You're only reinforcing my point that the point of presence for the Wifi antenna will not be shielded in CF.
Absolutely. As I said in my previous reply, the original point of this all is that the _entire_ laptop shell could not be made from CF. That would make the presence of internal antennae an impossiblity, since Carbon fiber is not RF transparent.
Carbon fibers themselves have the worst compressive properties due to kink banding. That's why you don't see high modulus ropes made from carbon fibers,
Ropes are used in applications of tension, not compression.
Quote:
Dyneema is a very poor material due to it's linear creep properties inherent in it's low temperature limitations (70 C max, 50 C for long lifetime).
"according to DSM, it is not advisable to use UHMWPE fibers at temperatures exceeding 80 to 100 °C for long periods of time. " - Wikipedia
Quote:
Dyneema is not 15 times stronger than high strength metals (A factor of 10 is the most I've ever seen the Dyneema literature claim)
"DSM Dyneema is the inventor and manufacturer of Dyneema®, the world?s strongest fibre.
... It is up to 15 times stronger than quality steel and up to 40% stronger than aramid fibres, on a weight-per-weight basis. "
, stainless steels can easily exceed ~250 ksi yield stress, aluminum ~80 ksi, and titanium ~200 ksi.
"Dyneema and Spectra are gel spun through a spinneret to form oriented-strand synthetic fibers of UHMWPE, which have yield strengths as high as 2.4 GPa and density as low as 0.97 kg/l (for Dyneema SK75)[5]. High strength steels have comparable yield strengths, and low carbon steels have yield strengths much lower (around 0.5 GPa). Since steel has a density approximately equal to 7.8 kg/l, this gives strength/weight ratios for these materials in a range from 10 to 100 times higher than for steel." - wikipedia
2.4 GPa is about 362.6 ksi I believe, giving Dyneema a tensile strength about 45% greater than the stainless steel you mention.
"Dyneema and Spectra are gel spun through a spinneret to form oriented-strand synthetic fibers of UHMWPE, which have yield strengths as high as 2.4 GPa and density as low as 0.97 kg/l (for Dyneema SK75)[5]. High strength steels have comparable yield strengths, and low carbon steels have yield strengths much lower (around 0.5 GPa). Since steel has a density approximately equal to 7.8 kg/l, this gives strength/weight ratios for these materials in a range from 10 to 100 times higher than for steel." - wikipedia
2.4 GPa is about 362.6 ksi I believe, giving Dyneema a tensile strength about 45% greater than the stainless steel you mention.
Nice try, but ...
I spent three years of R&D on a military project involving the use of high tenacity fibers.
So I know the real answers, not what is published as PR from DSM.
1) The published tenacity is ~20-30% higher than for large cross-sections of any high tenacity fiber, and this is also true for the modulus to a lesser extent, say 10-20%. The published tenacity/modulus is either a single fiber pull test or a small bundle (say 1500 denier) taken at the optimum twist angle of the fiber bundle. Commercial carbon fiber is like glass, it's good for all of one compression cycle in it's native state, that's why you only see it used as an FRP core material, this constrains/eliminates any possible bending of these fibers, the source of kink banding. Long chain polymers give all these high tenacity materials their high strength/modulus versus the native materials themselves.
2) Ropes are always considered tension elements. D'oh! However, all fibers are not under the same tensile stress, the rope goes slack, some fibers go into compression, cycled a few thousand times, kink banding occurs, more fibers fail over time, rope then fails. Got it? Heck, the API still does not have design guidence for high tenacity fiber ropes, it took them more than 10 years just to do PET (polyester ropes).
3) Independent peer reviewed journal papers show the real story of Dyneema's extremely poor temperature properties and linear creep properties. You won't find that type of information anywhere on the DSM website for all too obvious reasons. No one in their right mind would ever use Dyneema in a static force application. If you want a spaghetti laptop, than by all means make the superstructures out of Dyneema. Residual stresses and heat would cause the FRP material to warp over time. Guaranteed.
