LY/T 3133-2019Water-based coating for exterior wood (English PDF)

4.2 According to coating structure

a) primer;

a) intermediate paint;

b) Topcoat.

4.3 According to artificial aging performance

a) Type I. The artificial aging test is exposed for 12 weeks;

b) Type II. Artificial aging test exposure time is 6 weeks.

4.4 By Application

a) Class A. It is suitable for painting on the surface of woodware (such as wooden doors and windows, garden furniture) that allows small changes in size;

b) Class B. Suitable for coating on woodware that allows a partial change in size (such as sound-absorbing barriers, wooden frames, cladding with tongue and groove splicing) surface;

c) Category C. Suitable for painting on the surface of wooden utensils (such as fences, garden sheds, rain sheds, overlapped cladding) that do not require dimensional changes.

5.1 General performance requirements

General performance should meet the requirements of Table 1.

Table 1 General performance requirements

Inspection items. top coat, top coat Stir-free in the container Fineness/µm <=35 <=40-Non-volatile matter /% varnish and transparent color paint >=30; color paint >=40-Storage stability [(50 ± 3) °C, 7 d] No abnormality Freeze-thaw resistance does not deteriorate the appearance of the coating film is normal--Gloss (60 °) Agreed--Adhesion (2 mm grid spacing)/level <=1 Anti-blocking property [500 g, (50 ± 2) °C/4 h] (Only factory production time test) MM. A-0 MB. A-0

Drying time

Surface dry/min <=60 Hard dry/h single component <=6; two components <=24 Water resistance (room temperature, 96 h) No abnormality--Alkali resistance (50 g/L NaHCO3, 1 h) No abnormality--Temperature resistance a) No abnormality-Flexibility a) 50 mm diameter without cracks-Coating resistance to yellowing (168 h, deltaE *) (Limited to products with nominally similar yellowing resistance) <=3.0--a The performance can be tested according to the agreement of the relevant parties after matching with the primer or matching with the primer and intermediate paint.

5.2 Artificial aging performance requirements

The artificial aging performance shall meet the requirements of Table 2.

Table 2 Artificial aging performance requirements

Inspection item requirements (level) Foaming <=1 Cracking <=3 Exfoliation Adhesion <=1 the sum of 4 performance levels of 3 test pieces <= 19 the difference between the maximum value and the minimum value of 4 performance levels of each test specimen is <=4 Note. Type I artificial aging test exposure time is 12 weeks, type II artificial aging test exposure time is 6 weeks.

5.3 Water permeability requirements

Water permeability shall meet the requirements of Table 3.

Table 3 Water permeability requirements

Test items

use

Class A Class B Class C Water absorption (g/m2) 30 ~ 175 30 ~ 250 > 30

5.4 Limits of hazardous substances

The limit of hazardous substances should meet the requirements of GB 24410.

6.1 Sampling

The products are sampled according to the requirements of GB/T 3186, and the sampling volume is determined according to the inspection needs.

6.2 General requirements

6.2.1 Test environment

The condition adjustment of the test plate and the test environment of each inspection item shall meet the requirements of GB/T 9278.

6.2.2 Preparation of test samples

Unless otherwise specified, all board-making items with general properties are made with a single coating type, that is, with top-coat, middle-coat and primer.

See Table 3 for the test floor and coating requirements for each project.

Table 3 Board requirements

Inspection item substrate size/mm Coating appearance a), adhesion, Anti-blocking, water resistance, Alkali, temperature resistance Solid wood plank b) 150 × 70 Brush two coats, the first coat amount is (100.0 ± 10.0) g/m2, brush for a second time after 24 hours Channel; the second coating amount is (100.0 ± 10.0) g/m2, Test after 7 days.

Use 400 before painting the second pass Light black lacquered glass plate) 150 × 100 × 3 Apply by brushing, the coating amount is (180.0 ± 10.0) g/m2 Gloss Apply by scraping, wet film thickness of 150 µm, and leave for 48 h Post-test a When the appearance and gloss of the coating film are inspected at the factory, they can be inspected after the board is made by the agreed accelerated coating method.

b Solid wood boards, preferably linden or other light-colored wood with similar properties. The wood selected shall be a non-defective chopped chopping board.

(20 ± 2) ° C and relative humidity (65 ± 5)% for more than 7 days.

c The white external ceramic tiles used in the "yellowing resistance" project require that the deltaE * should not be greater than 0.5 after being exposed to UVA (340) lamp for 168 h.

