Does bleeder use is important?
Does bleeder use is important?
(OP)
During my last stage I was surprised to notice that bagging sequence learned at school (prepreg layup – oven/autoclave cure) is not exactly the same that is used in all aeronautic shops. More, now I saw a few of the same parts bagged without bleeder. Does it means that bleeder use is optional? What is the bleeders function? Also I found that the same part made in different shops is covered with different breather material thickness . . . Does breather thickness influence the cured part quality (thickness, resin content, mechanical properties, etc.)?





RE: Does bleeder use is important?
Bleeders help ensure the entire part is under vacuum evenly. Closer to the port it is easier, the farther away, harder. these materials are thrown away at the end and so only add cost, your economies are better if not needed. As well, bleeders may provide the ability to remove excess resin from the layup, particularly wet bag lay-up. In these cases varying the bleeder over a lay up change your performance factors drastically.
I have used your basic gauze type bleeders, the heavy batting bleeders as well as simple bubble wrap (by ththe way, bubble orientation is very important). It just depends on what you need to accomplish with the bag and what your costs are.
RE: Does bleeder use is important?