This standard specifies the technical conditions for the preparation of test panels for architectural coatings, plate making methods, film drying and state adjustment. This standard is applicable to the preparation of test panels used in performance testing of architectural coatings. JG/T 23-2001 Preparation of test panels for architectural coatings JG/T23-2001 Standard download decompression password: www.bzxz.net

The preparation of plate specimens for testingof building paints and coatingsJG/T23--2001
Approved and issued by the Ministry of Construction of the People's Republic of China on 12001-12-01 and implemented on 2001-08-07
This standard is a revision of the previous industry standard JG/T 23-1999, with some additions in technical content and comprehensive revisions in accordance with GB/T 1.1~1993 and GB/T1.3-1997. The main technical differences between this version and the previous version are: 1. Added wire rod coating plate;
2. Added scraper coating plate;
3. Added roller coating plate
This standard replaces JG/T23-1999 from the date of implementation. This standard is proposed by the Standard and Quota Research Institute of the Ministry of Construction. This standard is under the jurisdiction of the China Academy of Building Research under the Ministry of Construction. The responsible drafting unit of this standard is the Building Decoration Research Institute of the China Academy of Building Research; the participating drafting unit is Haiou Lao Ren Paint Co., Ltd.
The main drafters of this standard are Ding Linbao, Zhang Lequn, Su Jingjiao, and Lin Futian. This standard is entrusted to the Building Decoration Research Institute of the China Academy of Building Research for interpretation. 738
1 Scope
This standard specifies the technical conditions for the preparation of the base plate treatment, plate making method, coating film drying and state adjustment for the preparation of architectural coating test panels.
This standard is applicable to the preparation of test panels used in performance testing of architectural coatings. 2 Referenced standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards are subject to revision, and parties using this standard should explore the possibility of using the latest versions of the following standards.
GB3186-1982 (1989) Sampling of coating products JC/T412—1991 Asbestos cement flat plate for construction GB 9278—1988 Conditioning of coating sample state and temperature and humidity for testing 3 Materials and apparatus
3.1 Base plate
Asbestos cement flat plate, thickness 3~4mm, size and quantity determined according to relevant test methods. The technical requirements of the base plate shall comply with the provisions of JC/T412.
Boards of other materials specified in the relevant standards for architectural coatings may also be used. 3.2 Sandpaper
No. 0 (120 mesh) sandpaper and No. 2 (60 mesh) sandpaper, or sandpaper specified in the relevant standards for architectural coatings. 3.3 Wire rod applicator
Wire rod applicator: It is composed of a body and a metal wire. Metal wires of different diameters are wound around the body to form applicators of different specifications. It can produce wet films with a film thickness of 12~120um.
3.4 ​​Brush
Wool brushes and horsehair brushes are suitable. Brushes made of other materials such as polyester filaments can also be used. Its width is about 25~65mm.
Note: The brush weft of the paint shaving brush is preferably a mixture of long and short filaments. Short filaments adhere to the paint, and long filaments play a brushing role. There should also be a filter strip near the handle to intercept the paint well, so that the amount used during brushing is moderate and the brushing is uniform. 3.5 Balance: The sensitivity is 0.5g.
3.6 Spray gun
Ordinary or vacuum spray guns can be used.
The spray gun form and nozzle diameter shall be selected according to the relevant standards for architectural coatings. 3.7 Scraper
The head of the scraper should be soft and elastic (preferably made of metal or plastic sheet), and its width should be 60mm wider than the sample.
3.8 Scraper
The bottom plate is made of metal, and its surface roughness requirement is R.3.2um. The thickness of the longitudinal edge strip is determined according to the coating thickness required by the product standard.
3.9 Roller brush: It consists of a roller brush head and a roller brush frame. 3.10 Dipping trough: A plate-shaped trough.
