- 1 - ICS 77.150.10  
H 61  
 
 
 
 
National Standard  
of the People's Republic of China  
 
 
GB 5237.5 - 200X  
Replaces GB 5237.5 -2004  
 
 
Wrought aluminium alloy extruded 
profiles for architecture  
 
Part 5: PVDF coating profiles  
  
Draft for approval  
 
 
 
Issue Date: 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 (SAC)  
          
 
- 2 - GB 5237.5 - 200X  
 
Foreword  
 
 
 
Sections 4.5.3.1 and 4.5.5 of this Standard are mandatory, whilst the rest are recommended.  
 
GB 5237, “Wrought aluminium alloy extruded profiles for architecture” 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 5 of GB 5237.  
 
This Part replaces  Part 5 of GB 5237.5 – 2004 “Wrought aluminium alloy extruded profiles for 
architecture – Part 5: PVDF coating profiles””.  
 
This Part has been revised with reference to AAMA2605 -2005, “Performance requirements and test 
procedures for superior performing organic coatings on aluminium extrusions and panels.”  
 
The main technical differences between this Part when compared to GB5237.5 -2004 are:  
− the duration of the neutral salt spray test for the coatings has been specified as 4000 hours, 
unanimous with AAMA2605;  
− illumination with xenon lamp artificial accelerated  ageing test for the artificial accelerated 
weatherability of the coating has been adopted, the duration of the test being 2000 hours;  
− the duration of the heat -humidity test has been specified as 4000 hours, unanimous with 
AAMA2605.  
 
This part is proposed by the China Non -ferrous Metals Industry Association.  
 
This Part is under the jurisdiction of the National Technical Committee for Standardisation of Non -
ferrous Metals.  
 
Main organisations that participated in the drafting of this Part:  
Guangdong Xingfa Aluminium Co., Ltd;  
Fujian Minfa Aluminium Industry Co., Ltd;  
Fujian Nanping Aluminium Co., Ltd;  
Non-ferrous Metal Quality Supervision and Inspection Centre of the People's Republic of China;  
Chinese Industrial Standard of Non -ferrous Metal Measure Quality  Research Institute;  
Guangdong JMA Aluminium Profile Factory Co., Ltd;  
 
Other units that participated in the drafting of this Part:  
Non-ferrous Metal Quality Supervision and Inspection Centre of South China;  
GuangYa Aluminium Co., Ltd;  
GuangDong Fenglu Al uminium Co., Ltd;  - 3 - Foshan Xinhe Aluminium Co., Ltd.  
 
Main drafters of this Part:  ChenWenSi, ZhuYuHua, WuXiKun, ChenSuMei, LinJie, LuJiYan, 
HeYaoZu, ZhanHao, ZhangJiLin.  
 
This Part replaces the previously issued Standards:  
-GB/T 5237.5 -2000, GB/T 5237.5 -2004 
 
 
 
 - 4 -           GB 5237.5 - 200X  
Wrought aluminium alloy extruded profiles for architecture  
 
Part 5: PVDF coating profiles  
 
 
1 Scope  
This Part sets the requirements for the testing methods, inspection rules, packaging, marking, 
transportation, storage and  content of contracts (or orders) of PVDF coating profiles for 
architecture.  
 
This Part applies to aluminium alloy extruded profiles with PVDF (Polyvinylidene Fluoride)  
coatings for architecture (hereafter referred to as PVDF coating profiles).  
 
Other alu minium alloy materials that carry similar applications and similar surface treatments may 
refer to and adopt the content of this Part.  
 
2 Normative References  
The provisions 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 study whether the latest 
versions of these documents are applicable. For undated refe rence documents, the latest versions 
apply to this Part.  
 
