Making a Vacuum bag questions...

General Composites Discussions Equipment Talk
#1

So I do Cf overlays and just did my first vacuum bag project with fantastic results. What I’m trying to do is make a bag that would be more cost effective.

Here is a visual of my first bag. I pretty much took the nylon bagging folded it in half and used sealant tape around the perimeter. I have seen products that seal food up and wonder about the possibilites of using this to defer the price of using the sealing tape each time.

Also what would the possibilites be for sealing the bag? I would be using this all the time, so Is there something I can purchase that makes the bag seal only temporarily?

#2

There are reusable bags with ziplocks, which seem to do the job, especially in the veneering business. I do not see them around in composites often.

Tube film (nylon) should also work. About all nylon film starts as a tube…

#3

I use kitchen food sealer to hot melt the edges of my bagging material together. I’m using low temp material so if you oven cook and use bag material for higher temperatures that won’t work. Double seal the sides for “insurance”. make the bag longer than you need and cut the edge off to get the part out. I don’t get more than 3-4 uses per bag so I leave it long enough to cut the seal off 4 times.
There are industrial edge sealers that have a longer arm and I’m considering buying one. I just haven’t found any which are open on both ends i.e. don’t open like a “V”.

#4

These guys have something called quick lock seals.

http://www.acpsales.com/Vacuum-Bags-Films-Peel-Plys.html

I bought some but haven’t used them yet.

#5

Yup this is what I was going to throw out there. I’ve never used them either and wondered how well they seal, be sure to let us know how they work Shoe.

#6

I would be interested in how well they work. I used a similar system when making printed circuit boards. They weren’t watertight so I can’t see them being airtight.

#7

They’re ace! I some from the US a while ago and use them all the time. They Seal as well as tape as long as theres no pleats/folds in the bag.

They’re no so good against high temp. I melted one in to a gooey mess.

Well worth it i’d say.

I’ve also started using a zip loc bag used for cleaning kitchen cooker trays.