CA1255924A - Pre-testing method and apparatus for a weathering test - Google Patents
Pre-testing method and apparatus for a weathering testInfo
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- CA1255924A CA1255924A CA000541307A CA541307A CA1255924A CA 1255924 A CA1255924 A CA 1255924A CA 000541307 A CA000541307 A CA 000541307A CA 541307 A CA541307 A CA 541307A CA 1255924 A CA1255924 A CA 1255924A
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Abstract
Abstract This invention relates to a pre-testing method for a weathering test. Prior to the weathering test, samples, for example, plastic, fibre, or paint, are exposed to ultraviolet ray radiation emitted from high pressure metal vapor discharge lamp at an energy level capable of deteriorating the samples in a short time. The samples are maintained at a temperature which does not cause deterioration of the sample. Samples to be subjected to the weathering evaluation test are then selected according to the level of deterioration in the pre-test.
Description
9,2~5~2~
This invention relates to a pre-testing method for a weathering test on samples of plastic, fibre, coating material, or the like. This application is a divisional of Canadian Application No. 468,814 filed November 28, 1984.
Conventionally, in ~ea~u~em~n~. O;e w~atherabllit~
of plastic material or the like, weathering machines according to JIS B7751 to 77$4 are generally used.
In these testing machines, ordinarily, a light source such as a carbon arc lamp, xenon arc lamp or the like is used and the light emitted from this light source is irradiated onto a sample, thereby performing the accelerated weathering test.
However, in these weathering machines, the apparatus containing such a light source emits radiation at an ultraviolet irradiation intensity of about 6 mW per cm2 of the surface to be irradiated. Therefore, it takes approximately hundreds of hours or longer to measure and discriminate the ultraviolet deterioration characteristic that equivalent1y corresponds to one year o irradiation of solar light.
~2~
Also, in the known methods all the samples in each lot are subjected to testing so that there are problems in that measurement and discrimination of the result is time consuming and these methods are extrernely inefficient.
It is an object of the present invention to provide a pre-testing method for allowing the weathering test to be very eficiently performed.
According to this invention, there is provided a weathering test comprising the steps of: irradiating a plurality of samples with radiation that is generated by a metal halide lamp containing mainly halide of iron enclosed together with mercury and rare gas and that is iltered by a filter that substantially removes wavelength components other than ultraviolet wavelengths, the filtered radiation havln~ an energy level sufeicLent to deteriorate said samples in a short time; maintaining the samples at a temperature that is low enough to prevent substantial heat deterioration of the samples during the irradiating; and selecting from the plurality of samples a sample which should be subjected to the weathering test in accordance with the degree of the deterioration.
Use oE the pre-testing method allows the tendency and degree of ultraviolet deterioration characteristic of the sample to be determined with high accuracy in an extremely short time. Therefore, on the basis of these results, only the samples which should be tested by the weathering machine ~ay be selected and tested. Thus, there is an advantage in that the entire test may be ~ efficiently executed. Also, the testing apparatus for use ; 30 in the pre-test method has a simpler structure than the weathering machine and is economical.
~5~9:~
Fig. 1 shows a spectral energy distribution diagram of a metal halide lamp for an ultraviolet light source which is used in this invention;
Fig. ? shows a transmission characteristic diagram of a filter which is used in combination with the metal halide lamp;
Figs. 3A and 3B illustrate a front view and a side elevational view of the light source in combination with the metal halide lamp and filter, respectlvely;
Figs. 4A and 4B illustrate a front view and a side elevational view of a pre-testing apparatus for use in the present invention, respectlve~y; and Figs, 5 to 10 show comparlson diagrams between the test result in examples oE the invention and the test result by a conventional method.
; An embodiment of the present invention will now be described by way of example only. First, necessary samples are produced for every lot.
Next, ultraviolet rays having an intensity of 50 mW or more per cm2 of the surface to be irradiated ~re irradiated onto these samples by a light source in combination with a high pressure metal vapor electric discharge lamp and a filter which transmits only the ultraviolet rays within a wavelength range of 300 to 400 nm under the condition whereby the temperature of the sample is 80C or less. The reason for the wavelength range of the ultraviolet rays specified above is that the test conditions specified by a JIS rule are not satisfied if the wavelength range is less than 300 nm, and strictly ~25~ 4 speaking, less than 275 nm. Also, in the case where the wavelength range is over 400 nm, many visible and infrared rays are included in the light that is irradiated from the light source, so that the sample is largely thermally affected. Therefore, it is necessary to avoid such influences, and the like.
From an economical viewpoint a desirable range for irradiation intensity of the ultraviolet rays on a sample is approximately 80 to 200 mW per cm~ of the surface to be irradiated although a higher irradiation intensity may be preferable. More preferably, a range of about 100 to 150 mW is used. The optimum high pressure metal vapor discharge lamp to obtain such a wavelength range and intensity is set forth in, Eor example, the oEficial gazette o ~apanese Patent ~pplication P-~bliqati~n ~aid-open No. 187~3/19B3. This lamp is a metal halide l~mp irl which a halide oE a metal such as iron and tin is enclosed together with proper quantities of mercury and rare gas in a light emitting tube made of quartz glass and having at least a pair of electrodes. The light emission spectrum of this metal halide lamp has a fairly large energy distribution in the wavelength range of 300 to 400 nm as shown in Fig. 1. This metal halide lamp is not limited to the lamp wherein the halide of iron and tin has been added into the light emitting tube but also may be a lamp wherein metal halide, mainly containing halide of iron, has been enclosed in the light emitting tube.
A carbon arc lamp having an energy peak in the wavelength range of 300 to ~00 nm has been used in weathering machines to date. However, this lamp irradiates many infrared rays as well as ultraviolet rays. Also gases such as CO, CO2, NO, NO2, etc. are generated while the lamp is lighting. ThereEore~ as dis-closed in the official gazette of Japanese Utility Model 9~
Application Publication Laid-open No. 16796/1~77, the lamp itself has to be equipped with cooling and ventilating mechanisms, causing the lamp and overall apparatus to become complicated and to be increase~ in size and cost.
Thus, this type of lamp is not suited for implementation in the present invention.
