Coating standard: gb5211.17-88 comparison of contrast ratio (hiding power) of white pigment

Core tip: this standard refers to the international standard iso2814-1976 "paints and varnishes - comparison method of ratio (hiding power) of paints of the same type and color" 1 subject content and scope of application this standard specifies a general test method for comparison of contrast ratio (hiding power) of similar white pigments When this general method is not applicable to a specific product, a special method shall be specified to compare the contrast rate In principle, the sample and the standard sample are made into the paint paste with the same paint material in the same formula and method, and are made on the polyester film with the rotary paint applicator Application scope and advantages of roller ceramic coating Recommended introduction: the surface of ceramic rubber plate used for roller ceramic coating is cast into durable rubber plate by hundreds of independent small ceramic pieces Each ceramic piece has raised characteristics Under general conveyor belt pressure, thousands of unique cast bumps can produce positive traction, prevent slipping and extend the service life of conveyor belt roller At the same time, the bottom layer adopts high-quality rubber, which has strong elasticity and can play a good impact resistance role The scope of application of roller ceramic coating is one three six 83857180 (the same as V) 1 Roller coating in extremely harsh working environment 2 The belt joint is not suitable for fixing with iron buckle; 3 It is suitable for leather Home of coatings: this standard refers to the international standard iso2814-1976 "paints and varnishes - comparison method of ratio (hiding power) of paints of the same type and color" 1 subject content and scope of application this standard specifies a general test method for comparison of contrast ratio (hiding power) of similar white pigments When this general method is not applicable to a specific product, a special method shall be specified to compare the contrast rate In principle, the sample and the standard sample are made into the paint paste with the same formulation and method The film with the same thickness is made on the polyester film by the rotary coater The reflectivity on the black bottom and the reflectivity on the white bottom are measured by the reflectometer, and the contrast ratio is obtained by dividing the reflectivity on the black bottom by the reflectivity on the white bottom Compare the contrast ratio of the sample and the standard sample to evaluate their advantages and disadvantages 3 Linseed oil modified glycerol alkyd resin: oil degree 55%, content 50%; No 200 solution oil; mixed drier of lead naphthenate, cobalt naphthenate, manganese naphthenate, zinc naphthenate and calcium naphthenate 4 Instrument paint conditioner (680-690 times / min, 16mm distance, 30 ° swing angle of glass bottle into the conditioner; scraper fineness meter (0-50um); lever micrometer (range 0-25mm); glass plate (surface flat, 130mm long, 100mm wide); polyester film (20-40um thick, 120mm long, 90mm wide); rotary paint applicator (adjustable speed); reflectometer (accuracy within 1%); 5 Take representative samples of test pigments according to gb9285 6 All tests of measurement steps shall be carried out at 23 ± 2 ℃ and (50 ± 5)% relative temperature 6.1 for the preparation of paint slurry, weigh 100g glass beads in the glass bottle of paint conditioner, weigh 12g sample and put it in the bottle, then add 37G alkyd resin, and add proper 200 solution oil as needed Place the glass bottle with materials in the hole of the base frame of the paint conditioner, start the seasoning machine to vibrate, and check with the fineness meter of the scraper When the fineness of the grinding is less than 20um, add a proper amount of mixed drying agent, and mix well for standby 6.2 the thickness of the polyester film is measured by the lever micrometer card for the preparation of the film, and four points are measured up, down, left and right Drop a few drops of ethanol on the flat glass plate, and immediately spread the polyester film on it, without bubbles under the film Fix the glass plate in the center of the rotary paint applicator, add about 5g of paint paste in the center of the glass plate, rotate for 30s at the selected stable speed, and make a uniform film; change the speed, and then make several films Make two films at each speed 6.3 dry the glass plate with the film horizontally for at least 48h, but not more than 168h 6.4 film thickness measurement take off the film from the glass plate, measure the thickness of the upper, lower, left and right four points with the lever micrometer card, and calculate the average thickness of the film 6.5 measurement of reflectance cover the dried film on the white porcelain plate attached to the reflectometer, add a few drops of ethanol between the film and the porcelain plate, remove the air and make optical contact The reflectance of four points is measured by reflectometer, and the average value is obtained Then the coating is coated on the black porcelain plate, measured by the same method, and the average value is calculated The standard sample is also painted and filmed according to the test procedures in Chapter 6, and the average reflectivity is obtained 7 Calculate the contrast ratio (hiding power) x (%) of each coating film according to formula (1): x = Rb / RW × 100 (1), where RB is the reflectivity of the coating film on the black base; RW is the reflectivity of the coating film on the white base Calculate the average contrast ratio of two films with the same thickness (the difference between the average thickness is not more than 2um), and compare with the average contrast ratio of the standard samples with the same thickness to evaluate their advantages and disadvantages 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,