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06-27-2010, 02:32 AM
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#1
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Moderator
Join Date: Jun 2007
Home Port: Washington DC
Vessel Name: SV Mahdee
Posts: 3,236
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I know, I know, you all probably have this stuff already! But, we just purchased a couple shirts deeply discounted at a sporting goods store--the Columbia brand OmniShade sunblocking fabric kind. Awesome. Here's a link in case you haven't heard of it before. There are other companies selling sunblock/spf rated fabric clothes and Sailrite even sells the fabric so you can make your own stuff. Nifty.
Fair winds,
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07-15-2010, 12:01 PM
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#2
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Commander
Join Date: Apr 2008
Home Port: Edinburgh
Posts: 189
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Quote:
Originally Posted by redbopeep' date='27 June 2010 - 02:26 AM
I know, I know, you all probably have this stuff already! But, we just purchased a couple shirts deeply discounted at a sporting goods store--the Columbia brand OmniShade sunblocking fabric kind. Awesome. Here's a link in case you haven't heard of it before. There are other companies selling sunblock/spf rated fabric clothes and Sailrite even sells the fabric so you can make your own stuff. Nifty.
Fair winds,
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Red',
What is it made from and "IF" chemically treated how long does the treatment last? One of the biggest problem with many water proof materials is that they need to be treated or retreated to maintain their ability to do their job and/or need to be washed in only a certain way. Nothing against you or the idea, just very careful with claims like that these days as have run into a lot of out right lies by many different business'. Though I do know that Linen of a medium weave does a wonderful job of keeping the sun off and keeping getting burned as well. UV tends to not penetrate trough much easily so just wondering.
Fair winds and hope the trip up the coast is going well.
Michael
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What you see in the Universe, sees you.
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07-15-2010, 01:49 PM
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#3
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Admiral
Join Date: Jul 2004
Posts: 2,098
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It seems to me that Australia had UV-protective clothing before it appeared in the US, but I'm not sure.
Here's a link to a company offering sun-protective clothing with a partial answer to your question "Q: How is a fabric made to be sun protective fabric?
A: Most sun protective fabrics (also called SPF fabric) are tightly woven/knit and may (or may not) be chemically treated with UV inhibitors. Fabrics from cotton to polyester are used, with the most common being nylon." Sun Grubbies
I have several of the Columbia shirts and the weave is extremely close, probably why the shirts have air vents.
A few years ago I read an article that Australia was so successful at getting its citizens to "slip, slap, slop" to protect from the sun that they now needed Vitamin D supplements. I didn't think much about it, but recently I found that in my (belated) efforts to protect myself from the sun I, too, now have a Vitamin D deficiency and have to take a supplement. Easier to take a pill once a day than to worry about skin cancer and (in my case) cataracts. A long healthy life requires constant vigilance (since I'm not about to hide in a cocoon).
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07-15-2010, 02:04 PM
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#4
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Commander
Join Date: Sep 2009
Posts: 151
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I honestly don't get it. I sincerely doubt that a plain usual t-shirt would let through any serious amount of UV radiation
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07-15-2010, 03:10 PM
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#5
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Commander
Join Date: Apr 2008
Home Port: Edinburgh
Posts: 189
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Quote:
Originally Posted by magwas' date='15 July 2010 - 01:58 PM
I honestly don't get it. I sincerely doubt that a plain usual t-shirt would let through any serious amount of UV radiation
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That is my question as well. UV is high in the frequency of light and there for won't go through a whole of materials. This is why UV breaks done cloth and can cause skin problems, it transfers it's energy upon impact. UV will not penetrate the lenses of most prescription eye wear even though they sell UV special eye these days there is not a whole lot of solid science behind the added features. Most "sun glasses" function in two ways: 1) remove part of the blue spectrum near visible light to remove that eye strain and, 2) generalized polarization which acts as a mobile eye shade that is graded by amount of light it lets through.
With clothing I have a hard time understanding this UV protection item as most clothing will seriously inhibit UV penetration, if not completely block it just by the nature of the fabric itself. I have read the articles and going to do a bit more rsearch as somethings about both websites that the first one points too just does not sit right. They don't explain how they get their numbers or why and are using a lot of scare tactics as well wanting to sell items and have people fund them and get their rating on their product. Just does not sit well with me, call me a cynic but something smells rotten here.
