Week 16: Wildcard Week

Wildcard week! We can choose one out of few fields on which we wish to make our assigment.
I will got with composites!
Assignments for this week!
   group assignment:
      produce test coupons for your composite fabrication process(es)
   individual assignment:
      read the safety data sheet (SDS) and technical data sheet (TDS)
         for the resins that you're using
      design and fabricate a 3D mold (~ft2)
         and produce a fiber composite part in it,
         with resin infusion and compaction
Google drive with all files

Invidual Assignment

1st try

In this week my task is to create a composite with use of resin and CNC made form.
I decided to use the shape that I got from my wire cutter machine that I made on Mechanical Design week.

Next let's ready some stickers on the resins...

From this I know I have to mix the resin with solidifier in proportion 2:1.
Also both of the botlles contains all safety informations that I should respect during using the resin.
OK so lets mix them!

I also need to inform that I am not in the lab and I am performing this in my home in the kitchen... I putted everything on the sheet of plastic bag to make sure that my wife won't kill me!
Safety 1st! :P
As 1st I pour the resin, 100 ml.

And now 50g of solidifier.

OK now manual mixing of the mixture...
After everything is well mixed I can put the fabri on the 3D part.

As my vacuum I will use my vacuum cleaner and vacuum bags for home use... HOME DIY at it's finest :)

As it is said in on the bag "Quality everyday!" so I'm hoping for good resulsts!
OK lets put the patern with fabric in the bag.

It is not visibile but I also added a aluminium grid under the pattern and around it till the vaccum socket so the air suction is well distributed around the pattern.
After vacuuming:

Vacuuming itself worked quite nice but...
I left the resin to set for few days but unfortunately it did not. :(
After short consultation with my FabAcademy mate, Maciek, we concluded that cutting the air from the resin completly might disturb the solidification.
I have to try again but this time I will take the pattern out from the bag after 15-20 minutes.

2nd try

Final results of the second try:




The fabric holds the shape of the pattern and I am quite happy with it. One thing that I could do better next time is to put more layers of fabric or use more dense fibers.

Reason of 1s failute

After this assigment I got a bit into resins so I decided to make some more. Just for fun, not as an assigment. :)
Also I have learned that the lack of air should not be a reason for resin to not to set at all.
I printed a hexagonal shape of of PETG and poured the right mixture onto it. (I triple checked the values!).

The resin did not set even after three days!

But I made last test!
I had two separate bottles with resin so I tought that maybe something is wrong with one of them. For the PETG print I used one of them so I decided to use other one on something else. Due to the lack of specimen I poured the mixture to the simple plastic cup and it worked perfectly!
Here is the set resin already taken out:

It looks like the one of the resins must have been faulty!

Group Assignment

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