freakflyer69 0 #1 September 30, 2002 does anyone know if white zp would last longer do to reflection of the degrading uv rays, and would it be noticable over time? Quote Share this post Link to post Share on other sites
councilman24 37 #2 September 30, 2002 What's to notice? No colors to fade. Since there are no colors to fade it will look better longer, if you don't get it dirty! I don't believe that the fabric longevity will be significantly different. But the dyes will fade in a colored canopy and the white will get dirty in a white canopy. Don't worry about UV, keep it out of the sun, and get what you want.I'm old for my age. Terry Urban D-8631 FAA DPRE Quote Share this post Link to post Share on other sites
annaandbob 0 #3 September 30, 2002 i have always been led to beleive that darker colors absorbe uv more readily where as lighter colors reflect it more. As the sun is nylons worst enemy I have always steered towards the lighter colors. Quote Share this post Link to post Share on other sites franck102 0 #4 September 30, 2002 Not sure why, but all sailboat sail manufacters recommend that you choose white fabric on your spinnaker, especially in the high stress areas, for maximum longevity... Franck Quote Share this post Link to post Share on other sites BMFin 0 #5 September 30, 2002 Another question : Im thinking of buying a pretty black canopy.. Is there any reason why I shouldnt buy a black one ? Does UV-light make the color fade quickly or something else ? Quote Share this post Link to post Share on other sites Scoby 0 #6 September 30, 2002 Quotei have always been led to beleive that darker colors absorbe uv more readily where as lighter colors reflect it more. As the sun is nylons worst enemy I have always steered towards the lighter colors. That's not necessarily true. By definition, light colors are reflecting more visible light than dark colors. However, ultraviolet is a different part of the electromagnetic spectrum. Materials can be reflectors of visible light and absorbers of ultraviolet light. I have come across such dyes in my line of work. I doubt this is specifically true of canopy fabric, but it is within the realm of possibility. Quote Share this post Link to post Share on other sites alan 1 #7 September 30, 2002 Practically speaking, most of us seldom keep a canopy for more than a thousand or two thousand jumps. There is considerable field evidence that zero-P canopies last much longer than that when given a reasonable amount of care and that goes back to the early fabrics. The fabric commonly used today by the major/popular canopy manufacturers has improved UV resistant characteristics, so it will last even longer. Bottom line, for all pratical purposes it is unlikely you will still have the canopy if and when it begins to show evidence of significant degradation due to UV exposure unless you make a habit of leaving it lay out in the sun.alan Quote Share this post Link to post Share on other sites billvon 2,991 #8 September 30, 2002 >By definition, light colors are reflecting more visible light than dark > colors. However, the issue is not how much light is reflected, but how much passes through the fabric. If it were just reflection, fair-skinned people would never get sunburns, and darker-skinned people would burn like crazy. The reason they don't is that the pigment in people's skin blocks UV and prevents it from reaching the living part of your skin. Not much different in a canopy. Ever look up under a white canopy and notice light diffusing through it? That includes UV that's damaging the inside of the fabric, and even the lower skin. Compare that to a black canopy, that allows no light through. Light is more attenuated by the time it gets to the center of the fabric. >Materials can be reflectors of visible light and absorbers of >ultraviolet light. While this is true, it's also true that white nylon is generally undyed, and thus will be the most translucent to all parts of the spectrum. Pigments can only attenuate light, not amplify it. Of course, some materials (PABA for example) specifically attenuate UV. Quote Share this post Link to post Share on other sites ERICCONNELLY 0 #9 September 30, 2002 "Is there any reason why I shouldnt buy a black one ? " Try to find a black canopy after a chop. They hide very well. Quote Share this post Link to post Share on other sites Scoby 0 #10 September 30, 2002 Quotebut how much passes through the fabric. If it were just reflection, fair-skinned people would never get sunburns, and darker-skinned people would burn like crazy. The reason they don't is that the pigment in people's skin blocks UV and prevents it from reaching the living part of your skin. True, but the fact that a pigment absorbs visible light does not mean that it must absorb UV, or vice versa. Visible light and ultraviolet are different parts of the spectrum. Melanin happens to absorb visible light as well as UV, so people with melanin are dark. UV absorbing compounds can also reflect visible light, or be translucent to it. QuoteNot much different in a canopy. Ever look up under a white canopy and notice light diffusing through it? That includes UV that's damaging the inside of the fabric, and even the lower skin. Compare that to a black canopy, that allows no light through. Light is more attenuated by the time it gets to the center of the fabric. The fact that visible light passes through a material does not