Manufacturing of composite handlebar
Mörsky, Peter (2016)
Mörsky, Peter
Yrkeshögskolan Arcada
2016
All rights reserved
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:amk-201605168019
https://urn.fi/URN:NBN:fi:amk-201605168019
Tiivistelmä
Syftet med detta examensarbete var att undersöka hur det är möjligt att tillverka ett cykelstyre ut ur komposit material i Arcada – Nylands svenska yrkeshögskolas utrymmen. Vanligtvis tillverkas styre formade ihåliga sömlösa rör med industriella maskiner som är inte tillgängliga på Arcada. På grund av detta bestämde det att tillverka en expande-rande laminerings form. Denna form fungerar på följande vis, ett flätat komposit materi-al kombinerat med harts i sock form lagas runt en expanderbar blåsa. Blåsan med material runt den lagas in i en form som har en kavitet form av ett styre. När blåsan uppfylls med hjälp av tryckluft så expanderar komposit materialet så att den får formen av formens kavitet. När hartset har härdat kan formen öppnas och färdiga styret kan tas bort. För detta jobb tillverkades två former, den första var en prototyp form var över 20 test lamineringar tillverkades. Baserat på den information som erhållits från test lamine-ringarna konstruerades och byggdes den andra och slutliga full storleks form för styret. En av de viktigaste informationen med testen lagade med prototyp formen var att slut-liga formen måste vara ett sluten konstruktion. Med hjälp av ett sluten form konstrukt-ion var det möjligt höja på trycket upp till 7 bar, med högre truck expanderar komposit materialet bättre inne i formens kavitet. Några problem uppkom med de första testen som lagades med full storleks form för styret. Problemet var att komposit materialet inte expanderade tillräckligt som ledde till stora lamineringsfel på styret. Problemet löstes med att forma komposit materialet till formen av styret före formverktyget stängdes. Med användning av denna metod var det möjligt att producera högkvalitativa cykel-styren. Alla slutliga styren tillverkades med hjälp av 6K och 3K flätade kolfiber sock material kombinerat med epoxiharts. Slutliga produktens yta granskades med hjälp av ett optiskt mikroskop för att hitt potentiella mindre laminerings fel. Cykelstyrets böj-nings styvhet testades också med hjälp av en materialkontroll maskin. The aim of this thesis work was to study how it is possible to manufacture a composite handlebar in the Arcada University of Applied Sciences premises. Composite handlebar shaped seamless tubes are normally manufactured using a filament winder, pultruder or a filament braiding machine. Not having the possibility to use these kind of machinery, it was decided to design and manufacture an expanded lamination mould in which the han-dlebar could be produced. An expanded lamination mould works by placing a bladder with composite sleeve material combined with resin around it inside a mould that has a cavity shaped like a handlebar. The bladder is then filled up using air pressure so that the composite material will expand and get the shape of the moulds cavity. When the resin is cured the mould can be opened and the finished hollow handlebar can be taken out.
For this work two expanded lamination moulds where built, the first one was a small pro-totype mould in which over twenty test lamination were made. With the knowledge given from the test lamination a full sized handlebar mould was built. One of the most im-portant things learned from the test lamination was that the full sized mould had to be built to a closed mould construction. By having a closed mould construction it was possi-ble to use up to 7 bars of pressure, using high pressure the composite sleeve material can expand better inside the moulds cavity. There were some problems to get the composite material to expand to the whole moulds cavity in the first few lamination test made using the full sized handlebar mould. This lead to having large lamination faults on the handle-bar. The problem was solved by pre-forming the material to the shape of the cavity before closing the two mould halves. Using this method it was possible to produce high-quality bicycle handlebars. All the full sized handlebars was made using 6K and 3K carbon fibre braided sleeve material combined with epoxy resin. The final products surface quality was inspected using an optical microscope to find potential minor lamination faults. Using a material testing machine a full sized carbon fibre bicycle handlebars bending stiffness was also tested.
For this work two expanded lamination moulds where built, the first one was a small pro-totype mould in which over twenty test lamination were made. With the knowledge given from the test lamination a full sized handlebar mould was built. One of the most im-portant things learned from the test lamination was that the full sized mould had to be built to a closed mould construction. By having a closed mould construction it was possi-ble to use up to 7 bars of pressure, using high pressure the composite sleeve material can expand better inside the moulds cavity. There were some problems to get the composite material to expand to the whole moulds cavity in the first few lamination test made using the full sized handlebar mould. This lead to having large lamination faults on the handle-bar. The problem was solved by pre-forming the material to the shape of the cavity before closing the two mould halves. Using this method it was possible to produce high-quality bicycle handlebars. All the full sized handlebars was made using 6K and 3K carbon fibre braided sleeve material combined with epoxy resin. The final products surface quality was inspected using an optical microscope to find potential minor lamination faults. Using a material testing machine a full sized carbon fibre bicycle handlebars bending stiffness was also tested.