I don’t think you quite understand what the graph and table are showing. The graph shows a plot of the table so you are right, the increase in stiffness of 3mm steps decreases as a percentage of overall stiffness, just as the 3mm increase in thickness decreases as a percentage of overall thickness. The graph and table are correct.
If you double thickness, the stiffness increases by about 8 (as can be seen in the table). Pick a thickness on the table and then look at it’s double. The stiffness will increase about 8 times. For instance, 3mm has a stiffness value of 11250. 6mm has a value of 90000. 90000/11250 = 8. You can test the rest of the table if you like.
The graph of modulus is also correct. If you increase the modulus but keep the thickness the same, this is what you get. I’ve explained this before that in simple terms, the top of the table would be the cheapest laminate, maybe E-glass and polyester resin and the bottom of the table would represent the most expensive laminate, something like carbon/epoxy.
The point of these tables and graphs is to show that stiffness increases with thickness at a far greater rate and lower cost than trying to increase stiffness through material selection.
As for you wanting an example of a laminate stack to use, not knowing much about your product (loading, duty, etc.), it is just a shot in the dark but I’d consider a couple of layers of 1.5 oz mat, 0.5-0.75" core where needed for stiffness, 1708 biax patches for local stress and maybe a 1208 over the whole unit (at least over the core).
If you are going to infuse or LRTM, you can use continuous filament mat to increase flow in the stack. Rovicore (and similar products), used in one of the videos you posted, is a great product and it can greatly increase efficiency but that comes at a price. You’d need to carefully examine material cost vs labor expense when using it.
Yes, for RTMlight, you need some sort of resin channel. Rovicore-like materials have this built in.
If you say 5mm would be sufficient, I would look for an infusion mat which has enough CSM on the outsides, and can fill the 5mm cavity. Such as a M900-M05-M900 from Scott&Fyfe. (Polymat)
Use a good gelcoat, apply sufficiently thick, and use a peroxide which allows a better cure. Perhaps an AAP catalyst.
For the resin, you could try with a filled resin, which limits shrinkage. This can bring your so desired Class A finish (and honestly, I would not deviate from that. Better to have 2 moulds doing the same to give the output wanted, than rework on the parts).
Make sure your inserts are near the inner side, which can have a slightly lower quality finish. A piece of Soric under the insert can help limit telegraphing to the outside.
Also, Soric can be a viable option to get lighter weight products. However, placement of the material is more critical.
“Use a good gelcoat, apply sufficiently thick, and use a peroxide which allows a better cure. Perhaps an AAP catalyst.”
Ok usually I feel more comfortable to require the gelcoat supplier specify the ideal catalyst. So I am not sure what you mean there because is alot of sophisticated testing involved when they recommend a catalyst and often they will ship them together.
About the gelcoat I am also confused how those guys in the video demo are getting 5-7 cycles per day and have a cycle time of 30 minutes.
On a hand layup job I am waiting 2-4 hours for the gelcoat to feel the safe tackiness quality to continue with the first layup of fibre.
Obviousy they are using a gelcoat that is different from this.
Any ideas? Is it because the mould must be heated?
If it is heating then I am going to be keen to find a few illustrated examples of installed heating systems.
About the Infusion Mat, those a good leads. And yes I am sure 5mm will be safe thickness. ANd you have given me some good leads to hunt down more understanding about selection and usage of them.
Make sure your inserts are near the inner side, which can have a slightly lower quality finish. A piece of Soric under the insert can help limit telegraphing to the outside.
Also, Soric can be a viable option to get lighter weight products. However, placement of the material is more critical.
Ok I am confused trying to visualise this. This is where I am happy to pay for someone to bother illustrate it.
I’ve got a project right now I’d kill to be able to make even 5 a day. I’ve got a contract for C7 Corvette Side Skirt and front splitters I’d love to close in a week instead of a month.
Can anyone walk me through how to set this up? My issue is in cure time. I can’t understand how to get more parts out of the same mold in under an hour. My current fiberglass tech is taking a full day to lay up 4 fiberglass molds, with only one part per day coming out of them.
If you need the most output from a mould per day, the press moulding is the way to go. You just need a heated press and moulds with their closures able to whithstand heat and pressure.
With this system a long time ago I’ve been able to make 1 roof per hour for Fiat vans.
So let me me pay you $500 per hour to know how. My female can withstand the pressure but she is not heated. I dont want to strip her to heat her. And if you know that much about press then you know enough to help me. $500/hr. get an account on Odesk and make yourself available like a java programmer. The world needs 3D-printers, it needs fibreglass experts, and it needs java programmers. None of us are experts, God is the only expert of everything.
SOmeone once said that God can see the future. The NSA are trying to see if they can see the future. The Jews believe in God. They think that they are his “Chosen” and He will always forgive them their trespasses. Get on Odesk I will pay you $500/hr and so will the next guys and the next guys.
My market is like this. People ask me why dont you make just ONE xxxxing prototype to show people the product and see if they will buy it?
I ask them, “are you stupid?”
I dont make one because then they will have ONE to copy it. I need to have a machine ready to make nobody ever think about copying it.
I mentioned above two of my degrees. My third degree was a Masters in Business Systems. How business succeed, how they fail, why they failed, what tools they used in the corporate world to make things move and make money…
i was smart, too smart, too smart because I took the degrees and education of the new world order and then went and told them to xxxx themselves I will not be a slave-master, I will not turn your engine of misery and slavery. I fear God and He is my best friend today manifested in my black labrador.