6.2.3 Operation method

The reagents used are all chemically pure and above, and the water used is all Grade III water in accordance with GB/T 6682-2008. The test solution is being tested.

Adjust to the test temperature before the test.

6.2.3.1 State in container

Open the container and stir with a knife or stirring rod to allow sediment on the bottom of the container. If it is easy to mix evenly after stirring, it is judged as "after stirring "Homogeneous and free of lumps." Two-component coatings should be inspected separately.

6.2.3.2 Fineness

According to the provisions of GB/T 1724-1979. Two-component coatings need to be mixed and tested.

6.2.3.3 Non-volatile matter

According to the provisions of GB/T 1725-2007, the two-component coating is only tested for the main agent.

6.2.3.4 Storage stability

Put about 0.5 L of the sample into a well-sealed plastic or glass container, leaving about 10% of the space in the jar, and put it at (50 ± 2) °C in a constant temperature drying oven, take it out after 7 d and place it in (23 ± 2) °C for 3 h. Open the container according to the method specified in 6.2.3.1 of this document and observe the "state in the container" is rated as "no abnormality" if it is uniform and free of lumps after stirring. Each component of a two-component coating should be inspected separately.

6.2.3.5 Freeze-thaw resistance

According to the method A specified in GB/T 9268-2008, the number of cycles is 3 times. Two-component coatings are tested only for the main agent.

6.2.3.6 Coating appearance

Visually observe the test panel. If the coating film is uniform and free of coating film defects such as sagging, flowering, pinholes, cracking and peeling, it is rated as "normal".

6.2.3.7 Gloss (60 °)

According to GB/T 9754-2007.

6.2.3.8 Adhesion

According to GB/T 4893.4-2013. The grid space is 2 mm.

6.2.3.9 Anti-blocking

According to the provisions of GB/T 23982-2009. Test conditions. load with a weight of 500 g and a diameter of about 70 mm, temperature (50 ± 2) °C for 4 h.

6.2.3.10 Drying time

Surface drying time and actual drying time shall be carried out according to the provisions of GB/T 1728-1979, Surface Drying Method B and Hardening Method A.

6.2.3.11 Water resistance

According to GB/T 4893.1-2005. The test solution is distilled water. The middle part of each plate is taken in the test area. In each test area Place 5 layers of paper on the field. During the test, the filter paper should be kept moist, and if necessary, apply petroleum jelly to the contact area between the glass cover and the test plate.

seal. Remove the filter paper after 96 hours, blot dry, and leave it to stand for 2 hours to visually observe under scattered sunlight. If two of the three test plates do not appear blistering, Coating film defects such as cracking and peeling, but allowing slight discoloration and slight gloss change, are rated as "no abnormality". If the above coating film defects occur, press GB/T 33568-2017.

6.2.3.12 Alkali resistance

The test and result evaluation methods are the same as those in this document 6.2.3.11. The test solution is a 50 g/L NaHCO3 solution. The test time is 1 h. After the test, Observe after 1 hour.

6.2.3.13 Temperature resistance

In accordance with the provisions of JG/T 25-2017.

6.2.3.14 Flexibility

The test is carried out according to the provisions of GB/T 1748-1979, and the test bending diameter is 50 mm.

6.2.3.15 Resistance to yellowing

According to the provisions of GB/T 23983-2009.

6.3 Artificial aging performance

6.3.1 Principle, test device, sample and test procedure of artificial aging test According to LY/T ×××× -201 ×, artificial aging test shall be performed.

The exposure time of type I outdoor waterborne wood coating artificial aging test is 12 cycles, that is, 12 weeks, a total of 2016 h; type II outdoor water the exposure time of the artificial aging test of sex wood coatings was 6 cycles, that is, 6 weeks, for a total of 1,008 h.

6.3.2 After the aging cycle test is completed, remove the sample from the sample holder, evaluate the blistering within 1 hour, and then place the sample at a temperature of (20 ± 2) ° C.

And the relative humidity is (65 ± 5)% for 7 days, and the sample is evaluated for blistering, cracking, and cracking in accordance with GB/T 33568-2017.

Peeling and adhesion levels.

