The routine performance testing of the samples used in the test are all asbestos cement boards with fine specifications. Its surface treatment is carried out according to GB9271. The preparation of the test panel is carried out according to the standard, and it is placed in the natural environment for 7 days after painting.
water resistance
The water resistance of the coating refers to the resistance of the coating film to the action of water, that is, the performance of the coating film not absorbing water or seeping water. The dry coating film does not appear whitening, foaming, swelling, falling off and other disadvantages after being exposed to water. After leaving the water, the water evaporates and the coating can restore its original appearance, which shows that the coating film has a certain degree of water resistance. The determination method is carried out according to GB/T1733-93- "Determination of Water Resistance of Architectural Coating Films".
Carry out according to GB/T17331993 Law A. In addition to sealing the edge, the back of the test board needs to be sealed before putting it into the test. The three test panels are immersed in the specified third-grade water, and if two of the three test panels do not show any pathological phenomena such as blistering, powder falling, and obvious discoloration of the coating film, it can be evaluated as "no abnormality". If the above coating film morbidity occurs, describe it according to GB/T1766. Test temperature: 23±2°C, soak two-thirds of the plate, and the size of the tinplate plate is 120*25 (0.2-0.3) mm.
Alkali resistance
According to the provisions of GB/T9265. If two of the three test panels do not show any abnormalities in the coating film such as blistering, powder falling, and obvious discoloration, it can be rated as "no abnormality" . In order to add 0.12g of calcium hydroxide to 100ml of water and stir well, the value should reach 1. The size of the asbestos cement board is 120*70*3mm.
Scrub resistance
The scrub resistance of the coating refers to the ability of the coating film to withstand the cleaning of soap solution and synthetic washing liquid, remove the dust, oily smoke and other dirt on the surface, and maintain the original performance. The determination method is carried out according to GB/T9266-88-"Determination of Scrub Resistance ".
drying time
The period of time from the fluid layer to the solid coating film is called the drying time, that is, the time required for the coating to change from viscous to solid coating film. The drying time can be divided into two stages, namely surface drying time and surface drying time. Actual drying time Actual drying time. The test method is carried out according to GB/T1728-1979-"Determination of drying time of paint film and putty film".
construction performance
The paint was sprayed on the test board with a Spray Gun, and the effect of different spraying pressures on the particle size and shape of the paint , as well as the color mixing and gun blocking of the paint during spraying were investigated.
state in paint container
Open the container cover for storing paint, gently stir the sample in the container with a stirring handle, and observe whether the paint sample is uniform and whether there are hard lumps.
Coating Appearance
Leave the wicker for 24 hours after the constructability test. Visually observe the coating film, if there is no pinhole and the coating film is uniform, it is considered normal.
storage stability
Put the paint into a sealed container and store it in an oven at 60°C for fifteen days, then open the cover to observe its state, spray the paint, and observe the deformation of the particles after spraying. If the particles are broken after spraying, it means that the stability is not passed. If the particles are not broken after spraying, it means that the stability is passed.
low temperature stability
Put the sample into a plastic or glass container about 1L high, fill it up roughly, seal it, put it in a low-temperature box at -5±2°C, take out the container, and place it at 23±2°C and relative humidity ± 6h. After repeating this for three times, open the container, stir the sample, and observe whether there are hard lumps, agglomeration and separation. If there is no phenomenon, it is considered "no deterioration".
Coating resistance to temperature denaturation
Carry out according to the regulations, do 5 cycles of soaking in water at 23±2°C for 18 hours, freezing at -20±2°C for 3 hours, and drying at 50±2°C for one cycle . At least two of the three test panels should have no coating film pathological phenomena such as pulverization, cracking , blistering, peeling, and obvious discoloration, which can be evaluated as "no abnormality". If the above coating film pathological phenomenon occurs, describe it according to the hall.
Coating Stain Resistance
In this method, fly ash is used as the pollution medium, which is mixed with water and painted on the coating sample. Rinse with water after drying, and measure the decrease rate of the reflection coefficient of the coating after a specified cycle, which indicates the stain resistance of the coating.
Resistance to artificial weathering
The test shall be carried out according to the provisions of GB/T1865. The evaluation of the results shall be carried out according to GB/T1766.