Even in the metal halide lamps described abo~e, it is impossible to avoid irradiation of energy in a wave-length range other than 300 to 400 nm. Therefore, it is necessary to restrict the irradiated wavelength range of the lamps to 300 - 400 nm by use in combination with a proper filter. The optimum filter used for this purpose is a filter made of soft glass having a low meltiny point and which consists of, Eor example, 60 - ~5% SiO2, 15 -20~ Pb, 7 - 8~ Na, 7 - ~ K, l~ Co, and 1~ Ni, where all percen~ages are hy masY.
The ultraviolet transmission characteristic of this filter is as shown in Fig. 2. By combining this filter with the metal halide lamp, ultraviolet rays of wavelengths 290 to 460 nm, and particularly 300 to 400 nm, are obtained extremely efficiently. However, if this filter is merely attached around the metal halide lamp, radiation heat froM the lamp will immediately damaye the filter. Therefore, for example, as shown in ~igs. 3A and 3B, a water cooled light source 6 is suitably constituted in a manner such that: a water cooled jacket 2 has an inner tube 2a and an outer tube 2b which consist of quartz glass which can transmit the ultraviolet rays; a cooling liquid is circulated between the inner and outer tubes 2a and 2b; a light emitting tube 1 is arranged at the centre of the inner tube 2a of the wafer cooled jacket 2; and a filter 3 is disposed between the inner and outer tubes 2a an~ 2b.
~L~5~
In the official gazettes of Japanese Utility Model Application Publication Laid-open Nos. 29675/1977 and 29034/1979, apparatus are disclosed in which, in the weathering machine, the ultraviolet rays in a particular wavelength range of, say, 300 - 400 nm are controlled by combining a filter with a lamp. However, in both such apparatus, the radiation energy of thle lamp varies depend-ing upon the time lapsed since lighting of the lamp and upon changes in power source voltage, so that the energy components in a particular wavelength range also change.
m erefore, to ensure constant energy components, any energy change in the particular wavelength range is detected to control a voltage which is applied to the lamp in accordance with the change. Consequently, the above-ment~oned apparatus are ~uite dif~erent from the apparatuso~ thi~ invention in which the light emitted erom the lamp is irradiated onto the sample through the filter.
Figs. 4A and 4B illustrate a front view and a side elevational view of an example of a testing apparatus to implement the present invention. In the drawings, a reference numeral 4 denotes a testing apparatus main body;
4a is an ultraviolet irradiating chamber; and 4b is a chamber for enclosing attached apparatus. A light source apparatus 6' is provided over the ultraviolet irradiating chamber 4a. The light source apparatus 6' ~omprises a reflecting mirror 5 and the light source 6 such as a metal halide lamp or the like attached in the apparatus 6'. A
sample mounting plate 7 is disposed below the light source 6 so as to be vertically adjustable and rotatable as necessary. The distance between the sample mounting plate 7 and the light source 6 can be adjusted by vertically moving either of or both of the sample mounting plate 7 and the light source apparatus 6'.
9~2~
The reason for constituting the testing apparatus in this way is to eliminate a variation in distance between the sample and the light source 6 due to the capacity of the light source 6, thickness of sample, etc.
5 By suitably selecting the capacity of the light source 6 and the distance between the light source 6 and the sample, it is possible to irradiate onto the sample ultraviolet rays having an intensity of 50 mW or more per cm2, preferably, 80 to 200 mW, and more desirably, 100 to 150 mW. Also, in order to uniformly irradiate the ultraviolet rays onto the sample, the sample mounting plate 6 can be freely rotated as necessary.
An air blower 8 is used to cool the sample mount-ing plate 7 and the air in the ultraviolet irradiating lS chamber ~a is exhausted to the outside by an air exhaust-in~ apparatu~ n the case where the sample is irradiated with strony ul~raviolet rays, it i~ necessary to maintain the sample at temperatures below about 80C to prevent deformation of the sample due to the heat.
However, as mentioned above, this temperature can be easily controlled by using the means in which the water cooled metal halide lamp is used as the light source in combination with the filter and also by using the means in which the sample is cooled by use of the air blowing and ~5 exhausting apparatus, and the like~ Table 1 shows the ultraviolet irradiation time and the temperature of the sample when the surface of the sample is irradiated by the ultraviolet rays of a constant intensity in the cases where: only the water cooled metal halide lamp is used 3~ (no filter); the filter is combined with this lamp (filter is used); and the means for cooling the sample is also used in addition to the filter (filter and sample cooling means are used), respectively.
Table 1 _ __ .
Ultraviolet Filter and rays irradi- sample cool-ation intensity No filter Filte:r ing means (mW/cm2) is used are used For one For ten 20 - 60 hour and hours and at 100C at 100C For 100 or over or over hours or _ more and For 0.3 For one at 65C
80 - 120 second and hour and or below at 100C at 100C
or over or over _ ___. . _ ___ AS will be clear from this table, in the case where the filter is combined with the water cooled metal halide lamp and the sample cooling means is also utilized, even if the strong ultraviolet rays having an intensity of 80 to 120 mW/cm2 are irradiated onto the sample for more than a hundred hours, the sample can be maintained at temperatures of 65C or below.
Alternatively, the cooling of the sample may be controlled by control of the input to the lamp or the temperature of the sample mounting plate in addition to the control of the quantity and temperature of the cooling air. Further, a pump, cooler and the like for the cooling water to the light source are enclosed in the chamber 4b for enclosing the attached apparatus in addition to a power supplying apparatus, ballast apparatus and the li]ce for the light source.
- 9 - ~
In such a testing apparatus as described above, for example, in the case where a metal halide lamp of a rated input of 1.5 kW is used as the metal halide lamp of the light source and the distance between the light source - 5 6 and the sample mounting plate 7 is set to 10 cm and the light source 6 is used at the rated input, the ultraviolet irradiation intensity on the sample mounting plate 7 is about 100 mW per cm2. This value is approximately 10 to 15 times larger than the ultraviolet irradiation intensity of a conventional weathering machine. When it is assumed that the ultraviolet deterioration characteristic of the sample, when such strong ultraviolet rays are irracliated onto the sample, has a similar tendency to the ultraviolet deterioration characteristic of the sample which is tested by the actual weathering machine, it is possible to disc~iminate the ultraviolet deterioration characteristic eor the timQ interval. This tLme interval is about 1/10 -1/15 shorter than the time interval that is needed in the case where the weathering machine is used.
