What are the properties of the coating?

The performance of the coating is mainly determined by four parts: the original paint performance, construction performance, paint film performance, and environmental protection performance.

Original paint performance

The performance of the original paint refers to the performance of the paint in the process from the production qualified to the use.

1) The appearance of the original paint: also known as the can-opening effect, which refers to the state of the paint in the container.

2) Viscosity: refers to the viscous state of the liquid.

3) Density: refers to the mass of the paint per unit volume, generally in units: g/ml, kg/L, commonly known as specific gravity.

4) Fineness: indicates the size and dispersion of particles in the coating, and the unit is μm.

5) Storage stability: it indicates the performance change of the coating during storage.

Construction performance

Construction performance refers to the performance and construction parameters of the coating during the construction process.

1) Workability: Refers to the hand feel, paint splashing and defoaming properties during roller coating and brushing.

2) Coating amount: also known as paint consumption, which refers to the amount of paint consumed when the unit area of ​​the substrate reaches a certain thickness.

The factors that affect the coating amount are: the factors of the coating itself (viscosity, workability, etc.

3) Drying time: surface drying (refers to the time required for the surface of the paint film to dry), finger pressure drying (the time that the thumb is pressed hard on the paint surface without leaving finger pressure marks or destroying the coating surface), sanding dry ( The period from coating to sanding of non-stick sandpaper), hard drying (also called hard drying time, refers to the time required for the paint film to basically dry)

4) Re-coating time: refers to the time from the completion of one coat of paint to the beginning of the next coat of paint.

5) Filling: refers to the filling ability of the primer to the wood eye.

6) Sandability: After the paint film is dry, it is difficult to grind it into a flat surface with sandpaper (the primer with good sandability is more convenient for construction)

Paint film performance

Paint film performance refers to the performance of the paint film formed after coating.

1) Appearance of the coating film: refers to whether the coating film is smooth, whether there are particles, bubbles, shrinkage holes, blooming, construction marks, etc.

2) Gloss: a parameter to measure the ability of paint film to reflect light.

3) Hardness: refers to the resistance of the paint film to foreign objects invading its surface.
The hardness of the paint film is one of the important indicators of physical properties.
Generally speaking, the hardness of the paint film is related to the composition and drying degree of the paint.
You can use the Zhonghua brand pencil as the standard to mark and observe the damage of the paint film.

4) Adhesion: It indicates how firmly the paint film adheres to the substrate.
Adhesion is a very important indicator of paint film.
Poor adhesion makes the paint film easy to peel off.
Common cross-cut method for testing (1mm and 2mm grids)

5) Transparency: the degree of clarity of the paint film showing the condition of the substrate (the paint with good transparency makes the wood grain strong, and the dark-colored board has higher requirements for transparency)

6) Hiding power (solid color): indicates the ability of the solid color paint to cover the underlying color (paints with good hiding power can reduce the number of painting passes during construction).

7) Yellowing resistance: it means the ability of the paint film to maintain the original color and not easy to change color (light-colored sheets have higher requirements for yellowing resistance when used as a transparent process)

8) Scratch resistance: hard scratches (scratch, rub, and scratch the surface of the dried paint film with the same strength with an object of moderate hardness to observe the degree of damage), soft scratches (refer to the printing paper to rub the surface of the paint film with moderate strength , Observe the degree of damage)

9) Flexibility: The performance that can be restored or cannot be restored after being damaged or not damaged by bending, holding, winding, and torsion.

10) Fullness: The fleshy texture of the coating is an important performance of the topcoat, and it is generally measured by comparison.

11) Hand feeling: The lubricating feeling of touching the paint film by hand after it dries.

Environmental performance

1) Tribenzene content:

Pure benzene is extremely hazardous grade, which is harmful to the human body and is a carcinogen.
It has been banned from being used in the coating industry.
The molecular structure of toluene and xylene contains benzene rings, which belong to benzene series and are moderately hazardous solvents.
They are important organic solvents.
, Toluene and xylene are still used.
There are two kinds of benzene-free thinners advertised on the market: one is a thinner without pure benzene, toluene and xylene; the other is a thinner without tribenzene (benzene, toluene, xylene), in a strict sense Benzene-free diluent is triphenyl-free.

2) Free TDI:

Free TDI, namely toluene diisocyanate, exists in the two-component polyurethane coating curing agent.
Toluene diisocyanate (TDI) has a strong irritating odor and has a strong irritating effect on the skin, eyes and respiratory tract.
Long-term exposure or inhalation of high concentrations of TDI vapor can cause bronchitis, allergic asthma and other diseases.

3) Heavy metals:

The pollution of heavy metals such as lead and chromium in paint mainly comes from pigments, fillers and some additives.
Such as red lead pigment (lead oxide), chrome yellow pigment (lead chromate).
Soluble heavy metals such as lead, mercury, and chromium are common toxic pollutants.
Long-term skin contact can cause contact dermatitis or eczema.
Excessive lead, mercury, and chromium can cause serious harm to the human nervous and internal organs.

4) VOC:

VOC: is the sum of volatile organic compounds, the English abbreviation of Volatile Organic Compounds.
Solvent coatings contain a lot of solvents, and more thinners need to be used for dilution during construction, which is a large household with high VOC content in coatings.
The impact on the human body is mainly to irritate the eyes and respiratory tract, skin allergies, and cause headache, sore throat, fatigue and other symptoms in severe cases, endangering human health.