Automotive repair paint and color adjustment
Car repair paint and its color adjustment 1. Composition of car repair paint Car repair paint, as the name suggests, refers to the paint used to repair the original car body paint from scratch. It can only be manually applied by workers, and spraying is necessary to operate at low temperatures (below 60 degrees Celsius). Repair paint must have two functions: maintenance function and aesthetic function. These two functions cannot be completed independently by a single product. Therefore, high-quality repair paint brands generally have a series of products to combine, which mainly include: (1) Putty: used to fill defects in sheet metal (2) Primer: Used for rust prevention, promoting adhesion between paint layers, and increasing paint film thickness (3) Topcoat: used to improve appearance quality and add weather resistance Considering that the entire car cannot fully experience high-temperature baking, and the coating conditions in general car repair factories are poor, self drying primer, putty, center coating, self drying synthetic resin paint, evaporative dry nitro paint, and perchloroethylene paint are often used for car repair paint and innovative coating Nitro paint is easy to apply, quick to dry, and can be polished, making it an ideal top coat for car repair. However, nitro paint generally has poor weather resistance, and in the south, it can severely lose light and change color in just one summer. However, nitro paint modified with high-quality resins (acrylic resin and silicone resin) has good weather resistance. However, its solid content is low, and it requires 3-4 coats to achieve the required surface coating thickness, and the price is relatively expensive, so the repair cost is higher Alkyd paint has excellent weather resistance, usually reaching a thickness of over 40um by spraying two coats. The gloss and fullness of the coating are good. Its drawback is that it is dry and slow, requiring 16-24 hours for each coat to self dry. The construction cycle is long, and a clean coating environment is required. Other alkyd paints have poor moisture and heat resistance, are prone to foaming, and have poor decorative appearance, making them unsuitable as topcoats for sedans At present, most of the finished coatings are double-layer coatings, which are metal or pearl layers followed by a clear coat, while the rest are essentially two component pure color coatings. Two component coatings were first introduced by Akzo Nobel Company Xinjin Company in the 1960s, Its fundamental mechanism is to use the acrylic chain containing hydroxyl functional groups (- OH) to react with the (- NCO) groups in the cyanate ester to solidify into a network structure of polyurethane polymer. This two component polyurethane paint combines the advantages of nitro paint and alkyd paint, with fast drying, good gloss and fullness. It can reach a thickness of over 40um after 1-2 coats, and has excellent weather resistance, chemical resistance, and moisture heat resistance, which is quickly selected by various paint manufacturers. Metal paint, Pearl paint uses modified butyl acetate cellulose resin as the carrier and is coated with a transparent two component varnish 2. The difference between car repair paint and original factory paint The paint used for the original paint of sedans is different from that used for general car repair paint. The original paint of sedans is the paint used for uniform painting before leaving the factory. Car factories have specific requirements for the paint used for their entire vehicle, so most car factories have formulated special supply agreements with paint companies. However, for unprocessed metal bodies, due to the lack of other plastic accessories and the fact that the spraying operation is carried out in a temperature controlled environment on the painting production line, high-temperature baking paint is generally used Car repair paint is a coating used to treat the exterior of a car. Due to accident damage or years of aging (such as coating cracking, discoloration, loss of gloss, powdering, etc.), it needs to be repaired or repainted for