6.4 Water permeability

6.4.1 Test equipment

6.4.1.1 A microscope with a suitable illumination system can give the best image contrast. Select the magnification so that the field of view is 1.5 to 3 times the thickness of the paint film, the measurement accuracy of the eyepiece or photoelectric measuring device is at least 1 µm.

6.4.1.2 Constant temperature and humidity box or temperature and humidity control room, the temperature can be controlled at (20 ± 2) °C, relative humidity (65 ± 5)%;

6.4.1.3 Balance, the division value is 0.01 g.

6.4.1.4 The container shall be capable of holding all test specimens.

6.4.2 Test specimen

6.4.2.1 Test material selection

1) Specify the spruce wood as the coating substrate, with an air-dry density of 0.4 g/cm3 ~ 0.5 g/cm3;

2) Select straight texture, no knots, no cracks, no blue changes, normal growth rate (that is, 3 to 8 annual rings per 10 mm), end the inclination of the annual ring is 45 ° ± 10 ° (see Figure 1);

(A) 1. front side of the test plate; (b) 10a. 3 to 8 growth wheels per 10 mm width; (c) alpha. 35 ° to 55 ° between the growth wheel and the front surface ()

Figure 1 Schematic diagram of substrate for water permeability test

6.4.2.2 Test plate preparation

The sample is processed into a size of (340 ± 2) mm × (70 ± 2) mm × (20 ± 2) mm (L × R × T), the surface is smooth and flat without cracks Test block. Place the prepared test block in an environment of (20 ± 2) °C and relative humidity (65 ± 5)% until constant weight.

6.4.2.3 Test plate finishing

1) Weigh the test plate adjusted to constant weight and measure the size, calculate the density of each test substrate plate, and take the average of the density of 6 test pieces as the the density value of the test material.

2) Select 3 test panels as the coating substrate for the water permeability test of the coating, and the remaining 3 panels as blank control samples.

3) Finish the test surfaces (near the bark surface) of the three test panels according to the coating process provided by the coating supplier. Before finishing, the painted surface should be smoothed with sandpaper with a mesh size of not less than 150 mesh, and the surface wood powder should be removed with an air gun to keep the painted surface clean. After sanding Finish as soon as possible.

4) Finishing process and coating amount should be carried out according to the process and dosage recommended by the coating supplier. The coating amount does not exceed the value recommended by the coating supplier ± 20%. The coating should be evenly distributed on the surface of the substrate.

5) After the coating is dried, cut it into the coating water permeability test specimen and coating film thickness test specimen according to Figure 3.

Fig. 2 Schematic diagram of water permeability test piece processing

6.4.2.4 Coating dry film thickness

Remove 1 small piece of wood with coating from each coating thickness test piece (see Figure 2), according to GB/T 13452.2-2008 5.4.4 Method 6A requires a dry film thickness measurement of the coating using a microscope. Measure the thickness of the coating taken on the wood surface and penetrate the wood the paint is not in the measurement range. Take 5 test points for each small piece of wood, and calculate the arithmetic average of the test values of 5 test points as the coating of the sample.

Layer dry film thickness in mm.

6.4.2.5 Non-test surface closure method

1) Use sealant to seal and coat other faces and ends than the test surface of water permeability test piece. Sealant should cover water permeability the test piece has a width of 2 mm around the test surface (see Figure 3).

Figure 3 Schematic diagram of sealer finish for water permeability test specimens

2) The sealant should be a highly elastic waterproof coating (such as non-solvent epoxy paint, polyurethane paint), and the 72 hour water absorption of the sealant should not be More than 30 g/m2. The sealer is painted two times. After the coating is finished, the test piece is placed in an environment of (20 ± 2) °C and relative humidity (65 ± 5)%.

Dry and equilibrate, and measure the actual test area of the test piece.

6.4.2.6 Finishing of blank control samples

As a blank control for testing whether the sealing performance of the sealant is qualified, all surfaces of the sealant are completely painted with the sealant. Sealer finish Two passes. After finishing the coating, place the test specimen at (20 ± 2) °C and relative humidity (65 ± 5)% for drying and equilibration.

6.4.3 Test procedure

6.4.3.1 Pretreatment of test pieces

1) From the water permeability test coating test specimen and the blank control specimen, five test specimens are randomly selected for testing;

2) Add deionized water to the container and place in (20 ± 2) °C and relative humidity (65 ± 5)%. Placed at the bottom of the container Absorbent sponge, the liquid level does not exceed 2 mm on the top of the sponge. Place the test piece on the sponge with the test side facing down and absorb water for 24 hours. The test surface should be finished.

