I have had bags similarly slack before - especially on smaller pieces where it is easier to reduce the overall bag pressure with the resin coming in.  There is no leak there otherwise you would see the streaks of air shooting across the laminate surface.

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant

I did another test laminate today, same size, 60gram spread tow + 450 + 220, IN2

see video, this is how slack the bag was during infusion, before it was sucked dead hard to the stack..
https://www.youtube.com/watch?v=dHCltjiRH9s

any comments?

http://motoform.blogspot.se

Ok, thanks.
I will do more tests and pay attention to flow rate and resin temp / viscosity.
I will also place another silicone connector with hose and gauge at the inlet side of the part and monitor the vacuum there.

http://motoform.blogspot.se

Yeh, that will be a large part of the problem. For such a small part, you really need to throttle the resin flow right back. It is definitely something I would expect to happen on a small panel. 

Hi Warren

thanks for your reply, I agree, my point is that this has always occurred but at a much lower rate / level, this is significantly more.

However, and this is the reply to Hanaldo as well, these test parts are very small 10*12cm approx, and the stack was 4*220 twill with 2mm soric in the middle,
and yesterday 450+220 2mm soric 220+450.
To be considered a thick laminate with the size in mind?
and if so, is this to be expected?

And to be honest, when I say "all the other infusions I have done" I don´t mean parts of this size, only larger ones.

http://motoform.blogspot.se

How big are the panels and what is the layup? 

How loose the bag comes in infusion varies depending on viscosity of resin, thickness of laminate, size of part etc.  Height of the resin pot can make some difference.

Certainly with a thicker part, you will find the resin flows into the bag a lot quicker than it will initially be soaked into the laminate, so you can get an excess of resin in the bag at the resin end.  If you clamped the resin feed, as the resin soaks in, the bag would tighten up again and the vacuum level in the bag would even out.

Ideally the bag should tighten up again once the infusion has completed and the resin feed is clamped off, unless there is a lot of excess resin still there. You could suck some of this out into the catch pot but be careful not to go too far.

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant

It is at the same level, 15cm hose away.
But yes maybe I let it flow a bit fast, but still, this is different to all my other infusions.

If you have the resin mix set too high above the mould it can flow in  too fast and create a loose bag full of resin.

Thanks for your reply,
but I know that it normally is like you describe, but what I an experiencing now is not normal,
it is much worse, I can grab the bag with two finger and easily lift all the slack, there is lots of resin under and the resin flows slowly through the part.

http://motoform.blogspot.se