Michael
__________________
What you see in the Universe, sees you.
MM6WMU
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07-15-2010, 04:28 PM
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#6
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Moderator
Join Date: Jun 2007
Home Port: Washington DC
Vessel Name: SV Mahdee
Posts: 3,236
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Quote:
Originally Posted by chiroeurope' date='15 July 2010 - 07:04 AM
That is my question as well. UV is high in the frequency of light and there for won't go through a whole of materials. This is why UV breaks done cloth and can cause skin problems, it transfers it's energy upon impact. UV will not penetrate the lenses of most prescription eye wear even though they sell UV special eye these days there is not a whole lot of solid science behind the added features. Most "sun glasses" function in two ways: 1) remove part of the blue spectrum near visible light to remove that eye strain and, 2) generalized polarization which acts as a mobile eye shade that is graded by amount of light it lets through.
With clothing I have a hard time understanding this UV protection item as most clothing will seriously inhibit UV penetration, if not completely block it just by the nature of the fabric itself. I have read the articles and going to do a bit more rsearch as somethings about both websites that the first one points too just does not sit right. They don't explain how they get their numbers or why and are using a lot of scare tactics as well wanting to sell items and have people fund them and get their rating on their product. Just does not sit well with me, call me a cynic but something smells rotten here.
Michael
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The two mechanisms which determine how deeply light will penetrate a material (skin, fabric, etc) are reflection and absorption. Each material (glass, rock, skin, fabric, etc) has both reflective properties and absorption properties. These properties typically vary such that a material will reflect and absorb different wavelengths of light at different rates. One can run very accurate physics-based models of the reflection and absorption of specific wavelengths of interest through a specific material of interest.
There is a great body of knowledge in the scientific community regarding the damage that UV light and newer information about the damage that light in the "far blue" spectrum can do to human tissue. There is also a good deal of knowledge which allows scientists to quantify the amount of UV light which can pass deep into a material even though "most" UV light will be reflected or absorbed by the material rather than bounced around and scattered going quite a bit deeper into the material. While most light, of any wavelength, will only make it one or two scattering distances into the material, given a large quantity of light of a particular wavelength (e.g. sitting in the sun all day long...) quite a bit of the undesired wavelength can and will make it deep into the material.
We're talking about "material" here generically. Let us assume the material is the fabric protecting your skin from the sun's damaging UV rays. The materials marketed with SPF ratings carry ratings that have pretty high SPF numbers. Higher than just your average fabric would have. Now, the shirts we purchased were not that closely woven, they were quite breathable actually. And, they were light in color--therefore they are not colors that absorb heat (far red and infrared light which is present in the broadband illumination of the sun) but rather reflect heat too. Most fabrics that would have the ability to be rated with a HIGH SPF number would typically be darker colors which do happen to absorb more heat. I'd think that the nice trick in these "SPF fabrics" is that they are breathable, reflective of heat, but yet still live up to the high SPF numbers. It is very easy to test actual SPF ratings with relatively inexpensive spectrometry equipment. Therefore, I tend to believe the SPF ratings published by these companies. There is no snake oil here. Very matter of fact stuff. The average US consumer just wants a SPF number (at most) and doesn't really care to have an education about the science behind the SPF number. Therefore, that doesn't show up in the marketing materials--it provides no utility to the marketer in gaining market share nor does it provide utility to the clueless consumer who just doesn't want to know more than they're buying a reputable brand (in this case, Columbia which is a reputable brand for mainline outdoorsy clothing) and they trust what the marketer is telling them.
The tools available to any material to block light of a specific wavelength remain simply that material's (quantifiable) scattering properties and absorption properties. Whether it is fabric, skin, or sunglasses, everything works the same way.
