Photo Gallery for Composite Manufacturing Lab

Vaccum Bagging

 

(Click the link to see the photos at every step)

  1. Lay down pre-cut plastic sheeting on the heavy aluminum base plate. Tape the sheet to the base. This covers the aluminum to prevent contamination from epoxy for future use. Make sure that the entire top surface is covered either with plastic or scotch tape.
  2. Two 8"x16" sheets of straight-fiber (unidirectional fiber) and one 8"x16" sheet of CSM fiberglass has been pre-cut. Place one straight-fiber sheet on the center of the covered base. Using old sealant tape (since it is not being used as a seal), place it around the fiber sheet to create a dam. This will prevent epoxy from spreading, and reinforce from movement during the vacuum.
  3. Leaving the one straight-fiber piece in the dam, mix the epoxy. For this lab, mix 6 fl oz. of epoxy resin with 2 fl oz. or epoxy hardener (3 to 1 ratio by volume). Measure using the plastic measuring cups, and mix thoroughly using the electro-mechanical stirring device (about one minute). The epoxy may be stirred in one of the paper bowls provided.
  4. Using approximately 1/3 of the epoxy mix, dump it in the dam, spreading it around during pouring. Using the grooved roller, spread the epoxy around, ensuring that all surfaces are saturated with epoxy.
  5. Place the layer of CSM on top of the straight-fiber sheet currently in the dam. Place the next 1/3 of epoxy on the laminate under construction, and spread around as before.
  6. Apply the last straight-fiber sheet down and dump the rest of the epoxy. Spread the epoxy
    around and ensure that the laminate is thoroughly saturated
    ; however, any excess must be
    scraped off using the scraper. Excess epoxy can be sucked into the vacuum pump and cause
    damage.
  7. Take the pink-colored perforated sheeting and place it so that it is centered over the dam; the edges of the sheet should extend just beyond the edge of the dam. Trim if necessary. This provides a separation between the breather cloth and the laminate so the two will separate after curing.
  8. Place two layers of breather cloth on top of the perforated sheeting. At one end, add some
    breather cloth to create a "tongue" which will have the base of the connection post placed.
    This keeps the vacuum point away from the laminate to prevent epoxy from being sucked into the pump.
  9. Place new double-sided sealant tape around the edges of the aluminum plate. Do it as one
    continuous piece to prevent gaps.
  10. Take a sheet of plastic and cover the entire area, connecting it at the sealant tape areas. Press the plastic firmly so that it comes in contact with the plastic, forming a good seal. At places where the plastic gathers, take a little extra tape and place it in the pleat and close the gap.
  11. At the location of the connecting base, cut a slit in the center with the scissors, and attach the
    top part of the connection post. Attach the pump to the connection post.
  12. Turn on the vacuum pump. Apply a vacuum of roughly 10 in Hg by controlling the pressure
    valve
    . Listen for areas where air is leaking in and seal using sealant tape.
  13. Once all leaks have been sealed, apply the full vacuum (roughly 23-25 in Hg), and let set
    overnight
    .

 

Sept. 11, 2000 by Dr. Pizhong Qiao