various complex conditions, commonly known as repair paint. In detail, it is different from the coating production line of a general factory, with no single operation. The painted model, shape, and color are all different, Most operations cannot be carried out according to the regular sequence of processes, and the highest baking temperature cannot exceed 60 degrees Celsius, otherwise plastic accessories will be damaged. Therefore, repairing cars requires the use of different paint categories, and repairing cars needs to be carried out in repair factories. However, the facilities of repair factories are diverse, making it difficult to compare with car manufacturers Car repair coating can be divided into partial repair coating and whole vehicle repair coating according to the amount of repair work. The former only applies to the damaged parts of the coating or those damaged by accidents, and the parts corrected by sheet metal workers are repaired with paint; The latter is due to aging of the coating or the need to change the color for the entire vehicle to be repainted from scratch The process requirements for sedan repair painting are variable, so it requires operators to have high painting skills, especially in color matching during partial repair painting, so that the appearance, luster, and color of the repair surface and the original coating are fundamentally consistent. It is necessary to consider the color of the sedan, the texture of the topcoat, and the condition of the topcoat, as well as many potential factors that may cause color changes, Some of them are beyond the control of painters at the moment, so operators need to have rich practical experience and high operational skills 3. Color calibration of car repair paint There are three main factors that affect the appearance of a car: the color of the car, the texture of the topcoat, and the condition of the topcoat. Especially, color is the basis for judging the quality of the car (1) The factors that affect the color of sedans: There are mainly three concepts for defining and describing color: brightness and color: brightness refers to the degree of brightness of the color; Color is the color seen by the human eye; Chromaticity refers to the intensity and concentration of a color, including intensity, concentration, saturation, grayscale, etc In fact, different light sources have different effects on paint, causing changes in the color of the paint. This is because the content of various colorful light in the light source is different. For example, a certain type of paint contains blue components that may not be visible in sunlight, but are very obvious under mercury lamps. Due to the different content of blue light in sunlight and mercury lamps, the repair paint may match well with the color of the car when viewed under workshop lighting, But under sunlight, it is not good enough. The color distribution under workshop lighting conditions is closely related to the type of lighting used in the workshop. For example, incandescent lighting can cause the paint color to turn red; The difference in fluorescent powder in fluorescent lamps causes the paint color to turn yellow or blue; Both cold white light and soft white light can alter the color presented by the paint Sometimes the formula of the repair paint is not exactly the same as the pigment used in the top paint formula of the original car manufacturer. In this case, even if the repair paint matches the original top paint well under sunlight or simulated sunlight, it may not be the same when viewed under another light source (2) Identifying the color of the original brand sedan: The first step in color matching is to obtain the original color based on the paint code of the sedan manufacturer, in order to reduce the difference between the repair paint formula and the paint formula used by the original sedan manufacturer. The paint code of almost all brand sedans can be found on various car brand paint code location maps. A repair color compilation can be purchased on the market, This type of book includes almost all color cards and pigment information for brands and models. The first step