mean that ultraviolet light passes through. Witness glass, for example. QuoteWhile this is true, it's also true that white nylon is generally undyed, and thus will be the most translucent to all parts of the spectrum. Pigments can only attenuate light, not amplify it. Of course, some materials (PABA for example) specifically attenuate UV. Now this is more relevant. If undyed nylon is translucent to UV, then dyed nylon is more likely to be resistant to UV because of the pigment. Quote Share this post Link to post Share on other sites riddler 0 #11 September 30, 2002 Whenever I see a white canopy, I assume someone had a cutaway. Quite possibly a prejudice I need to get over. I had to chop mine this weekend and found that my reserve is yellow.Trapped on the surface of a sphere. XKCD Quote Share this post Link to post Share on other sites cobaltdan 0 #12 October 4, 2002 white zp is a color... what i mean is that the raw fiber is actually yellowish. to make white courmarin dies, sometimes called brightners are used. these brightners actually absorb uv light and reemit some light in the blue range making the fabric look whiter. this dye does degrade over time and the fabric will return to a yellowish color. the fabric strength is not effected by the color change. sincerely, dan<><> atair aerodynamicsDaniel Preston <><> atairaerodynamics.com (sport) atairaerospace.com (military) Quote Share this post Link to post Share on other sites riddler 0 #13 October 6, 2002 Are you saying my reserve is really old? I hope not I didn't know that they had to dye the fabric white - interesting.Trapped on the surface of a sphere. XKCD Quote Share this post Link to post Share on other sites christoofar 0 #14 October 6, 2002 Man, this weekend the pack room got full, mostly from people dumping their shit and then going off to chat and taking forever to get their pack jobs started, so I went outdoors and did one pack job in the grass. It was a bit sunny. I sure got treated like the Antichrist when I went back inside! One pack job out in the sun is not going to kill your canopy, is it? I pull high quite a few times and that puts more UV exposure under flight than it would ever get for me having the thing exposed for 15 minutes while I flake, seperate, roll, and stuff. ____________________________________________________________ I'm RICK JAMES! Fo shizzle. Quote Share this post Link to post Share on other sites AggieDave 6 #15 October 6, 2002 The grass would do more damage to your canopy then 15 minutes of sun exposure, BUT if you made this a habit, then the sun could and would start to take it's toll on the canopy.--"When I die, may I be surrounded by scattered chrome and burning gasoline." Quote Share this post Link to post Share on other sites drenaline 0 #16 October 8, 2002 UV rays eats the fabric, the more you keep it away from the sun, the more it will last. The only exposure to the sun we try to give is when we jump, then run to shade. HISPA 21 www.panamafreefall.com Quote Share this post Link to post Share on other sites Rdutch 0 #17 October 9, 2002 I have an all white stilletto 107. It has 800 jumps on it (I know cause I have to log all jumps on it.) And it is holding up great. I also have a demo colored velocity (fluorescent orange, yellow and Blackberry). The velocity has around 200+ jumps on it and the fluorescent colors are a lot worse off than the blackberry. Noticeably different! But my all white stilletto is holding up great. Noting that the fabric is great but the color is a little different. I just got new lines and they are really white, I never realized that my canopy was so yellow until I got new lines, So White canopies definitely don't hold their color as well. So you get a trade off, longer lasting canopy shorter lasting color. You decide what you would rather have. Oh yeah I am a little sick of people asking me what kind of malfunction I had when I was landing my main. Ray Ray Small and fast what every girl dreams of! Quote Share this post Link to post Share on other sites AggieDave 6 #18 October 9, 2002 QuoteOh yeah I am a little sick of people asking me what kind of malfunction I had when I was landing my main Since sooo many reserves have a D-bag and collapsible, throw out PC on them...--"When I die, may I be surrounded by scattered chrome and burning gasoline." Quote Share this post Link to post Share on other sites PhreeZone 20 #19 October 9, 2002 Hard to see those when you pull at 5k.Yesterday is history And tomorrow is a mystery Parachutemanuals.com Quote Share this post Link to post Share on other sites AggieDave 6 #20 October 9, 2002 I've done that, with people that have Orange or White canopies, but I'll usually watch until I see a PC trailing or not. That'll give me the chance to look up and around to see if their main is still in the air or not and go chase it if it is.--"When I die, may I be surrounded by scattered chrome and burning gasoline." Quote Share this post Link to post Share on other sites Rdutch 0 #21 October 9, 2002 Their observation not mine. Ray Small and fast what every girl dreams of! Quote Share this post Link to post Share on other sites phastasphuk 0 #22 October 11, 2002 QuoteThe grass would do more damage to your canopy then 15 minutes of sun exposure Really? I've heard that the absolutly best surface to pack on is grass, but maybe european grass is different to yank grass (assuming its ONLY grass you'e packing on) Try this thest. Make a buttslide on the grass and then make one on the mat you pack on. Or only light and smoke it AFTER you packed your chute on it chris Quote Share this post Link to post Share on other sites AggieDave 6 #23 October 11, 2002 See, I'm thinking of mowed Texas grass, this stuff can puncture feet if you land barefooted, imagine what it can do to a canopy.--"When I die, may I be surrounded by scattered chrome and burning gasoline." 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franck102 0 #4 September 30, 2002 Not sure why, but all sailboat sail manufacters recommend that you choose white fabric on your spinnaker, especially in the high stress areas, for maximum longevity... Franck Quote Share this post Link to post Share on other sites
