GB/T 9286-2021Paints and varnishes - Cross-cut test (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 replaces GB/T 9286-1998 "Paints and varnishes - Cross cut test

for films". Compared with GB/T 9286-1998, in addition to structural adjustments

and editorial changes, the main technical changes are as follows.

- Replace "steel" with "metal" and "plastic" with "plaster" (see Clause 1; 1.3

of the 1998 edition);

- Change the "Normative references" (see Clause 2; Clause 2 of the 1998

edition);

- Delete "Information to be supplemented" (see Clause 3 of the 1998 edition);

- Add "Terms and definitions" (see Clause 3);

- Add "Principle" (see Clause 4);

- Add "General" (see 5.1);

- Add "General requirements" for cutting tool (see 5.2.1); change the

requirements for "Single-blade cutting tools" (see 5.2.2; 4.1 of the 1998

edition), the requirements for "Multi-blade cutting tools" (see 5.2.3; 4.1 of

the 1998 edition), and the requirements for "Guiding and spacing edges"

(see 5.3; 4.2 of the 1998 edition);

- Delete "soft brush" (see 4.3 of the 1998 edition) and "transparent pressure-

sensitive adhesive tape" (see 4.4 of the 1998 edition);

- Change "Examples of single-blade cutting tools" (see Figure 1; Figure 1 of

the 1998 edition), "Examples of multi-blade cutting tools" (see Figure 2;

Figure 1 of the 1998 edition), and "Examples of guiding and spacing edges"

(see Figure 4; Figure 2 of the 1998 edition); add "Motor-driven apparatus"

(see Figure 3);

- Change "Sampling" (see Clause 6; Clause 5 of the 1998 edition);

- Delete "Treatment and painting of test panels" (see 6.2 of the 1998 edition)

and "Drying of samples" (see 6.3 of the 1998 edition);

- Add examples of hard substrates and soft substrates (see 8.1.4) and the

requirements for the number of routine tests (see 8.1.5); change the

requirements of "Cutting the coating using the manual procedure" (see 8.2;

5 on Paints & Pigments of Standardization Administration of China (SAC/TC 5).

Drafting organizations of this document. CNOOC Changzhou Paint and

Coatings Industry Research Institute Co., Ltd.; Biuged Laboratory Instruments

(Guangzhou) Co., Ltd.; Zhejiang Yu Tong New Materials Co., Ltd.; T&H

Chemicals Corporation Ltd.; Ningbo Xin'an Dope Co., Ltd.; Shenzhen

Grandland Hightech New Material Co., Ltd.; The China Paint MFG. Co.,

(Shenzhen) Ltd.; Forever Testing Int'l Co., Ltd.; Guohengxin (Changzhou)

Testing and Certification Technology Co., Ltd.; Fujian Wanan Group Co., Ltd.;

Zhejiang Transfar Co., Ltd.; Xuzhou Daguang Paint Factory; Zhejiang Feijing

New Material Technology Co., Ltd.; BEVS Industrial Co., Ltd.; Banfert New-

materials Technology Co., Ltd.; Dongguan Taiho Paint Products Co., Ltd.;

Qingdao Xingguo Painting Co., Ltd.; Zhuzhou Jiuhua New Material Coating

Industry Co., Ltd.; AVIC BIAM New Materials Technology & Engineering Co.,

Ltd.; Tian He Resin Co., Ltd.; Shunde Polytechnic; MACO Group Co., Ltd.;

Shanghai Baolijia New Material Co., Ltd.; Zhejiang Research Institute of

Product Quality and Safety; Hubei O - BAST Science and Technology Co., Ltd.;

Fujian Nianmeng Technology Co., Ltd.; Xiamen University; Longhai Dahua

Paint Co., Ltd.; Fujian Tenglong Industrial Company; Fujian Rongcheng

Detection Technology Co., Ltd.; Hui'erming (Fujian) Chemical Industry Co., Ltd.;

Zhangzhou Taixing Chemical Coating Co., Ltd.; Zhangzhou Xianghao Paint

Industry and Trade Co., Ltd.; Meijiale (Qingyuan) EP & New Materials Co., Ltd.

Main drafters of this document. Chen Gang, He Wenhua, Xu Yunli, Peng Jufang,

Li Yuewu, Yang Yaliang, Xu Jinbao, Gu Erning, Wang Zhi, Chen Lihong, Huang

Wen, Gao Dongmei, Liang Xizhen, Tang Hao, Zeng Yuling, Li Shizhen, Xiong

Guogang, Liu Caixia, Gong Wenjing, Liu Wei, Ma Yong, Chen Yanwu, Niu

Zhiqiang, Wang Wei, Wu Ruilang, Dai Yanzhong, Xu Yiting, Tang Xiaoyan,

Huang Wanglie, Lin Shishi, Fang Bin, Zheng Qingyun, Cai Dehe, Guan

Zhongxiang.

The previous releases of this document and the documents it replaces are as

follows.

- It was first issued as GB/T 9286-1988 in 1988.It was revised for the first

time in 1998;

- This is the second revision.

Paints and varnishes - Cross-cut test

1 Scope

This document specifies a test method for assessing the resistance of paint

coatings and varnishes (including wood stains) to separation from substrates

when a right-angle lattice pattern is cut into the coating, penetrating through to

the substrate. The property determined by this empirical test procedure

depends, among other factors, on the adhesion of the coating to either the

preceding coat or the substrate. This procedure is not, however, a means of

measuring adhesion.

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.

ISO 1513 Paints and varnishes - Examination and preparation of test

samples

ISO 2808 Paints and varnishes - Determination of film thickness

3 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO 4618

apply.

4 Principle

Six parallel cuts are introduced in the coating and another six cuts are

introduced perpendicular to the first cuts. Any loose paint particles are removed.

The cut area is examined visually and compared to a six-step classification.

5 Apparatus

The tools described in 5.2.2 and 5.2.3 are suitable for manual use, which is the

more usual method of use, but the tools may also be mounted on a motor-

driven apparatus, which gives more uniform cutting. The application of the latter

procedure shall be subject to agreement between the interested parties.

6 Sampling

Take a representative sample of the product to be tested, as described in ISO

15528.

7 Test specimen

Where panels consist of a relatively soft material such as wood, the minimum

thickness shall be 10 mm. Where panels consist of a hard material, the

minimum thickness shall be 0.25 mm.

Determine the thickness, in micrometres, of the dried coating by one of the

procedures specified in ISO 2808.Make the measurement at, or as near as

possible to, the positions at which the cross-cut is to be made. The number of

thickness determinations is dependent on the method used.

8 Procedure

The number of cuts in each direction of the lattice pattern shall be six.

If a higher precision is required, carry out the test in at least three different

places (see 7.1) on the panel. If the results do not match, the differences being

more than one classification unit, repeat the test at three other places, if

necessary using different panels, and record all the results.

original cuts at 90° to them so that a lattice pattern is formed.

9 Evaluation and expression of results

Carefully examine visually the cut area of the test coating in good lighting as

specified in ISO 13076, using normal or corrected vision or, if agreed between

the interested parties, using a viewing lens (5.4).

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