As described above, the use of the foregoing method enables the ultraviolet deterioration characteris-tics of the samples for every lot to be discriminated in an extremely short time. Therefore/ if the samples are selected from among these samples in accordance with a degree of ultraviolet deterioration and are tested by the weathering machine, the superfluous tests and time can be omitted, so that the test becomes very ef~icient.
The largest problem in use of the testing method is whether or not the ultraviolet deterioration character-istic of the sample irradiated by strong ultraviolet rayshave the same tendency as the ultraviolet deterioration characteristic of the sample which was tested by the weathering machine. Unless they have the same tendency, the pre-testing method according to the invention will be :;
~s~
meaningless. Therefore, as shown in the following exam-ples, many samples consisting of various kinds of plastic materials were tested by the testing apparatus (herein-after, referred to as the pre-testing apparatus) to imple-ment the invention and by the weathering machine (herein-a~ter, referred to as the formal testing machine~, and the tendency and degree of the ultravi~let deterioration were examined. The testing apparatus and machine used in each example and the test conclitions are as follows.
(1) Pre-testing apparatus Model ... The apparatus made by Iwasaki Electric Co., Ltd. (with a structure as shown in Figs. 4A and 4B) Con~itions r~,arnp u~ed: Metal halide lamp of 1.5 kW
~adiatLon wavelen~Jth: 300 - 400 nm Energy distribution: As shown in Fig. 1 Ultraviolet irradiation intensity on the surface of the sample: 100 + 5 mW/cm2 The highest temperature at the sample surface: 65C or less
This invention relates to a pre-testing method for a weathering test on samples of plastic, fibre, coating material, or the like. This application is a divisional of Canadian Application No. 468,814 filed November 28, 1984.
Conventionally, in ~ea~u~em~n~. O;e w~atherabllit~
of plastic material or the like, weathering machines according to JIS B7751 to 77$4 are generally used.
In these testing machines, ordinarily, a light source such as a carbon arc lamp, xenon arc lamp or the like is used and the light emitted from this light source is irradiated onto a sample, thereby performing the accelerated weathering test.
However, in these weathering machines, the apparatus containing such a light source emits radiation at an ultraviolet irradiation intensity of about 6 mW per cm2 of the surface to be irradiated. Therefore, it takes approximately hundreds of hours or longer to measure and discriminate the ultraviolet deterioration characteristic that equivalent1y corresponds to one year o irradiation of solar light.
~2~
Also, in the known methods all the samples in each lot are subjected to testing so that there are problems in that measurement and discrimination of the result is time consuming and these methods are extrernely inefficient.
It is an object of the present invention to provide a pre-testing method for allowing the weathering test to be very eficiently performed.
According to this invention, there is provided a weathering test comprising the steps of: irradiating a plurality of samples with radiation that is generated by a metal halide lamp containing mainly halide of iron enclosed together with mercury and rare gas and that is iltered by a filter that substantially removes wavelength components other than ultraviolet wavelengths, the filtered radiation havln~ an energy level sufeicLent to deteriorate said samples in a short time; maintaining the samples at a temperature that is low enough to prevent substantial heat deterioration of the samples during the irradiating; and selecting from the plurality of samples a sample which should be subjected to the weathering test in accordance with the degree of the deterioration.
Use oE the pre-testing method allows the tendency and degree of ultraviolet deterioration characteristic of the sample to be determined with high accuracy in an extremely short time. Therefore, on the basis of these results, only the samples which should be tested by the weathering machine ~ay be selected and tested. Thus, there is an advantage in that the entire test may be ~ efficiently executed. Also, the testing apparatus for use ; 30 in the pre-test method has a simpler structure than the weathering machine and is economical.
~5~9:~
Fig. 1 shows a spectral energy distribution diagram of a metal halide lamp for an ultraviolet light source which is used in this invention;
Fig. ? shows a transmission characteristic diagram of a filter which is used in combination with the metal halide lamp;
Figs. 3A and 3B illustrate a front view and a side elevational view of the light source in combination with the metal halide lamp and filter, respectlvely;
Figs. 4A and 4B illustrate a front view and a side elevational view of a pre-testing apparatus for use in the present invention, respectlve~y; and Figs, 5 to 10 show comparlson diagrams between the test result in examples oE the invention and the test result by a conventional method.
; An embodiment of the present invention will now be described by way of example only. First, necessary samples are produced for every lot.
Next, ultraviolet rays having an intensity of 50 mW or more per cm2 of the surface to be irradiated ~re irradiated onto these samples by a light source in combination with a high pressure metal vapor electric discharge lamp and a filter which transmits only the ultraviolet rays within a wavelength range of 300 to 400 nm under the condition whereby the temperature of the sample is 80C or less. The reason for the wavelength range of the ultraviolet rays specified above is that the test conditions specified by a JIS rule are not satisfied if the wavelength range is less than 300 nm, and strictly ~25~ 4 speaking, less than 275 nm. Also, in the case where the wavelength range is over 400 nm, many visible and infrared rays are included in the light that is irradiated from the light source, so that the sample is largely thermally affected. Therefore, it is necessary to avoid such influences, and the like.
From an economical viewpoint a desirable range for irradiation intensity of the ultraviolet rays on a sample is approximately 80 to 200 mW per cm~ of the surface to be irradiated although a higher irradiation intensity may be preferable. More preferably, a range of about 100 to 150 mW is used. The optimum high pressure metal vapor discharge lamp to obtain such a wavelength range and intensity is set forth in, Eor example, the oEficial gazette o ~apanese Patent ~pplication P-~bliqati~n ~aid-open No. 187~3/19B3. This lamp is a metal halide l~mp irl which a halide oE a metal such as iron and tin is enclosed together with proper quantities of mercury and rare gas in a light emitting tube made of quartz glass and having at least a pair of electrodes. The light emission spectrum of this metal halide lamp has a fairly large energy distribution in the wavelength range of 300 to 400 nm as shown in Fig. 1. This metal halide lamp is not limited to the lamp wherein the halide of iron and tin has been added into the light emitting tube but also may be a lamp wherein metal halide, mainly containing halide of iron, has been enclosed in the light emitting tube.