is to find the paint code of the car manufacturer, which is located around the paint code. For stability, it is best to compare the color card with the color of the car itself, as some cars may have already been painted in other colors (3) Recognition of the original paint type 1) Visual inspection method. If the skin tissue adjacent to the exterior line of the car body is rough, or if the paint surface appears after friction; Polished tissue", It indicates that the original paint used was a polishing type 2) Solvent method. Rub the paint film with a white cloth dipped in nitrocellulose paint releasing agent (banana water) to investigate the degree of dissolution of the paint film. If the paint film dissolves and leaves marks on the cloth, it is self drying paint; If there is no dissolution, it may be baking paint or two component paint. Acrylic polyurethane paint does not dissolve as easily as self drying paint, but sometimes solvents can penetrate and weaken the surface luster 3) Heating method. First, use fine sandpaper dipped in water to polish the paint film to lose its luster, and then use an infrared lamp to heat it. If the passivation surface appears shiny from scratch, it indicates that it is acrylic spray paint 4) Hardness testing method. The hardness of paint films varies after various paints become dry. Generally speaking, the hardness of paint films of two component paints and baking paints is higher than that of self drying paints. The most commonly used method to recognize the hardness and thickness of paint films is to use electromagnetic or mechanical thickness gauges (4) Repair paint color calibration: Based on brightness, color, and chromaticity, use graphical methods to recognize the process of the connection between paint and car color, and perform color calibration. Color calibration only has meaning when compared to the car itself. Master and use color calibration methods, and be able to distinguish differences in brightness, color, and chromaticity changes Table 4-1 Color Calibration Table Suitable for Metal Flash Paint Side Light Brightness □ Light □ Dark Car Color Side Light Color □ Blue □ Green Car Color □ Red □ Yellow. Color: Light Yellow Editor's Code Transformer Peugeot. Value Total Engineering Calculation 402 White 336.0 336.0 452 Yellow 49.0 385.0 451 Light Yellow 13.5 398.5 457 Yellow or Red 9.0 407.5 405 Black 11.5 419.0 465 Adhesive 3.71 790.5 485 Balancing Agent 184.5 975.0... Color calibration: It is beneficial to understand the paint formula, including the color matching base materials. However, it is necessary to note that the colors produced may not be exactly the same as the actual colors of cars, as all car topcoats will gradually change over time, some becoming lighter and some becoming darker. For example, yellow color fades quickly, and if it fades to beige, the paint should be mixed lighter and lighter; If it fades into a green color composed of blue and yellow, then the pigment should be paired with a bluer color and generally darker 4. Color matching of sedan repair topcoat Due to the different color components and lighting levels of the original topcoat of sedans, there is a significant difference in the degree of fading. For example, when a sedan is stored in a garage, the color fades more slowly, while when parked on the roadside, the color fades more quickly under trees; In the northwest plateau, due to the strong ultraviolet radiation in sunlight, the color of cars changes quickly; Cars used in industrial and mining cities have a significant impact on color due to strong acid mist. Therefore, in the process of color matching for car repair topcoats, consideration should be given to the modification of the faded topcoat. Generally speaking, new cars lose color the fastest in the first few months and then slow down (1) Preparation before color matching: Color matching is an important part of car repair paint color matching. If you understand the color matching theory, understand the impact of the surrounding environment on color, and develop a complete color matching program, you can make a routine procedure for the spraying process The fundamental