GB/T 228 -2002 Metallic materials – Tensile testing at ambient temperature;  
 
GB/T 1732 Determination of impact resistance of films;  
 
GB/T 1740 Determination of resistance to heat and humidity of pain t 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 radiation – 
Filtered xenon -arc radiation;  
 
GB/T 3199 Wrought aluminium and alumini um alloy products – Packaging, 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 5237.4 -2008 Wrought aluminium alloy extruded profiles for architecture – Part 4: Powder 
coating profiles;  
 
GB/T 6461, Methods for corrosion testing of metallic and other inorganic coating on metallic - 5 - substrates – Rating of  test specimens and manufactured articles subjected to corrosion tests;  
 
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 8013.3 -2007 Anodi c oxide coatings and organic polymer coatings on aluminium and its 
alloys – Part 3: Organic polymer coating;  
 
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 the colour of paints;  
 
GB/T 10125 Corrosion tests in artificial atmospheres – 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 16585 Rubber, vulcanised – Test method of resistance to artificia l weathering (Fluorescent 
UV lamp;  
 
GB/T 20975 (all parts), Chemical analysis methods of aluminium and aluminium alloys.  
 
JC/T 480, Unslaked Lime for architecture.  
3 Terms and definitions  
The terms and definitions set out in GB/T 8013.3 -2007 apply to this Part, as well as the 
following:  
3.1 Film  
Film refers to PVDF (polyvinylidene fluoride) painted on the surfaces of the metallic base, the 
film formed after the paint becomes solidified. Film is also referred to as coating.  
3.2 Exposed surfaces  
Exposed surfa ces refers to PVDF coating profiles that have been processed, manufactured and 
mounted onto a building; the surface PVDF coating profiles which can still be seen either in an 
open or shut state.  
3.3 Thickness of coating  
Coating thickness refers to the thic kness of the solidified PVDF paint covered on the metallic 
base.  - 6 - 3.4 Local thickness  
Measure the coating thickness of any one inspection area on the exposed surface of the PVDF 
coating profile that is not greater than 1cm2 several times (not less than 3 ti mes); the local 
thickness is the average value of the measured coating thickness.  
3.5 Minimum local thickness  
The smallest value of the many measured local thicknesses of the exposed surfaces on the 
PVDF coating profiles.  
3.6 Average thickness  
The average thickness is the average value of several (not less than 5 different places) measured 
and calculated local thickness of the exposed surfaces on the PVDF coating profiles.  
4 Requirements  
4.1 Product classification  
4.1.1 Alloy grades, states, specifications  and coating types  
The alloy grades, supply states and specifications of the PVDF coating profiles conform to the 
requirements set out in GB 5237.1. Coating types should conform to the requirements set out in 
Table 1.  
Table 1  
Two Coatings  Three Coatings  Four Coatings  
Undercoat and topcoat  Undercoat, topcoat and 
varnish  Undercoat, barrier coat, top coat 
and varnish  
 
4.1.2 Markings  
The arrangement of labelling of PVDF coating profiles should be presented in the following 
order: product name, alloy grade, su pply state, profile specification (profile specification 
consists of the code name and the cut -length of the PVDF coating profile), colour code name 
(indicated as colour xxxx), and the serial number of this Part. An example of the label is shown 
below:  
 
If the PVDF coating profile is made of 6063 aluminium alloy, its supply state is T5, its profile 
code is 421001, its cut -length is 6000mm, and its coating colour is grey (code number 8399), 
then the label should be:  
 
 PVDF coating profile 6063 -T5 421001x6000  Colour 8399 GB5237.5 -2008  
4.2 Preliminary treatment  
The preliminary treatments of the PVDF coating profiles should be carried out according to the 
provisions specified in Clause 5 of GB/T 8013.3 -2007.  
4.3 Chemical composition, mechanical properties  
The ch emical composition, mechanical properties of the PVDF coating profiles should conform 
to the requirements set out in GB 5237.1.  - 7 - 4.4 Dimension deviation  
The allowable dimension deviations of the profiles after the PVDF coatings are removed should 
conform to  the requirements set out in GB 5237.1. The installation and use of PVDF coating 
profiles should not be affected by the dimension deviations caused by the coatings.  
4.5 Coating properties  
4.5.1 Gloss  
The 600 gloss value of the coating should be consistent with the contract, and the allowable 
deviation should be ± 5 gloss units.  
4.5.2 Colour and chromaticism  
The colour of the PVDF coatings should be primarily identical with the colour sample plate 
agreed between the suppliers and buyers. When measuring with a colorimeter, the chromaticism 
between single colour coating and the colour sample plate should be Eab* 1.5 amongst the 
same batch of PVDF coating profiles (refers to delivery batch) should be Eab* 1.5. 
4.5.3 Coating thickness  
4.5.3.1 Coating thickness on the exposed surface should conform to the requirements set out in 
Table 2:  
 