Producing carbon fibers takes a lot of energy because you have to heat plastic fibers up to 2000°C without the presence of oxygen. Furthermore you can hardly recycle it (you can grind it and use it as a filler for less challenging purposes).
Not sure what you're saying here, as carbon fiber is not plastic. Methods of production do not use high temperatures like that. nothing even remotely close.
Grinding carbon fiber composites serves no purpose as there is no real use for it.
Quote:
And I don't believe Apple's statment that the new unibody MB's are enviromentally greener than the old ones, as long as you just look at the body. When you want to make aluminium you are digging bauxite and then invest hugh amounts of energy to melt the whole thing and extract the aluminium. Melting aluminium for recycling costs less money, but still you have to invest hugh amounts of electricity.
Believe what you want, but it is better. Aluminum production is well understood. Recovery of almost 100% of the initial metal, and cutting fluids, is possible, at a far lower cost in energy than the initial production. Other savings include the lack of molds, and stamping. That has large energy requirements. A simplification of manufacturing. That saves energy all around. Even if the computer case is thrown away in a landfill, the aluminum has no toxic effect as plastic can, as it breaks down.
Quote:
Wehreas if you are using injection molded plastic, it takes a significant smaller amount of energy to produce it, and if you burn it under controlled conditions you can get a not to small amount of energy back.
Not quite. Plastic has environmental consequences beyond that of initial energy use. You can't burn plastic as fuel, or for any other purpose. burning most all plastics results in various toxic chemicals, and carcinogens, being released. Carbon sequestering would be required as well, because the largest part of any plastic is carbon. We can all guess as to what the most important component to carbon fiber sheets would be. Under high temperatures, it breaks down into soot, and other carbon compounds such as carbon monoxide, etc. Depending on the exact nature of the plastic, and there are many kinds of blended materials, you could get dioxin, which is produced from plastics that contain chlorine (hence the removal of PVC). Quite a few other toxic chemicals, really too numerous to list, are produced.
So no, plastic is NOT a better material environmentally.
I didn't realize that the 777 was receiving wifi from outside the fuselage while in flight, nor is the entire fuselage made out of Carbon Fiber (actually only portions of the tail, control surfaces and engine nacelles are composed of CF, the majority of the airframe is aluminum).
My point was to the original poster that suggested making the entire laptop out of CF, which would pose problems for RF reception. Some CF would be fine, but not the whole thing.
I work on the 777 at the Boeing plant in Everett, Washington. You forgot the floor beams, the floor panels, the radome and most of the galley and Lavs are all made of CF. Only about 25% of the 777 is made from CF. Now I am thinking that folks are thinking about the 787 and it is about 60-70% CF, including the main airframe is CF barrels along with the wings.
I wasn't asking you to prove anything, I just wanted to know why you have that opinion.
I don't watch their job listings.
I got the impression that maybe you thought there were mechanical problems that suggest they don't have that kind of talent, I was curious to know what they might be.
I can only imagine that if Apple does indeed design their own cases, as well as the huge number of parts required for any product, that they must have a large number of ME's working for them. You simply can't do this any other way.
If all they do is to make sketches, and send all of that work out, then that's different. But I don't see them doing that, do you?
Absolutely. As I said in my previous reply, the original point of this all is that the _entire_ laptop shell could not be made from CF. That would make the presence of internal antennae an impossiblity, since Carbon fiber is not RF transparent.
In fact, it's used as an RF shield.
If it weren't still so expensive, it would make a better Faraday cage than the copper mesh which is usually used now.
I spent three years of R&D on a military project involving the use of high tenacity fibers.
So I know the real answers, not what is published as PR from DSM.
