- 1 - ICS 77.150.10  
H 61  
 
 
 
 
National Standard  
of the People's Republic of China  
 
 
GB5237.3 - 200X  
Replaces GB 5237.3 -2004  
 
 
Wrought aluminium alloy extruded 
profiles for architecture  
 
Part 3: Electrophoretic coating profiles  
  
Draft for approval  
 
 
 
Issue Dat e 200X – XX – XX Implementation Date: 200X – XX – XX 
 
 
 
 
Issued by the General Administration of Quality Supervision, Inspection and 
Quarantine of the People's Republic of China and the  
Standardisation Administration of the People's Republic of China (SA C) 
- 2 -       GB 5237.3 - 200X  
 
Foreword  
 
 
 
Section 4.4.4 and the requirements for combined coating thickness set out in Table 2 of this 
standard are mandatory clauses, while the rest are recommended.  
 
GB 5237, “Wrought aluminium alloy extruded profiles for arc hitecture” is divided into six parts:  
 
− Part 1: Untreated profiles  
− Part 2: Anodised profiles  
− Part 3: Electrophoretic coating profiles  
− Part 4: Powder coating profiles  
− Part 5: PVDF coating profiles  
− Part 6: Thermal barrier profiles  
 
This is Part 3 of GB 5237.  
 
This Part replaces  Part 3 of GB 5237.3 – 2004 “Wrought aluminium alloy extruded profiles for 
architecture – Part 3: Electrophoretic coating profiles”.  
 
This Part has been revised with reference to Japanese JIS H 8601 -1999, “Combined coatings of 
anodic oxi de and organic coating on aluminium and aluminium alloys” and American AAMA 612 -
2002, “Voluntary specifications, performance requirements and test procedures for combined 
coatings of anodic oxide and transparent organic coatings on architectural aluminium. ” 
 
The main technical differences between this Part when compared to GB5237.3 -2004 are:  
− the contents of YS/T 459 -2003, “Wrought aluminium alloy profiles for architecture with 
combined coatings of anodic and coloured organic coatings” have been adopted and revised;  
− the requirements for the average thickness of anodic oxide coating have been withdrawn, and 
Grade A and Grade B local thickness of anodic oxide coating has been increased to “not less 
than 9 m”;  
− Grade A, Grade B and Grade C wear resistance quota of falling sand test have been increased 
respectively to 3300g, 3000g and 2400g;  
− the requirements set out in AAMA 612 have been consulted, and the requirements for 
hydrochloric acid corrosion resistan ce, mortar resistance and heat -humidity resistance have been 
added;  
− the requirements for detergent resistance and solvent resistance have been added.  
− Article 5.6 has been amended from “but from profile end in the range of 80mm allow locality 
areas no paint  coating” to “but from profile end in the range of 80mm allow locality areas no 
coating.”  
 
This Part is proposed by the China Non -ferrous Metals Industry Association.  
 
Main organisations that participated in the drafting of this Part:  
Guangdong JMA Alumin ium Profile Factory Co., Ltd;  
Guangdong Xingfa Aluminium Co., Ltd;  
Chinese Industrial Standard of Non -ferrous Metal Measure Quality Research Institute;  - 3 - Fujian Minfa Aluminium Industry Co., Ltd;  
Fujian Nanping Aluminium Co., Ltd;  
Participation drawing up un its of this part:  
Non-ferrous Metal Quality Supervision and Inspection Centre of the People's Republic of China;  
Non-ferrous Metal Quality Supervision and Inspection Centre of South China;  
Foshan Xinhe Aluminium Co., Ltd;  
China Billion International Limit ed (CBIL);  
ZDOON Building Material Group.  
 
Main drafters of this Part:  LuJiYan, GeLiXin, DaiYueXing, ZhuZuFang, XiaXiuQun, HuangXiWei, 
XieZhiJun, ZhanHao, MaCunZhen.  
 
This Part replaces the previously issued Standards:  
-GB/T 5237.3 - 2000, GB 5237.3 -2004.  
 
 
 
 - 4 -           GB 5237.3 - 200X  
Wrought aluminium alloy extruded profiles for architecture  
 
Part 3: Electrophoretic coating profiles  
 
 
1 Scope  
This Part sets the requirements for the testing methods, inspection rules, packaging, marking, 
transportation, st orage and content of contracts (or orders) of electrophoretic coating profiles for 
architecture.  
 