A carbon arc lamp having an energy peak in the wavelength range of 300 to ~00 nm has been used in weathering machines to date. However, this lamp irradiates many infrared rays as well as ultraviolet rays. Also gases such as CO, CO2, NO, NO2, etc. are generated while the lamp is lighting. ThereEore~ as dis-closed in the official gazette of Japanese Utility Model 9~
Application Publication Laid-open No. 16796/1~77, the lamp itself has to be equipped with cooling and ventilating mechanisms, causing the lamp and overall apparatus to become complicated and to be increase~ in size and cost.
Thus, this type of lamp is not suited for implementation in the present invention.
Even in the metal halide lamps described abo~e, it is impossible to avoid irradiation of energy in a wave-length range other than 300 to 400 nm. Therefore, it is necessary to restrict the irradiated wavelength range of the lamps to 300 - 400 nm by use in combination with a proper filter. The optimum filter used for this purpose is a filter made of soft glass having a low meltiny point and which consists of, Eor example, 60 - ~5% SiO2, 15 -20~ Pb, 7 - 8~ Na, 7 - ~ K, l~ Co, and 1~ Ni, where all percen~ages are hy masY.
The ultraviolet transmission characteristic of this filter is as shown in Fig. 2. By combining this filter with the metal halide lamp, ultraviolet rays of wavelengths 290 to 460 nm, and particularly 300 to 400 nm, are obtained extremely efficiently. However, if this filter is merely attached around the metal halide lamp, radiation heat froM the lamp will immediately damaye the filter. Therefore, for example, as shown in ~igs. 3A and 3B, a water cooled light source 6 is suitably constituted in a manner such that: a water cooled jacket 2 has an inner tube 2a and an outer tube 2b which consist of quartz glass which can transmit the ultraviolet rays; a cooling liquid is circulated between the inner and outer tubes 2a and 2b; a light emitting tube 1 is arranged at the centre of the inner tube 2a of the wafer cooled jacket 2; and a filter 3 is disposed between the inner and outer tubes 2a an~ 2b.
~L~5~
In the official gazettes of Japanese Utility Model Application Publication Laid-open Nos. 29675/1977 and 29034/1979, apparatus are disclosed in which, in the weathering machine, the ultraviolet rays in a particular wavelength range of, say, 300 - 400 nm are controlled by combining a filter with a lamp. However, in both such apparatus, the radiation energy of thle lamp varies depend-ing upon the time lapsed since lighting of the lamp and upon changes in power source voltage, so that the energy components in a particular wavelength range also change.
m erefore, to ensure constant energy components, any energy change in the particular wavelength range is detected to control a voltage which is applied to the lamp in accordance with the change. Consequently, the above-ment~oned apparatus are ~uite dif~erent from the apparatuso~ thi~ invention in which the light emitted erom the lamp is irradiated onto the sample through the filter.
Figs. 4A and 4B illustrate a front view and a side elevational view of an example of a testing apparatus to implement the present invention. In the drawings, a reference numeral 4 denotes a testing apparatus main body;
4a is an ultraviolet irradiating chamber; and 4b is a chamber for enclosing attached apparatus. A light source apparatus 6' is provided over the ultraviolet irradiating chamber 4a. The light source apparatus 6' ~omprises a reflecting mirror 5 and the light source 6 such as a metal halide lamp or the like attached in the apparatus 6'. A
sample mounting plate 7 is disposed below the light source 6 so as to be vertically adjustable and rotatable as necessary. The distance between the sample mounting plate 7 and the light source 6 can be adjusted by vertically moving either of or both of the sample mounting plate 7 and the light source apparatus 6'.
9~2~
The reason for constituting the testing apparatus in this way is to eliminate a variation in distance between the sample and the light source 6 due to the capacity of the light source 6, thickness of sample, etc.
5 By suitably selecting the capacity of the light source 6 and the distance between the light source 6 and the sample, it is possible to irradiate onto the sample ultraviolet rays having an intensity of 50 mW or more per cm2, preferably, 80 to 200 mW, and more desirably, 100 to 150 mW. Also, in order to uniformly irradiate the ultraviolet rays onto the sample, the sample mounting plate 6 can be freely rotated as necessary.
An air blower 8 is used to cool the sample mount-ing plate 7 and the air in the ultraviolet irradiating lS chamber ~a is exhausted to the outside by an air exhaust-in~ apparatu~ n the case where the sample is irradiated with strony ul~raviolet rays, it i~ necessary to maintain the sample at temperatures below about 80C to prevent deformation of the sample due to the heat.
However, as mentioned above, this temperature can be easily controlled by using the means in which the water cooled metal halide lamp is used as the light source in combination with the filter and also by using the means in which the sample is cooled by use of the air blowing and ~5 exhausting apparatus, and the like~ Table 1 shows the ultraviolet irradiation time and the temperature of the sample when the surface of the sample is irradiated by the ultraviolet rays of a constant intensity in the cases where: only the water cooled metal halide lamp is used 3~ (no filter); the filter is combined with this lamp (filter is used); and the means for cooling the sample is also used in addition to the filter (filter and sample cooling means are used), respectively.
Table 1 _ __ .
Ultraviolet Filter and rays irradi- sample cool-ation intensity No filter Filte:r ing means (mW/cm2) is used are used For one For ten 20 - 60 hour and hours and at 100C at 100C For 100 or over or over hours or _ more and For 0.3 For one at 65C
80 - 120 second and hour and or below at 100C at 100C
or over or over _ ___. . _ ___ AS will be clear from this table, in the case where the filter is combined with the water cooled metal halide lamp and the sample cooling means is also utilized, even if the strong ultraviolet rays having an intensity of 80 to 120 mW/cm2 are irradiated onto the sample for more than a hundred hours, the sample can be maintained at temperatures of 65C or below.
