1、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS 3424-13:1999 ICS 59.08
2、0.40 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Testing coated fabrics Part 13: Guide to the selection of methods for colour fastness to light testingThis British Standard, having been prepared under the direction of the Sector Committee for Building and Civil Engineering
3、, was published under the authority of the Standards Committee and comes into effect on 15 November 1999 BSI 11-1999 The following BSI references relate to the work on this standard: Committee reference TCI/78 Draft for comment 98/124301 DC ISBN 0 580 33023 0 BS 3424-13:1999 Amendments issued since
4、publication Amd. No. Date Comments Committees responsible for this British Standard The preparation of this British Standard was entrusted to Technical Committee TCI/78, Coated fabrics, upon which the following bodies were represented: British Plastics Federation British Rubber Manufacturers Associa
5、tion Ltd. British Textile Technology Group FIRA International Home Office Made-up Textiles Association Maritime and Coastguard Agency Ministry of Defence RAPRA Technology Ltd. SATRA Technology Centre Textile InstituteBS 3424-13:1999 BSI 11-1999 i Contents Page Committees responsible Inside front cov
6、er Foreword ii Introduction 1 1 Scope 1 2 Normative references 1 3 Light source 1 4 Irradiance 2 5 Humidity/temperature control 2 6 Post exposure testing 3 7 Blue wool standards 3 8 Instrumental colour assessment 4 9 Colour vision deficiency 4 10 Summary of questionnaire results 5 11 Overall recomme
7、ndations 5 Table 1 Recommended exposure conditions 3 Bibliography Inside back coverii BSI 11-1999 BS 3424-13:1999 Foreword This British Standard has been prepared by Technical Committee TCI/78, Coated fabrics, which has the responsibility to: aid enquirers to understand the text; present to the resp
8、onsible national committee any enquirers on the interpretation, or proposals for change, and keep UK interests informed; monitor related national developments and promulgate them in the UK. A British Standard does not purport to include all the necessary provisions of a contract. Users of British St
9、andards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages 1 to 7 and a back cover. The BSI copyright notice
10、displayed in this document indicates when the document was last issued. BSI 11-1999 1 BS 3424-13:1999 Introduction This guide is intended to assist in the selection of procedures and apparatus for the colour fastness testing of coated fabrics to artificial light and also the subsequent physical test
11、ing of the coated fabric test specimens. A number of different techniques and methods are available which each have advantages and disadvantages. The guide aims to highlight these and provide sufficient information so that the best and most appropriate testing can be carried out. The guide has been
12、written after a two stage information gathering process. The first stage was to survey the opinion of European suppliers of coated fabrics as to their testing requirements and current practices. This took the form of a questionnaire circulated to over 70 companies (see clause 10). The second stage w
13、as to review the current test methods and to summarize and assess them. The ultimate criterion for judging a light fastness test is how the results compare with the real life situation. The purpose of laboratory testing is to simulate real exposure to light but at an accelerated rate. For each indiv
14、idual material, the end-use may be different, so the recommendations of this guide should be heeded whilst at the same time considering experience of real life situations. Where more quantitative results are sought, this guide will be particularly useful since it is designed to make the testing proc
15、edures as standardized, consistent and repeatable as possible. In the past, BS 3424 has recommended that either BS 1006 or BS 2782 is followed depending on which side of the coated fabric was being tested. Similarly, this guide makes significant reference to ISO 105. 1 Scope This document describes
16、the factors that need to be considered when assessing the colour fastness of coated fabrics to artificial light and when carrying out post exposure physical testing on the coated fabric test specimen. It is applicable to all forms of plastic and rubber coated materials. 2 Normative references The fo
17、llowing normative documents contain provisions which, through reference in this text, constitute provisions of this part of this British Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. For undated references, the latest edition of th
18、e publication referred to applies. BS 1006:1990, Methods of test for colour fastness of textiles and leather. BS 2782-5:Method 540D:1995, Methods of testing plastics Part 5: Optical and colour properties, weathering Method 540D: Methods of exposure to laboratory light sources. General guidance. BS 2