This Part applies to anodic oxide coating and electrophoretic coating (water soluble varnish or 
paint) combined treated aluminium alloy extruded profiles for architecture (hereafter referred to as 
electrophoretic coating profiles).  
 
Other aluminium alloy materials that carry similar applications and similar surface treatments may 
refer to and adopt the content of this Part.  
 
2 Normative References  
The provision s of the following documents become provisions of this Part after being referenced. 
For dated reference documents, all later amendments (excluding corrigenda) and versions do not 
apply to this Part; however, the parties to the agreement are encouraged to s tudy whether the latest 
versions of these documents are applicable. For undated reference documents, the latest versions 
apply to this Part.  
 
GB/T 228 -2002 Metallic materials – Tensile testing at ambient temperature;  
 
GB/T 629 Chemical reagent – Sodium hyd roxide;  
 
GB/T 1740 Determination of resistance to heat and humidity of paint films;  
 
GB/T 1766 Paints and varnishes – Rating schemes of degradation of coats;  
 
GB/T 1865 – 1997 Paints and varnishes – Artificial weathering and exposure to artificial radiatio n – 
Filtered xenon -arc radiation;  
 
GB/T 3199 Wrought aluminium and aluminium alloy products – Packing, marking, transporting and 
storing;  
 
GB/T 4957 Non -conductive coatings on non -magnetic basic metals – Measurement of coating 
thickness – Eddy Current;  
 
GB/T 5237.1 Wrought aluminium alloy extruded profiles for architecture - Part 1: Untreated 
profiles;  
 
GB/T 5237.2 Wrought aluminium alloy extruded profiles for architecture – Part 2: Anodised 
coloured profiles;  
 - 5 - GB/T 6461 Methods for corrosion testing of met allic and other inorganic coating on metallic 
substrates – Rating of test specimens and manufactured articles subjected to corrosion tests;  
 
GB/T 6462 Metallic and oxide coating – Measurement of coating thickness Microscopical method;  
 
GB/T 6682 Water for analytical laboratory use – specification and test methods;  
 
GB/T 6379 Paint and varnishes – determination of film hardness by pencil test;  
 
GB/T 8013.1 -2007 Anodic oxide coatings and organic polymer coatings on aluminium and its 
alloys – Part 1: Anodic ox ide coatings;  
 
GB/T 8013.2 – 2007 Anodic oxide coatings and organic polymer coatings on aluminium and its 
alloys – Part 2: Combined anodic oxide coating;  
 
GB/T 8014.1 Anodising of aluminium and its alloys – The measuring method of thickness of anodic 
oxide  coatings – Part 1: The measuring principle;  
 
GB/T 9276 Methods of exposure to natural weathering of coating;  
 
GB/T 9286 Paints and varnishes – cross -cut test for films;  
 
GB/T 9754 Paints and varnishes – Measurement of specular gloss of non -metallic paint films at 200, 
600 and 850; 
 
GB/T 9761 Paints and varnishes – Visual comparison of colour of paints;  
 
GB/T 9789 Metallic and other non -organic coatings – Sulphur dioxide test with general 
condensation of moisture;  
 
GB/T 10125 Corrosion tests in artificial a tmospheres – salt spray tests;  
 
GB/T 11186.2 Methods for measuring the colour of paint films – Part 2: Colour measurement;  
 
GB/T 11186.3 Methods for measuring the colour of paint films – Part 3: Calculation of colour 
differences;  
 
GB/T 12967.1 Anodising of  aluminium and aluminium alloys – Measurement of mean specific 
abrasion resistance of anodic oxidation coatings with an abrasive jet test apparatus;  
 
GB/T 14952.3 Anodising of aluminium and its alloys. Determination of colour differences and 
appearance of coloured anodic oxide films – Viewing method;  
 
GB/T 16585, Rubber, vulcanised – Test method of resistance to artificial weathering (Fluorescent 
UV lamp;  
 
GB/T 20975 (all Parts), Chemical analysis methods of aluminium and aluminium alloys;  
 
JC/T 480 Unslake d Lime for architecture.  - 6 - 3 Terms and definitions  
 
The terms and definitions set out in GB/T 8013.2 -2007 apply to this Part, as well as the following:  
3.1 Exposed surfaces  
Exposed surfaces refer to electrophoretic coating profiles that have been processed, 
manufactured and mounted onto a building; the surface of electrophoretic coating profiles which 
can still be seen either in an open or shut state.  
3.2 Local thickness  
Measure the coating thickness any one inspection area of the exposed surface of the 
elect rophoretic coating profile that is not larger than 1cm2 several times (not less than 3 times); 
the local thickness is the average value of the measured coating thickness.  
 