Table 2  
Coating typ e Average 
Thickness/m  Minimum Local 
Thickness/m  
Two coatings  30 25 
Three coatings  40 34 
Four coatings  65 55 
Note: due to the complex shape of the extruded profiles’ cross -section, the 
coating thickness on certain  surfaces (such as inner corner s, transverse 
grooves) of the PVDF coating profiles are permitted to be smaller than the 
values specified in Table 2, but a show -through phenomenon is not 
permissible.  
 
4.5.3.2 If spray painting is required on non -exposed surfaces, this request should be clearly 
indicated in the contract.  
4.5.4 Hardness  
After the Pencil Scratch Hardness Test, the hardness of the coating should not be lower than 1H.  
4.5.5 Adherence  
The dry adherence, wet adherence and boiling water adherence of the coating should all reach 
level 0.  
 
4.5.6 Impact resistance  
After the drop impact test, the coatings on the impact area are allowed to have tiny cracks, but - 8 - the coatings must not stick to the adhesive tape.  
4.5.7 Wear resistance  
After the Falling -sand Test, the abrasion coefficient  should not be smaller than 1.6L/ m 
4.5.8 Hydrochloric acid corrosion resistance  
After the hydrochloric acid corrosion resistance test, a visual inspection should be carried out to 
check the test coating surface; no bubbles or any other noticeable changes should be apparent.  
4.5.9 Nitric acid resistance  
After the nitric acid resistance test, the colour change of single colour coatings should be 
Eab* 5. 
4.5.10 Mortar resistance  
After the mortar resistance test, carry out a visual inspection to check the test coating surface; 
there should not be any coating falling off or other noticeable changes.  
4.5.11 Solvent resistance  
After the solvent resistance test, the coating should not become softened and there should be no 
other noticeable changes.  
4.5.12 Detergent resistance  
After the detergent  resistance test, carry out a visual inspection to check the test coating surface; 
there should be no bubbles, the coating should not come off and there should be no other 
noticeable changes.  
4.5.13 Salt spray corrosion resistance  
After 4000 hours of neutr al salt -spray test, the under coating corrosion width of unidirectional 
infiltration of both side of the cut -line should not exceed 2mm, and the surface coatings beyond 
2.0mm from the cut line on both sides should not have any corrosion phenomenon.  
4.5.14 heat and humidity resistance  
 After 4000 hours of the heat -humidity test, the coating changes should not be greater than level 
1.  
4.5.15 Weatherability  
4.5.15.1 Accelerated weatherability  
After 2000 hours irradiated with a xenon lamp for the artificial ac celerated ageing test, coating 
chalking should not occur (level 0), the gloss retention percentage (percentage of the after test 
gloss value compares to before test gloss value) should not be less than 85%, and the colour 
change degree should reach level 1  as a minimum.  
4.5.15.2 Natural weatherability  
If the buyer requests the natural weatherability test be carried out on the PVDF coatings, then 
the test conditions and the acceptance standard should be decided through consultations 
between the supplier and buyer, and should be clearly indicated in the contract.  - 9 - 4.5.16 Others  
4.4.16.1 If the buyer has special requests regarding the impact resistance, wear resistance, salt 
spray corrosion resistance, heat -humidity resistance, and weatherability of the PVDF coa tings,  
both the supplier and buyer may consult each other whilst referring to the requirements set out 
in GB/T 8013.3 -2007 in order to decide on the specific property requirements. The agreed test 
results should be clearly indicated in the contract.  
 
