Would you like to try PCR-3121 very good Resin system, RESIN333@aol.com
===Edited by Canyon===
Banned
If you google “RESIN333” you can see that he/she is pushing more than resin. 
Yes, despicable spammers! :mad: :mad: :mad: Abuse something for good, so you can make money at someone else’s expense. --That’s not honorable. :mad: :mad: :mad:
I’ve been trying to catch up on my projects after being down, and I’ve done some work on the calculation program. That said…
Although the %Vf calculations have been helpful, I believe they are a little too vague. Plus, I believe there are things missing. Much about E-Glass, and little on CF. I’ve asked for clarification, but no takers yet. 
Here are my questions from the 6th, which I’m raising to give it another shot. Hopefully someone will know the answers:
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P is a constant imposed on all layers equally? (Should be, right?)
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What determines the “type of composite”? Weight, weave, manufacturer, type? Is plain weave CF the same as twill 2x2 CF if they’re of the same weight? What about custom weaves, etc.? What about cores, they absorb resin, right? – Or is that why “what’s around it”, is so important?
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Mesh… (From the same source as the 60% vf above), they said mesh, (of all types!), has a standard uptake of 700gsm. That sounds like flawed thinking to me.
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What different characteristics of resin will affect our calculation? Density? viscosity? I know epoxy is stronger than VE which is stronger than PE, but how does that affect uptake, or doesn’t it matter. For mechanical properties, that info will be important and makes sense.
An expert in this field appears to be Dr. Young Roak Kim, which I’ve tried to contact, but my E-mail bounced.
There’s much more to do on this thing, but if anyone wants to take a quick look at it, I have it at:
http://black-lab.com/resin, (subject to change)
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P is constant over the layers.
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The engineer determines the type. Based on technical properties, but also way of manufacturing, and hopefully also on what is available locally.
Plain weave or twill: twill is drapable. Thickness between otherwise equally parameters can have a slight influence on thickness.
Foams or cores technically do not absorb resins, usually, with some expections. (balsa, and some others.) However, all use a certain amount of resin to fill the imperfections of the surface. -
Mesh: all meshes take up resin, one more than the other, and even the flexibility of the vacuum film has influence on it. Nice, huh?
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Density. Uptake for the 3 resins is the same. Technical properties are slightly different.
Did not check your link yet…
Checked the link. Looking good. If you need any input on the interface let me know.
On resin333: do not check Google Images. Firm buttocks… 
I checked the link and found some discrepancies.
19.7 ounce/yard carbon at a Vf at 59.7% with an area of 437.25 sq. in. would use 81.3 grams.
8.8 ounce/yard carbon would need 36.3 grams
Am I misunderstanding something?
Didn’t someone suggest it should work to NASA specs?
Seriously, this is exactly the sort of feedback I’m after, and not unexpected so early on.
Perhaps, I’m using resin% vs. fiber%??? Doing that I get closer to your number, but I’ll relate exactly how I’m calculating this:
Where:
a=34.00 Mystery Compression Factor A
b=25.55 Mystery Compression Factor B
P=1.015917 Pressure applied to bag (-Atm)
areaSqm=0.282026 Fabric area in sqM from 437.25 SqIn
weightOzy=19.7 Fabric weight in Imperial Units
vfPct=a+(b*sqrt§) %Vf
vFactor=vfPct/100.0 %Vf factor
weightGSM=weightOzy*33.906; Conversion of Eng to Metric
uptakeG=areaSqmweightGSMvFactor Individual Layer uptake
So, I get:
vfPct=59.379421728822
vFactor=0.59379421728822
uptakeG=112.56117776578
Please correct my poor thinking!
I have no idea how the mystery compression factors were derived. The volume of resin in a given laminate with a know Vf% is just simple math.
If one square yard of carbon fabric weighs 558.48 grams (19.7 ounces) and the density of the carbon is 1.8 grams/cc then we can calculate the total volume of fiber:
558.48 grams / 1.8 = 310.27 cc of fiber
If the Vf % is 59.8% (59.8:40.2) then we can calculate the volume of resin:
310.27 cc x 40.2 / 59.8 = 208.58 cc of resin
We can convert the resin volume to a weight using the mixed density of our epoxy resin which is 1.11 g/cc
208.58 cc x 1.11 = 231.52 grams of resin per yard.
Your area is 437.25"^2 or .337 square yards.
.337 square yards x 231.52 grams per yard = 78 grams of resin for437.25 square inches of 19.7 ounce/yard carbon fabric
This figure is a little different from my previous calculation because I used the resin density rather than the mixed density.
If your formula comes up with a Vf% 59.8 but the resin volume differs from the above math then something is off.
Yowza! It’s going to take me a little while to absorb what you’ve related. I convert everything upon initialization into metric units, and then do all the calculations in those units. Switching back and forth makes my head a bit numb. :blink: I know you’re just trying to keep me on my toes!
The “mystery” factors I got from an earlier post in this same thread, (~#4?), to determine %Vf based on type of layer. I call them “mystery” because there was no nomenclature provided, so until I can get clarification, they are values “a” and “b” based on the generic type of material for that layer.
In the mean time, I got the idea for writing this program from the following forum post:
http://www.talkcomposites.com/Topic11.aspx
They appear to determine resin density by weight, which is what I do. There are things in their post which I don’t agree with, and maybe this is yet another case in point.
I’ve got to run, but I hope to study and understand your calculation later tonight/tomorrow.