4 Requirements  
4.1 Product classification  
4.1.1 alloy grades, states, specifications  
The alloy grades, supply states and specifications of electrophoretic coating profiles should 
conform to the requirements set out in GB 5237.1.  
4.1.2 Thickness grades of the combined anodic oxide coatings, types of paint coatings, typical 
applications  
The thickness grades of the combined anodic oxide coating, types of paint coatings, and typical 
applications should conform to the requirements set out in Table 1. The thickness grade of 
combined anodic oxide coatings should be clearly indicated in the contra ct. 
 
Table 1  
Coating Thickness 
Grade  Surface Paint 
Coating Type  Typical Application  
A Outdoor construction 
parts under harsh 
environment  B Gloss or matt 
varnish  
Outdoor constructions or 
vehicle components  
C Gloss or matt 
coloured paint  Outdoor cons tructions or 
vehicle components  
 
 
4.1.3 Markings  
The arrangement of the labelling of electrophoretic coating profiles should be presented in the 
following order: product name, alloy grade, supply state, profile specification (profile 
specification consist s of the code name and the cut -length of the electrophoretic coating profile), - 7 - colour, coating thickness grade and the serial number of this part. An example of the label is 
shown below:  
 
If the electrophoretic coating profile is made of 6063 aluminium all oy, its supply state is T5, its 
profile code name is 421001, its cut -length is 6000mm, its surface treatment used anode 
oxidation and electrolytic colouring with electrophoretic coating, it is bronze coloured, and its 
coating thickness grade is A, then the  label should be:  
 
Electrophoretic coating profile 6063 -T5 421001x6000 Bronze A GB5237.3 -200X.  
 
Example 2:  
If the electrophoretic coating profile is made of 6063 aluminium alloy, its supply state is T5, its 
profile code name is 421001, its cut -length is 6 000mm, its surface treatment used anode 
oxidation and electrophoretic white coating, and its coating thickness grade is S, then the label 
should be:  
 
Electrophoretic coating profile 6063 -T5 421001x6000 White S GB5237.3 -200X.  
4.2 Chemical composition, mecha nical properties  
The chemical composition and mechanical properties of electrophoretic coating profiles in room 
temperature should conform to the requirements set out in GB 5237.1.  
4.3 Dimension deviation  
The dimension deviations of electrophoretic coating  profiles (including combined anodic oxide 
coatings) should conform to the requirements set out in GB 5237.1.  
4.4 Properties of the combined anodic oxide coating  
4.4.1 Colour and chromaticism  
The colour of the combined anodic oxide coatings should be prima rily identical to the colour 
plate agreed between the suppliers and buyers, or within the restricted colour range of upper 
limit and lower limit decided through consultation between the suppliers and buyers.  
 
If the buyers request the Instrumental Method b e carried out to test the colours of the combined 
anodic oxide coatings, the allowable chromaticism value should be decided through 
consultation between the suppliers and the buyers.  
4.4.2 Coating thickness  
The thickness of the combined anodic coatings sho uld conform to the requirements set out in 
Table 2.  
 
 
 
 
 
 
 
 
 - 8 -  
Table 2  
Coating Thickness/m  Coating 
Thickness 
Grade  Local 
thickness of 
the anodic 
oxide coating  Local thickness of 
the paint coating  Local thickness 
of the combined 
anodic oxide 
coating  
A 9 12 21 
B 9 7 16 
S 6 15 21 
 
4.4.3 Hardness of the paint coating  
After the Pencil Scratch Hardness test, the hardness of the paint coating for Grade A, Grade B 
should be at least 3H or more, and for Grade S at least 1H or more.  
4.4.4 Adherence of paint coating  
The dry adherence and wet adherence of the paint coating should both reach level 0.  
4.4.5 Boiling water resistance  
After the boiling water resistance test, no winkles, cracks, or bubbles should be apparent on the 
paint coating, no paint coati ng should come off and no colour change should be apparent.  
4.4.6 Wear resistance  
Carry out the Falling -sand Test to check wear resistance; the results of the Falling -sand Test 
should conform to the requirements set out in Table 3.  
 
