Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This standard is not equivalent to International Union of Railways standard UIC 842.2-1975 Technical Specification for Methods for Testing Paint Products. It adopts similar form with UIC standard. The testing contents and methods hereof are basically consistent with those in UIC standard. As for test methods, those given in ISO standard and the national standard equivalent or nonequivalent to foreign advanced standard are mainly adopted, meanwhile relevant test methods which are commonly-used at present and specified in national standard are listed.
This standard is Part 2 of the series standards "Railway Rolling Stock - Paint and Painting"; other parts are as follows:
TB/T 2879.1-1998 (neq UIC 842.1-1975) Part 1: Technical Specification for Supply of Paints
TB/T 2879.3-1998 (neq UlC 842.3-1979) Part 3: Technical Specification for Surface Treatment of Metallic and Nonmetallic Materials
TB/T 2879.4-1998 (neq UIC 842.4-1979) Part 4: Technical Specification for Protection and Painting of Freight Car
TB/T 2879.5-1998 (neq UIC 842.5-1975) Part 5: Technical Specification for Protection and Painting of Passenger Car and Tractive Units
TB/T 2879.6-1998 (neq UIC 842.6-1979) Part 6: Code for Quality Inspection & Acceptance of Painting
This standard was proposed by Dalian Diesel Locomotive Research Institute of MOR.
It is under the jurisdiction of Standards and Metrology Research Institute of MOR.
It was firstly issued in February 1998.
Railway Rolling Stock - Paint and Painting -
Part 2: Methods for Testing Paints
1 Scope
This standard specifies the methods for testing paints for railway rolling stock, and is applicable to protective paints for railway rolling stock.
2 Normative References
The following standards contained provisions which through reference in this standard, constitute provisions of this standard. At the time of publication, all editions indicated are valid. All standards are subject to revision, and parties to agreements based on this standard are encouraged to investigate the possibility of applying the latest editions of the following standards.
GB/T 1723-1993 Determination of Viscosity of Coatings
GB/T 1724-1979 (1989) Methods of Test for Fineness of Grind of Paints
GB/T 1726-1979 (1989) Methods of Test for Hiding Power of Paints
GB/T 1727-1992 General Preparation of Paint Film
GB/T 1728-1979 (1989) Methods of Test for Drying Time of Coatings of Paints and Putties
GB/T 1730-1993
(neq ISO 1522:1973) Determination of Hardness of the Paint Films - Pendulum Damping Test
GB/T 1731-1993 Determination of Flexibility of Films
GB/T 1732-1993 Determination of Impact Resistance of Film
GB/T 1733-1993 Determination of Resistance to Water of Films
GB/T 1734-1993 Determination of Resistance to Petrol of Films
GB/T 1735-1979 (1989) Method of Test for Heat Resistance of Paint Films
GB/T 1740-1979 (1989) Determination of Resistance to Heat and Humidity of Paint Films
GB/T 1748-1979 (1989) Method of Test for Flexibility of Putty Coatings
GB/T 1749-1979 (1989) Method of Test for Consistency of Pastes and Putties
GB/T 1763-1979 (1989) Methods of Test for Chemical Resistance of Paint Films
GB/T 1766-1979 (1989) Method of Evaluation of Degradation (Both Exterior and Accelerated) of Paint Films
GB/T 1767-1979 (1989) Determination Method for Film Weatherability
GB/T 1768-1979 (1989) Method of Test for Abrasion Resistance of Paint Films
GB/T 1770-1979 (1989) Method of Test for Sanding Property of Coatings of Primers and Putties
GB/T 1771-1991
(eqv ISO 7253:1984) Paints and Varnishes - Determination of Resistance to Neutral Salt Spray