Alternatively, the cooling of the sample may be controlled by control of the input to the lamp or the temperature of the sample mounting plate in addition to the control of the quantity and temperature of the cooling air. Further, a pump, cooler and the like for the cooling water to the light source are enclosed in the chamber 4b for enclosing the attached apparatus in addition to a power supplying apparatus, ballast apparatus and the li]ce for the light source.
- 9 - ~
In such a testing apparatus as described above, for example, in the case where a metal halide lamp of a rated input of 1.5 kW is used as the metal halide lamp of the light source and the distance between the light source - 5 6 and the sample mounting plate 7 is set to 10 cm and the light source 6 is used at the rated input, the ultraviolet irradiation intensity on the sample mounting plate 7 is about 100 mW per cm2. This value is approximately 10 to 15 times larger than the ultraviolet irradiation intensity of a conventional weathering machine. When it is assumed that the ultraviolet deterioration characteristic of the sample, when such strong ultraviolet rays are irracliated onto the sample, has a similar tendency to the ultraviolet deterioration characteristic of the sample which is tested by the actual weathering machine, it is possible to disc~iminate the ultraviolet deterioration characteristic eor the timQ interval. This tLme interval is about 1/10 -1/15 shorter than the time interval that is needed in the case where the weathering machine is used.
As described above, the use of the foregoing method enables the ultraviolet deterioration characteris-tics of the samples for every lot to be discriminated in an extremely short time. Therefore/ if the samples are selected from among these samples in accordance with a degree of ultraviolet deterioration and are tested by the weathering machine, the superfluous tests and time can be omitted, so that the test becomes very ef~icient.
The largest problem in use of the testing method is whether or not the ultraviolet deterioration character-istic of the sample irradiated by strong ultraviolet rayshave the same tendency as the ultraviolet deterioration characteristic of the sample which was tested by the weathering machine. Unless they have the same tendency, the pre-testing method according to the invention will be :;
~s~
meaningless. Therefore, as shown in the following exam-ples, many samples consisting of various kinds of plastic materials were tested by the testing apparatus (herein-after, referred to as the pre-testing apparatus) to imple-ment the invention and by the weathering machine (herein-a~ter, referred to as the formal testing machine~, and the tendency and degree of the ultravi~let deterioration were examined. The testing apparatus and machine used in each example and the test conclitions are as follows.
(1) Pre-testing apparatus Model ... The apparatus made by Iwasaki Electric Co., Ltd. (with a structure as shown in Figs. 4A and 4B) Con~itions r~,arnp u~ed: Metal halide lamp of 1.5 kW
~adiatLon wavelen~Jth: 300 - 400 nm Energy distribution: As shown in Fig. 1 Ultraviolet irradiation intensity on the surface of the sample: 100 + 5 mW/cm2 The highest temperature at the sample surface: 65C or less
(2) Formal testing machine Model ... WE-SUN-HC* made by Toyo Electrochemical Industry Co., Ltd. (testing machine which is used in the testing method based on JIS A1415) Conditions Lamp used: Carbon arc lamp of 4 kVA
Ultra~iolet irradiation intensity on the surface of the sample: 6 mW/cm2 Black panel temperature: 63 + 3 C
Spray: 18 min/120 min * Trade mark -~2S~24 Also, in this test, the tendency and degree of the ultraviolet deterioration were examined from the changes in color difference and physical property of the sample which had been tested by the above testing apparatus and machine. A discriminating method and the test result in the practical example with regard to each of the color difference test and physical property test will now be explained hereinbelow, respectively.
In the following examples, typical plastic materials were selected as samples and they were tested under the particular conditions as mentioned above. The invention is not limited to these examples.
(( ~ )) Color di~eerence test With respe~ct to the samples at every ti.me ob~lne~
by the above two testing apparatus and machine, the whole color differences before and after the test were obtained and they were plotted in the graph in which an axis of abscissa indicates the time and an axis of ordinate represents the color difference. Each time the same color difference was read and the ratios of the times regarding the formal testing machine and pre-testing apparatus were obtained. Then, the magnifications of the ultraviolet deterioration accelerating properties were derived. For the whole color difference,~ E (color difference) was obtained from CIEL* a* b* which is the colorimetric system on the basis of the International Illumination Commi~tee in 1976. As the color difference meter, CR-100* (Trade mark) made by Minolta Camera Co., Ltd. was used.
~L2~;5~
(Example 1) Sample: Hard transparent PVC sheet containing organic tin. The thickness is 0.4 mm.
The stimulus values of the XYZ system which is the colorimetric system on the basis of the International Commission on Illumination in 1931 are X, Y and Z, while the chromaticity coordinates are x and y, namely:
x = X
X + Y + Z
y = Y
X + ~ + ~
In this example, the reference color is set such that Y ~ 47.4, x ~ 0.307 and y ~ 0~311, wherein, behlnd the sample, a white sheek l~
placed.
Result: In case of the formal testing machine As shown in Fig. 5A.
In case o~ the pre-testing apparatus As shown in Fig. 5B.
Comparison: As shown in Table 2 (mean magnification:
12~7)-Table 2 _ ~E Formal testing machine Pre-testin~ apparatus R/P
R(hours) P(hours) _ _ .
42 o 450 35 132 97 308.0 920 76 12.1 10.0 1000 84 11.9 ___ (Mean: 12.7) -As will be clear from the above experimental exam ple, the use of the pre-testing apparatus enables the data regarding the ultraviolet deterioration of the sample to be obtained in a short time compared to the case where the formal testing machine was used. The difference between the test times was approximately a multiple of thirteen.
This result nearly coincides with the prediction value calculated from the difference in ultraviolet irradiation intensity per cm2 of the surface to be irradiated. Thus, it was confirmed that the ultraviolet deterioration characteristic of the sample in the case where the pre-testing apparatus was used has substantially the same tendency as that in the case where the sample was tested by the formal testing machine. In addition, the sample was maintained at a temperature below about 65C during the test and even in case of the hard vinyl chloride or the like, deformatlon or the like due to the heat was not caused at all.
tExample 2) 20 Sample: ABS sheet (Grade: A-322 made by Toray Industries, Inc., Natural). The thickness is 2.0 mm.