Table 3  
Coating Thickne ss 
Grade  A B S 
Sand Fallen Quantity  3300  3000  2400  
 
4.4.7 Hydrochloric acid corrosion resistance  
After the hydrochloric acid corrosion resistance test, perform a visual inspection to check the 
surface of the combined anodic oxide coating; no bubbles s hould appear and no other noticeable 
changes should be apparent.  
4.4.8 Alkali resistance  
After the alkali resistance test, the protection level (R) should be at least level 9.5 or more.  
4.4.9 Mortar resistance  
After the mortar resistance test, perform a vi sual inspection to check the surface of the 
combined anodic oxide coating; no paint coating should come off and there should be no other 
noticeable changes.  - 9 - 4.4.10 Solvent resistance  
After the solvent resistance test, the differential value of pencil hardn ess should not be more 
than 1H.  
4.4.11 Detergent resistance  
After the detergent resistance test, there should be no bubbles, no coating should come off and 
there should be no other noticeable changes on the surface of the combined anodic oxide 
coating.  
4.4.12 Salt spray corrosion resistance  
The test results of the CASS (copper accelerated acetic acid salt spray test) should conform to 
the requirements set out in Table 4.  
 
Table 4  
Coating Thickness 
Grade  Test Duration/hour  Protection Level (R)  
A, S 48 Level 9.5  
B 24 Level 9.5  
 
4.4.13 Heat and humidity resistance  
The combined anodic oxide coating after 4000 hours heat -humidity resistance test, its change 
should not be greater than level 1.  
4.4.14 Weatherability  
4.4.14.1 Accelerated weatherability  
The duration of the artificial accelerated ageing test for accelerated weatherability, when 
illuminated with a xenon lamp, is divided into three levels - see Table 5. The level of accelerated 
weatherability should be decided by the buyers and clearly indicate d in the purchase contract. If 
it is not indicated, then the goods should be delivered as level II.  
 
Table 5  
Test Result  Weatherability  
Level  Test 
Duration  
(hour)  Chalking 
Degree  Gloss 
Retention 
Ratea Colour change 
Degree Eab* 
IV 4000  
III 2000  
II 1000  Level 0  80  Level 1  
 a The gloss retention rate means the percentage of the gloss value after paint 
coating test comparatively to the gloss value before the tests.  - 10 -  
4.4.14.2 Natural weatherability  
If the buyer re quests the natural weatherability test be carried out, then the test conditions, 
checking and acceptance standards should be decided through consultation between the supplier 
and buyer, and should be clearly indicated in the contract.  
4.4.15 Others  
4.4.15. 1 If the buyer has special requests regarding boiling water resistance, wear resistance, 
alkali resistance, salt -spray corrosion resistance, heat and humidity resistance, and 
weatherability of the combined anodic oxide coating, both the supplier and buyer may consult 
each other whilst referring to the requirements set out in GB/T 8013.2 -2007 in order to decide 
on the specific property requirements. The agreed test requirements should be clearly indicated 
in the purchase contract.  
 