1) The published tenacity is ~20-30% higher than for large cross-sections of any high tenacity fiber, and this is also true for the modulus to a lesser extent, say 10-20%. The published tenacity/modulus is either a single fiber pull test or a small bundle (say 1500 denier) taken at the optimum twist angle of the fiber bundle. Commercial carbon fiber is like glass, it's good for all of one compression cycle in it's native state, that's why you only see it used as an FRP core material, this constrains/eliminates any possible bending of these fibers, the source of kink banding. Long chain polymers give all these high tenacity materials their high strength/modulus versus the native materials themselves.
2) Ropes are always considered tension elements. D'oh! However, all fibers are not under the same tensile stress, the rope goes slack, some fibers go into compression, cycled a few thousand times, kink banding occurs, more fibers fail over time, rope then fails. Got it? Heck, the API still does not have design guidence for high tenacity fiber ropes, it took them more than 10 years just to do PET (polyester ropes).
3) Independent peer reviewed journal papers show the real story of Dyneema's extremely poor temperature properties and linear creep properties. You won't find that type of information anywhere on the DSM website for all too obvious reasons. No one in their right mind would ever use Dyneema in a static force application. If you want a spaghetti laptop, than by all means make the superstructures out of Dyneema. Residual stresses would cause the FRP material to warp over time. Guaranteed.
Any more questions?
Frank, the problem is that unless you can give references as to those numbers, they aren't tenable.
I recently had a discussion with a guy, where I mentioned that the population of NYC proper was a bit over 8 million. He said that I was wrong, and that it was 14 to 15 million. I asked him if he meant the Greater New York Area, which is indeed about 14 to 15 million. He said, no, the 5 boroughs.
I told him that his number was wrong, and asked how he got his. After giving me generalized numbers about what he though were reasons, traffic, subway crowding, immigration, etc., I still didn't agree.
Then he pulled a fast one. He said that I was naive. Ok! I've been called worse.
But then he said that he knew, because he sat in on secret governmental committees that used to set these numbers for public consumption!
Right!
The point to this is that something said that can't be shown because it isn't available to us, isn't proof. It's just the statements of one person.
While I can't always find the information on the web for something I know to be true, even if the page was there before, it's difficult to use unpublished information in a discussion. There is no reason why someone would want to believe it, when undisputed published numbers are available.
I'm not saying that I don't believe you, just that we have to take your word for it in the face of actual numbers. I'm sure some test results are available.
I would have though it would be. Thanks for the reply. Is their a quick and dirty answer as to why the carbon prevents RF to pass?
Quote:
Graphite can conduct electricity due to the vast electrondelocalization within the carbon layers. These valence electrons are free to move, so are able to conduct electricity. However, the electricity is only conducted within the plane of the layers.
The molecules are aligned such that RF (err EM) will not pass normal to these aligned molecules. Normal to the surface of the carbon fiber FRP.
Frank, the problem is that unless you can give references as to those numbers, they aren't tenable.
I recently had a discussion with a guy, where I mentioned that the population of NYC proper was a bit over 8 million. He said that I was wrong, and that it was 14 to 15 million. I asked him if he meant the Greater New York Area, which is indeed about 14 to 15 million. He said, no, the 5 boroughs.
I told him that his number was wrong, and asked how he got his. After giving me generalized numbers about what he though were reasons, traffic, subway crowding, immigration, etc., I still didn't agree.
Then he pulled a fast one. He said that I was naive. Ok! I've been called worse.
But then he said that he knew, because he sat in on secret governmental committees that used to set these numbers for public consumption!
Right!
The point to this is that something said that can't be shown because it isn't available to us, isn't proof. It's just the statements of one person.
While I can't always find the information on the web for something I know to be true, even if the page was there before, it's difficult to use unpublished information in a discussion. There is no reason why someone would want to believe it, when undisputed published numbers are available.
I'm not saying that I don't believe you, just that we have to take your word for it in the face of actual numbers. I'm sure some test results are available.
The appeal to authority is valid in this case, as I'm a SME in this area, among many other areas of science and engineering and analysis and etceteras.