(Reference color: Y = 62.5, x = 0.328, y = 0.342) 25 Result: In case of the formal testing machine As shown in Fig. 6A.
In case of the pre-testing apparatus As shown in Fig. 6B.
Comparison: As shown in Table 3 (mean magnification:
15-4)-.
~ 9 Table 3 AE Formal testing machine Pre-testing apparatus R~P
R(hours) P(hours) _ . .
2.0 30 2 15.0 4.0 70 5 14~0 8.0 160 11 14,5 10.0 270 15 ~ a . o (Mean: 15.4) (Example 3) Sample: Acryl ic denaturat:ion PVC sheet (Trade mark:
Dalpla AV sheet). The thlckne~s i.s 3.0 mm.
(Reeerence color: Y = 73.7, x ~ 0~320, y ~ 0,31~) Result: In case of the formal testing machine As shown in Fig. 7A.
In case of the pre-testing apparatus As shown in Fig. 7B.
; Comparison: As shown in Table 4 (mean magnification:
14.3)-Table 4 _ _ _ ~E Formal testing machine Pre-testing apparatus R/P
R(hours) P(hours) . . _ . _ 4.0 250 25 10.0 8.0 480 3~ 12.6 12.0 740 47 15.7 ¦ 16.0¦ 1000 53 18.9 _ ._ _ (Mean: 14.3) (Example 4) Sample: Polycarbonate ~Trade mark: Daipla Double Skin sheet PD-600). The thickness is 6.0 mm.
(Reference color: Y = 34.9, x = 0.314, y = 0.317) Result: In case of the formal testing machine As shown in Fig. 8A.
In case of the pre-testing apparatus A5 shown in Fig. 8B. 0 Comparison: As shown in Table 5 (mean magnification:
13.8).
Table 5 _ _ ___~__ _ aE Formal testing machlne Pre-testin~ ~pparatus ~/P
R~hour~) P(hours) _. ___ _ 2.0 160 12 13.3 ~.0 320 27 11.9 6.0 500 43 11.6 8.0 1150 63 18.3 (Mean: 13.8) (Example 5) Sample: Polyethylene sheet ~Grade: Hizecks* 5000SF
made by Mitsui Petrochemical Industries, Ltd.).
The thickness is 0.5 mm.
(Reference color: Y = 57.2, x = 0.305, y = 0.309) * Trade mark , Result: In case of the forma] testing machine As shown in Fig. 9A~
In case of the pre-testing apparatus As shown in Fig. 9Bo Comparison: As shown in Table 6 (mean magnification:
10.3)-Table 6 __ ~E Formal testing machine Pre-testing apparatus R/P
R(hours) P~hours) 0.5 220 22 10.0 1.0 500 48 10.4 1.5 920 88 10.5 (Mean: 10.3) As will be clear from the comparison data in Examples 1 to 5, use of the pre-testing method enables data regarding the ultraviolet deterioration of the sample to be obtained in a short time as compared to the case where the formal testing machine was used. The difference between the test times was about 10 to 20 times and the mean value was about 15 times. This result almost coincides with the prediction values calculated from the difference in ultraviolet irradiation intensity per cm2 of the surface to be irradiated. Thus, it was confirmed that the ultraviolet deterioration characteristic of the sample in the case where the pre-testSng method was used has substantially the same tendency as that in the case where the sample was tested by the formal testing machine. The reason for the difference in acceleration of the ultraviolet deterioration in the various kinds of plastic materials is that the absorption characteristics of the ~25~ 24 ultraviolet rays differ due to the molecular structures and first hues of the plastic materials. On the other hand, there is a tendency such that the magnification also becomes large with an increase in ~E. It can be consi-dered that this is because no water is used in the pre-testing apparatus so that the degree of stain on the surface of the sample is less than that in the case where the formal testing machine was used and therefore the ultraviolet deterioration was accelerated.
(( B )) Physical property test B-1) Bending test at a bend angle of 180 After the ultraviolet rays had been irradiated - onto the portion of 30 mm2 of the central portion of the sample having a width of 10 mm and a length of 65 mm by the formal testing machine and by the pre testing appara tllS ~ the degree of physical property deterioration Oe the sample was examined due ~o the repetitive Eol~lng operations at a bend angle o 180.
(Example 6) 20 Samp~e: Polypropylene sheet (Grade: RB-110* made by Tokuyama Soda Co., ~td.). The thickness is 0.2 mm.
(Reference color: Y = 65.5, x = 0.312, y = 0.316) Result and comparison: As shown in Table 7.
* Trade mark ~s~
..
Table 7 , Formal testing machine Pre-testing apparatus Irradiation Degree of Irradiation Degree of time deterioration time deterioration (hours) * (hours) *
_ 500 40 _C
*A : The sample was not cut even when it had been folded 50 times or more.
B : The sample was cut when it had been Eolded 20 times or more.
C : The ~ample wa~ cut when it had been olded once.
B-2) Tensile impact test The test was performed on the basis of ASTMD1822 using the universal impact testing machine made by ToyO
Seiki Mfg. Co., ~td. The ratios of the times regarding formal testing machine and pre-testing apparatus were obtained in a similar manner as in case of the color difference. Then, the acceleration properties (magnifica-tions) of the ultraviolet deterioration were derived.
(Example 7) 30 Sample: Acrylic denaturation PVC sheet (Trade mark~
Daipla AV sheet). The thickness is 3.0 mm.
Result: In case of the formal testing machine As shown in Fig. 1OA.
In case of the pre-testing apparatus As shown in Fig. 1OB.
Comparison: As shown in Table 7 (mean magnification:
7.8) ~2~
- Table 8 Formal test-Pre-testing _ Impact value ing machinea]pparatus R/P
(kg-cm/cm2) R(hours) P~hours) _ 180 120 20 6.0 150 160 26 6.2 110 270 34 8.0 700 65 10.
(Mean: 7.8) ~s will be clear Erom the data in Examples 6 and 7, the u~e of the pre-te~ting method also enables the data regarding the ultraviolet deterioration on the phy~ical property sureace O;e the sample to be obtained in an extremely short time as compared to the case where the formal testing machine was used.
