I have recently encountered a little trouble with a part because of the way I ran my polyethylene hose to the center of the bag. I split the hose into 4 spots and melted the polyethylene back to create a little pronged/flange on the end of the hose and vacuum taped a little on the flange and mostly above on the hose and worked my bag onto vacuum tape and hose. The hose was mounted 90-degree angle from the part directly pointed into flow media. It is a divinycell core infusion. This worked great for 6 out of 8 parts with a little print through where the hose lied as expected without the hose stabbing or crushing the core. The two that had problems had vacuum tape sucked next to the prongs into the hose and sealed the hose off. There are tons of ways to do this, what ways have you guys found to be easy and practical? Also in talking to another co-worker about this he mentioned that it may be bad practice having your resin touching your vacuum tape because it can unstick it and cause leaks. Should I avoid this? I haven’t had this happen unless the tape was put on released areas.
The sealant tape will most definitely break down when it comes in contact with resins. If you are planning to make multiple cycles of the part, it may make sense to make a reusable silicone vacuum bag, which would have the vacuum around the perimeter and the resin flow channels where you need them. Since the resin flow feeds will be molded into the bag, you wont have as much print through where the current bagging system wants to crush/press the resin flow tubes into your part. The silicone vacuum bag takes a little bit of time, but it may be worth the effort.
if you run the hose over the part, you can make a pleat to put the tube into and then use some fiberglass to give a ‘bridge’ for the resin to transfer into the part.
This is just like you would do if you were bagging a part for the oven and you didn’t have a good flange on the mold to put a vacuum port. You would just make a pleat for the vacuum port to fit into and then use a piece breather to tie the vacuum into the main breather on the part.
not sure what your part setup looks like, but sounds like this approach might work. A reusable bag would be good, but this would be a much easier fix if you’re not making more than a few dozen of these.
I always place the resin feedline through the bag at smaller parts.
Therefore I make a little cut in the bagging film. I cut the inlet hose in an angle of about 45 degrees and after about 3 cm I wrap sealant tape around the inlet hose up to about 3cm thickness. Then put the hose through the little cut and seal it with the sealant tape. Make sure there are no pleats were you seal! I put a little bagging film batch over the sealant not to stick to it when pushing it to the bag.