Ok, here’s the new calculation for one layer:
areaSqM=0.282026 Area of reinforcements in sqM (from 437.25 sqIn)
pBar=1.015917 Pressure applied to bag in bar (from 30.0 inHg)
a=34.0 Compression Factor A for Carbon Fiber
b=25.55 Compression Factor B "
dC=1.8 Density of Carbon Fiber
dM=1.10 Density of mixed Matrix
weightGSM=667.9482 Weight of reinforcement layer gsm (from 19.7ozy)
vfPct=a+b*sqrt(pBar) Volume of Fiber % (59.752531841979 %)
vrPct=100.0-vfPct Volume of Matrix % (40.247468158021 %)
vf=weightGSM/dC Volume of Fiber (371.08233333333 cc/sqM)
vr=vf*vrPct/vfPct Volume of Resin (249.94964957024 cc/sqM)
wR=vr*dM Weight of Resin (274.94461452727 gsm)
resinG=areaSqM*wR Resin required for layer (77.54159859282 g)
Please give me feedback if you agree or disagree with this calculation…
Looks good. Although I still don’t understanding those mystery numbers.
In all honestly, I don’t know much about them either. In post #5 of this thread, wings kindly attached a graphic from a document listing various generic types of reinforcements, and an equation to determine the %Vf based on pressure. They’re all expressed as:
%Vf=A+B*SQRT§
P is pressure in bar, A & B are constants based on the material. For CF: A=34 and B=25.55. I wasn’t given the context of what those factors actually were, and because I needed to name those constants, I simply choose A & B.
Found it…
This document doesn’t say what A & B are, however they call it K1 & K2, so I’ll be changing the names of these factors internally.
Google does not like me. I only see an advert for a book. Does anyone have the document as PDF?
Goes right there for me… That said, I have a Google account, and perhaps it just shows it to me??? The book is: “Composites Design Manual” By James A. Quinn. Scrib also has the title for viewing, but I don’t have the URL for that right here.
My composites project is bumming me this week, and I’m waiting for some product, so I spent most of yesterday working on the tool instead. Here’s a minor list of what new:
[ul]I re-arranged the database tables, and populated them with data. (More is needed.)[/ul]
[ul]The calculator now actually uses the DB tables.[/ul]
[ul]The beginnings of a thickness calculation is in place.[/ul]
[ul]Now uses maximum batch size and shows multiple batches with smaller constituent weights.[/ul]
[ul]Corrected a multitude of bugs![/ul]
[ul]I added the quintessential disclaimer.[/ul]
Found it on Scribd. Will download it later, but browsed through the compressiblity section. This guys shows it extensively.
Looked at your calculator again. Looks good so far, does it? No real comments. For as far as I can see, it does what it needs to do. Just need to fill the database.
Or course now you can make all kind of extensions. One small addition might be to do the resin waste in percentage.
Moved to Engineering Talk
Jap, I don’t think that your thickness calculation is correct. I can show the math if you would like. There also seems to be glitch between the mm to inches. I understand that this portion is still a work a progress. If my critique is too early then just tell me to stuff it.
I’m also getting some small discrepancies in the resin volume when working is E-glass. Are you using 2.55 g/cc for the density of e-glass?
I find it strange that the Vf% prediction for 5 ounce Kevlar 29 is higher than the prediction for woven E-glass. In my experience the prediction is almost reversed than the mystery number prediction.
I also see that you have added a processing format option (hand layup etc.). The Vf% should change when this field is changed. I can get Vf% of 55-60% with 5 ounce woven Kevlar29 with pressure assisted processes but only around 38% with an unassisted hand layup.
Keep up the great work!
Adam
Did not check calculations, but can we include the thickness per layer (so in the “orange” table)
Also a tool to add materials would be nice (although that might be a bit early)
My apologies… It had been a few days without any posts, and I’d been busy with other things. I was thinking my thread had slipped to the next page of the forum, but this morning I started to actually look for it, and it was GONE! :eek: Now, I see it’s been moved. Ok. 
I worked on it yesterday, and I’ll do a little more today. I’ve made a different version, (with a different URL), which I’ll share as soon as it runs without puking. 
Adam, you’re correct, the “Method” control currently does nothing. Other than comparing the thickness figures to what my calipers show from my actual part, I assumed it was close. Please show your calculation, I was unsure of a thing or two. I’ll check on the other points you raise.
In this newer version:
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I’ve rearranged the fields a bit, and added separate resin and hardener fields.
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I’ve internally changed the pressure value from bar to Pa. (I still convert to bar in the %Vf calculation.)
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I’ve added a precision control, which will render things with fewer decimal places.
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I’ve added a “Also show US Units”, which will present a US results column in addition.
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Some cosmetic changes.
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The stack now only shows items with content.
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The results are now integral to the table, and not a separate text dump at the bottom.
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There is now a login sidebar, which currently does nothing.
Subsequent versions, will have the following attributes:
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URL re-arrangement. The “index” page, (i.e. where it currently is), will become a login/menu of sorts. You’ll link off it to get to the calculation, and the future material cutting calculator.
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Optional ability to store your calculations, (protected by a login). The first page will show a listing of your stored calculations. No login will be required if you don’t want to save your data.
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Database table builds. You’ll be able to pick your resin/reinforcements from a list, (partially there), and if it doesn’t exist yet, supply the information. A moderator will need to insure sanity and catch the spam tricks people play.
I hope today to get this latest version up, but we’ll see. Nonetheless, feel free to voice your opinions and insights at any time!