GB/T 1865-1980 (1989) Determination of Aging (Manual Accelerated Aging) of Film
GB 3186-1982 (1989)
(neq ISO 1512:1974) Sampling Paint Products
GB/T 5208-1985
(neq ISO 3679:1983) Coatings - Flash Point Test - Rapid Equilibrium Method
GB/T 5209-1985
(neq ISO 1521:1973) Paints and Varnishes - Determination of Resistance to Water - Water Immersion Method
GB/T 5210-1985
(neq ISO 4624:1978) Determination of Adhesion of Coats - Pull-off Test
GB/T 6739-1986 Determination of Film Hardness by Pencil Test
GB/T 6742-1986
(neq ISO 1519:1973) Bend Test for Coating (Cylindrical Mandrel)
GB/T 6750-1986
(neq ISO 2811:1974) Paints and Varnishes - Determination of Density
GB/T 6751-1986
(neq ISO 1515:1973) Paints and Varnishes - Determination of Volatile and Non-volatile Matter
GB/T 6753.1-1986
(neq ISO 1524:1983) Determination of Fineness of Grind for Coatings
GB/T 6753.2-1986
(neq ISO 1517:1973) Paints and Varnishes - Surface-drying Test - Ballotini Method
GB/T 6753.3-1986 Methods of Test for Package Stability of Paints
GB/T 6753.4-1986
(neq ISO 2431:1984) Determination of Flow Time of Paints and Varnishes by Use of ISO Flow Cups
GB/T 9264-1988 Test Method for Sagging of Paints
GB/T 9268-1988 Determination of Freeze-thaw Resistance of Latex and Emulsion Paints
GB/T 9269-1988 Determination of Viscosity of Architectural Paints and Coatings Using Stormer Viscosimeter
GB/T 9271-1988
(eqv ISO 1514:1984) Paints and Varnishes - Standard Panels for Testing
GB/T 9273-1988
(eqv ISO 3678:1976) Print-free Test of Film
GB/T 9274-1988
(eqv ISO 2812:1974) Paints and Varnishes - Determination of Resistance to Liquids
GB/T 9276-1988
(eqv ISO 2810:1974) Paint and Varnish - Methods of Exposure to Natural Weathering of Coating
GB/T 9277.1-1988
(eqv ISO 4628/1:1982) Evaluation of Degradation of Paint Coatings - Part 1: General Principles and Rating Schemes
GB/T 9277.2-1988
(eqv ISO 4628/2:1982) Evaluation of Degradation of Paint Coatings - Part 2: Designation of Degree of Blistering
GB/T 9277.3-1988
(eqv ISO 4628/3:1982) Evaluation of Degradation of Paint Coatings - Part 3: Designation of Degree of Rusting
GB/T 9277.4-1988
(eqv ISO 4628/4:1982) Evaluation of Degradation of Paint Coatings - Part 4: Designation of Degree of Cracking
GB/T 9277.5-1988
(eqv ISO 4628/5:1982) Evaluation of Degradation of Paint Coatings - Part 5: Designation of Degree of Flaking
GB/T 9278-1988
(eqv ISO 3270:1984) Temperatures and Humidities for Conditioning and Testing of Paint Specimens
GB/T 9279-1988
(eqv ISO 1518:1973) Paints and Varnishes - Scratch Test
GB/T 9286-1988
(eqv ISO 2409:1972) Paints and Varnishes - Cross Cut Test for Films
GB/T 9751-1988
(neq ISO 2884:1974) Determination of Viscosity of Coatings at a High Rate of Shear
GB/T 9752-1988
(neq ISO 1516:1981) Coatings and Related Products - Flash/No Flash Test - Closed cup Equilibrium Method
GB/T 9753-1988
(neq ISO 1520:1973) Paints and Varnishes - Cupping Test
GB/T 9754-1988
(neq ISO 2813:1978) Paints and Varnishes - Measurement of Specular Gloss of Non-metallic Paint Films at 20°,60°and 85°
GB/T 11186.2-1989
(eqv ISO 7724/2:1984) Methods for Measuring the Colour of Paint Films - Part 2: Colour Measurement
GB/T 11189.1-1989 Operating Light-exposure Apparatus (Xenon-arc Type) with and without Water and Testing Method for Exposure of Nonmetallic Materials
GB/T 11189.2-1989 Operating Light-exposure Apparatus (Carbon-arc Type) with and without Water and Testing Method for Exposure of Nonmetallic Materials
GB/T 11190-1989 Operating Light- and Water-exposure Apparatus (Carbon-arc Type) and Testing Method for Testing Paint, Varnish, Lacquer, and Related Products
GB/T 13452.2-1992
(eqv ISO 2808:1974) Paints and Varnishes - Determination of Film thickness
