kingofthehill

Thank you all for your comments

This particular test specimen is an electrical item that will be energised for the duration of the test. So the resultant response temperature of the materials would be combined effects of heat emitted from electrical components and IR. In this respect, the temperature could be quite severe (simulation of hottest dessert conditions) which is why I have mentioned IR. It will be impossible to determine what the resultant temperature will be without first testing with IR. Subsequent tests could perhaps be set up without IR when peak temperature has previously been obtained from the IR test. Some of the materials being evaluate are Nitrile rubber, Polyamide, TPU and FKM (fluorocarbon). I have no idea if radicals would be present in these materials as a result of UV exposure. Test duration is 10 days exposure. I should also add that I will be evaluating hardness changes in rubber parts (embrittlement). Various functional tests will be carried out to evaluate presence of structural defects (cracks, delamination, electrical defects, failure of bond lines etc.), as well as visual examination (surface coatings, crazing, blistering, fading etc.).

This is frustrating. I really need a feeling of certainty about this before I plump for a particular test method. I haven't got that warm fuzzy feeling at the moment.

Thanks for that! The only thing I could find that suggested that reaction to UV light was affected by temperature was a school science experiment that examines the effects of temperature on the duration of colour change using photochromic plastic beads. At 0°C, when exposed to sunlight, beads took in excess of 1 minute to change colour. At 60°C, colour change took less than 10 seconds. It's an ultra basic experiment but it seems to me that this answers my question? Photochemical reaction occurs at a faster rate at higher temperature in this particular example. Or is this something other than photochemical? Thoughts?

First of all Hello! I'm new here! Now for what I hope is a reasonably basic query.... I am trying to devise a test to evaluate detrimental effects of UV radiation, primarily on rubber and plastic components. There are many standards that I have found covering this sort of thing but I am having difficulty finding a suitable one because my understanding of UV radiation is limited. I don't have much time to research the subject extensively so here I am! Originally, I had a test planned in that requires the use of full spectrum lamps that replicate the full light spectrum emmited by the sun. This test obviously has an element of IR radiation that causes considerable heating effects on the product. However, I am primarily concerned about the effects of UV radiation on rubber and plastic components so have been considering finding a more straight forward test that may be cheaper (i.e. static UV lamp instead of motorised full spectrum lamps replicating diurnal cycle). My question....Is the actinic effect of UV radiation worsened if the temperature of the item that is subjected to the radiation is higher as a result of IR radiation? I have searched the net but have not found a basic article that may help understand this. If anybody could point me in the right direction for good information on the subject, that would be appreciated greatly. TIA Kingofthehill