All the information I've mentioned can be found in the peer reviewed engineering and scientific literature. Or more than one of several PhD theses of DSM employees or other independent investigators. That's a given. Because that is where I found it. Any SME in this area of expertise would agree with me 100% of the time, on my previous statements wrt Dyneema. SME's at DSM would not agree, for the obvious reason of institutional bias.
I would have though it would be. Thanks for the reply. Is their a quick and dirty answer as to why the carbon prevents RF to pass?
To really oversimplify, it's the high conductivity at high frequencies that is responsible. That's REALLY oversimplifying. A part of the reason, is also the length to the width of the strands. That's called the percolation threshold. That helps to "short circuit" the radiation.
This is similar to the way aircraft are made to be transparent to radar. instead of reflection most all of the energy back, they absorb much of it, only needing to reflect a small part away from the source, which is much easier.
Older shielding made of metal copper, or copper alloy (sometimes in less critical applications, aluminum) mesh or film, relies on reflection.
The appeal to authority is valid in this case, as I'm a SME in this area, among many other areas of science and engineering and analysis and etceteras.
All the information I've mentioned can be found in the peer reviewed engineering and scientific literature. That's a given. Because that is where I found it. Any SME in this area of expertise would agree with me 100% of the time, on my previous statements wrt Dyneema. SME's at DSM would not agree, for the obvious reason of institutional bias.
Also, I happen to be a polymath.
Mind you Frank, I'm not disagreeing with your statements made earlier, just saying that it's what you do to me when I make a statement you don't agree with.
Comments
You're only reinforcing my point that the point of presence for the Wifi antenna will not be shielded in CF.
Absolutely. As I said in my previous reply, the original point of this all is that the _entire_ laptop shell could not be made from CF. That would make the presence of internal antennae an impossiblity, since Carbon fiber is not RF transparent.
Carbon fiber is an extremely lightweight material...composed mostly of carbon atoms.
Wow, ya think? Who writes this crap?
Carbon fibers themselves have the worst compressive properties due to kink banding. That's why you don't see high modulus ropes made from carbon fibers,
Ropes are used in applications of tension, not compression.
Dyneema is a very poor material due to it's linear creep properties inherent in it's low temperature limitations (70 C max, 50 C for long lifetime).
"according to DSM, it is not advisable to use UHMWPE fibers at temperatures exceeding 80 to 100 °C for long periods of time. " - Wikipedia
Dyneema is not 15 times stronger than high strength metals (A factor of 10 is the most I've ever seen the Dyneema literature claim)
"DSM Dyneema is the inventor and manufacturer of Dyneema®, the world?s strongest fibre.
... It is up to 15 times stronger than quality steel and up to 40% stronger than aramid fibres, on a weight-per-weight basis. "
http://www.dsm.com/en_US/html/hpf/ho...?source=search
, stainless steels can easily exceed ~250 ksi yield stress, aluminum ~80 ksi, and titanium ~200 ksi.
"Dyneema and Spectra are gel spun through a spinneret to form oriented-strand synthetic fibers of UHMWPE, which have yield strengths as high as 2.4 GPa and density as low as 0.97 kg/l (for Dyneema SK75)[5]. High strength steels have comparable yield strengths, and low carbon steels have yield strengths much lower (around 0.5 GPa). Since steel has a density approximately equal to 7.8 kg/l, this gives strength/weight ratios for these materials in a range from 10 to 100 times higher than for steel." - wikipedia
2.4 GPa is about 362.6 ksi I believe, giving Dyneema a tensile strength about 45% greater than the stainless steel you mention.
Ropes are used in applications of tension, not compression.
"according to DSM, it is not advisable to use UHMWPE fibers at temperatures exceeding 80 to 100 °C for long periods of time. " - Wikipedia
"DSM Dyneema is the inventor and manufacturer of Dyneema®, the world’s strongest fibre.
