請問一下有誰知道抗UV,是甚麼化學材料

請問一下有誰知道抗UV,是甚麼化學材料( UV resistance)

可以請用英文回答嗎??

形狀是粉狀的嗎?

一般都用在哪裡?(用途)

Update:

還是用中文解釋好了.拜託囉!!

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    UV Resistance

    The UV Light Resistance of plastics involves a number of factors that can affect your material choice.

    Of all the factors involved in UV resistance, there are three that figure most prominently; thickness, opacity, and the use of stabilizers. These three factors are combined to defend plastics against Ultraviolet (UV) light.

    Ultraviolet (UV) light is the light at shorter wavelengths than visible light, past the violet end of the spectrum (ultra, or beyond violet). There are three categories of UV light, UVA, UVB, and UVC. UVA light is not normally strong enough to harm plastics. UVB usually does the most damage to plastics and is the type of light we need to test when checking plastic’s UV resistance. UVC light contains even more damaging energy but it is fortunately filtered out by the earth’s ozone layer.

    Light degrades plastics by transferring its energy into the plastic. This energy can cause damage by creating heat, or this energy can actually break molecular bonds in a plastic’s structure. Both the heat and the breaking of bonds can create a loss of physical properties in the plastic. The higher energy of the UVB rays causes almost all UV damage in plastics. Regular visible light causes almost no degradation even over many years of exposure.

    2007-06-13 11:50:58 補充:

    Opaque plastics are plastics that light does not pass through. In an opaque plastic the light has to break down the outer layer before it can break down the inner section of the plastic. The inner layer of plastic can retain its

    2007-06-13 11:51:17 補充:

    strength much longer the more opaque the plastic. If a plastic is completely black (or some other opaque colour) then the light only acts on the surface and much less damage will occur over time.

    2007-06-13 11:51:49 補充:

    In a clear plastic film, the UVB light acts on the entire thickness at once, and failure occurs at the same time throughout the thickness of the plastic (clear films degrade rapidly).

    2007-06-13 11:52:03 補充:

    So our first step is to make plastics that will be exposed as opaque as possible. Most lining materials used for exposed linings are heavily loaded with carbon black or other pigments to make them opaque.

    2007-06-13 11:52:17 補充:

    The thickness of the lining material is also a factor in UV resistance. Thicker materials allow the surface to suffer some UV degradation while still retaining the strength in the inner core material.

    2007-06-13 11:52:51 補充:

    In exposed lining materials a thickness over 40 mil (1.0 mm) is usually recommended for long term UV resistance. In materials where the strength is provided by a fabric (supported materials)

    2007-06-13 11:53:10 補充:

    an opaque coating of typically 0.4 mm (15 mils) on each side is required to prevent UV degradation of the fabric's strength.

    2007-06-13 11:53:30 補充:

    The UVB light that attacks plastics creates reactive degradation byproducts that can cause a chain reaction of molecule damage that can accelerate the breakdown of the material. UV stabilizers are added to plastics to prevent these degradation byproducts from causing additional damage.

    2007-06-13 11:53:45 補充:

    UV stabilizers act as “sponges” to soak up these reactive byproducts and to stop the chain reaction before additional damage occurs.

    2007-06-13 11:54:00 補充:

    One of the most common questions about geomembranes is, “how long will it last in exposed service?” Each liner material is tested for UV resistance,

    2007-06-13 11:54:32 補充:

    however each location where a liner is installed has a different UV exposure level. No two locations will get exactly the same amount of sunshine, and most locations do not get the same amount of sunshine from year-to-year.

    2007-06-13 11:54:43 補充:

    A test performed in Arizona or Florida may not be typical of the service life in your area. This makes it difficult to make general statements about UV resistance of lining materials.

    2007-06-13 11:54:57 補充:

    Typical UV tests quote ASTM G53, and state 500 hours or 2000 hours with 70% or 90% strength retained. Some tests will also state that a Xenon arc was used. Unfortunately this is not enough information to make a reasonable correlation to exposed life.

    2007-06-13 11:55:22 補充:

    There are a number of variations on the UV test methods, and there are many sources of UV light used in the test (Xenon light uses a number of different filters that can change the results).

    2007-06-13 11:55:35 補充:

    The best source of information is to look at actual exposure data collected from outdoor exposure tests.