4 Preparation before the test
4.1 Sampling shall be carried out in accordance with the provisions of GB3186.
4.2 Preparation of the base plate
First, use No. 2 (60 mesh) sandpaper, then use No. 0 (120 mesh) sandpaper to grind the front of the base plate flat, remove the dust on the surface, soak it in water to make the pH value of the base plate close to 10, and place it for at least 7 days under the conditions specified in GB9278. 4.3 Preparation of the sample
The sample should be carefully checked. If there is a crust on the surface, it should be carefully removed and then fully stirred. If the sample is still lumpy and uneven after being fully stirred, re-sample it. When the sample is multi-component, it should be mixed according to the ratio specified in the product and stirred evenly. After mixing evenly, it should be used within the time specified by the product. 5 Preparation method of test plate
Check whether the surface of the base plate is flat, whether there are defects and dust, and number the back of the base plate. 5.1 Wire rod coating method
5.1.1 Coating amount: Select a suitable wire rod coater according to the product standard requirements, and its usage will be controlled (see Figure 1). And check whether there is any residue in the wire rod thread seam, which should be cleaned up. d
Figure 1 Schematic diagram of wire rod coater
1--wire; 2-rod; 3-sample; 4-test plate; 5-workbench5.1.2 Place the base plate on a flat workbench, take a sample that has been stirred evenly and place it at one end of the base plate, so that there is no gap at the end of the short side, and lay out the hook evenly. Www.bzxZ.net
5.1.3 Hold the wire rod coater, push the paint to the other end at a uniform speed along the surface of the base plate, and apply it into a uniform coating (do not rotate or move the wire rod horizontally during the movement process). Unless there are special requirements for the product, it should generally be coated in two coats, and the interval between the two coats should meet the product requirements. If there are no requirements, the interval should be greater than 4h. 5.1.4 After each coat is applied, the excess paint around the test plate should be scraped off immediately, and the paint on the workbench should be removed. 5.1.5 After each coat is applied, the residue on the wire rod applicator should be cleaned immediately and carefully, and it should be wiped dry for reuse. After coating, the coating should be placed horizontally with the coating facing upward.
5.2 Brush coating method
5.2.1 Brush coating amount: The brush coating amount should comply with the relevant product standards. Generally, the actual brush coating amount can be determined by any of the following methods after brushing.
a) Weigh the base plate before brushing, and then weigh it again. The difference between the two masses is the brush coating amount. b) Take out a part of the sample and put it in a container, and weigh it together with the brush. After brushing, weigh the container and brush together 740
immediately. The difference between the two masses is the brush coating amount.
5.2.2 Brush coating steps: Select a suitable brush according to the product standard requirements. When painting, you should first brush along the long side, then along the short side, and finally brush along the long side carefully to make it a uniform coating. Unless there are special requirements for the product, generally two coats should be applied, and the interval between the two coats should meet the product requirements. If there are no requirements, the interval between the two coats should be greater than 4h. After brushing, the coating should face up and be placed horizontally.
5.3 Spraying method
5.3.1 Spraying amount: It should comply with the provisions of relevant product standards. Weigh the bottom plate before spraying, and then weigh it again. The difference between the two weights is the spraying amount.
5,3.2 Spraying steps: When spraying, the distance between the nozzle and the plate surface should be kept between 20 and 25cm, and move at a constant speed along the long side. Make the main direction of the mist paint perpendicular to the bottom plate surface as much as possible, and make the elliptical mist paint cross section perpendicular to the moving direction of the spray gun. The overlapping part of the mist paint during movement is about 1/3. If repeated spraying, the moving direction of the spray gun can be perpendicular to the previous direction. Spray the sample evenly on the base plate, or spray it into the required pattern in one time. No blanks or sagging are allowed. Immediately after spraying, turn the coating upwards and place the test plate horizontally. 5.4 Scrape coating method
5.4.1 Scrape coating steps: Place the base plate on the scraper and fix the longitudinal edge strip; make the scraper and the test plate roughly at a 45-degree angle, first move the scraper evenly along the short side, pull up the scraper; then move the scraper evenly along the long side to make the coating even and flat. Take out the sample with the coating facing upwards and place it horizontally. Clean the scraper and scraper for reuse. 5.5 Roller coating method
5.5.1 Roller coating amount: It should comply with the requirements of relevant product standards. Weigh the base plate, then coat it, and then weigh it again. The difference between the two weighings is the roller coating amount.
5.5.2 Rolling steps: Put the sample in the dip tank, immerse 1/2 of the roller brush in the sample, roll the roller brush in the tank several times to make the sample penetrate into the brush. First roll the roller brush on other base plates, and then dip it in the tank to evenly absorb the sample. Lay the base plate flat, and gently move the roller brush along the W shape on the surface of the base plate to gradually apply the paint on the base plate (the rolling operation should be light at the beginning, and then gradually increase the force), and finally roll the roller brush in the longitudinal direction. After the coating is dry, use the same method to roll the second coat. After rolling, place the coating horizontally with the coating facing up. 6 Maintenance of test panels
During and after coating, the sample should be placed for at least 7 days under the standard conditions specified in GB9278 unless there are special requirements, or placed according to the conditions required by the product standard. 741
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