19、782-5:Method 540E:1995, Methods of testing plastics Part 5: Optical and colour properties, weathering Method 540E: Methods of exposure to laboratory light sources. Xenon-arc sources. BS 2782-5:Method 552A:1981, Methods of testing plastics Part 5: Optical and colour properties, weathering Method 552A
20、: Determination of changes in colour and variations in properties after exposure to daylight under glass, natural weathering or artificial light. BS EN 20105-A02:1995, Textiles Tests for colour fastness Part A02: Grey scale for assessing change in colour. ISO 105-B02:1994, Textiles Tests for colour
21、fastness Part B02: Colour fastness to artificial light: Xenon arc fading lamp test. 3 Light source 3.1 General When testing colour fastness in general, it is vital that the test environment and conditions replicate real life or in-use conditions. Since this guide is concerned with light fastness as
22、opposed to weathering, the light to which the test specimens are exposed should mimic daylight as closely as possible. 3.2 Xenon-arc light Xenon-arc light (with the appropriate filters) is the source which best attains this goal. Over the wavelength range of 300 nm to 800 nm, which includes ultra-vi
23、olet (UV), visible and infra-red (IR) radiation, the spectrum of filtered xenon light resembles that of sunlight. It may be that UV radiation is the primary cause of material degradation but the temperature of the test specimen is also very significant. Consequently the heating effects caused by the
24、 IR part of the incident radiation are also vital, especially for coloured test specimens. Although with some types of xenon lamps, the heating effects due to the IR radiation may be greater than those which occur in real life, appropriate filters can minimize this difference. An additional benefit
25、of xenon lamps is that filters can be used whose output mimics that of daylight through window glass, a common in-situ application. The specifications in BS 2782-5:Method 540E:1995, 4.1 regarding the xenon-arc lamp apparatus should be adhered to. 3.3 Filtered mercury vapour lamps Filtered mercury va
26、pour lamps with the addition of metal halide or tungsten are also able to give a similar spectrum to sunlight although the IR portion of its output is slightly lower than for solar radiation. The intensity of the light is also far lower than for xenon-arc and hence test exposure times will be longer
27、.2 BSI 11-1999 BS 3424-13:1999 3.4 Carbon-arc light sources The light emitted by an arc between carbon electrodes was popular before the advent of xenon-arc light sources but, even with filters, carbon-arc light includes a significant amount of radiation between 350 nm and 450 nm which does not occu
28、r in natural daylight. Therefore the use of carbon-arc light sources is not recommended. 3.5 Fluorescent UV light sources Fluorescent UV light sources expose samples to the damaging UV portions of sunlight at controlled elevated temperatures. 4 Irradiance Irradiance is defined as the amount of radia
29、tion energy incident upon a square metre of material. It is dependent upon the spectrum of the emitted radiation, the intensity of the radiation, the distance of the test specimen from the energy source and the orientation of the test specimen surface with respect to the incident energy. The interna
30、tional colour committee, CIE, has compiled data which states that over the wavelength range 290 nm to 800 nm (UV, visible and IR radiation), an irradiance value of 550 W/m 2 is recommended when simulating solar radiation. When considering irradiance values caution is advised since it is easy to be m
31、isled. The energy of a radiation source is inversely proportional to the wavelength of the radiation (UV radiation is more “energetic” than IR radiation) so the same intensity of radiation can give different irradiance values depending on the wavelength range over which the measurements are made. Th
32、e importance of reproducing sunlight has already been emphasized but it is worth reiterating. A radiometer is a device for measuring irradiance. In the context of the testing apparatus it should be mounted in the same relative position as the test specimen and in the same orientation with respect to
33、 the light source. The radiation energy is not evenly distributed over the entire wavelength range. The xenon-arc lamp (when new) should conform to the spectral distribution of UV radiation specified in BS 2782-5:Method 540E:1995, 4.1. NOTE 1 Although the lamps may be manufactured to conform to BS 2
34、782-5:Method 540E:1995, 4.1, there will be significant variation between the spectral distributions of the lamps. Assuming that real life test experience has shown the need to mimic sunlight as closely as possible, the radiometer should measure over the wavelength range 290 nm to 800 nm and its outp