    2007-06-13 11:55:48 補充:

    There are two main outdoor exposure facilities in North America, one in Florida, and one in Arizona. At each of these facilities they expose plastic materials to the sun for extended periods of time, often with a series of mirrors of magnifying glasses to concentrate the sun onto the sample.

    2007-06-13 11:57:40 補充:

    The sun’s intensity is measured (in Langley’s) and a rating is given to the plastic material based on the number of Langleys it receives. Laboratory UV tests,

    2007-06-13 11:57:57 補充:

    such as ASTM G53 allow us to perform quality control checks on materials without having to perform 5 and 10 years tests outdoors.

    2007-06-13 11:59:08 補充:

    On the attached chart is an approximation of what kind of exposed lifetimes can be expected from a number of different lining materials. Each material contains UV stabilizers and has been carefully formulated for the maximum exposed lifetime.

    2007-06-13 11:59:29 補充:

    Please note that the values given are only approximate. The actual UV resistance of the material you receive may vary considerably and is heavily dependant on the amount of sunshine received at the installation location.

    2007-06-13 11:59:47 補充:

    One final note. The lifetime of any material can be increased dramatically by backfilling the liner. See the Layfield Tech Note on Backfill. Values shown in the chart are for exposed use only.

    2007-06-13 11:59:48 補充:

    One final note. The lifetime of any material can be increased dramatically by backfilling the liner. See the Layfield Tech Note on Backfill. Values shown in the chart are for exposed use only.

    2007-06-13 12:01:00 補充:

    all data from this webside:

    http://www.layfieldgroup.com/index_resources.cfm?c...

    2007-06-13 12:01:31 補充:

    Water proof 高度防水 可維持80分鐘的防水效果

    Water resistance 保護防水 可維持40分鐘的防水效果

    Sweat proof 30mins 防汗水 可保持30分鐘的防水效果

    2007-06-13 12:03:11 補充:

    http://tw.knowledge.yahoo.com/question/question?qi...

    http://tw.knowledge.yahoo.com/question/question?qi...

    these two informations provided by knowledge big big

    2007-06-13 12:11:29 補充:

    Not all UV resistance substances are trituration.

    The substance can resistant UV that are all called ''UV resistance''.

    Like cotton ,wood coal are good UV substances.

    (provided by knowledge big big )

    2007-06-13 12:20:00 補充:

    In normal,you can use UV resistance substances on sun glasses,

    wears,swimming suits,umbrella,even many car and house big glass.

    You can use it whenever you want,if you stand under big sun,you also can

    take some on your body to resistant UV.

    2007-06-13 12:20:19 補充:

    Some military medics will care your hurt by this UV resistance substances

    ,beacause it has good usage for your hurt.

    2007-06-14 00:13:10 補充:

    基本上我覺得你在整我

    所以基本上我現在沒空找資料

    基本上我想睡覺ㄌ

    基本上我還蠻累ㄉ

    只好明天在基本的回囉

    (基本上知識就快一百個類似問題ㄌ)

    基本上就這樣囉

    拜託你不要刪問題(最基本)

    因為我回答的問題基本上已經被刪快十個ㄌ

    2007-06-14 15:02:18 補充:

    紫外抵抗

    塑料紫外光抵抗介入可能影響您的材料選擇的一定數量的因素。

    所有因素被介入在紫外抵抗, 有三最突出地計算; 厚度、不透明, 和對安定器的用途。這些三個因素被結合保衛塑料反對紫外(紫外) 光。

    紫外(紫外) 光比可見光是光在更短的波長, 通過光譜的紫羅蘭色結尾(超, 或在紫羅蘭之外) 。有紫外光、UVA 、UVB, 和UVC 三個類別。

    UVA 光通常不是足夠強的危害塑料。UVB 造成對塑料的多數損害和通常是我們需要測試當檢查plastic4a. s 紫外抵抗的™類型光。UVC 光包含更加殘損的能量但它由earth4a. s 臭氧層™幸運地過濾掉。

    2007-06-14 15:02:35 補充:

    光貶低塑料由轉移它的能量入塑料。這能量可能造成損傷由創造熱, 或這能量可能實際上打破分子束縛在plastic4a.™s 結構。熱和打破債券可能創造有形資產損失在塑料。UVB 光芒的高能造成幾乎所有紫外損傷在塑料裡。規則可見光不導致幾乎退化經過許多歲月曝光。