Fully submerged in water (see Figure 4).

Figure 4 Schematic diagram of water permeability test

3) After removing the test piece from the container, place it in an environment with a temperature of (20 ± 2) °C and a relative humidity of (65 ± 5)% for 3 hours, and then at 50 °C Dry for 3 hours under the conditions, and finally place in (20 ± 2) °C and relative humidity (65 ± 5)% for 18 hours;

4) After repeating steps (2) to (3) once, place the test piece in an environment of (20 ± 2) °C and relative humidity of (65 ± 5)% until Constant weight.

6.4.3.2 Immersion cycle

1) Weigh the specimen (m0) to the nearest 0.01 g.

2) Add deionized water to the container and place in (20 ± 2) °C and relative humidity (65 ± 5)%.

3) Place the test surface of the test piece face down on the sponge. The test surface of the test piece should be completely immersed in water.

4) Take out the test piece after 72 hours, and wipe the test surface to measure the weight (m1) to the nearest 0.01 g.

5) All tests should be performed in an environment of (20 ± 2) °C and relative humidity of (65 ± 5)%.

6.4.3.3 Representation of results

Calculate the water absorption of each test piece for 72 h according to formula (1). Calculate the average water absorption of 5 painted specimens and 5 blank specimens and standard deviation. When the average water absorption of 5 blank specimens exceeds 30 g/m2, the test results are invalid.

New test. Calculate the arithmetic mean value (accurate to 1 g/m2) of the water absorption of 5 painted test pieces as the water absorption of this batch of coating samples.

m1- m0

In the formula.

Wp. water absorption, unit is gram per square meter (g/m2);

m1. the weight of the test piece after absorbing water, the unit is gram (g);

m0. indicates the mass of the specimen before water absorption, the unit is gram (g);

s. the area of the test surface of the test piece, the unit is square meter (m2).

6.4.3.4 Water permeability test record

Product information, specimen density, finishing process (coating method, coating amount, dry film thickness and other necessary information), test the water absorption of the sample and that of the blank.

6.5 Limit of hazardous substances

According to the provisions of GB 24410.

7.1 Inspection classification

Product inspection is divided into factory inspection and type inspection.

7.2 Inspection items

7.2.1 Factory inspection

The factory inspection includes the state in the container, the fineness, the appearance of the coating film, and the drying time.

7.2.2 Type inspection

The type inspection shall include all items required in Chapter 5 of this document. Under normal production conditions, type inspection should be performed at least once a year. Have the following in one of the cases, type inspection should be carried out.

a) When there are major changes in raw and auxiliary materials and production;

b) When production is suspended for a long time, when production is resumed;

c) When the quality supervision department requests the type inspection.

7.3 Lot rules and sampling plans

7.3.1 Group rules

The products delivered for inspection shall belong to the same model and specification of the same production batch.

7.3.2 Sampling plan

The performance inspection shall adopt the re-inspection sampling plan according to Table 5. Extract n1 units for the first time.

The n2 units are selected twice to re-examine the unqualified items; the performance value of the second sample n2 (the unqualified items in n1) should all meet the standard requirements.

Otherwise, the batch of products is judged as unqualified.

Table 5 Unit of performance sampling plan. barrel

Batch range N n1 n2

<=1.200 1 2

1.201 ~ 3.200 2 4

3.201 ~ 10 000 3 6

>=10 000 4 8

7.4 Decision rules

When all inspection items meet the corresponding technical requirements, the batch of products is judged to be qualified, otherwise it is judged to be unqualified.

7.5 Inspection report

The inspection report should include product information, the name of the wood species used to coat the substrate, the coating method of the test piece, the coating amount of the test surface, Start and end dates, test results, etc.

8.1 Logo

Carry out according to GB/T 9750, and mark the technical requirements for coating construction. For coatings consisting of two components, each group should be identified Distribution ratio. If dilution with water is needed, the dilution ratio should be specified.

8.2 Packaging

According to the requirements of secondary packaging requirements in GB/T 13491.

8.3 Storage and transportation

The product should be stored in a ventilated, dry and dark place, away from fire and heat sources, and prevent direct sunlight. Prevent rain when transporting the product Drench and sun exposure, a...