Ultra~iolet irradiation intensity on the surface of the sample: 6 mW/cm2 Black panel temperature: 63 + 3 C
Spray: 18 min/120 min * Trade mark -~2S~24 Also, in this test, the tendency and degree of the ultraviolet deterioration were examined from the changes in color difference and physical property of the sample which had been tested by the above testing apparatus and machine. A discriminating method and the test result in the practical example with regard to each of the color difference test and physical property test will now be explained hereinbelow, respectively.
In the following examples, typical plastic materials were selected as samples and they were tested under the particular conditions as mentioned above. The invention is not limited to these examples.
(( ~ )) Color di~eerence test With respe~ct to the samples at every ti.me ob~lne~
by the above two testing apparatus and machine, the whole color differences before and after the test were obtained and they were plotted in the graph in which an axis of abscissa indicates the time and an axis of ordinate represents the color difference. Each time the same color difference was read and the ratios of the times regarding the formal testing machine and pre-testing apparatus were obtained. Then, the magnifications of the ultraviolet deterioration accelerating properties were derived. For the whole color difference,~ E (color difference) was obtained from CIEL* a* b* which is the colorimetric system on the basis of the International Illumination Commi~tee in 1976. As the color difference meter, CR-100* (Trade mark) made by Minolta Camera Co., Ltd. was used.
~L2~;5~
(Example 1) Sample: Hard transparent PVC sheet containing organic tin. The thickness is 0.4 mm.
The stimulus values of the XYZ system which is the colorimetric system on the basis of the International Commission on Illumination in 1931 are X, Y and Z, while the chromaticity coordinates are x and y, namely:
x = X
X + Y + Z
y = Y
X + ~ + ~
In this example, the reference color is set such that Y ~ 47.4, x ~ 0.307 and y ~ 0~311, wherein, behlnd the sample, a white sheek l~
placed.
Result: In case of the formal testing machine As shown in Fig. 5A.
In case o~ the pre-testing apparatus As shown in Fig. 5B.
Comparison: As shown in Table 2 (mean magnification:
12~7)-Table 2 _ ~E Formal testing machine Pre-testin~ apparatus R/P
R(hours) P(hours) _ _ .
42 o 450 35 132 97 308.0 920 76 12.1 10.0 1000 84 11.9 ___ (Mean: 12.7) -As will be clear from the above experimental exam ple, the use of the pre-testing apparatus enables the data regarding the ultraviolet deterioration of the sample to be obtained in a short time compared to the case where the formal testing machine was used. The difference between the test times was approximately a multiple of thirteen.
This result nearly coincides with the prediction value calculated from the difference in ultraviolet irradiation intensity per cm2 of the surface to be irradiated. Thus, it was confirmed that the ultraviolet deterioration characteristic of the sample in the case where the pre-testing apparatus was used has substantially the same tendency as that in the case where the sample was tested by the formal testing machine. In addition, the sample was maintained at a temperature below about 65C during the test and even in case of the hard vinyl chloride or the like, deformatlon or the like due to the heat was not caused at all.
tExample 2) 20 Sample: ABS sheet (Grade: A-322 made by Toray Industries, Inc., Natural). The thickness is 2.0 mm.
(Reference color: Y = 62.5, x = 0.328, y = 0.342) 25 Result: In case of the formal testing machine As shown in Fig. 6A.
In case of the pre-testing apparatus As shown in Fig. 6B.
Comparison: As shown in Table 3 (mean magnification:
15-4)-.
~ 9 Table 3 AE Formal testing machine Pre-testing apparatus R~P
R(hours) P(hours) _ . .
2.0 30 2 15.0 4.0 70 5 14~0 8.0 160 11 14,5 10.0 270 15 ~ a . o (Mean: 15.4) (Example 3) Sample: Acryl ic denaturat:ion PVC sheet (Trade mark:
Dalpla AV sheet). The thlckne~s i.s 3.0 mm.
(Reeerence color: Y = 73.7, x ~ 0~320, y ~ 0,31~) Result: In case of the formal testing machine As shown in Fig. 7A.
In case of the pre-testing apparatus As shown in Fig. 7B.
; Comparison: As shown in Table 4 (mean magnification:
14.3)-Table 4 _ _ _ ~E Formal testing machine Pre-testing apparatus R/P
R(hours) P(hours) . . _ . _ 4.0 250 25 10.0 8.0 480 3~ 12.6 12.0 740 47 15.7 ¦ 16.0¦ 1000 53 18.9 _ ._ _ (Mean: 14.3) (Example 4) Sample: Polycarbonate ~Trade mark: Daipla Double Skin sheet PD-600). The thickness is 6.0 mm.
(Reference color: Y = 34.9, x = 0.314, y = 0.317) Result: In case of the formal testing machine As shown in Fig. 8A.
In case of the pre-testing apparatus A5 shown in Fig. 8B. 0 Comparison: As shown in Table 5 (mean magnification:
13.8).
Table 5 _ _ ___~__ _ aE Formal testing machlne Pre-testin~ ~pparatus ~/P
R~hour~) P(hours) _. ___ _ 2.0 160 12 13.3 ~.0 320 27 11.9 6.0 500 43 11.6 8.0 1150 63 18.3 (Mean: 13.8) (Example 5) Sample: Polyethylene sheet ~Grade: Hizecks* 5000SF
made by Mitsui Petrochemical Industries, Ltd.).
The thickness is 0.5 mm.
