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Matt (Staff)
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+x+x+xBut usually easylease should work very well. Have you cleaned the glass before applying the release agent? Maybe there is something on the glass, wich causes this issue. I really don't understand why it is not working? I cleaned the surface and even switched from tempered glass to special heat resitant glass but it does not work good enough to be called a repetitive process. The reason could be hidden in: - Glass Type - Epoxy System (in my case E320/E321/E322/E323 from SGL) - Heat Control (In my case according to Sigrapreg datasheet) - Application method - Application quantity - Panel stiffness This is what I did so far: - Varied glass type (from tempered to heat resistant glass) - Varied application method (Circular movments to linear movments) - Application method (more and less release agent) - I tried with a Mylar foil between the glass and the carbon and it worked - Changed stiffness of the panel What I noticed was, that it worked with stiffer panels like [0/90/+45/-45/+45/-45/90/0] or unidirectional 0° with a 2mm thickness. Therefore my question: - Could it be that the stiffness of the sheet influences the release of the sheet itself? Next I will try with the HP-HGR5 release agent... Hi Matt, thank you for commenting on this. Here are the answers to your questions: - I use the Sigrapreg C U200-0/NF-E322/40% Prepreg system from the SGL Group. - My cure cycle is considering the Sigrapreg Epoxy System Specification and is as follows: 40min ramp to 100°C/120min at 100°C/40min ramp down to 20°. My comments concerning your points: 1) Could be. This is the reason for which I tried with another glass that unfortunately failed as well. I guess I have to talk to a glass specialist here... 2) The release agent was always properly sealed but it is 2 years old. Are two years considered to as old? 3) This can be excluded because I checked it 4) I tried different procedures but no one worked to be considered a reliable repetitive process 5) This is very unlikely since I know the fiber and matrix system and have it documented in the specifications Looking forward to hear from you... I think the age of the Easy-Lease is the most likely (and a very likely) explanation. Easy-Lease has a shelf life of 12 months. It will continue to work after 12 months but 24 months should really be considered to be too old. A 12 month shelf-life is typical for chemical release agents (some of them are in the 6 months region) and most of them will not perform well once you start to exceed their shelf-life by too long. I very much expect you would get different results from fresh release agent. I did also notice that you mentioned the release was OK for a thicker laminate but not OK for a very thin laminate. This is not something that has been focused on much in this discussion but it is an interesting result worthy of some further consideration. For example, release problems are not uncommon if there is not proper resin flow on the surface of the laminate which can sometimes happens following a failed cure such as a burst bag or incorrect temperature settings. Is it possible that you thin laminate is too thin to allow proper resin flow and therefore this could cause release problems similar to those after a burst bag or incomplete cure? This seems quite possible to me; especially in conjunction with release agent which is twice past its shelf-life.
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Pier
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Group: Forum Members
Posts: 11,
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+x+xBut usually easylease should work very well. Have you cleaned the glass before applying the release agent? Maybe there is something on the glass, wich causes this issue. I really don't understand why it is not working? I cleaned the surface and even switched from tempered glass to special heat resitant glass but it does not work good enough to be called a repetitive process. The reason could be hidden in: - Glass Type - Epoxy System (in my case E320/E321/E322/E323 from SGL) - Heat Control (In my case according to Sigrapreg datasheet) - Application method - Application quantity - Panel stiffness This is what I did so far: - Varied glass type (from tempered to heat resistant glass) - Varied application method (Circular movments to linear movments) - Application method (more and less release agent) - I tried with a Mylar foil between the glass and the carbon and it worked - Changed stiffness of the panel What I noticed was, that it worked with stiffer panels like [0/90/+45/-45/+45/-45/90/0] or unidirectional 0° with a 2mm thickness. Therefore my question: - Could it be that the stiffness of the sheet influences the release of the sheet itself? Next I will try with the HP-HGR5 release agent... Hi Matt, thank you for commenting on this. Here are the answers to your questions: - I use the Sigrapreg C U200-0/NF-E322/40% Prepreg system from the SGL Group. - My cure cycle is considering the Sigrapreg Epoxy System Specification and is as follows: 40min ramp to 100°C/120min at 100°C/40min ramp down to 20°. My comments concerning your points: 1) Could be. This is the reason for which I tried with another glass that unfortunately failed as well. I guess I have to talk to a glass specialist here... 2) The release agent was always properly sealed but it is 2 years old. Are two years considered to as old? 3) This can be excluded because I checked it 4) I tried different procedures but no one worked to be considered a reliable repetitive process 5) This is very unlikely since I know the fiber and matrix system and have it documented in the specifications Looking forward to hear from you...