GB/T 13452.4-1992
(eqv ISO 4623:1984) Paints and Varnishes - Filiform Corrosion Test on Steel
GB/T 14826-1993 Determining and Evaluating Degree of Chalking of Paint Coats
GB/T 16259-1996
(neq ISO 4892:1993) Test Method for Color Changes in Accelerated Weathering of Colored Building Materials
GB/T 16406-1996
(neq ISO 6721-3:1994) Acoustics - Flexural Resonance Testing Method for Damping Properties of Acoustical Materials
GSB G51001-1994 Color Standard Cards for Films
TB/T 2260-1991 Technical Specification for Supply of Anti-rust Primer for Rolling Stock
TB/T 2393-1993 Technical Specification for Supply of Finish Paint for Rolling Stock
TB/T 2707-1996 Technical Specification for Alkyd Paste Paint for Use on Railway Wagons
TB/T 2879.1-1998
(neq UIC 842.1-1975) Railway Rolling Stock - Paint and Painting of - Part 1: Technical Specification for Supply of Paints
3 Sample Taking and Preparation
3.1 Sampling
In principle, samples are taken in the manufacturing factory by a representative of consumer. The manufacturer shall supply the staff and equipment necessary for correct rapid sampling of the paints submitted for acceptance of his own expense. Products shall be submitted in batches, which must only include those of the same kind from the same manufacturing batch. Sampling procedure shall be in strict accordance with the relevant requirements of GB 3186.
3.2 Test panels
Test panels shall be prepared according to the relevant requirements of GB/T 1727. The material of base panel shall be selected according to GB/T 9271 and subjected to surface treatment or determined as per the user's requirements and actual application conditions.
3.3 Sample state regulation and test temperature and humidity
According to GB/T 9278, the standard environmental condition is 23℃±2℃ in temperature and (50±5)% in relative humidity.
4 Testing Methods
4.1 Methods of testing paints in delivery condition
4.1.1 Determination of viscosity
For determining the viscosity of paint, one of the following methods can be selected:
a) Determining the flow time of paint by use of ISO flow cups according to GB/T 6753.4;
b) Determining viscosity of paint with coating-1 viscosimeter, coating-4 viscosimeter or falling ball viscosimeter according to the requirements of GB/T 1723;
c) Using Stormer viscosimeter according to the requirements of GB/T 9269;
d) For thixotropic or viscous paint, determining its viscosity with viscosimeter or inspecting brushability directly according to GB/T 9751.
e) For putty or other very sticky paint (paste paint), determining the consistency according to the requirements of GB/T 1749.
4.1.2 Determination of density
Paint density is determined according to the requirements of GB/T 6750.
4.1.3 Determination of volatile and non-volatile matters
Volatile and non-volatile matters in paint are determined according to the requirements of GB/T 6751.
4.1.4 Determination of fineness
The fineness of grind for coatings is determined according to the requirements of GB/T 6753.1 or GB/T 1724.
4.1.5 Determination of package stability
The package stability of paint is determined according to the requirements of GB/T 6753.3.
4.1.6 Determination of frost resistance of water soluble paint
Frost resistance of water soluble latex paint is determined according to the requirements of GB/T 9268; for other water soluble paints, the determination is carried out according to the user's requirements.
4.1.7 Determination of danger grade according to the flash point
Flash point of paint is determined according to the requirements of GB/T 9752 or GB/T 5208 to determine the danger grade of paint:
a) <21℃;
b) 21℃~55℃;
c) >55℃.
