ASTM D5208-01 “Standard Operating Rules for Fluorescent Ultraviolet Exposure of Photodegradable Plastics” covers the specific standard operating rules for fluorescent ultraviolet exposure of Photodegradable plastics in ASTM G151 and G154, and also includes the preparation of relevant experimental materials and the analysis of experimental results.
These rules of practice are described in ASTM book No. D5208; The number after the book number indicates the year in which the operating rule was first adopted, or the time when a new revision of the operating rule was published. The number in parentheses indicates the year in which the operating rule was newly approved. The superscript ε indicates an editorial change since the last edition or review.

1. Scope *
1.1 This code of practice covers the specific standard operating rules of ASTM G151 and G154 for fluorescent UV exposure of photodegradable plastics, and also includes the preparation process of relevant experimental materials and the analysis of experimental results.

Note 1 — The previous version of this operating rule referred to the fluorescent ultraviolet instrument described in the G53 operating Rule. The G53 operating rule has been replaced by the G151 operating rule, which describes the performance standards for all exposure meters using laboratory light sources, and the G154 operating rule, which specifies the requirements for non-metallic exposure materials for fluorescent UV meters.

1.2 ASTM standard D4329 describes the fluorescent UV exposure of plastics used for outdoor use for a long time.

1.3 The values expressed in SI units are the standard, and the values of other units in parentheses are for reference only.

1.4 This operating rule does not cover all safety problems that may occur in its use. It is the responsibility of the user of these operating rules to establish safe and healthy operating rules and to determine the applicability of each rule in the standard before use.

Note 2 — There is currently no ISO standard corresponding to this code of practice.

ASTM D5208-01-0 Standard Operating Rule for Fluorescent Ultraviolet Exposure of Photodegradable Plastics

2. References
2.1 ASTM Standard:

D3826 Code of Practice for determining degradation endpoints of degradable polyolefin by tensile test 2

D3980 Code of Practice for inter-laboratory testing of paints and related materials 3

D5870 Operation rule 4 for calculating the retention index of plastic properties

E691 Operating rules for the study of precision determination of an experimental method between laboratories 5

G53 Code of Practice for determining the Exposure of Nonmetallic Materials by light or water exposure meters

G113 Terms for natural and artificial weathering tests of non-metallic materials 7

G141 Guidelines for determining the variability of nonmetallic materials in exposure tests 7

G147 Non-metallic materials are treated to comply with Rule 7 of operation for natural and artificial weathering tests

G151 Operating Rules for exposure of non-metallic materials with the help of an accelerated tester applying a laboratory light source 7

G154 Operating rules for UV exposure of non-metallic materials using fluorescent apparatus 7

G169 Guidelines for the application of basic statistical methods in weathering tests 7

ASTM D5208-01-0 Standard Operating Rule for Fluorescent Ultraviolet Exposure of Photodegradable Plastics

Step 3: Terminology
3.1 The terms defined in G113 shall apply to these Operating Rules.

4. Significance and application
4.1 Various materials made from photodegradable plastics can be exposed to sunlight, heat and water after use, and show relatively rapid chemical, physical and mechanical degradation properties. The purpose of this operating rule is to estimate the performance changes of materials under environmental factors (including sunlight, moisture and heat effects) when they become garbage. The exposure used in this practice does not simulate degradation due to local climatic phenomena such as atmospheric pollution, biological invasion, and saline-water infiltration.

4.2 Note — When the conditions in the actual operation do not meet the criteria defined in this operation rule, the results obtained shall be corrected. Therefore, this operating rule is not to be referred to unless there is a report indicating that the test conditions are consistent with the specific operating conditions described in Part 9 of this operating Rule. Please refer to G151 Operating Rules for specific precautions regarding the use of the results obtained by this operating Rule.

Note 3 – For more information on sources of variability in the design, conduct, and data analysis of laboratory accelerated exposure tests and on addressing these variability, see Guide G141.

4.3 When the test samples are tested, the exposure of a similar material with known performance (reference group) is used as the comparison standard. The use of a set of references to ensure the stability of the test material is beneficial to improve the consistency of different laboratories. It is recommended to conduct at least three exposure tests for each material to be determined to facilitate statistical analysis of the results.

4.4 Test results depend on how carefully the instrument is operated according to G154 operating rules. Important factors include the degree of DC voltage stability, the room temperature at which the instrument operates, the temperature control, and the condition and life of the lamp.

ASTM D5208-01-0 Standard Operating Rule for Fluorescent Ultraviolet Exposure of Photodegradable Plastics

Step 5: Instrument
5.1 This operating rule requires the use of the fluorescent ultraviolet meter specified in G151 and G154 operating rules.

