KenWei Automation Technology CO.,LTD

powder coating vs painting, what is better?

2021.3.24

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paint-booth-2-600x450

powder coating

paint booth,paint wash,spray paint dipping in water

      

       define the difference, the difference between the text description of metal surface treatment powder coating vs painting

  1.          1. Painting is by means of compressed air to disperse liquid paint (commonly known as paint) into paint mist particles adhered to the surface of the object to be coated, while powder                       spray is dispersed into powder mist particles by means of compressed high-pressure static electricity. Adsorbed on the surface of the object to be coated.
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  3.          2. The correct name for dusting is that the electrostatic powder is not sprayed, and it is not simple to use a spray gun. The composition of the electrostatic powder unsprayed equipment is               composed of a powder drum (with compressed air for powder) and a static electricity generator electrostatic powder gun. Sprayed powder, also called plastic powder, is called plastic                       powder. The categories mainly include outdoor powder and indoor powder. Outdoor powders and paints of the epoxy type are simply two ingredients.
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        the characteristics of the spray and painting process difference analysis of the characteristics of the powder spray process:

1. The powder coating does not contain any solvent. It is a 100% solids coating. Its manufacture, transportation, storage and application solve the pollution problem caused by the solvent, improve the working conditions of the operators and benefit the operators. Healthy body.

2. simplify the painting process using the dusting process coating only three steps of dusting, solidification, cooling, etc., one film. It greatly simplifies the painting process, shortens the production cycle, and produces products on the same day. In the electrostatic coating of powder coating, the automatic coating machine and the recycling system can be configured to form an automated production, thereby saving energy and resources and improving production efficiency.

3. the powder coating has high utilization rate, the powder coating can be directly applied to the surface of the coated object, and after baking, the coating film is formed, and the uncoated powder can be recycled to the powder supply system for use. The utilization rate of the material is about 95% or more.

4. The powder coating film has good performance and is durable. The powder coating can be prepared by using a resin which is insoluble in a solvent at normal temperature or a polymer resin which is not easily dissolved and cannot be liquidized to prepare a high-performance coating film having various functions. Moreover, when the powder coating is prepared or formed into a film, no solvent is added and released, and the pinhole of the coating film is not penetrated so that the coating film is denser.

5. can achieve one-time coating powder coating, one coating can get 50 ~ 300μm thick coating film, and the group is not easy to produce dripping or stagnation (oil accumulation) when the paint is thick, no solvent pinholes, Does not cause defects in thick film coating, and the corner coverage is also high. The paint is generally applied at a film thickness of 5 to 20 μm. If a thick film or a medium-to-high-grade coating film is required, it must be painted several times.

6. the color change is difficult, the cycle is longer. Since the color of the powder coating can not be adjusted on-site with the original color material like paint, the color of the powder coating material has been determined at the factory. If you want to change the color, you need to change the side of the powder coating, so it is difficult in a short time. Finish the coloring work inside. Due to the electrostatic spraying, if the color change in the middle of the operation process, the spray gun, the powder feeder, the powder spraying chamber, the powder feeding tube, the recycling system, etc. must be cleaned up, otherwise the surface quality of the coating film will be seriously affected. In particular, the transformation of dark and light colors is more complicated, so it is not easy to change a plurality of tones in a short time.

7. it is not easy to achieve coating thin film, caused by the electrostatic spray process principle, the film thickness of the powder coating is generally above 50μm, even if the powder is not well coated, the construction conditions are good, the lowest film thickness is about 40μm, It is currently very difficult to form a coating film of 40 μm or less.

8. The appearance of the coating film is slightly flat. Since the powder coating is leveled on the object by heating and melting, the melt viscosity is high, and it is easy to be slightly orange peel, and the flatness of the film is not as good as paint.

9. has certain limitations, the limitations of the dusting process are mainly in three aspects: firstly because of the curing temperature of the powder coating – generally above 160 ° C, which limits it’s in some heat-resistant products (such as Plastic). Application; Bullying Because most of the spray molding process uses electrostatic spraying, the coated object must be electrically conductive, which requires the coated object to be a metal part. If it is not a metal part, the surface must be electrically treated. It can withstand temperatures above 160 °C.

        Painting process features:

1. a wide variety of paints, a wide range of choices. According to the film-forming materials, China divides the paint into ten categories. The various paints of the shovel have been planted in the morning, and new varieties are still emerging. The households can choose according to the performance use and environment of the products. Paint to achieve the best possible coating results.
2. the art section is complete, the nature of the current paint coating methods are brush coating, dip coating, coating, roller coating, scraping, air spraying, airless spraying, electrophoretic coating, Electrostatic spraying, etc., medium brushing, air spraying, and electrophoretic coating.

3. equipment one-time investment is small, air spraying method is currently the most widely used construction method of coating manufacturers, friendship, small painting operations. The bribe construction is simple, the coating film is even, smooth and so on. The only equipment required is the accessories such as spray gun, air compressor, oil-water separator and necessary gas hose. Compared with hundreds of thousands of injections and millions of equipment investment, the equipment has less sub-investment and low cost. The funds are recovered quickly.