purpose of color matching is mainly three: 1) Adjust the subtle differences between the repair paint and the original car paint to match 2) Match the repair paint with the faded sedan topcoat 3) Assign car repair paint without formula or paint code It is necessary for painters who assign car repair topcoats to correctly and carefully identify colors and distinguish their true colors. In particular, they should be able to distinguish between the colors to be processed and the heavy colors within this color scale in the paint, including darkness or brightness level, brightness or saturation of the colors. If the color of the repair topcoat is different from the original car topcoat, before deciding whether to proceed with color matching, It is necessary to first check if there is a color mismatch due to the following reasons: 1) Is the original paint of the car fading? If it has indeed faded, the polishing correction area can be appropriately expanded 2) Whether to use the wrong color to check the paint code of the car manufacturer, the paint code of the paint factory, and the paint material number of the paint factory, and admit whether to use the wrong color 3) Is the pigment or metal flake in the paint sufficiently and evenly mixed? If the repair paint is mixed unevenly, and there is still residual color at the bottom of the tank, the metal flake or pearl powder may cause color mismatch, so it is necessary to completely mix and evenly 4) Is the dosage of diluent accurate? Excessive dilution can make the color lighter or decrease saturation 5) Before making color comparisons, it is necessary to clean, polish, and remove dust and oxide layers from the old car paint 6) When using the test panel, it is necessary to leave some extra dry moments. The test panel usually needs to be sprayed several times, and after each spraying, it must be completely dry because the color of the dry paint is darker 7) It is best to use a mixing cup when spraying metal paint or pearlescent paint. Because metal chips or ring light chips simply sink deep into the paint film, affecting the color light 8) Wait until the paint dries before adjusting the color. You can use a heating lamp, a heating gun, or other drying methods to shorten the drying time 9) When adjusting colors, only a small amount of toner should be added at a time 10) The different spraying methods can result in different colors. The paint color near the test panel of the spray gun is darker than that far away from the spray gun, especially when spraying metal paint. The same decrease in spray gun speed is darker than adding spray gun speed; The distance between each coating is shorter and deeper than the distance when it is longer On the equipment, choose a larger liquid and a smaller liquid nozzle with a deeper depth; Reducing the width of the spray beam is deeper than increasing the width of the spray beam; Reducing the jet pressure is deeper than increasing the jet pressure; Increasing traffic is deeper than decreasing traffic In terms of workshop environment temperature, colors with lower workshop temperature are darker than those with higher temperature It is also necessary to note that there are more color mismatches during the whole panel renovation than during small-scale renovation. This is because the panels (such as workshops) have clear edges, such as the front and rear doors adjacent to each other, forming a sharp contrast. However, during small-scale renovation, the repaired area is mixed with the surrounding area, and the first coat is only applied to the repaired area, with each layer of coating being applied on a larger scale, The final mixed coating exceeds the scale of the original coating. This way, although there may be some color mismatch, there will be a transition between the new and old topcoats, and there will not be a fierce color difference (2) The fundamental process of color matching: In the process of color matching for car topcoats, we should use different spraying methods to adjust brightness, chromaticity, and color to achieve the best color. The general procedure for color matching is as follows:... 