Since we want to see things with more-or-less natural/recognizable colors, much broad spectrum light needs to come through sunglasses. The raw "blocking" that most sunglasses have still lets about 5% of the UV light through in order to preserve that natural view of the world. The better sunglasses do manage to block the UV 100% without unduly dark lenses. This being the quality trick: blocking UV without blocking most of the visible spectrum. It is a similar trick to blocking UV light from getting to our skin without absorbing heat and making us hot. Blocking far blue (violet) light helps block UV and it also, as it turns out, is blocking a wavelength that in itself is now thought to be damaging to the eye. As an aside, I personally know a biophysicist who goes around wearing "rose colored glasses" inside and out. He is blocking blue light from his eyes because his own personal research at the National Institutes of Health (NIH) is showing him that blue light is very damaging to the eyes.
Fair winds
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07-15-2010, 07:52 PM
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#7
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Commander
Join Date: Apr 2008
Home Port: Edinburgh
Posts: 189
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Red',
I agree with what you have written in the most part. It is the additional research behind it that causes me to question and the way this information is being used and access to the basic information that they are using limited ($66 to buy a copy of the parameters that the AATCC use to generate the ratings for UFP clothing. That and when a lot of academic research shows that natural fibers will do the same thing. I am not in any way meaning to demean you or your purchase. I just find the whole things a very good bit strange and not completely above board. I understand very well the effects of different forms of radiation as one of my required courses was graduate level studies in radiation due to dealing with x-ray equipment and having to be licensed to own and operate it. That and getting tested on that by national boards to even graduate. Also understanding the pathology involved with different diseases caused by the sun. I digress and apologize if my statements seem or where taken in any way personal. I just have a very strong distrust for self monitoring industries, it is my personal issue and in no reflects on others. I will take to a few colleagues to get the rest of the information for myself to form a somewhat more informed opinion (fully form will take a good bit longer).
Michael
__________________
What you see in the Universe, sees you.
MM6WMU
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07-15-2010, 09:05 PM
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#8
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Moderator
Join Date: Jun 2007
Home Port: Washington DC
Vessel Name: SV Mahdee
Posts: 3,236
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Oh, I wasn't taking it personal that you might have been questioning my purchase--but rather that you might not know what you're talking about since you spoke of "transferring energy upon impact" which is not the way that I'm used to the people in the field of optics and spectroscopy speaking of the matter of photons interacting with materials. Rather, we tend towards speaking in terms of reflection, scattering, absorption. Your language use makes sense in context of x-ray equipment, this I get.
Stating that it is "not above board" is a bit extreme though. We have consumer product out there making amazing claims all the time. Many of them on shaky ground because they're TOO amazing--but consumers buy the "latest, greatest, wonderful product x" all the time. Nothing fishy, and "scare tactics"??? what scare tactics do you speak of? I'll admit I don't peruse the advertising materials much and if they bring up skin cancer, well that is scary but???? It isn't against the law (but regular sensible marketing) for a company to extol the virtues of it's product against known weaker products without admitting there are good strong other alternatives. Look at every laundry detergent ad out there--you'd think there was nothing that works other than the brand being sold--but yet US Consumer reports has done testing showing that plain water with NO detergent is as effective as anything else in testing (caveat is grease/oil require surfactants though). Do you use laundry detergents? A good money saver is not to do so for most things.
Like you, I have a background and exposure to others in the biomedical field. Hubby has a PhD in the Biomedical Engineering. I am a mechanical engineer. We had a company for 5 years that used computer models of the physics of photons moving through tissue in predictable ways as an in vivo diagnostic tool, we provided equipment and software to the medical research community and worked on some joint ventures with commercial entities; we have both published in peer review journals and have patents in the area. We have played with a variety of laser, imaging, and spectroscopic equipment in an amazing assortment of ways. One of the few things that I can say I have some knowledge of is what light (broadband, multispectral, or narrow spectra from UV to infrared) will do in a variety of materials.
I love natural fibers. They're great and do a great job as a cover up for the sun. I prefer to wear natural fibers. However, I do not question the validity of the new materials being used with SPF ratings in sportswear. I've been "skimming" the information in nanotech and optics professional journals for years; I've never had an interest in the SPF materials but yet I've seen (on agendas for professional society meetings) enough to summarily think such materials have no reason not to live up to their claims.
You have no reason to have to purchase such materials and truly if you doubt their utility, stick with natural fibers, sunblock, and stay healthy  Wait for the prices to come down and for the fabrics to be prevalent and common.