4.4.15.2  If the buyer requ ests further tests be carried out on other properties, the supplier and the 
buyer should refer to the requirements set out in GB/T 8013.2 -2007 and come to a decision 
through mutual consultation.  
4.5 Appearance quality  
The appearance quality of the profile s before the painted coating should conform to the 
requirements set out in GB 5237.2. After painting, the paint coating should be even, smooth and 
free of any faults which may effect the use of the electrophoretic coating profiles, such as 
winkles, cracks,  bubbles, flow marks, inclusions, stickiness or paint coating falling off. Coating 
is not allowed for profile ends in the range of 80mm allow locality areas.  
5 Testing methods  
5.1 Chemical composition  
The reference analysis of chemical composition should b e carried out in accordance with the 
methods specified in GB/T 20957.  
5.2 Mechanical properties  
The reference test of the mechanical properties should be carried out in accordance with the 
methods specified in GB/T 228 -2002. The elongation percentage after  fracture should be 
decided in accordance with the requirements set out in Section 11.1 of GB/T 228 -2002.  
5.3 Dimension deviation  
The dimension deviation should be measured according to the methods specified in GB 5237.1.  
5.4 The properties of the combined  anodic oxide coatings  
5.4.1 Colour, chromaticism  
5.4.1.1 Visual inspection method  
Inspection should be carried out in accordance with the requirements set out in GB/T 14952.3.  - 11 - 5.4.1.2 Instrumental method  
Chromaticism measuring should be carried out accord ing to the requirements set out in GB/T 
11186.2 and GB/T 11186.3.  
5.4.2 Coating thickness  
5.4.2.1 Determination of local thickness for anodic oxide coating and combined anodic oxide 
coatings  
According to the measuring principles specified in GB/T 8014.1, a dopt either the Eddy Current 
Testing method specified in GB/T 4957 or the Microscopical Method – Measurement of Coating 
Thickness specified in GB/T 6462 to measure the local thickness of the anodic oxide coating 
and the local thickness of the combined anod ic oxide coating. The outcome should be 
determined according to GB/T 6462.  
5.4.2.2 Determination of local thickness for paint coating  
According to the measuring principles specified in GB/T 8014.1, adopt either the Eddy Current 
Testing method specified in GB/T 4957 or the Microscopical Method – Measurement of Coating 
Thickness method specified in GB/T 6462 to determine the measurements. The outcome should 
be determined according to GB/T 6462. When Eddy Current Testing method is adopted, the 
determination fo r the local thickness of the paint coating may be carried out using of the 
methods below:  
 
a) measure the local thickness of the combined anodic oxide coating first, then remove the 
local thickness of the anodic oxide coating that was measured in 5.4.2.1 - the differential 
value is regarded as the local thickness of the paint coating;  
b) first, measure the local thickness of the combined anodic oxide coating, then use a 
peeling agent or relative tool to remove the surface paint coating, again measure the 
local th ickness of the anodic oxide coating, the differential value between these two 
measured local thickness is regarded as the local thickness of the paint coating.  
5.4.3 Hardness of the paint coating  
Carry out the Pencil Scratch Hardness Test according to the test method specified in GB/T 6739; 
the test results can be evaluated on the basis of the scratched situation of the paint coating 
surface.  
5.4.4 Adherence of paint coating  
5.4.4.1 Dry adherence  
5.4.4.1.1  Draw squares according to the cross -cut test method  specified in GB/T 9286; the 
interval of each square should be 1mm.  
 
5.4.4.1.2  Cover the square drawing paint coating with adhesive tapeD; the adhesive force for the 
tape should be greater than 10N/25mm. Press the tape down tightly to remove any air from 
underneath the tape, pull off the tape quickly at a vertical angle from the paint coating surface, 
then carry out the evaluation.  
(D The suitable adhesive tapes on the market are Scotch Premium Cellophane tape 610 or Permacel P -99 adhesive 
tape. We list thi s product information here for the convenience of people who use this Part of Standard, we do not 
necessarily give acceptance to the products.)  - 12 - 5.4.4.2 Wet adherence  
According to the requirements set out in 5.4.4.1.1 draw squares on the sample, using third  
grade water as specified in GB/T 6682. With a temperature of 38C± 5C, soak the sample for 24 
hours. Remove the sample and wipe it dry. Carry out test and evaluation within 5 minutes, as 
according to 5.4.4.1.2.  
5.4.5 Boiling water resistance  
5.4.5.1  Pour a round 80ml third grade water into a beaker as specified in GB/T 6682, then place 
2 - 3 pieces of clean broken porcelain into the beaker, heating the water from the beaker bottom 
until the water boils.  
 
5.4.5.2  Hang the sample in the water to boil for 5 hou rs. The sample should be 10mm under the 
water surface, but it may not touch the bottom of the beaker. During the test, the water 
temperature should be kept at least at 950C; whenever necessary add boiled third grade water 
specified in GB/T 6682 into the be aker to maintain the depth of the water height as not lower 
than 80mm.  
 
