Vacuum Infusion process

[mgz]

I m trying to make parts with Vacuum Infusion process. I make a vacuum bag and check for leaks by leaving it untouched for 2 hrs minimum. After 2 hrs if I am not able to pull against the bag, I consider ther to be no leak. Only then do I proceed to the resin infusion. However, after infusion the bag changes shape. I understand it could be exothermic reaction and etc. But the data sheet of the resin says there is a rise to 130 degrees celsius in 5 hrs approimately. Now if I keep the pump on to achieve the compressive forces of compaction to keep the bag in shape, I lose resin and increase the chance of resin boiling. Could some one tell if there is another solution to this problem???

[CaptainPanic]

What plastic is your bag?

 

Some plastics cannot withstand 130 degrees C.

Also, maybe your resin is dissolving into your plastic, which changes the properties.

 

Just my 2 cents. Keep searching on the internet. A first google search showed quite a lot of information about the process.

[mgz]

What plastic is your bag?

 

Some plastics cannot withstand 130 degrees C.

Also, maybe your resin is dissolving into your plastic, which changes the properties.

 

Just my 2 cents. Keep searching on the internet. A first google search showed quite a lot of information about the process.

 

 

Thanks CaptainPanic. I am using a vacuum bag which my colleagues are using in the autoclave. I think it should be fine at 130 degrees celsius. Regarding the resin dissolving in the plastic, I can make careful observation 2moro. I think it could be a possibility as the resin gets trapped in the corners of the pleats. This could be the problem???I can tell u 2moro.

 

Secondly and most importantly my question is ----- Is the deformation of the bag normal after vacuum infusion or not????Should this happen or not as all over the internet no one tells what happens after the infusion to the bag.Theoretically it seems possible. I would appreciate if you could tell me from your experience if this happens or not.

[CaptainPanic]

Thanks CaptainPanic. I am using a vacuum bag which my colleagues are using in the autoclave. I think it should be fine at 130 degrees celsius. Regarding the resin dissolving in the plastic, I can make careful observation 2moro. I think it could be a possibility as the resin gets trapped in the corners of the pleats. This could be the problem???I can tell u 2moro.

 

Secondly and most importantly my question is ----- Is the deformation of the bag normal after vacuum infusion or not????Should this happen or not as all over the internet no one tells what happens after the infusion to the bag.Theoretically it seems possible. I would appreciate if you could tell me from your experience if this happens or not.

I can tell from experience that it sometimes pays off to give someone a phone call.

 

Try to find an expert in your country, and make a call... it may solve things so much faster

 

(Oh, and make sure to post a summary of your answer here for our entertainment).

 

Sorry that this email didn't help at all... I just fear that we may not have an expert in this particular field here. I hope the future will prove me wrong

[mgz]

I can tell from experience that it sometimes pays off to give someone a phone call.

 

Try to find an expert in your country, and make a call... it may solve things so much faster

 

(Oh, and make sure to post a summary of your answer here for our entertainment).

 

Sorry that this email didn't help at all... I just fear that we may not have an expert in this particular field here. I hope the future will prove me wrong

 

Hello CaptainPanic

 

I got good infusion today and less deformation of the bag.This is mainly due to excess resin pushing against the vacuum bag. However, I can see uniform distribution of resin on the sample where I have the following lay-up --- fabrics, perforated peel ply, spiral tube in the omega flow line and the breather. From the internet and scientific literature, this was the best lay-up to use without having a resin distribution medium. Also, after 12 hrs of infusion, the color on the outside of the breather did not change. I think I should get better impregnation in the system. Also, could you tell me if this is the usual lay-up or not. I am assuming here the resin flows through the perforations of the peel ply into the fabrics and wet them. Is that correect or not??

[Dune]

I am not understanding the problem here. Are you using the bag as a form? Or is the distortion of the bag distorting your form? The vacum/bag asembly should do little more than allow full atmospheric pressure to come to bear against your lamination, essentialy giving the densest cast possible combined with as little air inclusion as possible. Am I misunderstanding your process? http://www.westsystem.com/ss/use-guides/ Scroll down this page, to a downloadable vacum bag guide. If you have further questions, contact the manufacturer directly. They are very helpful.

[mgz]

I am not understanding the problem here. Are you using the bag as a form? Or is the distortion of the bag distorting your form? The vacum/bag asembly should do little more than allow full atmospheric pressure to come to bear against your lamination, essentialy giving the densest cast possible combined with as little air inclusion as possible. Am I misunderstanding your process? http://www.westsystem.com/ss/use-guides/ Scroll down this page, to a downloadable vacum bag guide. If you have further questions, contact the manufacturer directly. They are very helpful.

 

The distortion is from the excess resin which increases the pressure inside the mold against the atmospheric pressure. However, the result was better but not perfect as I got places with cracks. I think this can be only because of the resin flow control. Any suggestions for making a line infusion work around on the curvature of a cylinder??

[elektroda]

This may help you, a whole infusion process step by step. Nice video :