(Reference color: Y = 57.2, x = 0.305, y = 0.309) * Trade mark , Result: In case of the forma] testing machine As shown in Fig. 9A~
In case of the pre-testing apparatus As shown in Fig. 9Bo Comparison: As shown in Table 6 (mean magnification:
10.3)-Table 6 __ ~E Formal testing machine Pre-testing apparatus R/P
R(hours) P~hours) 0.5 220 22 10.0 1.0 500 48 10.4 1.5 920 88 10.5 (Mean: 10.3) As will be clear from the comparison data in Examples 1 to 5, use of the pre-testing method enables data regarding the ultraviolet deterioration of the sample to be obtained in a short time as compared to the case where the formal testing machine was used. The difference between the test times was about 10 to 20 times and the mean value was about 15 times. This result almost coincides with the prediction values calculated from the difference in ultraviolet irradiation intensity per cm2 of the surface to be irradiated. Thus, it was confirmed that the ultraviolet deterioration characteristic of the sample in the case where the pre-testSng method was used has substantially the same tendency as that in the case where the sample was tested by the formal testing machine. The reason for the difference in acceleration of the ultraviolet deterioration in the various kinds of plastic materials is that the absorption characteristics of the ~25~ 24 ultraviolet rays differ due to the molecular structures and first hues of the plastic materials. On the other hand, there is a tendency such that the magnification also becomes large with an increase in ~E. It can be consi-dered that this is because no water is used in the pre-testing apparatus so that the degree of stain on the surface of the sample is less than that in the case where the formal testing machine was used and therefore the ultraviolet deterioration was accelerated.
(( B )) Physical property test B-1) Bending test at a bend angle of 180 After the ultraviolet rays had been irradiated - onto the portion of 30 mm2 of the central portion of the sample having a width of 10 mm and a length of 65 mm by the formal testing machine and by the pre testing appara tllS ~ the degree of physical property deterioration Oe the sample was examined due ~o the repetitive Eol~lng operations at a bend angle o 180.
(Example 6) 20 Samp~e: Polypropylene sheet (Grade: RB-110* made by Tokuyama Soda Co., ~td.). The thickness is 0.2 mm.
(Reference color: Y = 65.5, x = 0.312, y = 0.316) Result and comparison: As shown in Table 7.
* Trade mark ~s~
..
Table 7 , Formal testing machine Pre-testing apparatus Irradiation Degree of Irradiation Degree of time deterioration time deterioration (hours) * (hours) *
_ 500 40 _C
*A : The sample was not cut even when it had been folded 50 times or more.
B : The sample was cut when it had been Eolded 20 times or more.
C : The ~ample wa~ cut when it had been olded once.
B-2) Tensile impact test The test was performed on the basis of ASTMD1822 using the universal impact testing machine made by ToyO
Seiki Mfg. Co., ~td. The ratios of the times regarding formal testing machine and pre-testing apparatus were obtained in a similar manner as in case of the color difference. Then, the acceleration properties (magnifica-tions) of the ultraviolet deterioration were derived.
(Example 7) 30 Sample: Acrylic denaturation PVC sheet (Trade mark~
Daipla AV sheet). The thickness is 3.0 mm.
Result: In case of the formal testing machine As shown in Fig. 1OA.
In case of the pre-testing apparatus As shown in Fig. 1OB.
Comparison: As shown in Table 7 (mean magnification:
7.8) ~2~
- Table 8 Formal test-Pre-testing _ Impact value ing machinea]pparatus R/P
(kg-cm/cm2) R(hours) P~hours) _ 180 120 20 6.0 150 160 26 6.2 110 270 34 8.0 700 65 10.
(Mean: 7.8) ~s will be clear Erom the data in Examples 6 and 7, the u~e of the pre-te~ting method also enables the data regarding the ultraviolet deterioration on the phy~ical property sureace O;e the sample to be obtained in an extremely short time as compared to the case where the formal testing machine was used.
Claims (4)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A pre-testing method for a weathering test comprising the steps of:
irradiating a plurality of samples with radiation that is generated by a metal halide lamp containing mainly halide of iron enclosed together with mercury and rare gas and that is filtered by a filter that substantially removes wavelength components other than ultraviolet wavelengths, the filtered radiation having an energy level sufficient to deteriorate said samples in a short time;
maintaining said samples at a temperature that is low enough to prevent substantial heat deterioration of said samples during said irradiating; and selecting from said plurality of samples a sample which should be subjected to the weathering test in accordance with the degree of the deterioration.
irradiating a plurality of samples with radiation that is generated by a metal halide lamp containing mainly halide of iron enclosed together with mercury and rare gas and that is filtered by a filter that substantially removes wavelength components other than ultraviolet wavelengths, the filtered radiation having an energy level sufficient to deteriorate said samples in a short time;
maintaining said samples at a temperature that is low enough to prevent substantial heat deterioration of said samples during said irradiating; and selecting from said plurality of samples a sample which should be subjected to the weathering test in accordance with the degree of the deterioration.
2. A pre-testing method according to claim 1, wherein the filtered radiation is constituted substantially of wavelengths of about 290 to 460 nm and the irradiation intensity level of the samples is at least 50 mW/cm2.
3. A pre-testing method according to claim 1, wherein the filter is water cooled and substantially removes wavelength components other than ultraviolet wavelengths of about 290 to 460 nm.
4. A pre-testing method according to claim 1, wherein said temperature maintaining step comprises cooling said samples with an airstream.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000541307A CA1255924A (en) | 1983-11-30 | 1987-07-03 | Pre-testing method and apparatus for a weathering test |
Applications Claiming Priority (6)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP224403/1983 | 1983-11-30 | ||
| JP22440383A JPS60117128A (en) | 1983-11-30 | 1983-11-30 | Pretesting method of weather proof test |
| JP224404/1983 | 1983-11-30 | ||
| JP22440483A JPS60117129A (en) | 1983-11-30 | 1983-11-30 | Pretester for weather proof test |
| CA000468814A CA1250762A (en) | 1983-11-30 | 1984-11-28 | PRELIMINARY TEST METHOD, AND WEATHER TESTING DEVICE |
| CA000541307A CA1255924A (en) | 1983-11-30 | 1987-07-03 | Pre-testing method and apparatus for a weathering test |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000468814A Division CA1250762A (en) | 1983-11-30 | 1984-11-28 | PRELIMINARY TEST METHOD, AND WEATHER TESTING DEVICE |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1255924A true CA1255924A (en) | 1989-06-20 |
Family
ID=27167479
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000541307A Expired CA1255924A (en) | 1983-11-30 | 1987-07-03 | Pre-testing method and apparatus for a weathering test |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1255924A (en) |
-
1987
- 1987-07-03 CA CA000541307A patent/CA1255924A/en not_active Expired
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