1) Color analysis. Color analysis is mainly carried out from three aspects: first, investigate the paint from the front or a certain perspective to see if the color is too deep or too light; Secondly, check the color to see if the paint is redder, bluer, greener, or yellower than the original topcoat; Thirdly, check if the color of the newly sprayed paint is higher or lower than the original topcoat 2) Brightness adjustment. The main factors that affect brightness include: workshop environment, spraying method, solvent application, paint dosage, spray gun pressure, and the amount of pigment mixed correctly. It is necessary to summarize and consider various factors when adjusting brightness to obtain the appropriate paint brightness 3) Color adjustment. Only after adjusting the brightness can color adjustments be made. The colors of each color can only be changed in two directions: at the top, the colors will turn green or red. Colors include blue, purple, yellow, beige, and brown; Secondly, colors that turn yellow or blue include green, black, maroon red, gray or silver, and white; Thirdly, the colors that turn yellow or red include bronze, red, and orange red; Fourthly, the colors that will turn blue or green include navy blue and turquoise. After selecting the correct color toner based on the information provided by the paint factory, the dosage of the toner can be calculated according to the minimum amount. After sufficient mixing and uniform spraying, a small test plate is sprayed, and after drying, the color is compared with the original topcoat 4) Adjust the chromaticity. After adjusting the brightness and color, start adjusting the chromaticity. If you want to make the color brighter, it is necessary to adjust the first two items from scratch; If you want to make the topcoat gray, you need to spray a wet coating, and then spray a coating mixed with a small amount of white and a small amount of black at a longer distance and lower air pressure 5) Review and proofread. Finally, you can view from three perspectives: the top spot, perpendicular to the exterior of the car; Secondly, from just beyond the point of view of the light source's reflection; Thirdly, from a perspective of less than 45 degrees, investigate the car's topcoat. Check if the color of the repaired and sprayed topcoat is consistent with other parts, and if not, proofread until satisfactory 5. Examples of Paint Color Adjustment In the paint care of sedans, it is often necessary to allocate the color of the purchased paint to be different from the exterior color of the sedan. It is necessary to make the color of the paint as common as possible with the original color of the sedan. In the allocation, the distribution of colors should be based on the fundamental knowledge and principles of color, combined with the detailed requirements of paint application. The following is an example of mixed paint to briefly describe the distribution of colors (1) Allocation of yellow paint: There are mainly medium yellow and lemon yellow in yellow. Using the five fundamental color matching materials of Yan Guei's yellow, red, blue, white, and black, according to different proportions, they can be allocated into light yellow, milk yellow, tooth yellow, brown yellow, orange yellow, and other colors When distributing, the medium yellow paint is customarily made by adding white paint with a volume fraction of 30% to 50% on top of the original dark yellow Light yellow is a mixture of 10% to 20% volume fraction of the original dark yellow paint and 90% to 80% volume fraction of white paint Brown yellow paint=yellow paint volume fraction 16.7% plus black volume fraction 5.77% plus iron red volume fraction 77.53%... Orange yellow paint equals yellow paint volume fraction 84.92% plus red paint volume fraction 15.08%... Tooth yellow paint equals white paint volume fraction 89.35% plus yellow paint volume fraction 10.65%... Milk yellow paint equals white paint volume fraction 94.57% plus yellow paint volume fraction 5.43%... The number in the above equation is the original nitro enamel monochrome paint The volume fraction allocated to the multi-color paint can be divided into several