Significance and Use

Materials made from photodegradable plastics are intended to show relatively rapid deterioration of chemical, physical, and mechanical properties when exposed to light, heat, and water after fulfilling their intended purpose. This practice is intended to induce property changes associated with conditions that might be experienced when the material is discarded as litter, including the effects of sunlight, moisture, and heat. The exposure used in this practice is not intended to simulate the deterioration caused by localized weather phenomena such as atmospheric pollution, biological attack, and salt water exposure.

Cautions Variation in results may be expected when operating conditions are varied within the accepted limits of this practice. Therefore, no reference to the use of this practice should be made unless accompanied by a report prepared in accordance with Section 9 that describes the specific operating conditions used. Refer to Practice G 151 for detailed information on the caveats applicable to use of results obtained in accordance with this practice.

Note 3Additional information on sources of variability and on strategies for addressing variability in the design, execution and data analysis of laboratory accelerated exposure tests is found in Guide G 141 .

Exposure of a similar material of known performance (a control) at the same time as the test specimens provides a standard for comparative purposes. Use of a control to rank the stability of test materials greatly improves agreement between different laboratories. ^, It is recommended that at least three replicates of each material evaluated be exposed to allow for statistical evaluation of results.

Test results will depend upon the care that is taken to operate the equipment in accordance with Practice G 154 . Significant factors include regulation of line voltage, temperature of the room in which the device operates, temperature control, and condition and age of the lamps.

1. Scope

1.1 This practice covers the specific procedures applicable for fluorescent Ultraviolet (UV) exposure of photodegradable plastics conducted in accordance with Practices G 151 and G 154 . This practice also covers the preparation of test specimens and the evaluation of test results.

Note 1Previous versions of this practice referenced fluorescent UV devices described by Practice G 53 , which described very specific equipment designs. Practice G 53 has been withdrawn and replaced by Practice G 151 , which describes performance criteria for all exposure devices that use laboratory light sources and by Practice G 154 , which gives requirements for exposing nonmetallic materials in fluorescent UV devices.

1.2 Practice D 4329 covers fluorescent UV exposures of plastics intended for long term use in outdoor applications.

1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only.

1.4 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

Note 2There is no known ISO equivalent to this practice.

2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.

ASTM Standards

D3826 Practice for Determining Degradation End Point in Degradable Polyethylene and Polypropylene Using a Tensile Test

D4329 Practice for Fluorescent UV Exposure of Plastics

D5870 Practice for Calculating Property Retention Index of Plastics

E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method

G53 Practice for Operating Light-and Water-Exposure Apparatus (Fluorescent UV-Condensation Type) for Exposure of Nonmetallic Materials

G113 Terminology Relating to Natural and Artificial Weathering Tests of Nonmetallic Materials

G141 Guide for Addressing Variability in Exposure Testing of Nonmetallic Materials

G147 Practice for Conditioning and Handling of Nonmetallic Materials for Natural and Artificial Weathering Tests

G151 Practice for Exposing Nonmetallic Materials in Accelerated Test Devices that Use Laboratory Light Sources

G154 Practice for Operating Fluorescent Light Apparatus for UV Exposure of Nonmetallic Materials

G169 Guide for Application of Basic Statistical Methods to Weathering Tests

Keywords

degradation; exposure; fluorescent UV; light exposure; ultraviolet; Degradation--plastics; Fluorescent UV-light apparatus; Light exposure--plastics; Photodegradation; Ultraviolet (UV) analysis--plastics ;

ICS Code

ICS Number Code 83.080.01 (Plast in general)

DOI: 10.1520/D5208-09

ASTM International is a member of CrossRef.

ASTM D5208