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Pier
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Group: Forum Members
Posts: 11,
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+xBut usually easylease should work very well. Have you cleaned the glass before applying the release agent? Maybe there is something on the glass, wich causes this issue. I really don't understand why it is not working? I cleaned the surface and even switched from tempered glass to special heat resitant glass but it does not work good enough to be called a repetitive process. The reason could be hidden in: - Glass Type - Epoxy System (in my case E320/E321/E322/E323 from SGL) - Heat Control (In my case according to Sigrapreg datasheet) - Application method - Application quantity - Panel stiffness This is what I did so far: - Varied glass type (from tempered to heat resistant glass) - Varied application method (Circular movments to linear movments) - Application method (more and less release agent) - I tried with a Mylar foil between the glass and the carbon and it worked - Changed stiffness of the panel What I noticed was, that it worked with stiffer panels like [0/90/+45/-45/+45/-45/90/0] or unidirectional 0° with a 2mm thickness. Therefore my question: - Could it be that the stiffness of the sheet influences the release of the sheet itself? Next I will try with the HP-HGR5 release agent...
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Matt (Staff)
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Group: Forum Members
Posts: 680,
Visits: 1.9K
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+xBut usually easylease should work very well. Have you cleaned the glass before applying the release agent? Maybe there is something on the glass, wich causes this issue. What type of prepreg are you using? - Also, what's your cure cycle? - Easy-Lease on glass should be very reliable at releasing epoxy-based prepreg following cures up to around 180'C so I'm very suprised to read that you're having this problem. If it's a conventional epoxy prepreg and you're not exceeding 180'C with your cure then the only explanations would be: 1) Contamination on the surface of the glass (sometimes you may have other release agents on there which have not been removed) 2) Problems with the release agent itself (it could be old or have been left with the top off for a long time) 3) Major user error (it's been known for customers to accidentally use Mould Cleaner instead of release agent) 4) Application error (unlikely, as it sounds like you're using the recommended 6 applications) 5) Process incompatibility - for example curing at a very high temperature or using an unusual prepreg resin system which is causing an unexpected problem. If you could fill in some of these blanks then hopefully we can identify the problem. All the best, Matt
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Hanaldo
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Yeh it's a strange one. Glass can be tricky, but generally with a chemical release agent it works perfectly.
Let us know how you get on with the new release agent!
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oekmont
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Group: Forum Members
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But usually easylease should work very well. Have you cleaned the glass before applying the release agent? Maybe there is something on the glass, wich causes this issue.
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Pier
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Group: Forum Members
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+xGlass is sometimes a tricky surface to get a good release. I always use https://shop.hp-textiles.com/shop/Formtrennmittel/Formtrennmittel-95/Hochglanz-Trennmittel-HP-HGR5.htmlNever had any issues with it, regardless of the surface. I use a hand spray bottle (like glass cleaner) to apply it to the mold, then wipe it in with a micro fibre cloth, and use a new one every day. When I got enough old ones, I put them in the washing machine. What I like about this release agent, is that is water based, and therefore can be washed of easily if there is the need to. So no build up issues. I usually only do one application, even on new molds. Oekmont, thank you for your comment. I will definitely try this release agent and test it. I just ordered one sample. I will post my results as soon as I get the product...
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oekmont
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Group: Forum Members
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Glass is sometimes a tricky surface to get a good release. I always use https://shop.hp-textiles.com/shop/Formtrennmittel/Formtrennmittel-95/Hochglanz-Trennmittel-HP-HGR5.htmlNever had any issues with it, regardless of the surface. I use a hand spray bottle (like glass cleaner) to apply it to the mold, then wipe it in with a micro fibre cloth, and use a new one every day. When I got enough old ones, I put them in the washing machine. What I like about this release agent, is that is water based, and therefore can be washed of easily if there is the need to. So no build up issues. I usually only do one application, even on new molds.
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Pier
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+xYeh the residue would have transferred to the pre-preg. I think this will be the issue. It's a bit of a strange one, as it doesn't always cause problems. It's a bit like rushing the application and just doing 5 coats one after another. Sometimes it works fine, sometimes you will get sticks. It's quite amazing that a product that works so well can be so finicky to apply, but you have to remember that it is actually a resin. When you try it again, if you accidentally over apply it and notice it streaking again, don't worry too much - just wait a few seconds and then gently wipe over it again with a clean lint-free cloth to spread the film out. I performed the fifth test to produce a 0° UD laminate with a 1mm thickness. You can see the results below. I used a new lint free cloth and cut 8 strips out of it. I then imbued the strips with Easy-Lease and buffed the Easy-Lease over the glass moving from top to bottom in a stipe like pattern, like moving the lawn. With the second strip I buffed 90° relative to the former direction and so on until I reached 8 coated layers. In between the coatings I waited for at least 20min. After curing the laminate, I was not able to detach it from the glass very well.I got break outs from the glass plate. I don't know how to preceed now. Any other suggestions? Is there another release agent that could work? !  
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Hanaldo
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Group: Forum Members
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Yeh the residue would have transferred to the pre-preg.
I think this will be the issue. It's a bit of a strange one, as it doesn't always cause problems. It's a bit like rushing the application and just doing 5 coats one after another. Sometimes it works fine, sometimes you will get sticks. It's quite amazing that a product that works so well can be so finicky to apply, but you have to remember that it is actually a resin.
When you try it again, if you accidentally over apply it and notice it streaking again, don't worry too much - just wait a few seconds and then gently wipe over it again with a clean lint-free cloth to spread the film out.
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