4.2 Methods of testing the paint to be coated
4.2.1 Determination of the available period of two-component paint
Available period of two-component paint is determined according to the following method: uniformly mix at least 200g of component A and component B in proportion and adjust it to applicable viscosity by adding diluent, put the solution into 100mm-diameter and 45mm-high tinplate vessel; the time when there is gel or precipitate after two components are mixed is the available period.
4.2.2 Determination of matchability
Matchability is determined according to the following methods: brush all paints on the steel plate of 300mm×300mm in minimum area according to the requirements of 3.2, dry the paints as required, then brush the next layer paint according to the requirements of painting system and record the construction of the next layer paint as well as the appearance of dry film.
4.2.3 Determination of drying time
Determine the drying time of paint film according to relevant requirements in GB/T 6753.2 and GB/T 9273 or GB/T 1728; the drying time of putty film is determined according to the relevant requirements of GB/T 1728.
4.2.4 Determination of hiding power
Hiding power is determined according to the requirements of GB/T 1726; or determine the minimum thickness of dry film of which the ground color is covered by paint.
4.2.5 Determination of coating thickness
4.2.5.1 Determination of dry film thickness
Dry film thickness of coating is determined according to the requirements of GB/T 13452.2. According to the property of base material, mechanical, optical, magnetic, electromagnetic or vortex flow method and the like are adopted for measurement; the error of measuring apparatus shall be less than 10%. Where selecting measuring apparatus and making measurement, the influence of such factors as roughness and object shape on the measurement result must be considered.
Dry film thickness is expressed in μm.
4.2.5.2 Determination of wet film thickness
Wet film thickness measurement shall be carried out immediately after painting.
The measuring apparatus is a hardened and polished steel disk of 50mm in diameter, accompanied with two concentric rolling surfaces at outer side and one eccentric test surface in the center as well as marked with division on both sides. It is able to measure wet film thickness of (0~300)μm.
Foreword i 1 Scope 2 Normative References 3 Sample Taking and Preparation 4 Testing Methods 5 Test Report Annex A (Normative) Determination of Solderability - Spot Welding Test Panel
Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This standard is not equivalent to International Union of Railways standard UIC 842.2-1975 Technical Specification for Methods for Testing Paint Products. It adopts similar form with UIC standard. The testing contents and methods hereof are basically consistent with those in UIC standard. As for test methods, those given in ISO standard and the national standard equivalent or nonequivalent to foreign advanced standard are mainly adopted, meanwhile relevant test methods which are commonly-used at present and specified in national standard are listed.
This standard is Part 2 of the series standards "Railway Rolling Stock - Paint and Painting"; other parts are as follows:
TB/T 2879.1-1998 (neq UIC 842.1-1975) Part 1: Technical Specification for Supply of Paints
TB/T 2879.3-1998 (neq UlC 842.3-1979) Part 3: Technical Specification for Surface Treatment of Metallic and Nonmetallic Materials
TB/T 2879.4-1998 (neq UIC 842.4-1979) Part 4: Technical Specification for Protection and Painting of Freight Car
TB/T 2879.5-1998 (neq UIC 842.5-1975) Part 5: Technical Specification for Protection and Painting of Passenger Car and Tractive Units
TB/T 2879.6-1998 (neq UIC 842.6-1979) Part 6: Code for Quality Inspection & Acceptance of Painting
This standard was proposed by Dalian Diesel Locomotive Research Institute of MOR.
It is under the jurisdiction of Standards and Metrology Research Institute of MOR.
It was firstly issued in February 1998.
Railway Rolling Stock - Paint and Painting -
Part 2: Methods for Testing Paints
1 Scope
This standard specifies the methods for testing paints for railway rolling stock, and is applicable to protective paints for railway rolling stock.
2 Normative References
The following standards contained provisions which through reference in this standard, constitute provisions of this standard. At the time of publication, all editions indicated are valid. All standards are subject to revision, and parties to agreements based on this standard are encouraged to investigate the possibility of applying the latest editions of the following standards.