5.4.5.3  Remove the sample and wipe it dry, then perform a visual inspection to check the paint 
coating surface of after the boiling water test (surrounding part of the sample is not in cluded).  
5.4.6 Wear resistance  
Carry out the Falling -sand Test to measure the abrasive resistance of the paint coating according 
to the requirements set out in Appendix A to GB/T 8013.1 -2007.  
5.4.7 Hydrochloric acid corrosion resistance  
Use chemical hydroc hloric acid (1.19g/ml) and third grade water as specified in GB/T 6682 to 
mix the hydrochloric acid test solution (hydrochloric acid and water as 1:9). Drip 10 drops of 
this hydrochloric acid test solution onto the paint coating surface of the sample, cov er up with a 
watch glass, then leave it in an environment with a temperature of 180C - 270C for 15 minutes. 
Rinse clean under tap water, air dry, then perform a visual investigation to check the paint 
coating surface.  
5.4.8 Alkali resistance  
5.4.8.1  Using ethyl alcohol carefully wipe off the dirt on the sample surface, use Vaseline or 
paraffin wax to fix an inner diameter 32mm, height 30mm glass (or synthetic resin) ring onto 
the prepared surface of the sample, and seal around the outside  
 
5.4.8.2  Use sodiu m hydroxide specified in GB/T 629 and third grade water as specified in GB/T 
6682 to mix sodium hydroxide test solution with concentration of 5g/l.  
 
5.4.8.3  Keep the sample level and under the test temperature of 200C± 20C, pour the sodium 
hydroxide test s olution up to the halfway point in the glass ring, then cover with a glass lid or 
synthetic resin lid. After 24 hours, take off the glass ring, carefully rinse the sample clean with 
water, and then leave it indoors. After one hour, draw a diameter of 30mm,  with the same centre 
as the glass ring circle. Use a 10 - 15 times magnifying glass to observe the corrosion situation 
inside of the circle, carrying out the evaluation according to GB/T 6461. The protection levels 
correspond to the percentages for differ ent total defect areas, as in Table 6.  - 13 - 5.4.9 Mortar resistance  
5.4.9.1  Take 75g lime powder as specified in JC/T 480 and 225g Standard Sand as specified in 
Section A.5.2 in Appendix A to GB 5237.4 -2008, then add into about 100g third grade water as 
specif ied in GB/T 6682 and mix into a lime and sand paste mortar.  
 
5.4.9.2  Put the paste mortar onto the surface of the sample, pile up to a cylinder with diameter 
of 15mm and thickness of 6mm. Leave in an environment with a temperature of 380C ± 30C and 
relativ e humidity of 95% ± 5% for 24 hours.  
 
5.4.9.3  Remove the paste mortar from the sample and, using a wet cloth, clean the residue off 
the surface, then air dry. Perform a visual investigation to check the surface of the paint coating 
after the test.  
5.4.10 S olvent resistance  
5.4.10.1  First carry out the Pencil Scratch Hardness Test in accordance with the requirements 
specified in GB/T 6379; the evaluation of the test results should be taken on the basis of the 
scratched condition of the paint coating surface.  For paint coating surfaces that are not scratched 
by the pencils, place a piece of cotton soaked with xylene for 30 seconds  
5.4.10.2  Remove the cotton and immediately rinse the sample clean using tap water, then wipe 
dry, leave at room temperature for 2 h ours, then carry out Pencil Scratch Hardness Test 
according to GB/T 6379 on the surface area that was covered up with the cotton.  
5.4.10.3 The evaluation of the test results should be taken on the basis of the scratched condition 
of the paint coating surf ace. 
5.4.11 Detergent resistance  
5.4.11.1  Use detergent (for composition see Table 6) and third grade water as specified in GB/T 
6682 to mix a detergent test solution with a concentration of 30g/l. Soak the sample in the 
detergent test solution with temper ature of 380C ± 10C for 72 hours, take the sample out and 
wipe it dry.  
 
5.4.11.2  Immediately use adhesive tape with adhesive force of 10N/25mm to cover up the 
surface of the paint coating, press the tape down tightly to remove any air from underneath the 
tape, then pull off the tape quickly at a vertical angle from the paint coating surface. Perform a 
visual inspection to check the paint coating surface.  
 
Table 6  
Composition  Content (Weight) %  
Tetrasodium Pyrophosphate  53 
Sodium Sulphate Anhydrous  19 
Sodium Linear alkylarylsulfonate  20 
Sodium Metasillicate Hydrated  7 
Sodium Carbonate Anhydrous  1 
Total  100 
 - 14 - 5.4.12 Salt spray corrosion resistance  
Carry out CASS test according to GB/T 10125. When the required test duration is complete, 
evaluate of the te st results according to GB/T 6461. The protection levels that correspond to the 
percentages of different total defect areas are shown in Table 7.  
 