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07-15-2010, 09:49 PM
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#9
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Commander
Join Date: Apr 2008
Home Port: Edinburgh
Posts: 189
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Would love to discuss some of the research into MRI tissue differentiation and some of the research that is being done with laser and oriental medicine. Thanks for the wishing for good health, can use all I can get. Things did not go completely well with the cancer tx and still trying to rebuild my body afterwards and the system here is not too interested in helping. But fair winds to you and hope to meet you folks out on the water one day.
Michael
__________________
What you see in the Universe, sees you.
MM6WMU
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07-15-2010, 11:44 PM
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#10
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Moderator
Join Date: Jun 2007
Home Port: Washington DC
Vessel Name: SV Mahdee
Posts: 3,236
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Quote:
Originally Posted by chiroeurope' date='15 July 2010 - 01:43 PM
Would love to discuss some of the research into MRI tissue differentiation and some of the research that is being done with laser and oriental medicine. Thanks for the wishing for good health, can use all I can get. Things did not go completely well with the cancer tx and still trying to rebuild my body afterwards and the system here is not too interested in helping. But fair winds to you and hope to meet you folks out on the water one day.
Michael
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A positive attitude is a wonderful help in healing. Broad spectrum light is also a good thing for you to be exposed to--without too much UV, of course! Even plant lights inside are a very good idea. Many visible wavelengths are now being studied for their benefits and actions with cell signaling. It is not unexpected that people go cruising and in the wonderful sunshine (with UV protection!) and fresh air, their health improves.
Fair winds,
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07-16-2010, 11:49 AM
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#11
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Commander
Join Date: Sep 2009
Posts: 151
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I do not doubt that clothes marketed as UV protecting ones actually block most of UV radiation. I just think that I can obtain as UV protective, light and breathable clothes made for example from ordinary flax, without the associated hype and price tag.
BTW did you know that excess of flax straw (byproduct of linseed oil production) present an environmental problem in northern America, while I guess the majority of clothes in the supermarkets are made of polimers (maybe in China, and most probably from mineral oil).
Regarding to sunglasses: I am the type who never wears sunglass, even though I am cycling every day. But last time I have tried a polarized one. It is definitely much easier to spot the change of color of water which means underwater reef with it. Although reading the depth sounder et al (Raymarine with liquid crystal display) was nearly impossible with it.
I had to conclude that a polarized sunglass do have advantages.
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07-16-2010, 12:58 PM
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#12
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Admiral
Join Date: Oct 2004
Posts: 3,067
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From a purely practical point of view - the objective when cruising in areas where there are high levels of UV radiation (eg Australia - South East Asia) is to protect exposed skin. Somewhere we have covered the subject in former topics - Pakistani white cotton kitchen clothing - inexpensive - good coverage - comfortable - and inhibits UV.
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07-16-2010, 10:09 PM
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#13
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Admiral
Join Date: Jul 2004
Posts: 2,098
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Magwas,
You've discovered that polarized sunglasses are very good in the terrible glare of the tropics, and they do, indeed, make it easier to see the changes in color that signify reef or shoal. Peter swears by his polarized sunglasses.
I learned several years ago that I am developing cataracts, which my doctor said was most likely from my aversion to sunglasses, and I am working very hard to overcome this because I would prefer not to have cataract surgery if it can be avoided.
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07-17-2010, 12:56 PM
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#14
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Commander
Join Date: Apr 2008
Home Port: Edinburgh
Posts: 189
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Quote:
Originally Posted by JeanneP' date='16 July 2010 - 10:03 PM
Magwas,
You've discovered that polarized sunglasses are very good in the terrible glare of the tropics, and they do, indeed, make it easier to see the changes in color that signify reef or shoal. Peter swears by his polarized sunglasses.
I learned several years ago that I am developing cataracts, which my doctor said was most likely from my aversion to sunglasses, and I am working very hard to overcome this because I would prefer not to have cataract surgery if it can be avoided.
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When I used to do a lot of long distance driving; fully polarized sunglasses really kept the eye strain down and allowed you to get the driving done safely without the fatigue that driving can give just from eye strain.
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