4.5.1 6.2 If the buyer requests further tests be carried out on other properties of the PVDF 
coatings, the supplier and the buyer should refer to the requirements set out in GB/T 8013.3 -
2007, and come to a decision through mutual consultation.  
4.6 Appearance qu ality  
The coatings on the exposed surface of the PVDF profiles should be smooth and even. Faults 
that may affect the use of the profiles such as flow marks, wrinkles, bubbles and coating falling 
off are not permissible.  
5 Testing methods  
5.1 Chemical compo sition  
The reference analysis of chemical composition should be carried out in accordance with the 
methods set out in GB/T 20957.  
5.2 Chemical properties  
The mechanical properties reference test should be carried out in accordance with the methods 
specifie d 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  
Dimension deviation should be measured according to the methods specified i n GB 5237.1.  
5.4 Properties of the coatings  
5.4.1 Gloss  
Use a gloss instrument to determine the gloss at a 600 incident angle in accordance with the 
procedures set out in GB/T 9754.  
5.4.2 Colour, chromaticism  
5.4.2.1 Visual inspection method  
Carry out the  test according to the provisions of GB/T 9761.  
5.4.2.2 Instrumental method  
For the single colour coating reference test, use a colorimeter to carry out the measurement as 
according to the methods specified in GB/T 11186.2 and GB/T 11186.3.  - 10 - 5.4.3 Coating t hickness  
Measure the coating thickness according to the procedures specified in GB/T 4957. At least 5 
suitable test spots should be measured (every spot should be about 1cm2) to determine the 
thickness of the test coating. In each test, measure the test sp ot 3 -5 times and record the 
readings. Determine the average value of the readings as the local thickness of the test spot, then 
record the average value of all the local thickness as the determined average thickness of the test 
coating.  
5.4.4 Hardness of the coating  
Carry out the pencil hardness test according to the test method specified in GB/T 6739. The test 
results may be evaluated on the basis of how scratched the paint coating surface becomes.  
5.4.5 Adherence  
5.4.5.1 Dry adherence  
5.4.4.1.1 Draw squ ares according to the cross -cut test method specified in GB/T 9286. The 
interval of each square should be 1mm.  
 
5.4.5.1.2 Cover the square drawing coating with adhesive tape, and the adhesive force for the 
tape should be greater than 10N/25mm. Press the ta pe down tightly to remove the air from 
underneath the tape, pull off the tape quickly at a vertical angle from the coating surface, then 
carry out the evaluation according to the provisions set out in GB/T 9286.  
5.4.5.2 Wet adherence  
According to the rule in 5.4.5.1.1, draw squares on the sample using the third grade water 
specified in GB/T 6682, with a temperature of 380C± 50C. Soak the sample for 24 hours. Take 
the sample out and wipe it dry. Carry out the test and evaluation within 5 minutes, as accordin g 
to 5.4.5.1.  
5.4.5.3 Boiling water adherence  
5.4.5.3.1 Draw squares on the sample according to the provisions set out in 5.4.5.1.1.  
 
5.4.5.3.2 Pour around 80mm of third grade water into a beaker as specified in GB/T 6682. 
Place 2 - 3 pieces of clean broke n porcelain into the beaker, and heat the water from the bottom 
of the beaker bottom until the water boils.  
 
5.4.5.3.3 Hang the sample in the water and allow it to boil for 20 minutes. The sample should be 
10mm under the water surface, but should not touch  the bottom of the beaker. During the test 
process, the water temperature should be kept at least at 950C. Whenever necessary, add boiled 
third grade water into the beaker as specified in GB/T 6682, so as to maintain the depth of the 
water at least to 80mm . 
 