4. can simplify the pre-processing sequence when using the painting process because the primer has excellent anti-rust performance, the adhesion of the substrate and the topcoat is good, so the corrosion resistance of the coating film is greatly improved, and the coating film can be ensured. The service life. The material to be coated can be sprayed with a primer by degreasing and descaling without phosphating. The simplification of the pre-treatment process saves production costs and improves production efficiency.

5. the operator’s skill requirements are higher, the variety of paints, this requires the operator’s use of various types of paint, performance, scope of use, application methods, operational matters and all kinds of paint compatibility To understand in detail, you need to have a certain knowledge of color, and you can use the original color to match the color required for the object to be coated. The general paint film consists of three parts: primer, putty, and topcoat. Therefore, it is necessary to master the correct coating process during construction to avoid the problem of film quality.

6. the production period is longer, the overall cost is high, and the painting work is moved to the spray molding process. In general, the typical painting process consists of the following six steps: First, the preparation work before painting, the specific content is:

    •                 Step1 Checking the performance of the material, mixing the paint, adjusting the viscosity of the paint, and adjusting the color of the paint filter;
    •                 Step 2 is to apply a primer;
    •                 Step 3 is to scrape the putty;
    •                 Step 4 is to apply the middle layer;
    •                 Step 5 is polished;
    •                 Step 6 is to apply a topcoat.
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          In the construction process, a variety of materials such as primer, putty, thinner, topcoat, etc. should be used, and drying time must be left between the various processes. Some paints                     cannot be naturally dried, and heat drying is required. Adjacent, in terms of material consumption, energy consumption, and labor cost, the overall cost of the painting process is higher                       than that of the spray process, and the production cycle is longer.

7. Poor environmental protection, which is detrimental to the health of the operator. Because the paint contains certain organic solvents, these organic solvents are easily volatilized into the air during the construction and curing process. When the air spray method is used, a large amount of overspray is generated. It is harmful to the body, so the operator needs to be equipped with a gas mask.

8, the fire risk is higher than the dusting process. We say that the fire hazard of the painting process is higher than the spray process, based on the following three reasons: First, because the paint contains volatile organic solvents, it can easily cause burning and explosion when exposed to open flames (sparks, sparks). The composition of the powder coating does not contain organic solvents, so the risk is lower than the painting process; the second is the burning point of the paint, the flashpoint, the ignition energy is lower than the powder coating, the combustion diffusion rate is faster than the powder coating; finally, the common air is used. When the spray coating is applied, the ventilation equipment, the construction environment and the operating procedures are inferior to the spray molding process, so the risk of the former is higher than the latter.

 
         It is important to note that although the fire risk of the painting process is higher than that of the spray process, once the powder coating explodes, the strength and destructive power of the             explosion will be much greater than that of the liquid coating.

 

        Analysis of the cost difference between painting and dusting, here for your reference:

1, the paint is calculated according to the polyurethane paint: the ratio is: paint: curing agent: thinner = 1: 0.4: 0.5, = 1.9kg. Spray thickness: 15 um total cost: 50RMB, spray with air spray: 6 square, about = 8RMB / square, primer about 7RMB / square; two spray total cost: about 15RMB / square

2, the powder is not calculated according to the future analysis of epoxy powder: spraying thickness is about 60um (can be discharged, the powder can not be recycled) 1kg powder can be sprayed 8 square, the cost is about: 2.5RMB/square

3, the powder needs to be solidified, and it needs heat energy (electricity, natural gas, petroleum gas, oil, diesel, coal, particles). According to the thickness of the workpiece, the heating cost will change greatly; for example, the heating value of fuel and diesel is about 10996 kcal/kg, curing a furnace about 100RMB, (at current oil price) a furnace: according to 100 square meters, heating cost: 1 yuan RMB, but the large workpiece is the machine chassis, and the outer casing, electric box, etc. The product is thicker and the heating cost is about 3RMB square. Plus the total cost of paint: 5.5RMB/square

4, other cost analysis: spray paint requires water curtain cabinet or dry spray booth, because 30-40% of the paint is wasted, this paint is also needed to be treated, the processing cost is about 0.5RMB / level defense, the utilization of powder is basically It is 100%, the exhaust gas is discharged indoors, no need to deal with the cost; the paint contains formaldehyde, account, xylene and other harmful substances, which is harmful to the workers, and the secondary spraying increases the manpower and material resources. The powdered workpiece, the coating is thicker, can cover-up, the paint can not make traces; and after the powder is cured, the coating is hard, it is not easy to touch, and the machine equipment is more high-grade.

 

       Through the above, we can conclude that:


        1. choose from the surface effect, if the surface wants to see a very delicate effect, then choose spray paint, if you choose rough, feel rough and feel, then choose to spray. Of course, the powder can also be very fine, but there is no fine paint.
        2
. from the choice of wear resistance, fouling, choose to spray because the spray is nearly 3-10 times thicker than the spray.
        3
. from the volume and price to choose, small pieces of paint, because the appearance of the effect can be more delicate, plus a beautiful, large selection of powder, so the cost is low.
        4
. from the choice of environmental protection, still spray powder. Due to the danger of fire, the gas is much less expensive.
        5
. from the choice of color diversity, then choose spray paint, spray powder color cycle is long, very troublesome.d