BACKGROUND

Challenges

A lot of this topic uses a lot industry experience, which is hard to replicate for industry standards.
Obtaining the materials for a cost affordable to 5 students.
Keeping certain variables constant and getting accurate measurements during the experiments.
Able to create a repeatable experiment because carbon fiber and epoxy is very hard to control. There are too many variables for us to control, given our knowledge of carbon fiber and resin.

References &

Links:

Dry Aligning Method of Discontinuous Carbon Fibers
[pdf] - http://www.eng.gifu-u.ac.jp/kikai/20550340.2016.pdf

High Performance Discontinuous Fibre Method (HiPerDif)
[pdf]: http://www.sciencedirect.com/science/article/pii/S0263822316308455

Through some of our inital questions and research, we wondered if a more laminar flow in a tube would orientate fibers in a solution. However for injection molding, you generally want fast injections to increase production, but the solution we will be using (epoxy resins) are very viscous. It cannot be pre-oriented either if we want to mix them in thoroughly. Once it's injected into the mold, does the orientation stay roughly the same? What are the effects of entanglement for longer fibers, and clumping or rotational motion through Jeffrey's orbit along the flow for shorter fibers? We wanted to see if we could align fibers using a casting method.

Initial Research

We had some trouble sticking with a topic we wanted. We at first wanted to build a bike lock and then to do research on layered deposition of composites/tapes. As some of this group of students are from the UC Berkeley Human Powered Vehicle Team, we worked a lot with composites and wanted to research into this field more. In addition, we did a research paper on recycled carbon fiber which often uses short carbon fiber (which is often a lot weaker than long continuous carbon strands).

The research we will be focusing on is determining if fiber orientation can be tailored into an injection molded part to have a pre-planned orientation by exploring the flow rate and/or injection method of the fiber and resin solution into the mold. If possible, to what degree? If not, why not? And how does this affect the strength of the final part.