Whats the best way to degass resin while infusing ? is it all about lowering the vacum or something more
Anyone ? something
What do you mean degassing while infusing? As in standard infusion where the vacuum is drawing the resin through the part but also extracting bubbles from the flow front?
I mean that many people say it is good to degass resin before infusing because bubbles may occur later in laminate.
But I also heard that there is a way to self-degas resin while infusing…
From my point I can also see that changing pressure has big effect on bubbles , but I dont have vacuum regulator to make further tests
Degas in a vacuum chamber before hand, as usual. Usually let it sit in their for 10 minutes after collapse since the odd bubble will still dissolve out of solution and appear from no where. Other thing to watch for when infusing is making sure you infusion feed tubing is as void of air as possible - set the clamp as far away from the part/close to your resin feed pot as possible. Also a good idea to have your resin feed pot below the level of the part, so the lighter air left in the line will ‘float’ above the incoming resin front when you unclamp. It’s actually not totally necessary for the pot to be below the part, but just whatever length of tubing is still aerated (behind the clamp at ATM pressure) should be upright.
Problem about trying to degas while the resin front is moving in the mesh/part, is that the resin behind that flow front, won’t see any degassing, since the gas that is trapped in the resin, has no place to go.
I don’t see how it would work.
Relative to absolute pressure . As you mentioned , changing the vacuum levels while infusing can develop/remove bubbles in/from the laminate . If you have no leaks in your vacuum bag and find bubbles in your finished product , you’ve more than likely boiled solvent gases out of your resin . The possibility of it being water vapor does exist as well . The high levels of humidity here in Florida can be unnerving at times. An absolute pressure gauge and/or vacuum regulator at a minimum , will help .
Yes its the case, resin is degassed , bag 100% sealed but some bubbles occur.
HCD can you point a solution cause I didnt understand
No problem , this link explains it well to save me the typing .:bigsmile:
http://www.vacmobiles.com/vapour_pressure.html
Solvent vapours from infusion resins
Also of possible concern when using the resin infusion process are vapours released from volatile resin components. Potential candidates for solvent vapour problems, particularly in warm climates, are styrene and initiators such as MEKP. Because of the wide range of raw materials used for resin manufacture the vapour pressure of mixed resins will be specific to an individual resin/hardener recipe. We recommend that users of the infusion process ask their resin supplier to provide a vapour pressure versus temperature curve for the mixed resin system you intend to use…
Initially, you will see entrained air bubbling out of the resin. However, once the entrained air has been completely removed, the bubbling should cease. If the bubbling does not cease and even becomes more vigorous with increasing vacuum, one or more solvent components have commenced boiling.
If able to observe the process, reduce the vacuum level until the resin ceases boiling and note the absolute pressure at which this occurs. This pressure will be the lowest absolute pressure you can apply whenever that particular resin system is present in liquid form.