pitcher. The purpose of the assignment was to further develop the serving pitcher, to adapt it for hot beverages and the manufacturing method injection molding, and to serve as a basis for decision making regarding how further investments in the previously produced ergonomic design solution was to be made. To achieve this, the following thesis question was formulated: Which are the leading factors that dictates the product development of plastic products that will be injection molded? To be able to answer the thesis question and complete the development of the pitcher a literature study about plastic design was conducted, that formed the foundation of the theoretical framework. Secondary data was collected using academic literature consisting of books and scientific papers. A product development process was formed for the case study, that was a derivative of the generic product development processes presented in the literature used. To complete the theoretical framework for the case study primary data was collected by conducting laboratory testing, simulations, tests and interviews. The main part of the work conducted in the case study consisted of finding a satisfactory insulation solution, that would prevent the user of the pitcher from getting burned by the heat from the hot beverage. This resulted in that the product development never reached beyond the conceptual phase. Two different methods of insulation were explored. The first method consisted of a thermoplastic elastomer overmolding that was located at the gripping area. It was concluded from the conducted laboratory testing and the simulations that the thickness of the grip had to be at least 10 mm. The thickness necessary was regarded as to thick because of the associated manufacturing costs and the proposed method was rejected. The second method explored was a pitcher containing an inner pitcher that formed an insulating air gap. The simulation result indicated that a 3.5 mm air gap was necessary to obtain adequate insulation. An insulation method using an air gap in combination with the ergonomic design solution brings several unsolved problems, that need further investigation to be solved if the combination is to be used. The employer had the request of investigating if a thermos effect could be achieved. The result showed that an air gap would insulate the pitcher so that a 10°C higher beverage temperature would be achieved during the 45 minutes than if an uninsulated pitcher was to be used. To attain a better thermos effect, the air gap could be filled with a foam to reduce the convective heat transfer in the air gap. Reaction Injection Molding could potentially be used to produce the insulating foam. It was concluded based upon the case study and the theoretical framework that the leading factors that dictates the product development of plastic products that will be injection molded was the structural constraints and the design guidelines of plastic design. Also, the cost of manufacturing in relation to the product performance, the products potential selling price and the production volume. In another word, to be able to asses which changes of the design that leads to increased manufacturing cost and if the increase is justifiable in relation to the obtained product performance. DFM turned out to be essential and have a central role in the product development of plastic products that will be injection molded.