GB/T 1723-1993 Determination of Viscosity of Coatings
GB/T 1724-1979 (1989) Methods of Test for Fineness of Grind of Paints
GB/T 1726-1979 (1989) Methods of Test for Hiding Power of Paints
GB/T 1727-1992 General Preparation of Paint Film
GB/T 1728-1979 (1989) Methods of Test for Drying Time of Coatings of Paints and Putties
GB/T 1730-1993
(neq ISO 1522:1973) Determination of Hardness of the Paint Films - Pendulum Damping Test
GB/T 1731-1993 Determination of Flexibility of Films
GB/T 1732-1993 Determination of Impact Resistance of Film
GB/T 1733-1993 Determination of Resistance to Water of Films
GB/T 1734-1993 Determination of Resistance to Petrol of Films
GB/T 1735-1979 (1989) Method of Test for Heat Resistance of Paint Films
GB/T 1740-1979 (1989) Determination of Resistance to Heat and Humidity of Paint Films
GB/T 1748-1979 (1989) Method of Test for Flexibility of Putty Coatings
GB/T 1749-1979 (1989) Method of Test for Consistency of Pastes and Putties
GB/T 1763-1979 (1989) Methods of Test for Chemical Resistance of Paint Films
GB/T 1766-1979 (1989) Method of Evaluation of Degradation (Both Exterior and Accelerated) of Paint Films
GB/T 1767-1979 (1989) Determination Method for Film Weatherability
GB/T 1768-1979 (1989) Method of Test for Abrasion Resistance of Paint Films
GB/T 1770-1979 (1989) Method of Test for Sanding Property of Coatings of Primers and Putties
GB/T 1771-1991
(eqv ISO 7253:1984) Paints and Varnishes - Determination of Resistance to Neutral Salt Spray
GB/T 1865-1980 (1989) Determination of Aging (Manual Accelerated Aging) of Film
GB 3186-1982 (1989)
(neq ISO 1512:1974) Sampling Paint Products
GB/T 5208-1985
(neq ISO 3679:1983) Coatings - Flash Point Test - Rapid Equilibrium Method
GB/T 5209-1985
(neq ISO 1521:1973) Paints and Varnishes - Determination of Resistance to Water - Water Immersion Method
GB/T 5210-1985
(neq ISO 4624:1978) Determination of Adhesion of Coats - Pull-off Test
GB/T 6739-1986 Determination of Film Hardness by Pencil Test
GB/T 6742-1986
(neq ISO 1519:1973) Bend Test for Coating (Cylindrical Mandrel)
GB/T 6750-1986
(neq ISO 2811:1974) Paints and Varnishes - Determination of Density
GB/T 6751-1986
(neq ISO 1515:1973) Paints and Varnishes - Determination of Volatile and Non-volatile Matter
GB/T 6753.1-1986
(neq ISO 1524:1983) Determination of Fineness of Grind for Coatings
GB/T 6753.2-1986
(neq ISO 1517:1973) Paints and Varnishes - Surface-drying Test - Ballotini Method
GB/T 6753.3-1986 Methods of Test for Package Stability of Paints
GB/T 6753.4-1986
(neq ISO 2431:1984) Determination of Flow Time of Paints and Varnishes by Use of ISO Flow Cups
GB/T 9264-1988 Test Method for Sagging of Paints
GB/T 9268-1988 Determination of Freeze-thaw Resistance of Latex and Emulsion Paints
GB/T 9269-1988 Determination of Viscosity of Architectural Paints and Coatings Using Stormer Viscosimeter
GB/T 9271-1988
(eqv ISO 1514:1984) Paints and Varnishes - Standard Panels for Testing
GB/T 9273-1988
(eqv ISO 3678:1976) Print-free Test of Film
GB/T 9274-1988
(eqv ISO 2812:1974) Paints and Varnishes - Determination of Resistance to Liquids
GB/T 9276-1988
(eqv ISO 2810:1974) Paint and Varnish - Methods of Exposure to Natural Weathering of Coating
GB/T 9277.1-1988
(eqv ISO 4628/1:1982) Evaluation of Degradation of Paint Coatings - Part 1: General Principles and Rating Schemes
GB/T 9277.2-1988
(eqv ISO 4628/2:1982) Evaluation of Degradation of Paint Coatings - Part 2: Designation of Degree of Blistering
