The feasibility of using oriented polymer technology in the design and manufacture of mechanical power transmission belts has been investigated. Working from an initial selection of polymers a die-drawing technique for orienting the polymers was devised, and the static and dynamic mechanical properties of the oriented polymers were investigated. These results indicated that PP, PBT, PPS and PEEK were suitable for further research. Of these 4 materials PBT was selected as the most appropriate material for belt manufacture based on cost, processability (drawing temperature, natural draw ratio) and limitations of laboratory equipment. A technique based on free-tensile drawing combined with simultaneous rotational motion was designed and used to manufacture oriented PBT flat belts from cylindrical injection moulded preforms. The technique used a tensile machine with two pulley-clamps, a fitted heated chamber and an electric motor to provide rotational motion to the belt during drawing. Two types of oriented PBT flat belts with different cross sections were produced successfully, termed 'thick' and 'thin'. These belts were tested on a purpose-built rig comprising two equal diameter pulleys, one driven by an electric motor and the other connected to a generator to provide load. The belt life and power transmission performance was investigated at various conditions of speed, transmitted torque and tension, and the results indicated that despite their smaller cross section 'thin' flat belts demonstrated up to 3 times longer life. However life was only 100hours, which was very low compared with conventional flat belts that last for many thousands of hours at higher speeds and much greater power transmission capacity. Synchronous belts were then produced through the same manufacturing method used for flat belts. This aspect of the research concentrated on the initial pitch design and size, i.e. the timing. Initially a rectangular tooth profile was selected for its simplicity in terms of manufacture. The produced belts exhibited high pitch length variation as well as deformed teeth and were not usable for synchronous power transmission. An extra timing feature was included to control orientation; reducing the pitch length variation enabling consistent tooth production. It was observed that the areas between the extra timing feature and the tooth edges did not orient completely with some regions remaining undrawn. Finite Element Analysis (FEA) was used to predict the drawing behaviour of different shapes and dimensions of the timing features. The results suggested that a 4mm wide and 7mm long slot provided the highest possible extension and the minimum non-oriented regions on the groove. Whilst, the thickness and width of the drawn belt timing features showed differences to the FEA predictions, manufactured synchronous belts based on that design had much better controlled dimensions and the lowest achieved pitch length variation ( ±1%), compared to initial attempts. It is concluded that oriented polymers have the potential to be used in power transmission belts since they offer higher stiffness, tensile strength and creep resistance compared with isotropic polymers that are currently used in commercially available belts such as thermoplastic polyurethane (TPU) and polyvinyl chloride (PVC). The main disadvantages were the lack of dimensional stability and number of cycle to failure.

I dagens byggprocess läggs enormt mycket tid och resurser på hantering av pappersritningar och andra utskrivna dokument som är nödvändiga för att produktion och förvaltning ska fungera. Vid stora projekt kan det handla om tusentals olika ritningar och dokument som ska hanteras och dokumenteras vilket kan vara oerhört omständligt, inte minst när revideringar måste utföras. När ett BIM-projekt utförs idag så tappas en hel del av den information som modellen innehåller till följd av att det ska skrivas ut på en pappersritning, vilket i sin tur gör att mycket av informationen inte kommer till sin rätt. I dagsläget finns ett flertal programvaror med syftet att hantera BIM-modeller och andra dokument rent digitalt i datorn eller i surfplattan. Här har man kommit en bra bit på vägen mot ett ritningsfritt projekt men det finns mycket kvar att arbeta vidare med. Sweco Architects och NCC påbörjade under 2012 ett projekt vid namn ”Det ritningsfria projektet” som till en början delvis gått ut på att kartlägga vilka problem som kan uppkomma vid övergången till ett ritningsfritt projekt. Utifrån författarnas egna funderingar och dessa frågeställningar har examensarbetet formats. Med detta examensarbete vill författarna belysa att det i dagsläget finns ett flertal olika verktyg för hantering av BIM-modeller i byggprocessens olika led även om de inte är fullt utvecklade ännu. Genom att själva testa programmen utifrån given frågeställning kan svagheterna och styrkorna med programvaran kartläggas. Detta är viktigt för att vidare utveckling av programmen och de nya arbetssätt som dessa medför ska kunna ske. Förhoppningsvis leder examensarbetet till vidare arbete mot ett ritningsfritt projekt. / In the building process today, an enormous amount of time and resources are sacrificed to the management of paper drawings and other printed documents, which are all necessary for the production- and management-phases to work. In large projects this could mean thousands of drawings and documents that have to be managed and documented. This can be extremely tedious, especially when revisions need to be made. When BIM-projects are being performed today a lot of the information that the model contains are lost just because it has to be printed as a paper drawing. This makes it redundant to fill the model with that much information in the first place. As of today there are several software programs whose purpose are to handle BIM-models and other documents entirely digitally on the computer or on a tablet device. These software programs have contributed a lot to the movement towards the drawing free project, but there is still a long way to go. In 2012 Sweco Architects and NCC began a project named “Det ritningsfria projektet” which initially passed on to identify the problems faced in the transition to a drawing free project. Based on the author’s own thoughts and these identified problems the thesis has been formed. With this thesis the authors want to highlight that there are a number of tools for managing BIM-models today in the various stages of the building process, even though they all need further development. By testing the software available today based on the given issues the weaknesses and strengths can be highlighted and mapped. This is very important for further work with the software and the new work procedure that the software provides. Hopefully the thesis will lead to further work towards a drawing free project.