Coating standard: Determination of film adhesion

Core tip: this standard (GB 1720-1979) is applicable to the determination of film adhesion The fastness of film adhesive substrate is usually called adhesion It is evaluated according to the integrity of the film in the scratch range of the rolling line, usually expressed in grades 1、 General provisions Materials and equipment are as follows: Tinplate: 50x 100x0.2-0.3mm; Quadruple magnifier; Paint brush: 25-35mm wide; 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: this standard (gb1720-1979) is applicable to the determination of film adhesion The fastness of film adhesive substrate is usually called adhesion It is evaluated according to the integrity of the film in the scratch range of the rolling line, usually expressed by grade 1、 Generally specified materials and instruments are as follows: Tinplate: 50 x100x0.2-0.3mm; quadruple magnifier; paint brush: 25-35mm wide; adhesion tester: as shown in Figure 1 The specifications of the relevant parts of the adhesion tester are as follows: the pitch of the lead screw (9) of the test bench is 1.5mm, and its rotation is synchronous with that of the rotating needle; the rotating needle adopts the three or five brand phonograph needle, and the no-load pressure is 200g; the brick code can be placed on the load plate (1), and its weight is 1002005001000g; the rotating radius of the rotating needle can be adjusted, and the standard rotating radius value is 5.25mm 2、 The determination method is to prepare three sample plates on the tinplate (or the substrate specified in the product standard) according to the general preparation method of paint film (gb1727-79), and to determine under the condition of constant temperature and humidity after the paint film is dry Check the needle of the adhesion tester before the test If it is not sharp, it should be replaced: lift the half nut (7) and pull out the test stand (6), then the needle can be replaced When it is found that the scratch does not conform to the standard turning radius, the turning radius shall be adjusted The method is to loosen the bolt behind the card pin plate (3) and the turning radius adjusting bolt (4) After the card pin plate is properly moved, the above bolts shall be tightened in turn The scratch is compared with the standard round roll line drawing If it still does not conform to the standard round roll line drawing, the turning radius shall be readjusted until it is the same as the standard round roll line with a turning radius of 5.25mm BI During the measurement, place the sample plate on the test bench (6), tighten the adjusting bolts (5), (8) and adjusting bolts (10) of the fixed sample plate, move the lifting rod (2) backward, so that the tip of the rotating needle contacts the paint film If the scratch does not expose the bottom plate, the enamel code shall be added Shake the handle (11) evenly in a clockwise direction The rotating speed should be 80-100 rpm The standard drawing length of the round roll line scratch is 7.5 ± 0.5cm Move the lifting rod (2) forward to lift the card pin plate, loosen the bolts (5), (8), (10) that fix the sample plate, take out the sample plate, remove the paint chips on the scratch with a paint brush, and check the scratch with a quadruple magnifier and grade it 3、 The evaluation method of film adhesion test takes the upper side of the scratch on the sample plate as the inspection target, and marks seven parts successively, i.e 1, 2, 3, 4, 5, 6, 7, etc There are seven levels Check the integrity of each part of the paint film in sequence If more than 70% of the grids in a certain part are intact, it is determined that the part is intact, otherwise it shall be considered as damaged For example, Part 1 with good film and best adhesion is classified as grade I; Part 1 with bad film and Part 2 with good adhesion is classified as grade II By analogy, Grade 7 is the worst adhesion ·The standard scratch roll line is shown in Figure 2 The results shall be based on the level of at least two samples Note: since the implementation of this standard, the original standard hg2-462-78 is invalid The above is a detailed introduction of the determination of film adhesion Home of coatings is specialized in coatings, diatom mud, paint coating, coating technology, fire retardant coating news and coating, diatom mud, paint coating, coating technology, fire retardant coating decoration knowledge and decoration renderings,