Table 7  
Defect Area 
Percentage after Test 
% Protection Level 
(R) Defect Area 
Percentage after 
Test %  Protecti on 
Level (R)  
None  10 >0.05 ~ 0.07  9.3 
<0.02  9.8 >0.07 ~ 0.10  9 
>0.02 ~ 0.05  9.5 >0.10 ~ 0.25  8 
 
5.4.13 Heat -humidity resistance  
Carry out heat -humidity resistance test according to the rules specified in GB/T 1740. The test 
temperature should be 470C± 10C. 
5.4.14 Weatherability  
5.4.14.1 Accelerated weatherability  
Carry out the xenon lamp accelerated weatherability test according to method 1 specified in 
GB/T 1865 -1997. According to GB/T 9754 to measure the gloss value. Evaluate the chalking 
degree and c olour change degree according to GB/T 1766.  
5.4.14.2 Natural weatherability  
Carry out natural weatherability test according to the stipulations of GB/T 9276.  
Note: among the atmospheric corrosion test stations in China, the only test station in which the 
atmospheric conditions are very near to the specified Florida Atmospheric in international 
Standards is the Qionghai Exposure Test Station.  
5.4.15 Others  
Tests on other properties should be performed according to test methods specified in GB/T 
8013.2 – 2007  or in accordance with the method agreed between the suppliers and the buyers.  
5.5 Appearance quality  
The examination for appearance quality should be carried out under diffuse sunlight (diffuse 
sunlight refers to the 3 hours following sunrise to 3 hours b efore sunset), and according to the 
provisions set out in GB/T 9761. The required luminance level for artificial illumination should 
be above 1000lx and the light source should be a D65 standard light source. The background 
should be matt black or grey; a coloured background cannot be used.  
6 Inspection rules  
6.1 Examination and checking acceptance  
 - 15 - 6.1.1  An examination of the electrophoretic coating profiles should be carried out by the 
suppliers so as to ensure that the quality of the electrophoretic coat ing profiles conform to the 
requirements set out in this Part (or purchase contract), and the quality certificate should also be 
completed by them.  
 
6.1.2  Buyers may carry out examinations that are specified in this Part regarding the 
electrophoretic coati ng profiles they receive. If the examination results do not conform to the 
requirements set out in this Part or in the purchase contract, the buyer may submit the 
disagreement in writing to the supplier, in order to come to an agreement through mutual 
consultation. If the disagreement is related to appearance quality and dimension deviation, the 
buyer should submit the problems within one month of the date on which the electrophoretic 
coating profiles were received. If the disagreement is related to other p roperties, then the buyer 
may submit the problems within three months of receiving the electrophoretic coating profiles. 
If a negotiation is required, the suppliers should provide the agreed samples and the problem 
should be resolved between the supplier a nd buyer together.  
6.2 Batch approval  
The electrophoretic coating profiles should be submitted to gain approval and acceptance in 
batches, the electrophoretic coating  profiles which is the same alloy, have same supply states, 
same specifications, same gra des of coating thickness can form a batch. The quantity of each 
batch of electrophoretic coating profiles is unrestricted.  
6.3 Inspection item  
Inspections of chemical composition, mechanics properties, dimension deviation, colour and 
chromaticism, local th ickness of the combined anodic oxide coating, hardness of the paint 
coating, adhesive force of the paint coating, and appearance quality should be carried out on 
every batch of electrophoretic coating profiles. Inspections of other properties are not usual ly 
carried out (the suppliers carry out these types of inspections at least once every three years), 
but the supplier should ensure these properties conform to the requirements set out in this Part. 
If the buyer requests to carry out inspection on these pr operties, then these requests should be 
clearly indicated in the contract.  
6.4 Sampling  
Electrophoretic coating profile sampling procedures carried out in accordance with the 
provisions set out in Table 8.  
Table 8  
Test Item  Sampling Rules  Requested 
Clause 
Number  The Clause 
Number of Test 
Method  
Chemical composition, 
mechanics properties, 
dimension deviation,  According to the rules specified 
in GB 5237.1  4.3, 4.4  5.1, 5.2, 5.3  
Colour, chromaticism, 
appearance quality  The inspection of the profiles 
should b e carry out one by one 
with the products  4.4.1, 4.5  5.4.1, 5.5  
Coating thickness  Sampling according to Table 9  4.4.2  5.4.2  
Hardness, adherence, Take 2 pieces of electrophoretic 4.4.3, 4.4.4, 5.4.3, 5.4.4, - 16 - boiling water resistance, 
wear resistance, 
hydrochloric acid corrosion 
resistance, alkali resistance, 
mortar resistance, solvent 
resistance, detergent 
resistance, salt -spray 
corrosion resistance, heat -
humidity resistance and 
weatherability of the paint 
coating  coating profiles per test item 
from each batch, when the paint 
coating solidified and left for 
another 24 hours later, cut one 
sample from each piece profile.  4.4.5, 4.4.6, 
4.4.7, 4.4.8, 
4.4.9, 4.4.10, 
4.4.11, 4.4.12, 
4.4.13, 4.4.14  5.4.5, 5.4.6, 
5.4.7, 5.4.8, 
5.4.9, 5.4.10, 
5.4.11, 5.4.12, 
5.4.13,  5.4.14  
Others  According to GB/T 8013.2 – 
2007 or decide by agreement 
between the buyer and the 
supplier.  4.4.15  5.4.15  
 
