Making Unidirectional Fabric Plies

General Composites Discussions Composites Talk
#1

Hello Everyone,

Another task in my current research involves making natural fiber composites using unidirectional fabric. Since unidirectional jute fabric is largely unavailable, I have been tasked with making it using jute yarn. However, I have been having some difficulty in successfully making unidirectional fabric that will stay together. So far I have experimented with tightly wrapping the yarn around a glass plate and painting the yarns with epoxy, but the yarns tend to split apart upon removal from the plate.

Does anyone here have any experience making unidirectional fabric from yarn? And if so do you have any suggestions?

Thank you very much for any advice you can give

#2

With a yarn, you can not just paint on resin. The resin will saturate only the top surface of the yarn (depth of resin penetration relates to density of the packing of the yarn.) What you want to do is infuse the plate, that way the resin will be sucked into all the voids of the yarn more efficiently. You can first try painting the yarn and putting the whole system in a vacuum bag, OR chamber, but infusion is the way to go.

#3

riff, thank you for your response, I’m not entirely sure what you mean by infusing the plate.
Infusion was my eventual plan, but i need a way to align and hold together the unidirectional layers so I can stack them before infusion.

#4

Is it small quantities? What about a light binder?

#5

I only need 6-8 10" x 10" layers per sample, and I’m thinking I’ll need about 5 samples.

What would you suggest as a binder?
I will be using these samples to characterize the strength/fracture properties of the composite material so I don’t want to introduce too many impurities that might add additional compliances

#6

not sure how y ou will evenly stack that many layers of yarns, besides maybe trying a tack spray, like 3M Super 77, sprayed VERY lightly.