different shades of yellow paint by changing its share number (2) Allocation of red paint: In the allocation of red paint, there are often single color paints such as bright red, iron red, and vermilion. By participating in other colors according to a certain proportion, multiple color paints such as gold red (orange red), rose red, flesh red, pink, purple red, etc. can be allocated If bright red is added with a small amount of chrome yellow, it is equal to vermilion; Red plus chrome yellow equals golden red; Iron red with a small amount of black equals purple red; Tooth yellow plus pink equals flesh red; Mainly white with a small amount of bright red equals pink; Big red with a small amount of black is equal to jujube red; Big red with ultramarine blue and a small amount of white equals rose red; Purple red with appropriate yellow equals chestnut For example, a white volume fraction of 96.17% plus a yellow volume fraction of 3.28% plus a red volume fraction of 0.55% is equivalent to light flesh red A yellow volume fraction of 52.7% plus a yellow volume fraction of 47.3% equals orange The volume fraction of white is 43.3%, plus the volume fraction of yellow is 26.7%, plus the volume fraction of red is 30.0%, which is equal to light fishy red... Similarly, changes in the percentage of monochrome in the above equations will result in changes in the color depth of the multicolor color, which can be modulated into thousands of different colorful coatings (3) Allocation of blue: Blue often comes in colors such as Prussian blue (iron blue, Chinese blue), ultramarine blue (Yangfo Qing), etc. It can be used in two different ways種或兩種以上 的單色漆分配成多種復(fù)色漆. ... 如深藍加上白等于中藍;深藍是指原裝的普魯藍色漆.實際上用的深藍色是在原裝的普魯士藍的基礎(chǔ)上,加適量的白色漆而成.加白色漆可使色彩艷麗,呈帶黑藍色,天藍是在以白色漆為主的 基礎(chǔ)上加適量的藍色而成,能夠調(diào)成多種淺藍色漆.湖藍等于群青加上白;深灰等于中藍加上在灰色;群青色與鈷藍色挨近. ...又如天藍色等于白體積分數(shù)為93.55%加上藍體積分數(shù)為6.54%; ...海藍色等于白體積分數(shù)為46.78%加上藍體積分數(shù)為41.63%加上黃體積分數(shù)為11.59%; ...藍灰色等于白體積分數(shù)為77.31%加上藍體積分數(shù)為6.22%加上黑體積分數(shù)為16.47%; 淺孔雀等于白體積分數(shù)為82.25%加上藍體積分數(shù)為15.64%加上黃體積分數(shù)為2.11%; ...(4)綠色漆的分配:綠色漆常有中鉻綠,草綠,碧綠等色漆.能夠參加其他單色漆分配成淺綠,粉 綠,嫩豆綠,果綠,墨綠,深黃綠,深灰綠,鴨蛋青等色漆. ...如檸檬黃加上中藍等于中綠(碧綠); ...中鉻黃加上中藍等于深綠; ...白色為主加上淺綠等于水綠(粉綠); ...檸檬黃加上淺藍等于嫩豆綠; ...以檸檬黃為主加上淺藍等于果綠; ...中鉻黃加上中藍加上少量赤色等于深藍綠色; ...淺藍加上淺黃等于草綠; ...草綠加上墨綠等于深草綠; ...鐵灰加上綠等于深灰綠; ...以白色為主加上少量藍加上適量黃等于玉綠(鴨蛋青). ...又如白色體積分數(shù)為84.23%加上藍色體積分數(shù)為1.18%加上淺黃體積分數(shù)為14.59%等于果綠; ...白色體積分數(shù)為67.82加上黃體積分數(shù)為10.29%加上黑體積分數(shù)為1.58%加上淺黃體積分數(shù)為3.96%加上綠體積分數(shù)為16.35%等于淺豆綠; ...白體積分數(shù)為75.44%加上黃體積分數(shù)為8.67%加上黃體積分數(shù)為3.31%加上淺黃體積分數(shù)為12.58%等于淺碧綠. ...(5)灰色漆的分配:同理,灰色漆也能夠參加其他單色漆而分配成數(shù)種灰色系列漆,如銀灰,淺灰, 淡灰,瓦灰,灰色黃,灰色藍,鐵灰色等. ...如以白色為主加上藍加上黑加上黃等于淡灰色; ...白色為主加上黑加上藍等于瓦灰; ...又如白體積分數(shù)為90.73%加上藍體積分數(shù)為1.30%加上黃體積分數(shù)為3.25%加上黑體積分數(shù)為4.72%等于銀灰色; ...白體積分數(shù)為88.88%加上藍體積分數(shù)為0.98%加上黑體積分數(shù)為10.94%等于淺灰色. ...白色和黑色幾乎與其他任何色(金色,銀色除外)分配,能夠起到分配色彩深淺的共同作用. ...6,電腦調(diào)漆 ...因為科學(xué)技能的飛速發(fā)展,特別是電子計算機技能的發(fā)展,在涂裝技能中也得到必定的使用.運用電腦調(diào)漆,把極其復(fù)雜的調(diào)漆作業(yè),改動為很正規(guī),作業(yè)起來極簡單而又很精確. ...(1)電腦調(diào)漆的根本原理:在電腦調(diào)漆的作業(yè)中,電腦實際上便是一個大型的色漆配方的資料庫, 儲存了各種色漆的規(guī)范配方.各種色漆均由數(shù)碼進行標記,不僅復(fù)色漆由數(shù)碼標記,并且單色漆也 數(shù)碼標記.各類色漆種類數(shù)量達千種標準,完全能滿意轎車制造和轎車修理的運用. 當(dāng)送修補的轎車到修補廠之后,有的轎車車身面漆在必定部位涂有漆的標號,假如修補廠有相同標號的色漆,那就能夠直接選用;若沒有時,就可將此標號輸入電腦.從熒光屏上就能夠顯示出此種 標號復(fù)色漆組成各單色漆的組份及分量.按其組份和分量進行分配,就可得出所需求標號的色漆了. ...(2)電腦調(diào)漆的操作進程:首要是承認所修轎車面漆的漆色種類,一般有兩種辦法:對現(xiàn)代高級轎 車的面漆有的有漆號標志,找到其漆號標志;有的從修理手冊上找到面漆的運用資料種類標準;若都無記載,最后一種辦法,就用色標卡進行測定. ...色標卡,是一種專門印制的涂料色彩卡片.按其色彩的種類和同一種類的不同色度而擬定的規(guī)范色彩卡片.在卡片上標注其數(shù)碼編號,每一個色卡編號便是一種色漆的標志. ...一種紫色漆的不同色度的色漆,301A5,色度最淺,301H1最深.每一個方塊色中心有一個圓孔,在 認定轎車面漆時,首要目測出近似轎車面漆的色卡.然后將色卡平鋪在車身外表,從色卡方塊的圓孔 中露出轎車車身成漆本色,找出與色卡最近似,乃至相同色的那個方塊,這就測出轎車的面漆 便是那個方塊的數(shù)碼所代表的色漆. ...假若測定的轎車面漆數(shù)碼為301A5,而庫存中又無現(xiàn)成的這種色漆,則將此編碼輸入到電腦中.從電腦熒光屏中顯示出301A5的配方:956為179.9g;744為1.5g;957為71.8g;666為81.5g;333mL為 153.4g.依據(jù)以上配方,用電子秤量出各組份的分量,按份額量出所需用量,放入必定的分配容器中. 用手藝機械拌和均勻,按施工要求調(diào)到所需濃度,色漆的分配這就已完成了. ...運用電腦調(diào)漆,可使對轎車面漆分配作業(yè)簡便而精確.采購的各種數(shù)碼的色漆有必要嚴格保證其質(zhì)量. 別的,所用色漆種類標準雖多,可是每種標準的數(shù)量較少,因為修理護理不同于批量出產(chǎn).
文章來源：清遠汽車修補漆 http://www.jinliangxincai.com
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