6.5 Determination of inspection results  
 
6.5.1  If the inspection for chemical composition does not meet the required standard, then t his 
batch of electrophoretic coating profiles is deemed as not qualified.  
 
6.5.2 If any one of the samples fails to meet the required standard during the inspection for 
mechanical properties, re -sampling should take place using double the original number o f test 
samples from this batch of profiles (including the original unqualified sample). If the repeated 
test results qualify, then this batch of electrophoretic coating profiles is deemed to be qualified. 
If any of the repeated test results continues to fa il to meet the required standard, then this batch 
is deemed as not qualified.  
 
6.5.3  If dimension deviation does not meet the required standard, then the batch of 
electrophoretic coating profiles is deemed to be not qualified. The pieces may, however, be 
tested one by one, and pieces that qualify may be delivered.  
 
6.5.4 If the colour, chromaticism or appearance quality does not meet the required standard, 
then this batch of electrophoretic coating profiles is deemed as not qualified.  
 
6.5.5 If the number o f unqualified coating thickness exceeds the specified allowable unqualified 
upper limit numbers shown in Table 9, then this batch of electrophoretic coating profiles is 
deemed as not qualified. The supplier may, however carry out individual testing, and th e 
qualified pieces may be delivered.  
 
Table 9  
Quantity Range in Each 
Batch  Random Sampling  Upper Limit of 
Unqualified Items  
1 ~ 10  Entire Batch  0 
11 ~ 200  10 1 
201 ~ 300  15 1 - 17 - 301 ~ 500  20 2 
501 ~ 800  30 3 
Over 800  40 4 
 
 
 
7 Labels, packaging, transp ortation, storage  
7.1 The label (or quality certificate) on the qualified electrophoretic coating profiles should contain 
the following information:  
a) the name and address of the supplier;  
b) the examination stamp from department of quality control of supplier;  
c) alloy grade and state;  
d) the name and specification of the product;  
e) coating thickness grade, colour and the grade of weatherability;  
f) production date or batch number;  
g) serial number from this Part;  
h) production license number and QS mark.  
7.2 The pack age symbol  of the electrophoretic coating profiles should conform to the requirements 
set out in  GB/T 319 9. 
7.3 The profiles should be bundled up and packed in paper, and the exposed surfaces of the profiles 
should be protected with paper padding or bubble wrap.  
 
7.4 The transportation and storage of the electrophoretic coating profiles should conform to the 
provisions set out in GB/T 3199.  
 
7.5 A copy of the quality certificate should be attached to each batch of electrophoretic coating 
profiles, on which the follow ing should be clearly indicated:  
a) the name of the supplier;  
b) profile name and specification;  
c) alloy grade and state;  
d) coating thickness grade, colour, weatherability grade;  
e) batch number or production date;  
f) weight or quantity;  
g) the serial nu mber of this part;  
h) every analysed inspection results and the examination stamp from department of quality 
control of supplier;  
I) production license number;  
j) factory shipment date (or package date).  
8 The contents of the contract (or order list)  
The c ontract (or the order list) to purchase listed materials in this part should contain the following 
information:  
a) product names  
b) alloy grades;  
c) supply states;  - 18 - d) profiles specifications;  
e) accuracy grades of allowable dimension deviation;  
f) coating thickness grades, colour and weatherability grades;  
g) weight or quantities;  
h) serial number of this Part;  
i) other special requests.