... It is up to 15 times stronger than quality steel and up to 40% stronger than aramid fibres, on a weight-per-weight basis. "
http://www.dsm.com/en_US/html/hpf/ho...?source=search
"Dyneema and Spectra are gel spun through a spinneret to form oriented-strand synthetic fibers of UHMWPE, which have yield strengths as high as 2.4 GPa and density as low as 0.97 kg/l (for Dyneema SK75)[5]. High strength steels have comparable yield strengths, and low carbon steels have yield strengths much lower (around 0.5 GPa). Since steel has a density approximately equal to 7.8 kg/l, this gives strength/weight ratios for these materials in a range from 10 to 100 times higher than for steel." - wikipedia
2.4 GPa is about 362.6 ksi I believe, giving Dyneema a tensile strength about 45% greater than the stainless steel you mention.
Nice try, but ...
I spent three years of R&D on a military project involving the use of high tenacity fibers.
So I know the real answers, not what is published as PR from DSM.
1) The published tenacity is ~20-30% higher than for large cross-sections of any high tenacity fiber, and this is also true for the modulus to a lesser extent, say 10-20%. The published tenacity/modulus is either a single fiber pull test or a small bundle (say 1500 denier) taken at the optimum twist angle of the fiber bundle. Commercial carbon fiber is like glass, it's good for all of one compression cycle in it's native state, that's why you only see it used as an FRP core material, this constrains/eliminates any possible bending of these fibers, the source of kink banding. Long chain polymers give all these high tenacity materials their high strength/modulus versus the native materials themselves.
2) Ropes are always considered tension elements. D'oh! However, all fibers are not under the same tensile stress, the rope goes slack, some fibers go into compression, cycled a few thousand times, kink banding occurs, more fibers fail over time, rope then fails. Got it? Heck, the API still does not have design guidence for high tenacity fiber ropes, it took them more than 10 years just to do PET (polyester ropes).
3) Independent peer reviewed journal papers show the real story of Dyneema's extremely poor temperature properties and linear creep properties. You won't find that type of information anywhere on the DSM website for all too obvious reasons. No one in their right mind would ever use Dyneema in a static force application. If you want a spaghetti laptop, than by all means make the superstructures out of Dyneema. Residual stresses and heat would cause the FRP material to warp over time. Guaranteed.
Any more questions?
Producing carbon fibers takes a lot of energy because you have to heat plastic fibers up to 2000°C without the presence of oxygen. Furthermore you can hardly recycle it (you can grind it and use it as a filler for less challenging purposes).
Not sure what you're saying here, as carbon fiber is not plastic. Methods of production do not use high temperatures like that. nothing even remotely close.
Grinding carbon fiber composites serves no purpose as there is no real use for it.
And I don't believe Apple's statment that the new unibody MB's are enviromentally greener than the old ones, as long as you just look at the body. When you want to make aluminium you are digging bauxite and then invest hugh amounts of energy to melt the whole thing and extract the aluminium. Melting aluminium for recycling costs less money, but still you have to invest hugh amounts of electricity.
Believe what you want, but it is better. Aluminum production is well understood. Recovery of almost 100% of the initial metal, and cutting fluids, is possible, at a far lower cost in energy than the initial production. Other savings include the lack of molds, and stamping. That has large energy requirements. A simplification of manufacturing. That saves energy all around. Even if the computer case is thrown away in a landfill, the aluminum has no toxic effect as plastic can, as it breaks down.
Wehreas if you are using injection molded plastic, it takes a significant smaller amount of energy to produce it, and if you burn it under controlled conditions you can get a not to small amount of energy back.
Not quite. Plastic has environmental consequences beyond that of initial energy use. You can't burn plastic as fuel, or for any other purpose. burning most all plastics results in various toxic chemicals, and carcinogens, being released. Carbon sequestering would be required as well, because the largest part of any plastic is carbon. We can all guess as to what the most important component to carbon fiber sheets would be. Under high temperatures, it breaks down into soot, and other carbon compounds such as carbon monoxide, etc. Depending on the exact nature of the plastic, and there are many kinds of blended materials, you could get dioxin, which is produced from plastics that contain chlorine (hence the removal of PVC). Quite a few other toxic chemicals, really too numerous to list, are produced.