5.2 The spectral energy distribution of the fluorescent UV instrument lamp shall meet the requirements of UVA 340 lamp in G154 operation rules.

5.3 Location of the test and measurement chamber

5.3.1 Place the instrument at a temperature between 18℃ and 27℃(65℉ and 80℉). The ambient temperature is measured from a position not more than 150mm(6in.) away from the instrument measuring room door. Because the heat generated by the lower instrument can affect the operation of the upper instrument, controlling the ambient temperature is especially important when two instruments are stacked on top of each other.

5.3.2 Place the instrument at least 300mm away from the wall or other instruments. Do not place the instrument near a heat source, such as an oven, etc.

5.3.3 Ventilate the room where the instrument is placed to remove heat and moisture.

ASTM D5208-01-0 Standard Operating Rule for Fluorescent Ultraviolet Exposure of Photodegradable Plastics

6. Test samples
6.1 The size and shape of the sample to be exposed is determined by the specifics of the particular test method used to evaluate the exposure effect of the material; The method of trial is determined by the participants involved. In practice, it is recommended to use a sample of a size suitable for the material chamber and bracket of the insolator. The portion of the sample obscured by the support of the measuring chamber should be minimized unless a specific background for the test digital portion is provided. This unexposed surface cannot be used as part of the test area.

6.2 For samples of insulating materials, such as foam, the maximum thickness of the sample should be 20mm in order to have sufficient heat effect.

6.3 To obtain toughness, the soft sample was attached to an aluminum pad with a thickness of 0.635mm(0.025in.). Aluminum alloy 5052,6061 or 3003 is recommended.

6.4 Glue holes larger than 2mm in the sample and openings larger than 1mm in the irregularly shaped sample to prevent loss of water pressure. The porous sample was attached to a solid aluminum gasket that served as a pressure barrier.

6.5 In addition to other special circumstances, the samples and reference materials of each test shall be exposed to the sun at least 3 times.

6.6 Follow the procedures described in G147 Operating Rules before, during, and after exposure. The identification, handling and standardization of test samples, references, reference materials are specified in G147.

6.7 In order to display the effect of different exposure times on the dashboard, please do not cover the surface of the sample. This method can also lead to some erroneous results, because the covered part of the sample will still be exposed to the temperature and humidity of the test, which will affect the results.

6.8 As the thickness of the sample will greatly affect the results of the test, the samples of the test group and the control group can only be allowed to fluctuate by 10% above and below the specified size.

6.9 Keep one unexposed sample for all materials tested.

6.10 Samples should be placed outside the insolator for more than 24 hours before being put into the insolator for other tests to avoid the phenomenon that all materials will produce the same results due to continuous testing. All discontinuities should be recorded in the report as introduced in Section 9 of this article.

Note 4 — As the stability of the sample may also change over time, users are reminded that the difference between the exposed sample and the standard sample may not be correct if the exposure period is extended or due to errors allowed by the test. Instrumental measurements are recommended in all cases.

ASTM D5208-01-0 Standard Operating Rule for Fluorescent Ultraviolet Exposure of Photodegradable Plastics

7. Operation process
7.1 When the test and reference samples are not completely filled with the sample holder, empty panels are used to fill the remaining space to ensure the test conditions of the measurement chamber.

7.2 Except for special circumstances, the irradiation dose should be controlled to 340nm wavelength, 0.78±0.02W/(㎡•nm)

Note 5 — 0.78±0.12W/(㎡•nm) at a wavelength of 340nm in an instrument without exposure control operated by a non-insulated black panel at 50±3 ° C.

7.3 Except under special circumstances, use any of the following test procedures to continuously operate the instrument.

7.3.1A Operation process — Control the temperature of the non-insulated black plate to 50±3℃ and irradiate it under UV for 20 hours. The temperature of the non-insulated black plate was controlled to 40±3 ° C for 4 hours.

7.3.2B Operation process — Control the temperature of the non-insulated black plate to 50±3℃ and irradiate it under UV for 4 hours. The temperature of the non-insulated black plate was controlled to 40±3 ° C for 4 hours.

7.3.3C Operation process — Control the temperature of the non-insulated black plate to 50±3℃, and continuously irradiate under ultraviolet light.

The values and errors specified in Notes 6 — 7.2 and in operation A, B, and C only represent the values controlled under equilibrium conditions at one point in the cabinet and do not indicate the consistency of such conditions at all locations in the cabinet. ASTM Committee G03 is engaged in the study of these errors and demonstrates their consistency.

7.3.4 It is critical that the materials to be subjected to toxicity testing after exposure should be subjected to Operation C, as the use of operation A and B will remove the photochemical degradation by-products.