GB/T 9277.3-1988
(eqv ISO 4628/3:1982) Evaluation of Degradation of Paint Coatings - Part 3: Designation of Degree of Rusting
GB/T 9277.4-1988
(eqv ISO 4628/4:1982) Evaluation of Degradation of Paint Coatings - Part 4: Designation of Degree of Cracking
GB/T 9277.5-1988
(eqv ISO 4628/5:1982) Evaluation of Degradation of Paint Coatings - Part 5: Designation of Degree of Flaking
GB/T 9278-1988
(eqv ISO 3270:1984) Temperatures and Humidities for Conditioning and Testing of Paint Specimens
GB/T 9279-1988
(eqv ISO 1518:1973) Paints and Varnishes - Scratch Test
GB/T 9286-1988
(eqv ISO 2409:1972) Paints and Varnishes - Cross Cut Test for Films
GB/T 9751-1988
(neq ISO 2884:1974) Determination of Viscosity of Coatings at a High Rate of Shear
GB/T 9752-1988
(neq ISO 1516:1981) Coatings and Related Products - Flash/No Flash Test - Closed cup Equilibrium Method
GB/T 9753-1988
(neq ISO 1520:1973) Paints and Varnishes - Cupping Test
GB/T 9754-1988
(neq ISO 2813:1978) Paints and Varnishes - Measurement of Specular Gloss of Non-metallic Paint Films at 20°,60°and 85°
GB/T 11186.2-1989
(eqv ISO 7724/2:1984) Methods for Measuring the Colour of Paint Films - Part 2: Colour Measurement
GB/T 11189.1-1989 Operating Light-exposure Apparatus (Xenon-arc Type) with and without Water and Testing Method for Exposure of Nonmetallic Materials
GB/T 11189.2-1989 Operating Light-exposure Apparatus (Carbon-arc Type) with and without Water and Testing Method for Exposure of Nonmetallic Materials
GB/T 11190-1989 Operating Light- and Water-exposure Apparatus (Carbon-arc Type) and Testing Method for Testing Paint, Varnish, Lacquer, and Related Products
GB/T 13452.2-1992
(eqv ISO 2808:1974) Paints and Varnishes - Determination of Film thickness
GB/T 13452.4-1992
(eqv ISO 4623:1984) Paints and Varnishes - Filiform Corrosion Test on Steel
GB/T 14826-1993 Determining and Evaluating Degree of Chalking of Paint Coats
GB/T 16259-1996
(neq ISO 4892:1993) Test Method for Color Changes in Accelerated Weathering of Colored Building Materials
GB/T 16406-1996
(neq ISO 6721-3:1994) Acoustics - Flexural Resonance Testing Method for Damping Properties of Acoustical Materials
GSB G51001-1994 Color Standard Cards for Films
TB/T 2260-1991 Technical Specification for Supply of Anti-rust Primer for Rolling Stock
TB/T 2393-1993 Technical Specification for Supply of Finish Paint for Rolling Stock
TB/T 2707-1996 Technical Specification for Alkyd Paste Paint for Use on Railway Wagons
TB/T 2879.1-1998
(neq UIC 842.1-1975) Railway Rolling Stock - Paint and Painting of - Part 1: Technical Specification for Supply of Paints
3 Sample Taking and Preparation
3.1 Sampling
In principle, samples are taken in the manufacturing factory by a representative of consumer. The manufacturer shall supply the staff and equipment necessary for correct rapid sampling of the paints submitted for acceptance of his own expense. Products shall be submitted in batches, which must only include those of the same kind from the same manufacturing batch. Sampling procedure shall be in strict accordance with the relevant requirements of GB 3186.
3.2 Test panels
Test panels shall be prepared according to the relevant requirements of GB/T 1727. The material of base panel shall be selected according to GB/T 9271 and subjected to surface treatment or determined as per the user's requirements and actual application conditions.