BMFin 0 #5 September 30, 2002 Another question : Im thinking of buying a pretty black canopy.. Is there any reason why I shouldnt buy a black one ? Does UV-light make the color fade quickly or something else ? Quote Share this post Link to post Share on other sites
Scoby 0 #6 September 30, 2002 Quotei have always been led to beleive that darker colors absorbe uv more readily where as lighter colors reflect it more. As the sun is nylons worst enemy I have always steered towards the lighter colors. That's not necessarily true. By definition, light colors are reflecting more visible light than dark colors. However, ultraviolet is a different part of the electromagnetic spectrum. Materials can be reflectors of visible light and absorbers of ultraviolet light. I have come across such dyes in my line of work. I doubt this is specifically true of canopy fabric, but it is within the realm of possibility. Quote Share this post Link to post Share on other sites
alan 1 #7 September 30, 2002 Practically speaking, most of us seldom keep a canopy for more than a thousand or two thousand jumps. There is considerable field evidence that zero-P canopies last much longer than that when given a reasonable amount of care and that goes back to the early fabrics. The fabric commonly used today by the major/popular canopy manufacturers has improved UV resistant characteristics, so it will last even longer. Bottom line, for all pratical purposes it is unlikely you will still have the canopy if and when it begins to show evidence of significant degradation due to UV exposure unless you make a habit of leaving it lay out in the sun.alan Quote Share this post Link to post Share on other sites
billvon 2,991 #8 September 30, 2002 >By definition, light colors are reflecting more visible light than dark > colors. However, the issue is not how much light is reflected, but how much passes through the fabric. If it were just reflection, fair-skinned people would never get sunburns, and darker-skinned people would burn like crazy. The reason they don't is that the pigment in people's skin blocks UV and prevents it from reaching the living part of your skin. Not much different in a canopy. Ever look up under a white canopy and notice light diffusing through it? That includes UV that's damaging the inside of the fabric, and even the lower skin. Compare that to a black canopy, that allows no light through. Light is more attenuated by the time it gets to the center of the fabric. >Materials can be reflectors of visible light and absorbers of >ultraviolet light. While this is true, it's also true that white nylon is generally undyed, and thus will be the most translucent to all parts of the spectrum. Pigments can only attenuate light, not amplify it. Of course, some materials (PABA for example) specifically attenuate UV. Quote Share this post Link to post Share on other sites
ERICCONNELLY 0 #9 September 30, 2002 "Is there any reason why I shouldnt buy a black one ? " Try to find a black canopy after a chop. They hide very well. Quote Share this post Link to post Share on other sites
Scoby 0 #10 September 30, 2002 Quotebut how much passes through the fabric. If it were just reflection, fair-skinned people would never get sunburns, and darker-skinned people would burn like crazy. The reason they don't is that the pigment in people's skin blocks UV and prevents it from reaching the living part of your skin. True, but the fact that a pigment absorbs visible light does not mean that it must absorb UV, or vice versa. Visible light and ultraviolet are different parts of the spectrum. Melanin happens to absorb visible light as well as UV, so people with melanin are dark. UV absorbing compounds can also reflect visible light, or be translucent to it. QuoteNot much different in a canopy. Ever look up under a white canopy and notice light diffusing through it? That includes UV that's damaging the inside of the fabric, and even the lower skin. Compare that to a black canopy, that allows no light through. Light is more attenuated by the time it gets to the center of the fabric. The fact that visible light passes through a material does not mean that ultraviolet light passes through. Witness glass, for example. QuoteWhile this is true, it's also true that white nylon is generally undyed, and thus will be the most translucent to all parts of the spectrum. Pigments can only attenuate light, not amplify it. Of course, some materials (PABA for example) specifically attenuate UV. Now this is more relevant. If undyed nylon is translucent to UV, then dyed nylon is more likely to be resistant to UV because of the pigment. Quote Share this post Link to post Share on other sites