7.4 Except for special cases, the sample is rearranged as follows to reduce the effect caused by the instability of temperature and UV light line.

7.4.1 The samples should be transversely rearranged at least every three days by (1) moving the two rightmost sample tanks to the left of the exposed area; (2) Then shift the other sample tanks to the right.

7.4.2 Arrange the samples longitudinally so that the exposure time of each sample in each longitudinal position in the sample tank is the same. For example, if two samples are close together lengthwise, then the upper and lower samples should switch places halfway through the experiment. If there are four types of samples arranged lengthwise, then the samples should be rearranged lengthwise three times during the experiment.

7.5 Each reference sample shall be described in the report.

ASTM D5208-01-0 Standard Operating Rule for Fluorescent Ultraviolet Exposure of Photodegradable Plastics

8. Analysis of exposure time and test results
8.1 A standard or specification that is generally applicable, if a specified level of performance is required to be achieved within a specified period of time after exposure or after radiation exposure in accordance with these rules, shall be based on the results of cyclic testing, by which the repeatability of the test can be determined by the process of exposure and performance measurement. Please perform the cyclic test in accordance with Practice E691 or Method D3980 and provide a representative statistical sample from any laboratory or organization that can properly perform exposure and performance test tests. The accuracy and deviation section of this rule contains the results of a cycle method test.

8.1.1 Any standard or specification between two or three participants that requires a defined level of performance to be achieved after a specified period of time or after radiation exposure in accordance with this Rule shall be based on the results of two relatively independent experiments in each laboratory, By this method, the repeatability of the test can be determined by the test process of exposure and performance measurement. The exposure/PERFORMANCE testing process is then used to determine a minimum level of post-exposure performance acceptable to each participant.

8.2 If the repeatability of the results of exposure tests conducted in accordance with these rules is not determined by cyclic testing, the performance requirements of the material may be determined by comparison with the reference material. Reference materials and experimental materials should be exposed in the same equipment at the same time. At the same time, the participants concerned shall use the reference materials of the agreement.

8.2.1 Error analysis can be used to determine whether there is a significant statistical difference between the experimental and reference materials. Significant differences in statistics can be determined by repeated exposure tests of experimental and reference samples.

Note 7 – Fischer gives a detailed description of the use of grade comparisons between test and reference samples.

Note 8 – The G169 guide gives examples of error analysis for material comparisons.

8.3 In most cases, periodic evaluation of test and reference materials is necessary to determine the magnitude and trend of change from exposure time or effects of radiation exposure.

8.4 The time or radiation exposure required to produce a certain change in material properties may be used to evaluate and assess the stability of the material. This method is more commonly used than the analysis of material changes after any period of exposure or radiation exposure.

8.4.1 With the consent of the relevant participants, the method of analyzing the changes of the material after any period of exposure or radiation exposure can also be used.

8.5 Evaluate the exposure test sample or determine the size of the change according to the corresponding rules of ASTM.

8.5.1 When testing degradable polyethylene and polypropylene, determine the end point of degradation according to operating Rule D3826.

8.5.2 Polyethylene or polypropylene materials are not considered photodegradable in accordance with EPA 40 Regulation CFR Part 238 if, for the purposes of this practice Rule determination, A light exposure of Operation A over 250 light load is used and the degradation endpoint is determined by Operation Rule D3826.

Note 9 — For some materials, the material will continue to change after the sample is removed from the insolator. Some measurement (either visual or instrumental) should be taken at a standardized time period or at a time period agreed upon by the relevant participants. Test conditions should be considered before testing when determining the standardized time period.

8.6 Comparison of the results of reference and experimental samples by error analysis.

ASTM D5208-01-0 Standard Operating Rule for Fluorescent Ultraviolet Exposure of Photodegradable Plastics

9. Experiment report
9.1 Write the following information in the report:

9.1.1 Type and model of exposure meter,

9.1.2 The service life of the fluorescent lamp before the exposure test, and whether the lamp tube has been replaced during the exposure process,

9.1.3 If necessary, indicate the measured amount of luminescence (in W/(㎡•nm)) and radiant energy (in J/(㎡•nm)) at a single wavelength. Do the test in a wide band, such as 300-400nm wavelength, indicate the spectral illumination (unit W/ ㎡) and radiation exposure (unit J/ ㎡), and indicate the spectral band measured in detail.

9.1.3.1 It is not necessary to indicate spectral illuminance and radiation exposure unless direct testing has been carried out during exposure.