5.4.5.3.4 Remove the sample and wipe it dry. According to 5.4.5.1.2, carry out the test and 
evaluation within 5 minutes.  
5.4.6 Impact resistance  
Use a punch ball with a diameter of 16mm± 0.3mm to carry out the drop impact test, as 
according to the test procedures specified in GB/T 1732: place an impact hammer (1000g± g) at - 11 - a suitable height and allow it to fall freely, then drop the hammer directly onto the coating 
surface of the standard sample plate (Frontal Impact), which will result in an indentation  with a 
depth of 2.5mm±  0.3mm. Cover the indentation with 20mm width adhesive tapeD, then press 
down to remove the air under the tape and quickly pull off the tape at a vertical angle from the 
coating surface. Carry out a visual inspection to check the ch ange in situation of the indenter 
and its surrounding area.  
 
(D The suitable adhesive tapes on the market are Scotch Premium Cellophane tape 610 or Permacel P -99 adhesive 
tape. We list these product information here is just for the convenience purpose for people who use this part of 
standard, it doesn't mean that we give acceptance to these products.)  
5.4.7 Wear resistance  
Carry out the wear resistance test according to the methods specified in Appendix A to GB 
5237.4 -2008.  
5.4.8 Hydrochloric acid corrosion  resistance  
Use chemical hydrochloric 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 coating s urface of the sample, cover up with a watch 
glass and then leave it in an environment with a temperature of 180C ~ 270C for 15 minutes. 
Wash clean under tap water, air dry, then carry out a visual investigation to check the test 
coating surface.  
5.4.9 Nitr ic acid resistance  
Pour 100ml analytically pure nitric acid ( 1.4g/ml) into a 200ml wide -opening bottle, in a 
temperature of 230C± 20C. Put the coating side of the sample on the bottle opening for 30 
minutes, then remove the sample and rinse it clean under tap water and wipe dry. Leave for one 
hour then carry out a  visual inspection to check test coating surface.  
5.4.10 Mortar resistance  
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 about 100g third grade water as specifie d in 
GB/T 6682. Mix together into a lime and sand paste mortar. Put the paste mortar onto the 
surface of the sample and pile up to a cylinder with a diameter of 15mm and thickness of 6mm. 
Leave in an environment with a temperature of 380C± 30C and relative  humidity of 95%± 5% 
for 24 hours. Remove the paste mortar from the sample and, using a wet cloth, clean the residue 
off the surface and allow it to dry in the air. Carry out a visual investigation to check the test 
coating surface.  
5.4.11 Solvent resistan ce 
Soak a piece of absorbent cotton in butanone solution until the cotton is saturated, then place 
onto the sample for 30 seconds. Next, take the cotton off, rinse the sample clean under tap water 
and wipe it dry, then leave it in an ambient temperature fo r 2 hours. Using a fingernail, carry out 
a scratch test. No noticeable scratch marks should be apparent.  
5.4.12 Detergent resistance  
5.4.12.1 Use detergent (composition see to Table 3) and third grade water as specified in GB/T 
6682 to mix up the detergent  test solution with a concentration of 30g/l. Soak at least 2 samples 
in detergent test solution at a temperature of 380C± 10C for 72 hours, then remove the sample - 12 - and wipe it dry. Carry out a visual inspection to check the test coating surface.  
 
 
 
 
 
 
Tabl e 5 
Composition  Content (Weight) %  
Tetrasodium Pyrophosphate  53 
Sodium Sulphate Anhydyous  19 
Sodium Linear alkylarylsulfonate  20 
Sodium Metasillicate Hydrated  7 
Sodium Carbonate Anhydrous  1 
Total  100 
 
5.4.12.2 Immediately cover the after -test coatin g surface with a piece of adhesive tape, the 
adhesive force of which should be greater than 10N/25mm. Press down tightly to remove the air 
underneath the tape, then pull the tape off quickly at a vertical angle from the coating surface. 
Carry out a visual inspection to check the test coating surface.  
5.4.13 Salt spray corrosion resistance  
5.4.13.1 On a piece of sample sized 150mm x 75mm, along the diagonal line to cut two cross 
lines as deep as reach to the metallic basis, the line segment should not run th rough the opposite 
corner, and the distances from each end point of the line segments to the corresponding opposite 
angle (corner) should be the same. According to the test methods specified in GB/T 10125 then 
carry out the 4000 -hour neutral salt -spray tes t. 
 