riddler 0 #11 September 30, 2002 Whenever I see a white canopy, I assume someone had a cutaway. Quite possibly a prejudice I need to get over. I had to chop mine this weekend and found that my reserve is yellow.Trapped on the surface of a sphere. XKCD Quote Share this post Link to post Share on other sites
cobaltdan 0 #12 October 4, 2002 white zp is a color... what i mean is that the raw fiber is actually yellowish. to make white courmarin dies, sometimes called brightners are used. these brightners actually absorb uv light and reemit some light in the blue range making the fabric look whiter. this dye does degrade over time and the fabric will return to a yellowish color. the fabric strength is not effected by the color change. sincerely, dan<><> atair aerodynamicsDaniel Preston <><> atairaerodynamics.com (sport) atairaerospace.com (military) Quote Share this post Link to post Share on other sites
riddler 0 #13 October 6, 2002 Are you saying my reserve is really old? I hope not I didn't know that they had to dye the fabric white - interesting.Trapped on the surface of a sphere. XKCD Quote Share this post Link to post Share on other sites
christoofar 0 #14 October 6, 2002 Man, this weekend the pack room got full, mostly from people dumping their shit and then going off to chat and taking forever to get their pack jobs started, so I went outdoors and did one pack job in the grass. It was a bit sunny. I sure got treated like the Antichrist when I went back inside! One pack job out in the sun is not going to kill your canopy, is it? I pull high quite a few times and that puts more UV exposure under flight than it would ever get for me having the thing exposed for 15 minutes while I flake, seperate, roll, and stuff. ____________________________________________________________ I'm RICK JAMES! Fo shizzle. Quote Share this post Link to post Share on other sites
AggieDave 6 #15 October 6, 2002 The grass would do more damage to your canopy then 15 minutes of sun exposure, BUT if you made this a habit, then the sun could and would start to take it's toll on the canopy.--"When I die, may I be surrounded by scattered chrome and burning gasoline." Quote Share this post Link to post Share on other sites
drenaline 0 #16 October 8, 2002 UV rays eats the fabric, the more you keep it away from the sun, the more it will last. The only exposure to the sun we try to give is when we jump, then run to shade. HISPA 21 www.panamafreefall.com Quote Share this post Link to post Share on other sites
Rdutch 0 #17 October 9, 2002 I have an all white stilletto 107. It has 800 jumps on it (I know cause I have to log all jumps on it.) And it is holding up great. I also have a demo colored velocity (fluorescent orange, yellow and Blackberry). The velocity has around 200+ jumps on it and the fluorescent colors are a lot worse off than the blackberry. Noticeably different! But my all white stilletto is holding up great. Noting that the fabric is great but the color is a little different. I just got new lines and they are really white, I never realized that my canopy was so yellow until I got new lines, So White canopies definitely don't hold their color as well. So you get a trade off, longer lasting canopy shorter lasting color. You decide what you would rather have. Oh yeah I am a little sick of people asking me what kind of malfunction I had when I was landing my main. Ray Ray Small and fast what every girl dreams of! Quote Share this post Link to post Share on other sites
AggieDave 6 #18 October 9, 2002 QuoteOh yeah I am a little sick of people asking me what kind of malfunction I had when I was landing my main Since sooo many reserves have a D-bag and collapsible, throw out PC on them...--"When I die, may I be surrounded by scattered chrome and burning gasoline." Quote Share this post Link to post Share on other sites
PhreeZone 20 #19 October 9, 2002 Hard to see those when you pull at 5k.Yesterday is history And tomorrow is a mystery Parachutemanuals.com Quote Share this post Link to post Share on other sites
AggieDave 6 #20 October 9, 2002 I've done that, with people that have Orange or White canopies, but I'll usually watch until I see a PC trailing or not. That'll give me the chance to look up and around to see if their main is still in the air or not and go chase it if it is.--"When I die, may I be surrounded by scattered chrome and burning gasoline." Quote Share this post Link to post Share on other sites
Rdutch 0 #21 October 9, 2002 Their observation not mine. Ray Small and fast what every girl dreams of! Quote Share this post Link to post Share on other sites
phastasphuk 0 #22 October 11, 2002 QuoteThe grass would do more damage to your canopy then 15 minutes of sun exposure Really? I've heard that the absolutly best surface to pack on is grass, but maybe european grass is different to yank grass (assuming its ONLY grass you'e packing on) Try this thest. Make a buttslide on the grass and then make one on the mat you pack on. Or only light and smoke it AFTER you packed your chute on it chris Quote Share this post Link to post Share on other sites
AggieDave 6 #23 October 11, 2002 See, I'm thinking of mowed Texas grass, this stuff can puncture feet if you land barefooted, imagine what it can do to a canopy.--"When I die, may I be surrounded by scattered chrome and burning gasoline." Quote Share this post Link to post Share on other sites