    不透明的塑料是光不通過的塑料。在不透明的塑料光必須劃分外面層數在它可能劃分塑料的內在部分之前。塑料內在層數可能長期保留它的力量更加不透明塑料。如果塑料是完全地黑(或一些其他不透明的顏色) 然後光唯一行動在表面和較少損傷將發生在時間期間。

    2007-06-14 15:02:48 補充:

    在清楚的塑料膠膜, UVB 光立即行動在整個厚度, 並且失敗同時發生在塑料的厚度過程中(清楚的影片迅速地貶低) 。如此我們的第一步將製造將是被暴露的一樣不透明的儘可能的塑料。多數襯裡材料被用於為被暴露的襯裡用炭黑或其它顏料沉重被裝載使他們不透明。

    襯裡材料的厚度並且是一個因素在紫外抵抗。更加厚實的材料允許表面遭受一些紫外退化當仍然保留力量在內核材料。在被暴露的排行的材料裡一種厚度40 米爾(1.0 毫米) 通常被推薦為長期紫外抵抗。

    2007-06-14 15:03:00 補充:

    在力量由織品的材料裡(支撐材料) 提供不透明的塗層典型地0.4 毫米(15 米爾) 在各邊必需防止fabric4a. s 力量的紫外™退化。

    攻擊塑料的UVB 光創造可能導致分子損傷一個鏈式反應可能加速材料的故障的易反應的退化副產物。紫外安定器增加來塑料防止這些退化副產物造成另外的損傷。紫外安定器作為4a.oesponges4a.. 浸泡這些易反應的副產物和停止鏈式反應在另外的損傷之前發生。

    2007-06-14 15:03:13 補充:

    關於geomembranes 的最共同的問題的當中一個長期是, 4a.oehow 意志它前在各劃線員材料被測試為紫外抵抗的被暴露的service?4a.., 然而劃線員被安裝的各個地點有一個另外紫外曝光水平。二個地點確切地不會得到同樣相當數量陽光, 並且多數地點不得到同樣相當數量陽光從每年。測試執行了在亞利桑那或佛羅里達不能是特點產品使用期限在您的區域。這使它難做一般聲明關於襯裡材料紫外抵抗。

    2007-06-14 15:03:26 補充:

    典型的紫外測試引述ASTM G53, 和陳述500 個小時或2000 個小時以70% 或90% 力量被保留。一些測試並且闡明, 氙弧被使用了。這不幸地不是足夠的資訊做一種合理的交互作用對被暴露的生活。有一定數量的變異在紫外測試方法, 並且有許多源泉的紫外光被使用在測試(氙光使用可能改變結果) 的一定數量不同的過濾器。最佳的資訊源將看實際曝光資料從室外曝光測試被收集。

    2007-06-14 15:03:37 補充:

    有二主要室外曝光設施在北美洲, 一個在佛羅里達, 和一個在亞利桑那。在每個這些設施他們暴露塑料材料於太陽延長的時期, 與放大鏡一系列的鏡子經常集中太陽樣品。sun4a.™s 強度被測量(在Langley4a.™s) 和規定值被給塑料材料根據它接受Langleys 的數字。實驗室紫外測試, 譬如ASTM G53 允許我們執行質量管理檢查在材料沒有必須執行5 和10 年測試戶外。

    2007-06-14 15:03:54 補充:

    在附上圖是什麼樣的被暴露的終身的略計可能期望從一定數量不同的襯裡材料。各材料包含紫外安定器和仔細地被公式化了為最大被暴露的終身。請注意價值被測量是只近似。您接受材料的實際紫外抵抗也許可觀地變化和沉重依靠相當數量陽光被接受在設施地點。

    一結束語。任一材料終身可能被重新填沒巨大增加劃線員。看Layfield 技術筆記重新填沒。價值被顯示在圖是至於被暴露的使用唯一

    2007-06-14 15:06:32 補充:

    並不是所有都是粉狀ㄉ

    有些是像棉 木炭等物質

    基本上有抗ㄉ都是能抗的物質

    2007-06-14 15:07:59 補充:

    像太陽眼鏡 雨傘 衣服 游泳衣 防曬液 遮陽板 車子的擋風玻璃

    2007-06-14 15:09:16 補充:

    軍方也用作止血材料

    直接塗抹使用

    2007-06-14 23:47:26 補充:

    請問大大基本上有滿意ㄌㄇ

    Source(s): 快被英文搞死的我, 字數限制搞死我也, provided by knowledge big big, 基本禮儀, 看知識長知識學知識, 基本禮儀
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