5.4.13.2 Measure the unidirectional infiltration corrosion width under the coating on both side 
of the cut cross line, then check both side areas beyond 2.0mm from the cross line for corrosion 
on the coating surface.  
5.4.14 Heat -humidity resistance  
Carry out the heat -humidity resistance test according to the provisions of GB/T 1740. The test 
temperature should be 470C± 10C. 
5.4.15 Weatherability  
5.4.15.1 Accelerated weatherability  
Carry out the xenon lamp accelerated weatherability test according to met hod 1 as specified in 
GB/T 1865 -1997. The gloss value measuring procedure should conform to the provisions of 
GB/T 9754, and the evaluations for the chalking degree and colour change degree should 
conform to GB/T 1766.  
5.4.15.2 Natural weatherability  
Carry  out the test according to the provisions set out in GB/T 9276.  - 13 - 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.  
5.4.16 Others  
Tests on other properties should be performed according to test methods specified in GB/T 
8013.3 – 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 before sunset), and according to the 
provisions set out in GB/T 9761. The required luminance le vel 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, checking and acceptanc e 
6.1.1  An examination of the PVDF coating profiles should be carried out by the suppliers so as 
to ensure that the quality of the PVDF coating profiles conform to the requirements set out in 
this Part (or purchase contract), and the quality certificate sh ould also be completed by them.  
 
6.1.2  Buyers may carry out examinations that are specified in this Part regarding the PVDF 
coating profiles they receive. If the examination results do not conform to the requirements set 
out in this Part or in the purchase  contract, and result in a disagreement related to appearance 
quality and dimension deviation, the buyer should submit the problems within one month of the 
date on which the PVDF coating profiles were received. If the disagreement is related to other 
prope rties, then the buyer may submit the problems within three months of receiving the PVDF 
coating profiles, and both supplier and buyer should come to an agreement through consultation. 
If a negotiation is required, the suppliers should provide the agreed sa mples and the problem 
should be resolved between the supplier and buyer together.  
6.2 Batch approval  
PVDF coating profiles should be submitted for approval and acceptance in batches. PVDF 
coating profiles with the same alloy grades, same supply states, sam e specifications, same 
grades of coating thickness and the same surface treatments may constitute a batch. The 
quantity of each batch of PVDF coating profiles is unrestricted.  
6.3 Inspection item  
Inspections of chemical composition, mechanical properties, dimension deviation, coating 
thickness, gloss, appearance quality, hardness, adhesive force and impact resistance should be 
carried out on every batch of PVDF coating profiles. Inspections of other properties are not 
usually carried out (the suppliers carr y 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 properties, then these requests 
shou ld be clearly indicated in the contract.  
 - 14 - 6.4 Sampling  
PVDF coating profile sampling procedures should be carried out in accordance with the 
provisions set out in Table 5.  
 
Table 5  
Test Item  Sampling Rules  Requested 
Clause 
Number  The Clause 
Number of 
Test 
Method  
Chemical composition, 
mechanics properties, 
dimension deviation,  According to the rules in GB 5237.1  4.3, 
4.4 5.1, 
5.2, 
5.3 
Coating colour and 
chromaticism  One by one inspection method  4.5.2  5.4.2  
Coating thickness   4.5.3  5.4.3  
Coating glossines s 4.5.1  5.4.1  
Coating hardness  4.5.4  5.4.4.  
Coating adherence 
force Take 2 pieces of PVDF coating profiles per 
test item from each batch; when the paint 
coating has solidified and has been left for a 
further 24 hours, cut one sample from each 
piece profile.  4.5.5  5.4.5  
Coating impact 
resistance  Make two standard sample plates.  
Method for making standard sample plates: 
choose two pieces pure aluminium sample 
plates, one with state of H24, another with 
state of H14, both plates with the same 
dimension as  150mm x 75mm x 1.0mm, 
adopt the same technology and same 
production line as the batches of profiles the  
samples are representing to have the paint 
sprayed (the coating thickness should be 
appropriately kept in the range of 60m ~ 80 
m), solidified, soon after leave it for 24 
hours.  4.5.6  5.4.6  
Coating wear resistance  4.5.7  5.4.7  
4.5.8  5.4.8  Hydrochloric acid 
resistance  4.5.9  5.4.9  
Nitric acid resistance  4.5.10  5.4.10  
Mortar resistance  4.5.11  5.4.11  
Solvent resistance  4.5.12  5.4.12  
Detergent resistance  4.5.13  5.4.13  
Coating salt -spray 
resistance  Take 2 pieces of PVDF coating profiles  per 
test item from each batch. When the paint 
coating solidifies leave for a further 24 hours, 
then cut one sample from each piece profile.  
4.5.14  5.4.14  - 15 - Coating heat -humidity 
resistance  
Coating weatherability  4.5.15  5.4.15  
Appearance quality  One by one inspection  4.6 5.5 
 