So no, plastic is NOT a better material environmentally.
[/QUOTE]
I didn't realize that the 777 was receiving wifi from outside the fuselage while in flight, nor is the entire fuselage made out of Carbon Fiber (actually only portions of the tail, control surfaces and engine nacelles are composed of CF, the majority of the airframe is aluminum).
My point was to the original poster that suggested making the entire laptop out of CF, which would pose problems for RF reception. Some CF would be fine, but not the whole thing.
I work on the 777 at the Boeing plant in Everett, Washington. You forgot the floor beams, the floor panels, the radome and most of the galley and Lavs are all made of CF. Only about 25% of the 777 is made from CF. Now I am thinking that folks are thinking about the 787 and it is about 60-70% CF, including the main airframe is CF barrels along with the wings.
I wasn't asking you to prove anything, I just wanted to know why you have that opinion.
I don't watch their job listings.
I got the impression that maybe you thought there were mechanical problems that suggest they don't have that kind of talent, I was curious to know what they might be.
I can only imagine that if Apple does indeed design their own cases, as well as the huge number of parts required for any product, that they must have a large number of ME's working for them. You simply can't do this any other way.
If all they do is to make sketches, and send all of that work out, then that's different. But I don't see them doing that, do you?
Absolutely. As I said in my previous reply, the original point of this all is that the _entire_ laptop shell could not be made from CF. That would make the presence of internal antennae an impossiblity, since Carbon fiber is not RF transparent.
In fact, it's used as an RF shield.
If it weren't still so expensive, it would make a better Faraday cage than the copper mesh which is usually used now.
Nice try, but ...
I spent three years of R&D on a military project involving the use of high tenacity fibers.
So I know the real answers, not what is published as PR from DSM.
1) The published tenacity is ~20-30% higher than for large cross-sections of any high tenacity fiber, and this is also true for the modulus to a lesser extent, say 10-20%. The published tenacity/modulus is either a single fiber pull test or a small bundle (say 1500 denier) taken at the optimum twist angle of the fiber bundle. Commercial carbon fiber is like glass, it's good for all of one compression cycle in it's native state, that's why you only see it used as an FRP core material, this constrains/eliminates any possible bending of these fibers, the source of kink banding. Long chain polymers give all these high tenacity materials their high strength/modulus versus the native materials themselves.
2) Ropes are always considered tension elements. D'oh! However, all fibers are not under the same tensile stress, the rope goes slack, some fibers go into compression, cycled a few thousand times, kink banding occurs, more fibers fail over time, rope then fails. Got it? Heck, the API still does not have design guidence for high tenacity fiber ropes, it took them more than 10 years just to do PET (polyester ropes).
3) Independent peer reviewed journal papers show the real story of Dyneema's extremely poor temperature properties and linear creep properties. You won't find that type of information anywhere on the DSM website for all too obvious reasons. No one in their right mind would ever use Dyneema in a static force application. If you want a spaghetti laptop, than by all means make the superstructures out of Dyneema. Residual stresses would cause the FRP material to warp over time. Guaranteed.
Any more questions?
Frank, the problem is that unless you can give references as to those numbers, they aren't tenable.
I recently had a discussion with a guy, where I mentioned that the population of NYC proper was a bit over 8 million. He said that I was wrong, and that it was 14 to 15 million. I asked him if he meant the Greater New York Area, which is indeed about 14 to 15 million. He said, no, the 5 boroughs.
I told him that his number was wrong, and asked how he got his. After giving me generalized numbers about what he though were reasons, traffic, subway crowding, immigration, etc., I still didn't agree.
Then he pulled a fast one. He said that I was naive. Ok! I've been called worse.
But then he said that he knew, because he sat in on secret governmental committees that used to set these numbers for public consumption!
Right!
The point to this is that something said that can't be shown because it isn't available to us, isn't proof. It's just the statements of one person.
