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    Home > Coatings News > Paints and Coatings Market > Coating standard: relevant performance and test standard of primer and finish in coating

    Coating standard: relevant performance and test standard of primer and finish in coating

    • Last Update: 2020-04-03
    • Source: Internet
    • Author: User
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    Core tips: 1

    Differences and functions of primer and topcoat 1

    Comparison of primer and topcoat: composition of primer: transparent primer = film forming substance + filler + solvent + assistant solid color primer = film forming substance + pigment + solvent + assistant topcoat: transparent topcoat (varnish) = film forming substance + solvent + assistant solid color topcoat = film forming substance + opaque pigment + solvent + assistant Transparent and colored topcoat = transparent topcoat (varnish) + chromatin and colored sealer = sealer + chromatin 2

    Functions of primer: generally divided into two types: sealer and primer

    Sealing agent: mainly used for sealing Paint knowledge | precautions for wall paint color selection Recommended introduction: when painting the wall, the owner sometimes has difficulty in choosing what color of the wall paint to paint

    In fact, there is no ugly color in the wall paint, only the disharmonious color matching

    The use of wall color contains the knowledge of health

    Too strong color will stimulate people's perception, make people have a sense of fidgety, affect people's mental health

    Grasp the basic principles of wall color and paint a colorful space

    1、 Wall paint color selection notice 1

    Light color is generally used for the top surface

    Light colors make people feel light, dark colors make people feel heavy

    Usually, the treatment of rooms is from top to bottom, from shallow to deep

    For example, the ceiling and walls of rooms are white and Paint Home News: 1

    Difference and function of primer and finish 1

    Comparison of primer and finish: composition of primer: transparent primer = film forming substance + filler + solvent + auxiliary solid primer = film forming substance + pigment filler + solvent + auxiliary finish: transparent finish (varnish) = film forming substance + solvent + auxiliary finish Solid color topcoat = film forming substance + opaque pigment + solvent + assistant transparent color topcoat = transparent topcoat (varnish) + color sealer = sealer + color sealer 2

    Function of bottom topcoat: Primer: generally divided into two types: sealer and primer

    Sealer: the main function is to seal the base material, protect the plate and ensure the coating quality

    Primer: the main function is to fill the pores, improve the thickness of the film, so that the objects can achieve a certain decorative effect, thus reducing the amount of top coat

    Primer generally has certain filling and polishing properties

    Solid primer also has certain covering power

    Top coat is mainly used for decoration and protection

    From the functional point of view, the top coat must have a considerable light, color, hardness, adhesion, leveling and so on

    This is also the reason why topcoat does not have good filling and polishing properties

    2、 How to evaluate the quality of primer and top coat: 1

    Surface dryness (touch dryness): touch the surface of paint film with fingers, feel some sticky, but there is no paint on fingers, that is to say, the surface dryness (paint film at this time, does not stick to dust particles)


    Finger press dry: the thumb is forced on the coating surface, without leaving finger press marks or damaging the dry condition of the coating surface


    Grindable time: the time from the time when the primer is applied to the time when the non stick sandpaper is grinded

    (the primer with short grindable time can shorten the construction period) 4

    Filling ability: the filling ability of the primer itself to the wood hole, filling ability is a relative performance, generally a comparative test

    The filling ability is closely related to the pigment content of the primer, so the filling ability often conflicts with the transparency

    (the primer with good filling property has few finishing times) 5

    Burnishing: the degree of difficulty when the paint film is dry and grinded to a flat surface with sandpaper

    (the primer with good grindability is easy to construct) 6

    Hardness: hardness refers to the resistance of the paint film to foreign objects invading its surface

    It is determined by the resin content of the coating itself and the quality of the resin

    The hardness measurement is based on a set of Chinese brand pencils

    The pencil hardness that just can scratch the coating on the hardness tester is the hardness of the coating

    Generally, Pu: 2h, NC: h-hb


    Adhesion: the fastness of lacquer desert to the adhesion of base material is adhesion

    The adhesion is generally measured by the hundred grid method, i.e

    the damage degree of the coating is distinguished by the hundred grid on 1C


    Yellowing resistance: the process of aging resistance of paint film is called weather resistance

    Generally, it refers to yellowing, peeling, etc

    The paint turns yellow mainly because of the benzene ring and sulfur in the paint

    Yellowing resistance is mainly measured by the time of yellowing after sun exposure, or the degree of yellowing


    Transparency: the clarity of the paint to show the substrate condition

    It is generally opposite to burnishing and filling

    The paint with good transparency is generally poor in burnishing and filling performance, and it is also a relative performance, general comparative test

    (the primer with good transparency has strong three-dimensional effect of wood grain) 10

    Covering power (solid color): refers to the ability of solid color paint to cover the underlying color

    Grindable time: grindability, filling, transparency, covering power of solid color primer

    Several main properties that affect the quality of finish paint 1

    Surface drying (touch drying): it is of great significance to finish paint

    The final surface effect of surface drying fast coating is clean, but too fast drying speed affects leveling and flexibility of coating


    Leveling: the time required to form a smooth film surface after painting


    Gloss evenness: refers to the gloss evenness after the paint is dry


    Dry time (packable): refers to the time when the paint is completely dry


    Transparency 6

    Yellowing resistance 7

    Hardness 8

    Adhesion 9

    Scratch resistance: hard scratch and soft scratch

    Hard scratch refers to the surface of the paint film with moderate hardness (metal or wood), which is scraped, rubbed and scratched with the same strength to observe the damage degree; soft scratch refers to the surface of the paint film with moderate strength to observe the scratch degree

    It should be noted that hardness and scratch resistance are not the same concept

    High hardness is not necessarily good scratch resistance


    Flexibility: it is the main index of paint in the process of bending, holding, twisting, being damaged or not, being able to recover or not


    Gloss stability: the retention of the paint to the set gloss


    Fullness: the coating gives people a sense of fleshy quality, which is an important performance of the top coat

    Generally, it is also determined by comparison


    Hand feeling: the lubricating feeling of touching the paint film with hands after the film is dry

    Several key properties of the topcoat quality are evaluated: surface dryness, gloss uniformity, fullness and hand feel

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