GB/T 3681.1-2021Plastics - Methods of exposure to solar radiation - Part 1: General guidance (English PDF)

Foreword

This document is drafted in accordance with GB/T 1.1-2020 "Directives for

standardization - Part 1: Rules for the structure and drafting of standardizing

documents".

This document is Part 1 of GB/T 3681 "Plastics - Methods of exposure to solar

radiation". GB/T 3681 has issued the following parts:

- Part 1: General guidance;

- Part 2: Direct weathering and exposure behind window glass.

This document, as the general guidance of GB/T 3681, replaces the general technical

content of relevant guidance test method A, method B and method C in GB/T 3681-

2011 "Plastics - Methods of exposure to direct weathering, to weathering using glass-

filtered daylight, and to intensified weathering by daylight using Fresnel mirrors".

Compared with GB/T 3681-2011, in addition to structural adjustment and editorial

changes, the main technical changes are as follows:

a) Change the content of "Terms and definitions" (see Clause 3; Clause 3 of the 2011

edition);

b) Change the specific requirements for inert materials and backings in "Apparatus"

(see 5.1; 5.1 of the 2011 edition);

c) Change the requirements for apparatus for measurement of radiant exposure and

its calibration, which shall comply with ISO 9370 (see 5.2.1; 5.5.1 of the 2011

edition);

d) Change the passband of total-ultraviolet radiometers from "300 nm ~ 400 nm" to

"290 nm ~ 400 nm" (see 5.2.1.4 and 8.3.2.3; 5.5.1.3 and 8.2.1.2 of the 2011

edition);

e) Change the content of "Other climate-measuring instruments" (see 5.2.2; 5.5.3 of

the 2011 edition);

f) Add "Conditions of exposure of the test specimens" and "Mounting of reference

materials" (see Clause 7 and 9.2);

g) Delete "Blue wool reference sample", "Mounting of pyranometer and material

standard", and "Use blue wool reference sample to test radiant exposure" (see

8.2.2, 9.2, Annex A of the 2011 edition);

h) Change the contents of "Expression of exposure stages" and "Climate conditions"

(see 10.2 and 10.3; 10.2 of the 2011 edition);

I) Add "Classification of climates" (see Annex A);

j) Delete "Climate divisions and climatic characteristics of China" (see Annex B of

the 2011 edition).

This document is identical to ISO 877-1:2009 "Plastics - Methods of exposure to solar

radiation - Part 1: General guidance".

The following minimal editorial changes have been made to this document:

- To explain the term "fillet", add Note 1 to 9.1;

- To provide the benchmark climate regions in China, add Note 2 to Table A.1 of

Annex A.

Attention is drawn to the possibility that some of the elements of this document may be

the subject of patent rights. The issuing authority of this document shall not be held

responsible for identifying any or all such patent rights.

This document was proposed by China Petroleum and Chemical Industry Federation.

This document shall be under the jurisdiction of National Technical Committee 15 on

Plastic of Standardization Administration of China (SAC/TC 15).

Drafting organizations of this document: Guangzhou Research Institute of Synthetic

Materials, Beijing Tiangang Auxiliary Co., Ltd., Shandong Dawn Polymer Co., Ltd.,

Polyrocks Chemical Co., Ltd., Heilongjiang Xinda Enterprise Group Co., Ltd., Shaanxi

Yanchang Jingwei New Material Technology Industrial Park Co., Ltd.,

Guangdong Huabiao Testing Center Co., Ltd., Atlas Material Testing Technology Co.,

Ltd., Orinko Advanced Plastics Co., Ltd.

Main drafters of this document: Ma Mei, Liu Gang, Zhao Lei, Tie Wen'an, Zhu

Hongfang, Yang Xin, Xie Xinhong, Cheng Ge, Wu Luo, Li Jing, Chen Xintai, Tian

Xiaoyan, Zhang Yanli, Cao Lingling.

This document was first issued in 1983; and first revised in 2000. The second revision

in 2011 incorporated the content of GB/T 14519-1993 "Plastics - Method of exposure

to indirect weathering using glass-filtered daylight". This is the third revision.

Plastics - Methods of exposure to solar radiation - Part 1:

General guidance

1 Scope

This document provides information and general guidance on the selection and use of

the methods of exposure to solar radiation described in detail in GB/T 3681. These

methods of exposure to solar radiation are applicable to plastics materials of all kinds

as well as to products and portions of products.

This document also specifies methods for determining radiant exposure.

This document does not include direct weathering using black-box test fixtures, which

simulate higher end-use temperatures in some applications.

Note: ASTM G7 and ASTM D4141 describe black-box exposure tests.

2 Normative references

The contents of the following documents, through normative references in this text,

constitute indispensable provisions of this document. Among them, for dated references,

only the edition corresponding to that date applies to this document. For undated

references, the latest edition (including all amendments) applies to this document.

GB/T 3681.2-2021 Plastics - Methods of exposure to solar radiation - Part 2: Direct

weathering and exposure behind window glass (ISO 877-2:2009, IDT)

ISO 291 Plastics - Standard atmospheres for conditioning and testing

Note: GB/T 2918-2018 Plastics - Standard atmospheres for conditioning and testing (ISO

291:2008, MOD)

ISO 472 Plastics - Vocabulary

Note: GB/T 2035-2008 Terms and definitions for plastics (ISO 472:1999, IDT)

ISO 877-3 Plastics - Methods of exposure to solar radiation - Part 3: Intensified

weathering using concentrated solar radiation

ISO 2818 Plastics - Preparation of test specimens by machining

Note: GB/T 39812-2021 Plastics - Preparation of test specimens by machining (ISO 2818:2018,

IDT)

ISO 4582 Plastics - Determination of changes in colour and variations in properties

after exposure to glass-filtered solar radiation, natural weathering or laboratory

radiation sources

Note: GB/T 15596-2021 Plastics - Determination of changes in colour and variations in

properties after exposure to glass-filtered solar radiation, natural weathering or laboratory

radiation sources (ISO 4582:2017, IDT)

ISO 4892-1 Plastics - Methods of exposure to laboratory light sources - Part 1:

General guidance

Note: GB/T 16422.1-2019 Plastics - Methods of exposure to laboratory light sources - Part 1:

General guidance (ISO 4892-1:2016, IDT)

ISO 9370 Plastics - Instrumental determination of radiant exposure in weathering

tests - General guidance and basic test method

ASTM G179 Standard Specification for Metal Black Panel and White Panel

Temperature Devices for Natural Weathering Tests

ASTM G183 Standard Practice for Field Use of Pyranometers, Pyrheliometers and

UV Radiometers

3 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO 472 and ISO

9370 apply.

Note: ASTM G113 defines terms used for artificially accelerated and natural weathering exposures.

Submission of these definitions has been proposed for inclusion in ISO 472 and/or ISO 9370,

or ISO 877, as appropriate.

4 Principle

Specimens meeting the test provisions or sheets or other shapes from which specimens

can be cut, are exposed to direct natural solar radiation (GB/T 3681.2-2021, method A),

or to window-glass-filtered solar radiation (GB/T 3681.2-2021, method B) or to

intensified solar radiation using a Fresnel-reflecting concentrator (ISO 877-3). After the

prescribed exposure period, the specimens are removed from exposure and, if a

characterization is required, tested for changes in optical, mechanical or other properties

of interest. The exposure stage may be a given period of time or may be expressed in

terms of a given total radiant exposure or UV radiant exposure. The latter is preferred

whenever the main objective of the exposure is to determine resistance to solar radiation,

since it minimizes the effect of variations in spectral irradiance with climate, location

and time.

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