While I can't always find the information on the web for something I know to be true, even if the page was there before, it's difficult to use unpublished information in a discussion. There is no reason why someone would want to believe it, when undisputed published numbers are available.
I'm not saying that I don't believe you, just that we have to take your word for it in the face of actual numbers. I'm sure some test results are available.
There was a comment that stated that CF is not RF transparent. Is that true?
Very much so.
Very much so.
I would have though it would be. Thanks for the reply. Is their a quick and dirty answer as to why the carbon prevents RF to pass?
I would have though it would be. Thanks for the reply. Is their a quick and dirty answer as to why the carbon prevents RF to pass?
Graphite can conduct electricity due to the vast electron delocalization within the carbon layers. These valence electrons are free to move, so are able to conduct electricity. However, the electricity is only conducted within the plane of the layers.
The molecules are aligned such that RF (err EM) will not pass normal to these aligned molecules. Normal to the surface of the carbon fiber FRP.
Frank, the problem is that unless you can give references as to those numbers, they aren't tenable.
I recently had a discussion with a guy, where I mentioned that the population of NYC proper was a bit over 8 million. He said that I was wrong, and that it was 14 to 15 million. I asked him if he meant the Greater New York Area, which is indeed about 14 to 15 million. He said, no, the 5 boroughs.
I told him that his number was wrong, and asked how he got his. After giving me generalized numbers about what he though were reasons, traffic, subway crowding, immigration, etc., I still didn't agree.
Then he pulled a fast one. He said that I was naive. Ok! I've been called worse.
But then he said that he knew, because he sat in on secret governmental committees that used to set these numbers for public consumption!
Right!
The point to this is that something said that can't be shown because it isn't available to us, isn't proof. It's just the statements of one person.
While I can't always find the information on the web for something I know to be true, even if the page was there before, it's difficult to use unpublished information in a discussion. There is no reason why someone would want to believe it, when undisputed published numbers are available.
I'm not saying that I don't believe you, just that we have to take your word for it in the face of actual numbers. I'm sure some test results are available.
The appeal to authority is valid in this case, as I'm a SME in this area, among many other areas of science and engineering and analysis and etceteras.
All the information I've mentioned can be found in the peer reviewed engineering and scientific literature. Or more than one of several PhD theses of DSM employees or other independent investigators. That's a given. Because that is where I found it. Any SME in this area of expertise would agree with me 100% of the time, on my previous statements wrt Dyneema. SME's at DSM would not agree, for the obvious reason of institutional bias.
Also, I happen to be a polymath.
I don't need or care if anyone believes me.
I would have though it would be. Thanks for the reply. Is their a quick and dirty answer as to why the carbon prevents RF to pass?
To really oversimplify, it's the high conductivity at high frequencies that is responsible. That's REALLY oversimplifying. A part of the reason, is also the length to the width of the strands. That's called the percolation threshold. That helps to "short circuit" the radiation.
This is similar to the way aircraft are made to be transparent to radar. instead of reflection most all of the energy back, they absorb much of it, only needing to reflect a small part away from the source, which is much easier.
Older shielding made of metal copper, or copper alloy (sometimes in less critical applications, aluminum) mesh or film, relies on reflection.
The appeal to authority is valid in this case, as I'm a SME in this area, among many other areas of science and engineering and analysis and etceteras.
All the information I've mentioned can be found in the peer reviewed engineering and scientific literature. That's a given. Because that is where I found it. Any SME in this area of expertise would agree with me 100% of the time, on my previous statements wrt Dyneema. SME's at DSM would not agree, for the obvious reason of institutional bias.
Also, I happen to be a polymath.
Mind you Frank, I'm not disagreeing with your statements made earlier, just saying that it's what you do to me when I make a statement you don't agree with.
I heard they were going to make it out of hydrogen..
Well, at very low temperature and very high pressure hydrogen becomes a metal.
Sooo, I guess it's possible if you want to use it somewhere in the center of a cold neutron star.