35、ut should be used to automatically adjust the intensity of the lamp so that an irradiance of 550 W/m 2 is applied constantly. The lamp burner should be discarded and replaced when this irradiance cannot be achieved. NOTE 2 The output of an adjusted lamp will decrease in intensity over time. ASTM D34
36、24 1 indicates that the average daily dose of radiation energy received in Miami and Arizona is 1 MJ/m 2 over the range 295 nm to 400 nm. An irradiance of 550 W/m 2 over the wider range specified earlier is equivalent to 60 W/m 2 over this narrower range. Correspondingly in 1 h a radiation dose of 2
37、20 kJ/m 2 will be emitted. Therefore the total daily Miami radiation dose will be received by the test specimen in less than 5 h. If it is also assumed that Miami sunshine is four to five times more severe than in Europe, then 1 h exposure at 550 W/m 2 is equivalent to the average daily dose of radi
38、ation energy in typical European sunshine. This is not a very accurate statistic and it should only be considered as a rule of thumb. More data needs to be collected either by individuals or by the textiles/plastics/rubber industries to relate exposure time in a laboratory test to real life exposure
39、. NOTE 3 UV testing using lamp options span the range 295 nm to 400 nm. 5 Humidity/temperature control It has already been stated that temperature is an important factor in any photochemical reaction that will occur within the test specimen. Humidity is also important, especially for the textile com
40、ponent of the test specimen. In each case, the critical area is at the test specimen itself. The temperature and humidity of the test specimen chamber influence the test but any measurements should be focused at the surface of the test specimen. Although the mercury vapour lamp light can be made to
41、resemble that of daylight, the test method which utilizes this light source, BS 1006:1990, Method UK-TN specifies quite simple apparatus. Some account is made for humidity and temperature control but not to a sufficient level for the method to be regarded as a quantitative test. Indeed the method st
42、ates that it is intended for use as a quality control test. It is recommended that a red azoic dyed cotton cloth is used to measure the “effective humidity”, as defined in ISO 105-B02:1994, 4.1.3, and the apparatus adjusted accordingly. There is also a limit as to how accurately the apparatus can co
43、ntrol the humidity within the chamber. Utilizing electronic control systems and sensitive water dispersal systems the relative humidity can be maintained at a given level within a 2 % range. Using less sophisticated control systems will broaden the range and increase the inaccuracy of the humidity l
44、evel within the test chamber. BSI 11-1999 3 BS 3424-13:1999 Table 1 Recommended exposure conditions Exposure condition Effective humidity Blue wool rating of humidity control fabric Black-standard temperature 8C Europe: extreme Low 6 to 7 Maximum 65 Europe: normal Moderate 5 Maximum 50 Europe: extre
45、me High 3 Maximum 45 America Low 6 to 7 63 1 (black-panel) The instrument used to measure the temperature of the test specimen is significant. Ideally, the temperature at the surface of the specimen would be measured directly but in reality the best that can be achieved is to position a measurement
46、device so that it is exposed to the light source in the same manner as the test specimen. Two types of thermometer are commonly used in light fastness equipment: a black-standard and a black-panel thermometer. Differences in design means that typically the black-panel temperature indicated is signif
47、icantly less than the black-standard temperature. Black-standard devices approximate the temperature of dark test specimens which have a low thermal conductivity. Since coated fabrics are poor conductors of heat, it is recommended that a black-standard thermometer is used. In order to make the tempe
48、rature measurement more applicable to a range of coloured test specimens, a white-standard thermometer should also be used. Both the black-standard and white-standard thermometers are described in BS 2782-5:Method 540D. The commonly used ASTM G26 2 recommends a black-panel temperature of 63 3 8C. Th
49、e in-use exposure conditions, both in terms of humidity and temperature, will vary depending on the country of end-use. It is recommended that the exposure conditions specified in ISO 105-B02:1994, clause 6 (see Table 1) are followed. This will enable normal and extreme European conditions to be recreated as well as facilitating meaningful comparisons with American test results. 6 Post exposure testing In addition to assessing the colour change of a test specimen material, it may be desirable to study the effects of light exposure on other p