9.1.4 Duration of interruption,

9.1.5 Water condensation or moisture cycling under light and dark conditions,

9.1.6 Operating temperature of non-insulated black plate

9.1.7 The humidity at the time of operation shall be indicated if required,

9.1.8 If the sample rearrangement process is different from that described in 7.3, it shall be indicated,

9.1.9 Results of performance tests. When writing the report, the holding force of the specific performance shall be calculated according to operating rule D5870.

ASTM D5208-01-0 Standard Operating Rule for Fluorescent Ultraviolet Exposure of Photodegradable Plastics

10. Accuracy and bias
10.1 Accuracy

10.1.1 The repeatability and reproducibility of exposure test results obtained in accordance with this operating rule are determined by a number of factors, including the test material, the properties of the tested material, and the specific test conditions and procedures. Special attention should be paid to the repeatability of the exposure test/performance test process when describing the product in accordance with this operating code.

10.1.2 E691 Rules of Operation describes the cyclic method and its analysis method. According to the cyclic method, Table 1 shows the repeatability of the exposure test results of three degradable polyolefin using tensile elongation.

Note 10 — In this cyclic test, six laboratories performed exposure tests on three different materials (which were provided by TWO laboratories). Each participating laboratory performed exposure tests on five replicates of samples. The samples were then sent back to the original laboratory for tensile tests. For a complete introduction to the circular method, please contact the person responsible for plastics in ASTM Committee D20.

10.2 Deviation

10.2.1 As there is no standard weathering reference material available for use, the deviation cannot be determined.

ASTM D5208-01-0 Standard Operating Rule for Fluorescent Ultraviolet Exposure of Photodegradable Plastics

11. Keywords
11.1 Degradation; Exposure to sun; Fluorescent ultraviolet light; Light exposure; Ultraviolet light.

The results of the cyclic method test

Table 1 Results of the cyclic method test

A ECO material is a polyethylene/carbon monoxide copolymer that degrades under UV exposure.

B Procedure A of this SOPS is used for the exposure test cycle method.

C LLPDE and white LLDPE are brown low-density thin polyethylene containing an additive that promotes photodegradation. The color of Clear LLDPE is natural, while white LLDPE contains TiO2 and appears white.

Note: * SEE the final section of this standard for a summary of the changes.

ASTM Committee D20 on Plastics is directly responsible for subcommittee D20.96 on environmentally degradable plastics. The current version was reviewed and approved on December 10, 2001 and published in February 2002. The original version, D5208-91, was discontinued in 2000 and renamed D5208-01.

Astm Standard Manual, Volume 08.02.

3 has been terminated; See 1997 ASTM Manual of Standards, volume 06.01.

Astm Manual of Standards, Volume 08.03.

Astm Manual of Standards, Volume 14.02.

6 has been terminated; See 2001 ASTM Manual of Standards, Volume 14.04.

Astm Standard Manual, Volume 14.04.

8 Fischer, R., “Results of Round Robin Studies of light-and Water-Exposure Standard Practices,” Accelerated and

Outdoor Durability Testing of Organic Materials, ASTM STP 1202, Warren D. Ketola and Douglas Grossman, Eds., American Society for Testing and Materials, Philadelphia, 1993

9 Ketol, W. , and Fischer, R. , “Characterization and Use of Reference Materials in Accelerated Durability Tests,” VAMAS Technical Report No.30.Available from NIST, Gaithersburg, MD.

10 Fischer, R., Ketol, W. , “Impact of Research on Development of ASTM Durability Testing Standards,” Durability Testing of Non-Metallic Materials, ASTM STP 1294, Robert Herling, Editor, American Society for Testing and Materials, Philadelphia, 1995

ASTM D5208-01-0 Standard Operating Rule for Fluorescent Ultraviolet Exposure of Photodegradable Plastics

Summary of changes

This part indicates the location of changes in these rules. For the convenience of the reader, the D-20 Association highlights changes that may affect the use of these rules. This section will describe the content of the rule change or the reasons for the change, or both.

D 5208-01:

(1) Standards for renaming

(2) Fully revised version

ASTM D5208

The American SOCIETY FOR Testing MATERIALS does not recognize the validity of patent rights in connection with any item in these Rules. Users of these Rules are expressly advised that the decision on the legality of any such patent right, and the risk of infringement of such right, is solely the responsibility of the user.

This standard shall be revised at any time by the technical committee for which it is responsible and shall be revised every five years or, if not revised, re-approved or withdrawn. Your comments will be accepted in this revision or will be sent to ASTM headquarters as additional rules. Your comments will be carefully considered at a meeting of the Technical Committee, which you may also participate in. If you feel that your proposal has not been notarized, you may send a letter to ASTM at the address below to let ASTM know what you think.