6.5 Determination of the inspection results  
6.5.1 If the inspection for chemical composition does not meet the required standard, then this 
batch is deemed as not qualified.  
 
6.5.2 If any one of the samples f ails to meet the required standard during the inspection for 
mechanical properties, re -sampling should take place using double the original number of test 
samples from this batch of profiles (including the original unqualified sample). If the repeated 
test results qualify, then this batch of PVDF coating profiles deemed to be qualified. If any of 
the repeated test results continues to fail to meet the required standard, then this batch is deemed 
as not qualified.  
 
6.5.3 If the colour, chromaticism or appear ance quality of the coating does not meet the required 
standard, then this single piece is not qualified, however individual inspections are allowed, and 
PVDF coating profiles that qualify should be delivered.  
 
6.5.4 If dimension deviation does not meet th e required standard, then the batch of PVDF 
coating profiles is deemed as not qualified. Individual testing is permitted, however, and 
qualified pieces should be delivered.  
 
6.5.5 If the number of unqualified coating thickness exceeds the specified allowab le unqualified 
upper limit numbers, as set out in Table 6, then the batch of profiles is deemed as not qualified. 
The supplier may, however, carry out individual inspection, and qualified pieces should be 
delivered.  
 
Table 6  
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 
301 ~ 500  20 2 
501 ~ 800  30 3 
Over 800  40 4 
 
6.5.6 With regard to other property test results of the coating, if any one sample fails to qualify, 
then the batch of PVDF coating profiles is deemed as not qualified.  - 16 - 7 Labels, packaging, transportation, storage  
7.1 The label (or quality certificate) on the qualified PVDF 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 profile;  
e) production date or batch number;  
f) the colour or number of the coating  
g) serial number of this Part;  
h) the producti on license number and QS mark.  
 
7.2 The package symbols of the PVDF coating profiles should conform to the requirements set 
out in GB/T 3199.  
 
7.3 The profiles should be bundled up and packed in paper, and the exposed surfaces of the 
profiles should be pro tected by paper padding or bubble wrap.  
 
7.4 The transportation and storage of PVDF coating profiles should conform to the provisions 
set out in GB/T 3199.  
7.5 Quality certificate  
A copy of the quality certificate should be attached to each batch of PVDF c oating profiles, on 
which the following should be clearly indicated:  
a) name of the supplier;  
b) the name and specification of the PVDF coating profiles;  
c) alloy grade and state;  
d) the colour or number of the coating;  
e) weight or quantity;  
f) batch number or production d ate; 
g) serial number of this part;  
h) all analysed inspection results and the examination stamp from the department of quality 
control of the supplier;  
i) production license number;  
j) factory shipment date (or package date).  
8 The contents of the contract (or order list) 
The contract (or the order list) for purchasing materials listed in this Part should contain the 
following information:  
 
a) product names  
b) alloy grades, supply states;  
c) profiles specifications;  
d) dimension deviations, accuracy grades;  
e) coating glossiness, co lour and the colour number;  
f) weight or quantity;  
g) serial number of this part;  
h) other requests.