3.3 Sample state regulation and test temperature and humidity
According to GB/T 9278, the standard environmental condition is 23℃±2℃ in temperature and (50±5)% in relative humidity.
4 Testing Methods
4.1 Methods of testing paints in delivery condition
4.1.1 Determination of viscosity
For determining the viscosity of paint, one of the following methods can be selected:
a) Determining the flow time of paint by use of ISO flow cups according to GB/T 6753.4;
b) Determining viscosity of paint with coating-1 viscosimeter, coating-4 viscosimeter or falling ball viscosimeter according to the requirements of GB/T 1723;
c) Using Stormer viscosimeter according to the requirements of GB/T 9269;
d) For thixotropic or viscous paint, determining its viscosity with viscosimeter or inspecting brushability directly according to GB/T 9751.
e) For putty or other very sticky paint (paste paint), determining the consistency according to the requirements of GB/T 1749.
4.1.2 Determination of density
Paint density is determined according to the requirements of GB/T 6750.
4.1.3 Determination of volatile and non-volatile matters
Volatile and non-volatile matters in paint are determined according to the requirements of GB/T 6751.
4.1.4 Determination of fineness
The fineness of grind for coatings is determined according to the requirements of GB/T 6753.1 or GB/T 1724.
4.1.5 Determination of package stability
The package stability of paint is determined according to the requirements of GB/T 6753.3.
4.1.6 Determination of frost resistance of water soluble paint
Frost resistance of water soluble latex paint is determined according to the requirements of GB/T 9268; for other water soluble paints, the determination is carried out according to the user's requirements.
4.1.7 Determination of danger grade according to the flash point
Flash point of paint is determined according to the requirements of GB/T 9752 or GB/T 5208 to determine the danger grade of paint:
a) <21℃;
b) 21℃~55℃;
c) >55℃.
4.2 Methods of testing the paint to be coated
4.2.1 Determination of the available period of two-component paint
Available period of two-component paint is determined according to the following method: uniformly mix at least 200g of component A and component B in proportion and adjust it to applicable viscosity by adding diluent, put the solution into 100mm-diameter and 45mm-high tinplate vessel; the time when there is gel or precipitate after two components are mixed is the available period.
4.2.2 Determination of matchability
Matchability is determined according to the following methods: brush all paints on the steel plate of 300mm×300mm in minimum area according to the requirements of 3.2, dry the paints as required, then brush the next layer paint according to the requirements of painting system and record the construction of the next layer paint as well as the appearance of dry film.
4.2.3 Determination of drying time
Determine the drying time of paint film according to relevant requirements in GB/T 6753.2 and GB/T 9273 or GB/T 1728; the drying time of putty film is determined according to the relevant requirements of GB/T 1728.
4.2.4 Determination of hiding power
Hiding power is determined according to the requirements of GB/T 1726; or determine the minimum thickness of dry film of which the ground color is covered by paint.
4.2.5 Determination of coating thickness
4.2.5.1 Determination of dry film thickness
Dry film thickness of coating is determined according to the requirements of GB/T 13452.2. According to the property of base material, mechanical, optical, magnetic, electromagnetic or vortex flow method and the like are adopted for measurement; the error of measuring apparatus shall be less than 10%. Where selecting measuring apparatus and making measurement, the influence of such factors as roughness and object shape on the measurement result must be considered.
Dry film thickness is expressed in μm.
4.2.5.2 Determination of wet film thickness
Wet film thickness measurement shall be carried out immediately after painting.
The measuring apparatus is a hardened and polished steel disk of 50mm in diameter, accompanied with two concentric rolling surfaces at outer side and one eccentric test surface in the center as well as marked with division on both sides. It is able to measure wet film thickness of (0~300)μm.
Contents of TB/T 2879.2-1998
Foreword i
1 Scope
2 Normative References
3 Sample Taking and Preparation
4 Testing Methods
5 Test Report
Annex A (Normative) Determination of Solderability - Spot Welding Test Panel