If anyone wants to put their hands on this project I got to warn you I live in the most sexy women capital of the world, Floripa. California is nothing compared to this. All the sexiest women in Brasil come to live in Floripa waiting for some rich guy to fall in love with them. Your eyes will leave your head I will have to slap you in the face 50 times per day if we drive anywhere it is like babe paradise I cant believe i am living here sometimes I even have to slap MYSELF!If you insist on smelling the gelcoat which smells like your ex-wife’s xxxxx, if you really need to smell around and cant use iphones in 3D to be here and you really need smell all the xxxxxxs, even the dog;s xxxxxxs and their sperm (you must know something I dont know about science if you really need to be here in person or unless you want to try and xxxx my wife)
It went nowhere because there was no links to any useful knowledge and everyone is working on carbon fibre and different technologies.
Press is expensive moulds. Its never just about the technology. Its about the market. The objective is never your product, the objective is profits. Lawyers, copyrights, patents, scammers, stupid businessmen who setup companies trying to offer consulting services for their expertise and then suddenly someone makes their expertise obsolete with a new way of doing it and then that person is stuck over invested in their consulting mould-production Old-RTM company selling resin injection machines they spent 5 years designing and building and their wife is threatening to leave them or simultaneously having an affair in their face with a “So you going to break the children’s hearts and let them know about this???” grin on her face.
The point is its almost never about the technology. IT IS ALWAYS ABOUT THE PROFIT$!
Profit is a motivator, for sure, but I suspect the lack of information is driven by the fact that most of us are making up and figuring out how it all works as we go.
I own a carbon fiber company.
Even the reps selling me product don’t know what they’re talking about.
It’s ridiculous, really, and for a person to try to charge you for sharing the knowledge that they have not formally it and, well, I think that should be Considered borderline criminal.
Ok I may have found an excellent company and their simulation software for fiber injection mould systems.
You only need send them a 3D scale model of your female mould and they can do the rest. Or probably even can send them 3D model of just your product and teh software can do the rest, even identifying unfavourable areas of the product shape and allowing you to edit the product design if you want to improve its producability.You can play around with all variables (injection pressure, vacuum pressure, injection port positions, everything: Injection simulations to save cost of trial-and-error. There are some minor injection experiements you need to do on simple small sample mats to get the right flow-parameters to input their software.
You can buy the software outright and learn to use it yourself or pay them for one-off mould.
I just got my 3D female mould finished yesterday and am going to test them out. I will keep progress reports here in this thread -
This sounds excellent as I would love to avoid resin-injection and just use vacuum-assisted (lower capital investment).
The OP example of VARTM (also called Prestovac) seems ideal to me HOWEVER I just realised too many fumes for me to run this in my domestic house. So I want to go with resin-injection where the resin and catalyst are contained. But would be great to be able to test a resin-injection with a air-pressurized chamber (up to 120psi) and vacuum below. I dont want buy a damn injection machine, they are too expensive for me right now.
The above software allows you to test all configurations and see the simulated result of the resin flow front.
I have this problem as well. Reichhold and the big companies you can only trust for consistent ISO9000 quality do not sell less than 25 44 gallon drums in one order.
This has created a middle-market of resellers so that small manufacturers can access the chemicals. Problem with that though is you notice that most of these companies dont have reps who understand squat about the products and technology they are selling and most of these reseller companies relabel the Originally-Reichhold resins with their own trademark, and usually have added fillers, and obviously could even lie about the Use-By date and sell products that really are already passed Reichhold’s original Use-By Date, and then us small businesses are trying to make a reliable manufacturing process that doesnt include nightmares and you ask Criminal? FROM THE VERY TOP!!!
And these reseller companies who add fillers and all this PLUS with reps who dont understand squat, AND these reseller companies dont have access to the testing equipment and ISO9000 standards of the original product therefore obviously they dont REALLY know what they are doing and this is the best us small manufacturers have access to. CRIMINAL??? DAMN STRAIT! It is the NEW WORLD ORDER conspiracy to destroy the middle-class and control the world of everything!
REICHHOLD should be forced by the local government to sell single 44 gallon drums as their minimum order so that small manufacturers can access quality guaranteed resins. No, no, but our corrupt government makes life too easy for Reichhold, excusing them any obligation to have support forums for us scum small manufacturers but giving them the whole market of the country at the same time, a total xxxxing monopoly. Scum should all be in prison.
meanwhile, I am going to do this small manufacturing business regardless. Look on the bright side of it - If you can find a process that works for you, the current ENTRY BARRIER for any competing small manufacturer is higher due to the volatility described above. This is a way to see it as an ADVANTAGE personally but generally my sentiments are expressed above.
I wrote to this company 3 weeks ago including copy of 3D mould in specified format they required. Got no reply yet. I guess they only talk with Israeli Airforce and punks like that.
Am still looking for consultant to finish this prestovac system.
try to call them, they might be busy. There are some other dutch companies who use their software to offer consulting, I can ask if you are interested. Send me your contact details and what you need (like part size) in a pm.
(I’ve talked to the owner a couple of years ago about working there )
There are some minor injection experiements you need to do on simple small sample mats to get the right flow-parameters to input their software
If you know those, it isn’t rocket size to determine the inlets and evac points/lines althoug the software is a lot easier with complex geometry/layups.
)
althoug the software is a lot easier with complex geometry/layups.